0001628280-21-014270 | S-1 | XBRL Viewer | Nautilus Biotechnology INC

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Cover	3 Months Ended
Cover	Mar. 31, 2021
Cover [Abstract]
Document Type	S-1
Entity Registrant Name	NAUTILUS BIOTECHNOLOGY, INC.
Entity Incorporation, State or Country Code	DE
Entity Primary SIC Number	3826
Entity Tax Identification Number	98-1541723
Entity Address, Address Line One	425 Pontius Ave N, Ste 202
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98109
City Area Code	206
Local Phone Number	333-2001
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Central Index Key	0001808805
Amendment Flag	false

CONDENSED BALANCE SHEETS - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Total current assets	$ 69,445,000	$ 77,659,000
Total assets	76,148,000	85,011,000
Current liabilities:
Accounts payable	2,120,000	470,000
Total current liabilities	4,525,000	3,018,000
Total liabilities	4,525,000	6,314,000
Commitments and contingencies
Redeemable convertible preferred stock	108,418,000	108,418,000
Stockholders’ deficit:
Common stock, $0.0001 par value, 27,196,999 and 19,189,462 shares authorized as of December 31, 2020 and 2019, respectively; 9,114,904 and 9,077,062 shares issued and outstanding as of December 31, 2020 and 2019, respectively	1,000	1,000
Additional paid-in capital	1,936,000	600,000
Accumulated deficit	(38,734,000)	(30,325,000)
Total stockholders’ deficit	(36,795,000)	(29,721,000)
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	76,148,000	85,011,000
Arya Sciences Acquisition Corp III
Current assets:
Cash	682,010	1,001,032
Prepaid Expense, Current	253,630	303,759
Total current assets	935,640	1,304,791
Investments held in Trust Account	149,563,934	149,552,952
Total assets	150,499,574	150,857,743
Current liabilities:
Accounts payable	116,827	0
Accrued expenses	1,652,522	388,507
Due to related party	30,000	0
Total current liabilities	1,799,349	388,507
Deferred underwriting commissions	5,232,500	5,232,500
Total liabilities	7,031,849	5,621,007
Redeemable convertible preferred stock	138,467,720	140,236,730
Stockholders’ deficit:
Preferred Stock, Value, Issued	0	0
Additional paid-in capital	7,291,565	5,522,572
Accumulated deficit	(2,292,094)	(523,083)
Total stockholders’ deficit	5,000,005	5,000,006
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	150,499,574	150,857,743
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Stockholders’ deficit:
Common stock, $0.0001 par value, 27,196,999 and 19,189,462 shares authorized as of December 31, 2020 and 2019, respectively; 9,114,904 and 9,077,062 shares issued and outstanding as of December 31, 2020 and 2019, respectively	160	143
Common Class B [Member] \| Arya Sciences Acquisition Corp III
Stockholders’ deficit:
Common stock, $0.0001 par value, 27,196,999 and 19,189,462 shares authorized as of December 31, 2020 and 2019, respectively; 9,114,904 and 9,077,062 shares issued and outstanding as of December 31, 2020 and 2019, respectively	$ 374	$ 374

CONDENSED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Liabilities, Redeemable Convertible Preferred Stock, and Stockholders’ Deficit
Outstanding (in shares)	14,381,190	14,381,190
Stockholders’ deficit:
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	27,196,999	27,196,999
Common stock, shares issued (in shares)	9,114,904	9,114,904
Common stock, shares outstanding (in shares)	9,114,904	9,114,904
Arya Sciences Acquisition Corp III
Stockholders’ deficit:
Preferred Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Shares issued (in shares)	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	479,000,000	479,000,000
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Liabilities, Redeemable Convertible Preferred Stock, and Stockholders’ Deficit
Ordinary shares, par value (in dollars per share)	$ 0.0001	$ 0.0001
Outstanding (in shares)	13,846,772	14,023,673
Temporary Equity, Redemption Price Per Share	$ 10.00	$ 10.00
Stockholders’ deficit:
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	479,000,000	479,000,000
Common stock, shares issued (in shares)	1,602,228	1,425,327
Common stock, shares outstanding (in shares)	1,602,228	1,425,327
Common Class B [Member] \| Arya Sciences Acquisition Corp III
Stockholders’ deficit:
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	3,737,500	3,737,500
Common stock, shares outstanding (in shares)	3,737,500	3,737,500

UNAUDITED CONDENSED STATEMENT OF OPERATIONS - USD ($)	3 Months Ended	9 Months Ended
UNAUDITED CONDENSED STATEMENT OF OPERATIONS - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Operating Income (Loss) [Abstract]
General and administrative	$ 3,582,000
Nonoperating Income (Expense) [Abstract]
Net loss	$ (8,409,000)
Weighted Average Number of Shares Outstanding, Basic	9,095,711
Weighted Average Number of Shares Outstanding, Diluted	9,095,711
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.92)
Earnings Per Share, Diluted	$ (0.92)
Arya Sciences Acquisition Corp III
Operating Income (Loss) [Abstract]
General and administrative	$ 1,779,993	$ 576,035
Loss from operations	(1,779,993)	(576,035)
Nonoperating Income (Expense) [Abstract]
Gain (Loss) on Investments	10,982	52,952
Net loss	$ (1,769,011)	$ (523,083)
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Nonoperating Income (Expense) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	14,950,000
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ 0.00
Weighted Average Number of Shares Outstanding, Basic and Diluted		14,950,000
Earnings Per Share, Basic and Diluted		$ 0.00
Common Class B [Member] \| Arya Sciences Acquisition Corp III
Nonoperating Income (Expense) [Abstract]
Weighted Average Number of Shares Outstanding, Basic	4,236,500
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.42)
Weighted Average Number of Shares Outstanding, Basic and Diluted		3,764,852
Earnings Per Share, Basic and Diluted		$ (0.15)

UNAUDITED CONDENSED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($)	Total	Arya Sciences Acquisition Corp III	Common Stock	Common Stock Common Class A [Member] Arya Sciences Acquisition Corp III	Common Stock Common Class B [Member] Arya Sciences Acquisition Corp III	Additional Paid-in Capital	Additional Paid-in Capital Arya Sciences Acquisition Corp III	Accumulated Deficit	Accumulated Deficit Arya Sciences Acquisition Corp III
Beginning balance at Dec. 31, 2018	$ (5,048,000)		$ 1,000			$ 43,000		$ (5,088,000)
Beginning balance (in shares) at Dec. 31, 2018			9,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(9,618,000)							(9,618,000)
Ending balance at Dec. 31, 2019	(14,509,000)		$ 1,000			189,000		(14,706,000)
Ending balance (in shares) at Dec. 31, 2019			9,077,062
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,934,000)							(2,934,000)
Ending balance at Mar. 31, 2020	(17,390,000)		$ 1,000			208,000		(17,640,000)
Ending balance (in shares) at Mar. 31, 2020			9,077,062
Beginning balance at Dec. 31, 2019	(14,509,000)		$ 1,000			189,000		(14,706,000)
Beginning balance (in shares) at Dec. 31, 2019			9,077,062
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(15,619,000)							(15,619,000)
Ending balance at Dec. 31, 2020	(29,721,000)	$ 5,000,006	$ 1,000	$ 143	$ 374	600,000	$ 5,522,572	(30,325,000)	$ (523,083)
Ending balance (in shares) at Dec. 31, 2020			9,114,904	1,425,327	3,737,500
Beginning balance at Mar. 26, 2020		0		$ 0	$ 0		0		0
Beginning balance (in shares) at Mar. 26, 2020				0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(523,083)		$ 0	$ 0		0		(523,083)
Ending balance at Dec. 31, 2020	(29,721,000)	5,000,006	$ 1,000	$ 143	$ 374	600,000	5,522,572	(30,325,000)	(523,083)
Ending balance (in shares) at Dec. 31, 2020			9,114,904	1,425,327	3,737,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued (in shares)				0	3,737,500
Stock Issued During Period, Value, New Issues		25,000			$ 374		24,626		0
Shares Issued in Initial Public Offering During Period Shares New Issues				14,950,000	0
Shares Issued in Initial Public Offering During Period Value New Issues		149,500,000		$ 1,495	$ 0		149,498,505		0
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs		(8,755,181)		$ 0	$ 0		(8,755,181)		0
Sale of Units to Sponsor in Private Placement Shares				499,000	0
Sale of Units to Sponsor in Private Placement, Value		4,990,000		$ 50	$ 0		4,989,950		0
Reclassifications of Permanent to Temporary Equity, Shares				(14,023,673)	0
Reclassifications Of Permanent To Temporary Equity Value		(140,236,730)		$ (1,402)	$ 0		(140,235,328)		0
Shares subject to possible redemption		1,769,010		$ 17			1,768,993		0
Shares subject to possible redemption (in shares)				176,901
Net loss	(8,409,000)	(1,769,011)		$ 0	0		0	(8,409,000)	(1,769,011)
Ending balance at Mar. 31, 2021	$ (36,795,000)	$ 5,000,005	$ 1,000	$ 160	$ 374	$ 1,936,000	$ 7,291,565	$ (38,734,000)	$ (2,292,094)
Ending balance (in shares) at Mar. 31, 2021			9,114,904	1,602,228	3,737,500

UNAUDITED CONDENSED STATEMENT OF CASH FLOWS - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
UNAUDITED CONDENSED STATEMENT OF CASH FLOWS - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2020
Changes in operating assets and liabilities:
Accounts payable	$ 724,000		$ 123,000
Net cash used in operating activities	(6,253,000)		(13,996,000)
Net loss	(8,409,000)		(15,619,000)
Net Cash Provided by (Used in) Operating Activities	(6,253,000)		(13,996,000)
Net cash (used in) provided by investing activities	23,518,000		(25,279,000)
Payments of Stock Issuance Costs	(2,069,000)
Net cash provided by financing activities	(2,069,000)		75,899,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	52,415,000	$ 37,219,000	37,219,000
Cash, cash equivalents and restricted cash at beginning of period	37,219,000		595,000
Cash, cash equivalents and restricted cash at end of period	52,415,000	37,219,000	37,219,000
Arya Sciences Acquisition Corp III
Adjustments to reconcile net loss to net cash used in operating activities
Gain (Loss) on Investments	(10,982)	(52,952)
Changes in operating assets and liabilities:
Prepaid expenses	50,129	(303,759)
Accounts payable	116,827
Accrued expenses	1,264,015	318,507
Due to related party	30,000
Net cash used in operating activities	(319,022)	(549,570)
Net loss	(1,769,011)	(523,083)
Net income on investments	10,982	52,952
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party		11,717
Increase (Decrease) in Prepaid Expenses, Other	(50,129)	303,759
Accrued expenses	1,264,015	318,507
Net Cash Provided by (Used in) Operating Activities	(319,022)	(549,570)
Cash Deposited in Trust Account		(149,500,000)
Net cash (used in) provided by investing activities		(149,500,000)
Proceeds from Related Party Debt		136,590
Repayments of Related Party Debt		(200,000)
Gross proceeds from initial public offering		149,500,000
Gross proceeds from private placement		4,990,000
Payments of Stock Issuance Costs		(3,375,988)
Net cash provided by financing activities		151,050,602
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	(319,022)	1,001,032
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	682,010	1,001,032	1,001,032
Change in value of Class A common stock subject to possible redemption	(1,769,010)
Net change in cash	(319,022)	1,001,032
Cash, cash equivalents and restricted cash at beginning of period	1,001,032	0
Cash, cash equivalents and restricted cash at end of period	682,010	1,001,032	$ 1,001,032
Supplementary cash flow information on non-cash investing activities
Deferred Offering Costs Paid by Sponsor in Exchange for Issuance of Ordinary Shares		25,000
Offering Costs Included in Accrued Expenses		70,000
Offering Costs Included in Note Payable		51,693
Deferred Underwriting Commissions Assumed in Underwriting Agreement		5,232,500
Initial value of Class A common stock subject to possible redemption		140,714,240
Increase (Decrease) in Value of Common Stock Subject to Redemption		$ (477,510)
Change in value of Class A common stock subject to possible redemption	$ (1,769,010)

Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 51,803	$ 36,607	$ 595
Short-term investments	16,034	40,135	16,064
Prepaid expenses and other current assets	1,608	917	305
Total current assets	69,445	77,659	16,964
Property and equipment, net	1,714	1,371	1,119
Operating lease right-of-use assets	1,175	4,842	0
Other long term assets	3,814	1,139	459
Total assets	76,148	85,011	18,542
Current liabilities:
Accounts payable	2,120	470	289
Accrued expenses and other liabilities	1,130	1,069	201
Current portion of operating lease liability	1,275	1,479	0
Total current liabilities	4,525	3,018	490
Operating lease liability, net of current portion	0	3,296	0
Total liabilities	4,525	6,314	490
Commitments and contingencies
Redeemable convertible preferred stock	108,418	108,418	32,561
Stockholders’ deficit:
Common stock, $0.0001 par value, 27,196,999 and 19,189,462 shares authorized as of December 31, 2020 and 2019, respectively; 9,114,904 and 9,077,062 shares issued and outstanding as of December 31, 2020 and 2019, respectively	1	1	1
Additional paid-in capital	1,936	600	189
Accumulated other comprehensive income	2	3	7
Accumulated deficit	(38,734)	(30,325)	(14,706)
Total stockholders’ deficit	(36,795)	(29,721)	(14,509)
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	76,148	85,011	18,542
Series Seed
Current liabilities:
Redeemable convertible preferred stock	5,494	5,494	5,494
Series A
Current liabilities:
Redeemable convertible preferred stock	27,067	27,067	27,067
Series B
Current liabilities:
Redeemable convertible preferred stock	$ 75,857	$ 75,857	$ 0

Statements of Operations - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
Statements of Operations - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating expenses
Research and development	$ 4,835	$ 2,470	$ 12,432	$ 8,488
General and administrative	3,582	527	3,312	1,622
Total operating expenses	8,417	2,997	15,744	10,110
Other income (expense), net	8	63	125	492
Net loss	$ (8,409)	$ (2,934)	$ (15,619)	$ (9,618)
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.92)	$ (0.40)	$ (1.95)	$ (1.59)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.92)	$ (0.40)	$ (1.95)	$ (1.59)
Weighted average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	9,095,711	7,292,773	8,017,976	6,066,928
Weighted average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	9,095,711	7,292,773	8,017,976	6,066,928

Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
Statements of Comprehensive Loss - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (8,409)	$ (2,934)	$ (15,619)	$ (9,618)
Other comprehensive income (loss):
Unrealized (loss) gain on securities available-for-sale	(1)	34	(4)	11
Total other comprehensive income (loss)	(1)	34	(4)	11
Comprehensive loss	$ (8,410)	$ (2,900)	$ (15,623)	$ (9,607)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Statements of Redeemable Convertible Preferred Stock and Stockholders’ Deficit - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Series Seed	Series A	Series B
Redeemable Convertible Preferred Stock, beginning balance (in shares) at Dec. 31, 2018						3,631,354	4,640,604
Redeemable Convertible Preferred Stock, beginning balance at Dec. 31, 2018						$ 5,494	$ 27,067
Redeemable Convertible Preferred Stock, ending balance (in shares) at Dec. 31, 2019	8,271,958					3,631,354	4,640,604	0
Redeemable Convertible Preferred Stock, ending balance at Dec. 31, 2019	$ 32,561					$ 5,494	$ 27,067	$ 0
Beginning balance (in shares) at Dec. 31, 2018		9,000,000
Beginning balance at Dec. 31, 2018	$ (5,048)	$ 1	$ 43	$ (4)	$ (5,088)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of vested stock options (in shares)	77,062	77,062
Issuance of common stock upon exercise of vested stock options	$ 36		36
Stock-based compensation expense	110		110
Other comprehensive income (loss)	11			11
Net loss	(9,618)				(9,618)
Ending balance (in shares) at Dec. 31, 2019		9,077,062
Ending balance at Dec. 31, 2019	(14,509)	$ 1	189	7	(14,706)
Redeemable Convertible Preferred Stock, ending balance (in shares) at Mar. 31, 2020						3,631,354	4,640,604
Redeemable Convertible Preferred Stock, ending balance at Mar. 31, 2020						$ 5,494	$ 27,067
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	19		19
Other comprehensive income (loss)	34			34
Net loss	(2,934)				(2,934)
Ending balance (in shares) at Mar. 31, 2020		9,077,062
Ending balance at Mar. 31, 2020	$ (17,390)	$ 1	208	41	(17,640)
Redeemable Convertible Preferred Stock, beginning balance (in shares) at Dec. 31, 2019	8,271,958					3,631,354	4,640,604	0
Redeemable Convertible Preferred Stock, beginning balance at Dec. 31, 2019	$ 32,561					$ 5,494	$ 27,067	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series B redeemable convertible preferred stock (in shares)								6,109,232
Issuance of Series B redeemable convertible preferred stock								$ 75,857
Redeemable Convertible Preferred Stock, ending balance (in shares) at Dec. 31, 2020	14,381,190					3,631,354	4,640,604	6,109,232
Redeemable Convertible Preferred Stock, ending balance at Dec. 31, 2020	$ 108,418					$ 5,494	$ 27,067	$ 75,857
Beginning balance (in shares) at Dec. 31, 2019		9,077,062
Beginning balance at Dec. 31, 2019	$ (14,509)	$ 1	189	7	(14,706)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of vested stock options (in shares)	37,842	37,842
Issuance of common stock upon exercise of vested stock options	$ 42		42
Stock-based compensation expense	369		369
Other comprehensive income (loss)	(4)			(4)
Net loss	(15,619)				(15,619)
Ending balance (in shares) at Dec. 31, 2020		9,114,904
Ending balance at Dec. 31, 2020	$ (29,721)	$ 1	600	3	(30,325)
Redeemable Convertible Preferred Stock, ending balance (in shares) at Dec. 31, 2020	14,381,190					3,631,354	4,640,604	6,109,232
Redeemable Convertible Preferred Stock, ending balance at Dec. 31, 2020	$ 108,418					$ 5,494	$ 27,067	$ 75,857
Ending balance (in shares) at Dec. 31, 2020		9,114,904
Ending balance at Dec. 31, 2020	$ (29,721)	$ 1	600	3	(30,325)
Redeemable Convertible Preferred Stock, ending balance (in shares) at Mar. 31, 2021	14,381,190					3,631,354	4,640,604	6,109,232
Redeemable Convertible Preferred Stock, ending balance at Mar. 31, 2021	$ 108,418					$ 5,494	$ 27,067	$ 75,857
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of vested stock options (in shares)	0
Stock-based compensation expense	$ 1,336		1,336
Other comprehensive income (loss)	(1)			(1)
Net loss	(8,409)				(8,409)
Ending balance (in shares) at Mar. 31, 2021		9,114,904
Ending balance at Mar. 31, 2021	$ (36,795)	$ 1	$ 1,936	$ 2	$ (38,734)

Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net loss	$ (8,409)	$ (2,934)	$ (15,619)	$ (9,618)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	214	158	710	548
Stock-based compensation	1,336	19	369	110
Amortization of premiums and gain on investments, net	115	52	282	(223)
Amortization of operating lease right-of-use assets	413	447	1,636	0
Loss on disposal of property and equipment			13	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(391)	(75)	(624)	(519)
Accounts payable	724	(41)	123	66
Accrued expenses and other liabilities	(9)	189	695	(26)
Operating lease liability	(246)	(436)	(1,581)	0
Net cash used in operating activities	(6,253)	(2,621)	(13,996)	(9,662)
Cash flows from investing activities
Purchases of securities			(68,359)	(25,374)
Proceeds from sale and maturities of securities	24,000	8,001	44,001	30,350
Purchases of property and equipment	(482)	(115)	(921)	(926)
Net cash (used in) provided by investing activities	23,518	7,886	(25,279)	4,050
Cash flows from financing activities
Proceeds from issuance of convertible preferred stock, net of issuance costs			75,857	0
Proceeds from exercise of stock options			42	36
Payments of deferred offering costs	(2,069)	0
Net cash provided by financing activities	(2,069)	0	75,899	36
Net increase (decrease) in cash, cash equivalents and restricted cash	15,196	5,265	36,624	(5,576)
Cash, cash equivalents and restricted cash at beginning of period	37,219	595	595	6,171
Cash, cash equivalents and restricted cash at end of period	52,415	5,860	37,219	595
Supplemental disclosure of other cash flow information:
Deferred offering costs in accounts payable and accrued expenses and other liabilities	1,133	0	212	0
Supplementary cash flow information on non-cash investing activities
Acquisitions of property and equipment included in accounts payable	142	14	$ 67	$ 13
Modification to reduce right-of-use assets and lease liability	$ 3,254	$ 0

Subsequent Events	3 Months Ended	9 Months Ended
Subsequent Events	Mar. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Subsequent Events	Subsequent Events The Company has evaluated subsequent events through June 9, 2021, the date on which the condensed financial statements were available to be issued. On June 9, 2021, the Company consummated the Business Combination with ARYA. ARYA was renamed to Nautilus Biotechnology, Inc. and the Company became a wholly owned subsidiary of New Nautilus. In addition, concurrently with the Closing Date and pursuant to the subscription agreement, PIPE Investors purchased an aggregate of 20,000,000 shares of New Nautilus Common Stock at a price of $10.00 per share, for aggregate gross proceeds of $200 million and the Company received gross proceeds of approximately $145 million from ARYA, offset by approximately $18 million of transaction costs and underwriters’ fees relating to the closing of the Business Combination.
Arya Sciences Acquisition Corp III
Subsequent Event [Line Items]
Subsequent Events	Subsequent EventsManagement has evaluated subsequent events to determine if events or transactions occurring through the date the unaudited condensed financial statements were available for issuance, require potential adjustment to or disclosure in the unaudited condensed financial statements and has concluded that all such events that would require recognition or disclosure have been recognized or disclosed.	Subsequent Events As discussed in Note 1, on February 7, 2021, the Company entered into the Business Combination Agreement and a series of other agreements related to the Business Combination. The Company evaluated subsequent events and transactions that occurred up to the date financial statements were available to be issued. Based upon this review, the Company determined that there have been no events that have occurred that would require adjustments to the disclosures in the financial statements, except as disclosed in Note 1.

Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Redeemable convertible preferred stock, shares authorized (in shares)	14,481,191	14,481,191	8,271,962
Redeemable convertible preferred stock, shares outstanding (in shares)	14,381,190	14,381,190	8,271,958
Redeemable convertible preferred stock, liquidation preference	$ 110,533,000	$ 110,523,000	$ 34,463,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	27,196,999	27,196,999	19,189,462
Common stock, shares issued (in shares)	9,114,904	9,114,904	9,077,062
Common stock, shares outstanding (in shares)	9,114,904	9,114,904	9,077,062
Series Seed
Redeemable convertible preferred stock, par value (n dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized (in shares)	3,631,354	3,631,354	3,631,354
Redeemable convertible preferred stock, shares issued (in shares)	3,631,354	3,631,354	3,631,354
Redeemable convertible preferred stock, shares outstanding (in shares)	3,631,354	3,631,354	3,631,354
Redeemable convertible preferred stock, liquidation preference	$ 7,263,000	$ 7,263,000	$ 7,263,000
Series A
Redeemable convertible preferred stock, par value (n dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized (in shares)	4,640,604	4,640,604	4,640,608
Redeemable convertible preferred stock, shares issued (in shares)	4,640,604	4,640,604	4,640,604
Redeemable convertible preferred stock, shares outstanding (in shares)	4,640,604	4,640,604	4,640,604
Redeemable convertible preferred stock, liquidation preference	$ 27,200,000	$ 27,200,000	$ 27,200,000
Series B
Redeemable convertible preferred stock, par value (n dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Redeemable convertible preferred stock, shares authorized (in shares)	6,209,233	6,209,233	0
Redeemable convertible preferred stock, shares issued (in shares)	6,109,232	6,109,232	0
Redeemable convertible preferred stock, shares outstanding (in shares)	6,109,232	6,109,232	0
Redeemable convertible preferred stock, liquidation preference	$ 76,070,000	$ 76,060,000	$ 0

Description of Organization, Business Operations and Basis of Presentation	3 Months Ended	9 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Arya Sciences Acquisition Corp III
Organization and Business Operations [Line Items]
Description of Organization, Business Operations and Basis of Presentation	Description of Organization, Business Operations and Basis of Presentation Organization and General ARYA Sciences Acquisition Corp III (the “Company”) was incorporated as a Cayman Islands exempted company on March 27, 2020. The Company was formed for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (the “Business Combination”). The Company is an emerging growth company and, as such, the Company is subject to all of the risks associated with emerging growth companies. As of March 31, 2021, the Company had not commenced any operations. All activity for the period from March 27, 2020 (inception) through August 11, 2020 relates to the Company’s formation and its initial public offering (“Initial Public Offering”) and had minimal activity, and since the closing of the Initial Public Offering, the search for a prospective initial Business Combination. The Company will not generate any operating revenues until after the completion of its initial Business Combination, at the earliest. The Company will generate non-operating income in the form of interest income on cash and cash equivalents from the proceeds derived from the Initial Public Offering. The Company has selected December 31, as its fiscal year end. Initial Public Offering The Company’s sponsor is ARYA Sciences Holdings III, a Cayman Islands exempted limited company (the “Sponsor”). The registration statement for the Company’s Initial Public Offering was declared effective on August 6, 2020. On August 11, 2020, the Company consummated its Initial Public Offering of 14,950,000 Class A ordinary shares (the “Public Shares”), including the 1,950,000 Public Shares as a result of the underwriters’ full exercise of their over-allotment option, at an offering price of $10.00 per Public Share, generating gross proceeds of $149.5 million, and incurring offering costs of approximately $8.8 million, inclusive of approximately $5.2 million in deferred underwriting commissions (Note 5). Simultaneously with the closing of the Initial Public Offering, the Company consummated the private placement (“Private Placement”) of 499,000 Class A ordinary shares (the “Private Placement Shares”), at a price of $10.00 per Private Placement Share to the Sponsor, generating gross proceeds of approximately $5.0 million (Note 4). Trust Account Upon the closing of the Initial Public Offering and the Private Placement, $149.5 million ($10.00 per share) of the net proceeds of the Initial Public Offering and certain of the proceeds of the Private Placement were placed in a trust account (“Trust Account”), located in the United States at J.P. Morgan Chase Bank, N.A., with Continental Stock Transfer & Trust Company acting as trustee, and will be invested only in U.S. government securities, within the meaning set forth in Section 2(a)(16) of the Investment Company Act of 1940, as amended (the “Investment Company Act”), with a maturity of 185 Days or less or in money market fund meeting the conditions of paragraphs (d)(1), (d)(2), (d)(3) and (d)(4) of Rule 2a-7 of the Investment Company Act, as determined by the Company, until the earlier of: (i) the completion of a Business Combination and (ii) the distribution of the Trust Account as described below. Initial Business Combination The Company’s management has broad discretion with respect to the specific application of the net proceeds of the Initial Public Offering and the sale of Private Placement Shares, although substantially all of the net proceeds are intended to be applied generally toward consummating a Business Combination. There is no assurance that the Company will be able to complete a Business Combination successfully. The Company must complete one or more initial Business Combinations having an aggregate fair market value of at least 80% of the net assets held in the Trust Account (as defined below) (excluding the amount of deferred underwriting commissions and taxes payable on the interest earned on the Trust Account) at the time of the signing of the agreement to enter into the initial Business Combination. However, the Company will only complete a Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act. The Company will provide the holders (the “Public Shareholders”) of Public Shares, with the opportunity to redeem all or a portion of their Public Shares upon the completion of a Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) by means of a tender offer. The decision as to whether the Company will seek shareholder approval of a Business Combination or conduct a tender offer will be made by the Company, solely in its discretion. The Public Shareholders will be entitled to redeem their Public Shares for a pro rata portion of the amount then in the Trust Account (initially anticipated to be $10.00 per Public Share, plus any pro rata interest earned on the funds held in the Trust Account and not previously released to the Company to pay income taxes). The per-share amount to be distributed to Public Shareholders who redeem their Public Shares will not be reduced by the deferred underwriting commissions the Company will pay to the underwriters (as discussed in Note 5). The Public Shares are classified as temporary equity upon the completion of the Initial Public Offering in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) Topic 480 “Distinguishing Liabilities from Equity.” In such case, the Company will proceed with a Business Combination if the Company has net tangible assets of at least $5,000,001 upon such consummation of a Business Combination and, only if a majority of the ordinary shares, represented in person or by proxy and entitled to vote thereon, voted at a shareholder meeting are voted in favor of the Business Combination. If a shareholder vote is not required by law and the Company does not decide to hold a shareholder vote for business or other reasons, the Company will, pursuant to the amended and restated memorandum and articles of association which the Company will adopt upon the consummation of the Initial Public Offering (the “Amended and Restated Memorandum and Articles of Association”), conduct the redemptions pursuant to the tender offer rules of the U.S. Securities and Exchange Commission (“SEC”) and file tender offer documents with the SEC prior to completing a Business Combination. If, however, shareholder approval of the transactions is required by law, or the Company decides to obtain shareholder approval for business or other reasons, the Company will offer to redeem shares in conjunction with a proxy solicitation pursuant to the proxy rules and not pursuant to the tender offer rules. Additionally, each Public Shareholder may elect to redeem their Public Shares irrespective of whether they vote for or against the proposed transaction or vote at all. If the Company seeks shareholder approval in connection with a Business Combination, the initial shareholders (as defined below) have agreed to vote their Founder Shares (as defined below in Note 4) and any Public Shares purchased during or after the Initial Public Offering in favor of a Business Combination. Subsequent to the consummation of the Initial Public Offering, the Company will adopt an insider trading policy which will require insiders to: (i) refrain from purchasing shares during certain blackout periods and when they are in possession of any material non-public information and (ii) to clear all trades with the Company’s legal counsel prior to execution. In addition, the initial shareholders have agreed to waive their redemption rights with respect to their Founder Shares, Private Placement Shares and Public Shares in connection with the completion of a Business Combination. Notwithstanding the foregoing, if the Company seeks shareholder approval of its Business Combination and does not conduct redemptions in connection with its Business Combination pursuant to the tender offer rules, the Amended and Restated Memorandum and Articles of Association provide that a Public Shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the Class A ordinary shares sold in the Initial Public Offering, without the prior consent of the Company. The Company’s Sponsor, officers and directors (the “initial shareholders”) have agreed not to propose an amendment to the Amended and Restated Memorandum and Articles of Association (a) that would modify the substance or timing of the Company’s obligation to provide holders of its Public Shares the right to have their shares redeemed in connection with a Business Combination or to redeem 100% of the Company’s Public Shares if the Company does not complete its Business Combination within 24 months from the closing of the Initial Public Offering, or August 11, 2022 (the “Combination Period”) or (b) with respect to any other provision relating to the rights of Public Shareholders, unless the Company provides the Public Shareholders with the opportunity to redeem their Class A ordinary shares in conjunction with any such amendment. If the Company has not completed a Business Combination within the Combination Period, the Company will (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public Shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to the Company to pay for its income taxes, if any (less up to $100,000 of interest to pay dissolution expenses), divided by the number of the then-outstanding Public Shares, which redemption will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of the Company’s remaining shareholders and its board of directors, liquidate and dissolve, subject in the case of clauses (ii) and (iii) to the Company’s obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. The initial shareholders have agreed to waive their liquidation rights with respect to the Founder Shares and Private Placement Shares held by them if the Company fails to complete a Business Combination within the Combination Period. However, if the initial shareholders acquire Public Shares in or after the Initial Public Offering, they will be entitled to liquidating distributions from the Trust Account with respect to such Public Shares if the Company fails to complete a Business Combination within the Combination Period. The underwriters have agreed to waive their rights to their deferred underwriting commission (see Note 5) held in the Trust Account in the event the Company does not complete a Business Combination within the Combination Period and, in such event, such amounts will be included with the other funds held in the Trust Account that will be available to fund the redemption of the Public Shares. In the event of such distribution, it is possible that the per share value of the assets remaining available for distribution (including Trust Account assets) will be only $10.00 per share initially held in the Trust Account. In order to protect the amounts held in the Trust Account, the Sponsor has agreed to be liable to the Company if and to the extent any claims by a third party for services rendered or products sold to the Company, or a prospective target business with which the Company has discussed entering into a transaction agreement, reduce the amount of funds in the Trust Account to below the lesser of (i) $10.00 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account if less than $10.00 per Public Share due to reductions in the value of the trust assets. This liability will not apply with respect to any claims by a third party who executed a waiver of any right, title, interest or claim of any kind in or to any monies held in the Trust Account or to any claims under the Company’s indemnity of the underwriters of the Initial Public Offering against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”). Moreover, in the event that an executed waiver is deemed to be unenforceable against a third party, the Sponsor will not be responsible to the extent of any liability for such third party claims. The Company will seek to reduce the possibility that the Sponsor will have to indemnify the Trust Account due to claims of creditors by endeavoring to have all vendors, service providers (excluding the Company’s independent registered public accounting firm), prospective target businesses or other entities with which the Company does business, execute agreements with the Company waiving any right, title, interest or claim of any kind in or to monies held in the Trust Account. Proposed Nautilus Business Combination and related Proposed Transactions On February 7, 2021, we entered into a business combination agreement (“Business Combination Agreement”), by and among the Company, Mako Merger Sub, Inc., a Delaware corporation (“Merger Sub”), and Nautilus Biotechnology, Inc., a Delaware corporation (“Nautilus”). The Business Combination Agreement provides for, among other things, the following transactions: (i) Nautilus will changes its name to “Nautilus Subsidiary, Inc.” (or another name mutually agreed to by us and Nautilus); (ii) we will become a Delaware corporation (the “Domestication”) and, in connection with the Domestication, (A) our name will be changed to “Nautilus Biotechnology, Inc.” (“New Nautilus”) and (B) each of our outstanding Class A ordinary shares and outstanding Class B ordinary shares will become one share of common stock of New Nautilus (the “New Nautilus Common Stock”); and (iii) following the Domestication, Merger Sub will merge with and into Nautilus, with Nautilus as the surviving company in the merger and, after giving effect to such merger, continuing as a wholly-owned subsidiary of New Nautilus (the “Merger”). The Domestication, the Merger and the other transactions contemplated by the Business Combination Agreement are hereinafter referred to as the “Nautilus Business Combination.” In accordance with the terms and subject to the conditions of the Business Combination Agreement, outstanding shares of Nautilus (other than treasury shares and any Company Dissenting Shares (as defined in the Business Combination Agreement) will be exchanged for shares of New Nautilus Common Stock and outstanding Nautilus options to purchase shares of Nautilus (whether vested or unvested) will be exchanged for comparable options to purchase New Nautilus Common Stock, in each case, based on an implied Nautilus equity value of $900 million. The Nautilus Business Combination is expected to close in the second quarter of 2021, following the receipt of the required approval by our shareholders and the fulfillment of other customary closing conditions. Concurrently with the execution of the Business Combination Agreement, the Company, the Sponsor, and each other holder of Class B ordinary shares of ARYA (the “Other Class B Shareholders”) and Nautilus entered into the Sponsor Letter Agreement (the “Sponsor Letter Agreement”), pursuant to which the Sponsor and the Other Class B Shareholders, among other things, (i) vote in favor of each of the transaction proposals to be voted upon at the meeting of ARYA shareholders, including approval of the Business Combination Agreement and the transactions contemplated thereby (including the Merger) and (ii) waive any adjustment to the conversion ratio set forth in the governing documents of the Company or any other anti-dilution or similar protection with respect to the Class B ordinary shares (whether resulting from the transactions contemplated by the Subscription Agreements (as defined below) or otherwise); and (iii) be bound by certain transfer restrictions with respect to his, her or its shares in the Company prior to the closing of the Nautilus Business Combination, in each case, on the terms and subject to the conditions set forth in the Sponsor Letter Agreement. Concurrently with the execution of the Business Combination Agreement, we entered into subscription agreements (the “Subscription Agreements”) with certain investors, including, among others, Perceptive Life Sciences Master Fund Ltd., a fund managed by Perceptive Advisors, an affiliate of the Sponsor, as well as certain equity holders of Nautilus and additional third party investors. Pursuant to the Subscription Agreements, each investor agreed to subscribe for and purchase, and the Company agreed to issue and sell to such investors, on the Closing Date (as defined in the Business Combination Agreement) immediately prior to the Closing (as defined in the Business Combination Agreement), an aggregate of 20,000,000 shares of the New Nautilus Common Stock for a purchase price of $10.00 per share, for aggregate gross proceeds of $200,000,000. Within 24 hours of the signing of the Business Combination Agreement, certain directors, officers and stockholders of Nautilus entered into a Transaction Support Agreement with the Company, pursuant to which such parties have agreed to, among other things, (i) support and vote in favor of the Business Combination Agreement and the transactions contemplated thereby (including the Merger), and (ii) be bound by certain other covenants and agreements related to the Nautilus Business Combination, including a restriction on transfers with respect to his, her or its shares in Nautilus prior to the closing of the Nautilus Business Combination. The Company, the Perceptive Shareholders (as defined in the Business Combination Agreement), the Other Class B Shareholders and certain Nautilus shareholders entered into an amended and restated registration rights and lock-up agreement, pursuant to which, among other things, the Perceptive Shareholders, the Other Class B Shareholders and the certain Nautilus shareholders agreed not to effect any sale or distribution of the company equity securities during the lock-up period described therein and will be granted certain customary registration rights, in each case subject to, and conditioned upon and effective as of, the effective time of the Merger. A copy of each of the above referenced agreements is filed as exhibits with a Current Report on Form 8-K, filed with the SEC on February 8, 2021. Liquidity and Capital Resources As of March 31, 2021, the Company had approximately $682,010 in its operating bank account and a working capital deficit of approximately $864,000. The Company’s liquidity needs to date have been satisfied through a contribution of $25,000 from the Sponsor to cover certain of the Company’s offering costs in exchange for the issuance of the Founder Shares, the loan proceeds of $200,000 from the Sponsor pursuant to the promissory note (the “Note”) (see Note 4), and the proceeds from the consummation of the Private Placement not held in the Trust Account. The Company fully repaid the Note on August 11, 2020. In addition, in order to finance transaction costs in connection with a Business Combination, the Sponsor or an affiliate of the Sponsor, or certain of the Company’s officers and directors may, but are not obligated to, provide the Company Working Capital Loans (see Note 4). As of March 31, 2021, there were no amounts outstanding under any Working Capital Loan. In connection with the Company’s assessment of going concern considerations in accordance with Financial Accounting Standard Board’s Accounting Standards Updated (“ASU”) 2014-15, “Disclosures of Uncertainties about an Entity’s Ability to Continue as a Going Concern”, management has determined that the working capital deficit raises substantial doubt about the Company’s ability to continue as a going concern. The financial statements do not include any adjustment that might be necessary if the Company is unable to continue as a going concern. Risk and Uncertainties On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus (the “COVID-19 outbreak”). In March 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The full impact of the COVID-19 outbreak continues to evolve. The impact of the COVID-19 outbreak on the Company’s results of operations, financial position and cash flows will depend on future developments, including the duration and spread of the outbreak and related advisories and restrictions. These developments and the impact of the COVID-19 outbreak on the financial markets and the overall economy are highly uncertain and cannot be predicted. If the financial markets and/or the overall economy are impacted for an extended period, the Company’s results of operations, financial position and cash flows may be materially adversely affected. Additionally, the Company’s ability to complete an Initial Business Combination may be materially adversely affected due to significant governmental measures being implemented to contain the COVID-19 outbreak or treat its impact, including travel restrictions, the shutdown of businesses and quarantines, among others, which may limit the Company’s ability to have meetings with potential investors or affect the ability of a potential target company’s personnel, vendors and service providers to negotiate and consummate an Initial Business Combination in a timely manner. The Company’s ability to consummate an Initial Business Combination may also be dependent on the ability to raise additional equity and debt financing, which may be impacted by the COVID-19 outbreak and the resulting market downturn. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.	Description of Organization and Business Operations Organization and General ARYA Sciences Acquisition Corp III (the “Company”) was incorporated as a Cayman Islands exempted company on March 27, 2020. The Company was formed for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (the “Business Combination”). The Company is an emerging growth company and, as such, the Company is subject to all of the risks associated with emerging growth companies. All activity for the period from March 27, 2020 (inception) through December 31, 2020 relates to the Company’s formation and its initial public offering (“Initial Public Offering”), and since the closing of the Initial Public Offering, the search for a prospective initial Business Combination. The Company will not generate any operating revenues until after the completion of its initial Business Combination, at the earliest. The Company will generate non-operating income in the form of interest income on cash and cash equivalents and gains on investments from the proceeds derived from the Initial Public Offering. The Company has selected December 31 as its fiscal year end. Sponsor and Initial Public Offering The Company’s sponsor is ARYA Sciences Holdings III, a Cayman Islands exempted limited company (the “Sponsor”). The registration statement for the Company’s Initial Public Offering was declared effective on August 6, 2020. On August 11, 2020, the Company consummated its Initial Public Offering of 14,950,000 Class A ordinary shares (the “Public Shares”), including the 1,950,000 Public Shares as a result of the underwriters’ full exercise of their over-allotment option, at an offering price of $10.00 per Public Share, generating gross proceeds of $149.5 million, and incurring offering costs of approximately $8.8 million, inclusive of approximately $5.2 million in deferred underwriting commissions (Note 5). Simultaneously with the closing of the Initial Public Offering, the Company consummated the private placement (“Private Placement”) of 499,000 Class A ordinary shares (the “Private Placement Shares”), at a price of $10.00 per Private Placement Share to the Sponsor, generating gross proceeds of approximately $5.0 million (Note 4). Trust Account Upon the closing of the Initial Public Offering and the Private Placement, $149.5 million ($10.00 per Unit) of the net proceeds of the Initial Public Offering and certain of the proceeds of the Private Placement were placed in a trust account (“Trust Account”), located in the United States at J.P. Morgan Chase Bank, N.A., with Continental Stock Transfer & Trust Company acting as trustee, and were invested only in U.S. government securities, within the meaning set forth in Section 2(a)(16) of the Investment Company Act of 1940, as amended (the “Investment Company Act”), with a maturity of 185 days or less or in money market funds meeting the conditions of paragraphs (d)(1), (d)(2), (d)(3) and (d)(4) of Rule 2a-7 of the Investment Company Act, as determined by the Company, until the earlier of:(i) the completion of a Business Combination, and then only in connection with those Class A ordinary shares that the holders of public shares (the “Public Shareholders”) properly elected to redeem, subject to certain limitations described in the IPO Registration Statement, (ii) the redemption of any Public Shares properly tendered in connection with a shareholder vote to amend the Company’s amended and restated memorandum and articles of association (the “Amended and Restated Memorandum and Articles of Association”) (A) to modify the substance or timing of the Company’s obligation to provide holders of Class A ordinary shares the right to have their shares redeemed in connection with the Company’s initial Business Combination or to redeem 100% of the Company’s Public Shares if the Company does not complete its initial Business Combination within 24 months from the closing of the Initial Public Offering, or October 26, 2022 (the “Combination Period”) or (B) with respect to any other provision relating to the rights of holders of Class A ordinary shares, and (iii) the redemption of the Class A ordinary shares if the Company has not consummated its Business Combination within the Combination Period, subject to applicable law. The remaining net proceeds (not held in the Trust Account) may be used to pay for business, legal and accounting due diligence on prospective acquisitions and continuing general and administrative expenses. The Company may use the interest income generated by the assets in the Trust Account to pay for taxes that were paid by the Company or are payable by the Company and, in case the Company does not complete its initial Business Combination within the Combination Period, $100,000 of the interest income may be used to pay dissolution expenses. Initial Business Combination The Company’s management has broad discretion with respect to the specific application of the net proceeds of the Initial Public Offering and the sale of Private Placement Shares, although substantially all of the net proceeds are intended to be applied generally toward consummating a Business Combination. There is no assurance that the Company will be able to complete a Business Combination successfully. The Company must complete one or more initial Business Combinations having an aggregate fair market value of at least 80% of the net assets held in the Trust Account (excluding the amount of deferred underwriting commissions and taxes payable on the interest earned on the Trust Account) at the time of the signing of the agreement to enter into the initial Business Combination. However, the Company will only complete a Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act. The Company will provide the Public Shareholders, with the opportunity to redeem all or a portion of their Public Shares upon the completion of a Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) by means of a tender offer. The decision as to whether the Company will seek shareholder approval of a Business Combination or conduct a tender offer will be made by the Company, solely in its discretion. The Public Shareholders will be entitled to redeem their Public Shares for a pro rata portion of the amount then in the Trust Account (initially anticipated to be $10.00 per Public Share, plus any pro rata interest earned on the funds held in the Trust Account and not previously released to the Company to pay income taxes). The per-share amount to be distributed to Public Shareholders who redeem their Public Shares will not be reduced by the deferred underwriting commissions the Company will pay to Goldman Sachs & Co. LLC and Jefferies LLC, as underwriters of the Company’s Initial Public Offering (as discussed in Note 5). The Public Shares are classified as temporary equity upon the completion of the Initial Public Offering in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) Topic 480 “Distinguishing Liabilities from Equity.” In such case, the Company will proceed with a Business Combination if the Company has net tangible assets of at least $5,000,001 upon such consummation of a Business Combination and, only if a majority of the ordinary shares, represented in person or by proxy and entitled to vote thereon, voted at a shareholder meeting are voted in favor of the Business Combination. If a shareholder vote is not required by law and the Company does not decide to hold a shareholder vote for business or other reasons, the Company will, pursuant to the Amended and Restated Memorandum and Articles of Association, conduct the redemptions pursuant to the tender offer rules of the U.S. Securities and Exchange Commission (“SEC”) and file tender offer documents with the SEC prior to completing a Business Combination. If, however, shareholder approval of the transactions is required by law, or the Company decides to obtain shareholder approval for business or other reasons, the Company will offer to redeem shares in conjunction with a proxy solicitation pursuant to the proxy rules and not pursuant to the tender offer rules. Additionally, each Public Shareholder may elect to redeem their Public Shares irrespective of whether they vote for or against the proposed transaction or vote at all. If the Company seeks shareholder approval in connection with a Business Combination, the initial shareholders (as defined below) have agreed to vote their Founder Shares (as defined below in Note 4) and any Public Shares purchased during or after the Initial Public Offering in favor of a Business Combination. Subsequent to the consummation of the Initial Public Offering, the Company has adopted an insider trading policy which requires insiders to: (i) refrain from purchasing shares during certain blackout periods and when they are in possession of any material non-public information and (ii) to clear all trades with the Company’s legal counsel prior to execution. In addition, the initial shareholders have agreed to waive their redemption rights with respect to their Founder Shares, Private Placement Shares and Public Shares in connection with the completion of a Business Combination. Notwithstanding the foregoing, if the Company seeks shareholder approval of its Business Combination and does not conduct redemptions in connection with its Business Combination pursuant to the tender offer rules, the Amended and Restated Memorandum and Articles of Association provides that a Public Shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the Class A ordinary shares sold in the Initial Public Offering, without the prior consent of the Company. The Company’s Sponsor, officers and directors (the “initial shareholders”) have agreed not to propose an amendment to the Amended and Restated Memorandum and Articles of Association (a) that would modify the substance or timing of the Company’s obligation to provide holders of its Public Shares the right to have their shares redeemed in connection with a Business Combination or to redeem 100% of the Company’s Public Shares if the Company does not complete its Business Combination within 24 months from the closing of the Initial Public Offering, or August 11, 2022 (the “Combination Period”) or with respect to any other provision relating to the rights of Public Shareholders, unless the Company provides the Public Shareholders with the opportunity to redeem their Class A ordinary shares in conjunction with any such amendment. If the Company has not completed a Business Combination within the Combination Period, the Company will (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public Shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to the Company to pay for its income taxes, if any (less up to $100,000 of interest to pay dissolution expenses), divided by the number of the then-outstanding Public Shares, which redemption will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of the Company’s remaining shareholders and its board of directors, liquidate and dissolve, subject in the case of clauses (ii) and (iii) to the Company’s obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. The initial shareholders have agreed to waive their liquidation rights with respect to the Founder Shares and Private Placement Shares held by them if the Company fails to complete a Business Combination within the Combination Period. However, if the initial shareholders acquire Public Shares in or after the Initial Public Offering, they will be entitled to liquidating distributions from the Trust Account with respect to such Public Shares if the Company fails to complete a Business Combination within the Combination Period. The underwriters have agreed to waive their rights to their deferred underwriting commission (see Note 5) held in the Trust Account in the event the Company does not complete a Business Combination within the Combination Period and, in such event, such amounts will be included with the other funds held in the Trust Account that will be available to fund the redemption of the Public Shares. In the event of such distribution, it is possible that the per share value of the assets remaining available for distribution (including Trust Account assets) will be only $10.00 per share initially held in the Trust Account. In order to protect the amounts held in the Trust Account, the Sponsor has agreed to be liable to the Company if and to the extent any claims by a third party (excluding the Company’s independent registered public accounting firm) for services rendered or products sold to the Company, or a prospective target business with which the Company has discussed entering into a transaction agreement, reduce the amount of funds in the Trust Account to below the lesser of (i) $10.00 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account if less than $10.00 per Public Share due to reductions in the value of the assets in the Trust Account, in each case net of the interest that may be withdrawn to pay for the Company’s tax obligations. This liability will not apply with respect to any claims by a third party who executed a waiver of any right, title, interest or claim of any kind in or to any monies held in the Trust Account or to any claims under the Company’s indemnity of the underwriters of the Initial Public Offering against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”). Moreover, in the event that an executed waiver is deemed to be unenforceable against a third party, the Sponsor will not be responsible to the extent of any liability for such third party claims. The Company will seek to reduce the possibility that the Sponsor will have to indemnify the Trust Account due to claims of creditors by endeavoring to have all vendors, service providers (excluding the Company’s independent registered public accounting firm), prospective target businesses or other entities with which the Company does business, execute agreements with the Company waiving any right, title, interest or claim of any kind in or to monies held in the Trust Account. The Company has not asked the Sponsor to reserve for such indemnification obligations, nor has the Company independently verified whether the Sponsor has sufficient funds to satisfy its indemnity obligations and the Company believes that the Sponsor’s only assets are securities of the Company. The Sponsor may not be able to satisfy those obligations. None of the Company’s officers or directors will indemnify the Company for claims by third parties including, without limitation, claims by vendors and prospective target businesses. Proposed Nautilus Business Combination and related Proposed Transactions On February 7, 2021, we entered into a business combination agreement (“Business Combination Agreement”), by and among the Company, Mako Merger Sub, Inc., a Delaware corporation (“Merger Sub”), and Nautilus Biotechnology, Inc., a Delaware corporation (“Nautilus”). The Business Combination Agreement provides for, among other things, the following transactions: (i) Nautilus will changes its name to “Nautilus Subsidiary, Inc.” (or another name mutually agreed to by us and Nautilus); (ii) we will become a Delaware corporation (the “Domestication”) and, in connection with the Domestication, (A) our name will be changed to “Nautilus Biotechnology, Inc.” (“New Nautilus”) and (B) each of our outstanding Class A ordinary shares and outstanding Class B ordinary shares will become one share of common stock of New Nautilus (the “New Nautilus Common Stock”); and (iii) following the Domestication, Merger Sub will merge with and into Nautilus, with Nautilus as the surviving company in the merger and, after giving effect to such merger, continuing as a wholly-owned subsidiary of New Nautilus (the “Merger”). The Domestication, the Merger and the other transactions contemplated by the Business Combination Agreement are hereinafter referred to as the “Nautilus Business Combination.” In accordance with the terms and subject to the conditions of the Business Combination Agreement, outstanding shares of Nautilus (other than treasury shares and any Company Dissenting Shares (as defined in the Business Combination Agreement) will be exchanged for shares of New Nautilus Common Stock and outstanding Nautilus options to purchase shares of Nautilus (whether vested or unvested) will be exchanged for comparable options to purchase New Nautilus Common Stock, in each case, based on an implied Nautilus equity value of $900 million. The Nautilus Business Combination is expected to close in the second quarter of 2021, following the receipt of the required approval by our shareholders and the fulfillment of other customary closing conditions. Concurrently with the execution of the Business Combination Agreement, the Company, the Sponsor, and each other holder of Class B ordinary shares of ARYA (the “Other Class B Shareholders”) and Nautilus entered into the Sponsor Letter Agreement (the “Sponsor Letter Agreement”), pursuant to which the Sponsor and the Other Class B Shareholders, among other things, (i) vote in favor of each of the transaction proposals to be voted upon at the meeting of ARYA shareholders, including approval of the Business Combination Agreement and the transactions contemplated thereby (including the Merger) and (ii) waive any adjustment to the conversion ratio set forth in the governing documents of the Company or any other anti-dilution or similar protection with respect to the Class B ordinary shares (whether resulting from the transactions contemplated by the Subscription Agreements (as defined below) or otherwise); and (iii) be bound by certain transfer restrictions with respect to his, her or its shares in the Company prior to the closing of the Nautilus Business Combination, in each case, on the terms and subject to the conditions set forth in the Sponsor Letter Agreement. Concurrently with the execution of the Business Combination Agreement, we entered into subscription agreements (the “Subscription Agreements”) with certain investors, including, among others, Perceptive Life Sciences Master Fund Ltd., a fund managed by Perceptive Advisors, an affiliate of the Sponsor, as well as certain equity holders of Nautilus and additional third party investors. Pursuant to the Subscription Agreements, each investor agreed to subscribe for and purchase, and the Company agreed to issue and sell to such investors, on the Closing Date (as defined in the Business Combination Agreement) immediately prior to the Closing (as defined in the Business Combination Agreement), an aggregate of 20,000,000 shares of the New Nautilus Common Stock for a purchase price of $10.00 per share, for aggregate gross proceeds of $200,000,000. Within 24 hours of the signing of the Business Combination Agreement, certain directors, officers and stockholders of Nautilus entered into a Transaction Support Agreement with the Company, pursuant to which such parties have agreed to, among other things, (i) support and vote in favor of the Business Combination Agreement and the transactions contemplated thereby (including the Merger), and (ii) be bound by certain other covenants and agreements related to the Nautilus Business Combination, including a restriction on transfers with respect to his, her or its shares in Nautilus prior to the closing of the Nautilus Business Combination The Company, the Perceptive Shareholders (as defined in the Business Combination Agreement), the Other Class B Shareholders and certain Nautilus shareholders entered into an amended and restated registration rights and lock-up agreement, pursuant to which, among other things, the Perceptive Shareholders, the Other Class B Shareholders and the certain Nautilus shareholders agreed not to effect any sale or distribution of the company equity securities during the lock-up period described therein and will be granted certain customary registration rights, in each case subject to, and conditioned upon and effective as of, the effective time of the Merger. A copy of each of the above referenced agreements is filed as exhibits with a Current Report on Form 8-K, filed with the SEC on February 8, 2021. Liquidity and Capital Resources As of December 31, 2020, the Company had approximately $1.0 million in its operating bank account and working capital of approximately $916,000. The Company’s liquidity needs to date have been satisfied through a contribution of $25,000 from the Sponsor to cover certain of the Company’s offering costs in exchange for the issuance of the Founder Shares, the loan proceeds of $200,000 from the Sponsor pursuant to the Note (see Note 4), and the proceeds from the consummation of the Private Placement not held in the Trust Account. The Company fully repaid the Note on August 11, 2020. In addition, in order to finance transaction costs in connection with a Business Combination, the Sponsor or an affiliate of the Sponsor, or certain of the Company’s officers and directors may, but are not obligated to, provide the Company Working Capital Loans (see Note 4). As of December 31, 2020, there were no amounts outstanding under any Working Capital Loan. Based on the foregoing, management believes that the Company will have sufficient working capital and borrowing capacity from the Sponsor or an affiliate of the Sponsor, or certain of the Company’s officers and directors to meet its needs through the earlier of the consummation of a Business Combination or one year from this filing. Over this time period, the Company will be using these funds for paying existing accounts payable, identifying and evaluating prospective initial Business Combination candidates, performing due diligence on prospective target businesses, paying for travel expenditures, selecting the target business to merge with or acquire, and structuring, negotiating and consummating the Business Combination. Risk and Uncertainties On January 30, 2020, the World Health Organization (“WHO”) announced a global health emergency because of a new strain of coronavirus (the “COVID-19 outbreak”). In March 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The full impact of the COVID-19 outbreak continues to evolve. The impact of the COVID-19 outbreak on the Company’s results of operations, financial position and cash flows will depend on future developments, including the duration and spread of the outbreak and related advisories and restrictions. These developments and the impact of the COVID-19 outbreak on the financial markets and the overall economy are highly uncertain and cannot be predicted. If the financial markets and/or the overall economy are impacted for an extended period, the Company’s results of operations, financial position and cash flows may be materially adversely affected. Additionally, the Company’s ability to complete an Initial Business Combination may be materially adversely affected due to significant governmental measures being implemented to contain the COVID-19 outbreak or treat its impact, including travel restrictions, the shutdown of businesses and quarantines, among others, which may limit the Company’s ability to have meetings with potential investors or affect the ability of a potential target company’s personnel, vendors and service providers to negotiate and consummate an Initial Business Combination in a timely manner. The Company’s ability to consummate an Initial Business Combination may also be dependent on the ability to raise additional equity and debt financing, which may be impacted by the COVID-19 outbreak and the resulting market downturn. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Summary of Significant Accounting Policies	3 Months Ended	9 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2021	Dec. 31, 2020
Arya Sciences Acquisition Corp III
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed financial statements of the Company have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) for interim financial information and Article 8 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP. In the opinion of management, all adjustments (consisting of normal accruals) considered for a fair presentation have been included. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the period ending December 31, 2021 or for any future interim periods. The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Form 10-K filed by the Company with the SEC on March 30, 2021. Use of Estimates The preparation of the unaudited condensed financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Making estimates requires management to exercise significant judgment. It is at least reasonably possible that the estimate of the effect of a condition, situation or set of circumstances that existed at the date of the financial statements, which management considered in formulating its estimate, could change in the near term due to one or more future confirming events. Accordingly, the actual results could differ significantly from those estimates. Emerging Growth Company The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act, as modified by the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002, reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. Further, Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such an election to opt out is irrevocable. The Company has elected not to opt out of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of the Company’s financial statements with another public company that is neither an emerging growth company nor an emerging growth company that has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used. Cash and Cash Equivalents The Company considers all short-term investments with an original maturity of three months or less when purchased to be cash equivalents. The Company had no cash equivalents as of March 31, 2021. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash accounts in a financial institution, which, at times, may exceed the Federal Depository Insurance Coverage of $250,000, and investments held in Trust Account. At March 31, 2021, the Company has not experienced losses on these accounts and management believes the Company is not exposed to significant risks on such accounts. Investment Securities Held in Trust Account Upon the closing of the Initial Public Offering and the Private Placement, the Company was required to place net proceeds of the Initial Public Offering and certain of the proceeds of the Private Placement in a Trust Account, which may be invested in U.S. government securities, within the meaning set forth in Section 2(a)(16) of the Investment Company Act, with a maturity of 185 days or less, or in money market funds meeting certain conditions under Rule 2a-7 promulgated under the Investment Company Act which invest only in direct U.S. government treasury obligations, as determined by management of the Company, until the earlier of: (i) the completion of a Business Combination and (ii) the distribution of the Trust Account. Investments held in Trust Account are classified as trading securities, which are presented on the condensed balance sheets at fair value at the end of each reporting period. Gains and losses resulting from the change in fair value of trading securities is included in investment income on Trust Account in the accompanying unaudited condensed statements of operations. The estimated fair values of investments held in Trust Account are determined using available market information, other than for investments in open-ended money market funds with published daily net asset values (“NAV”), in which case the Company uses NAV as a practical expedient to fair value. The NAV on these investments is typically held constant at $1.00 per unit. Fair Value of Financial Instruments Fair value is defined as the price that would be received for sale of an asset or paid for transfer of a liability, in an orderly transaction between market participants at the measurement date. U.S. GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). These tiers include: •Level 1, defined as observable inputs such as quoted prices for identical instruments in active markets; •Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable such as quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active; and •Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions, such as valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. In some circumstances, the inputs used to measure fair value might be categorized within different levels of the fair value hierarchy. In those instances, the fair value measurement is categorized in its entirety in the fair value hierarchy based on the lowest level input that is significant to the fair value measurement. As of March 31, 2021, the carrying values of cash, accounts payable and accrued expenses approximate their fair values due to the short-term nature of the instruments. The Company’s portfolio of investments held in the Trust Account is comprised of investments in U.S. Treasury securities with an original maturity of 185 days or less or investments in money market funds that invest in U.S. government securities, or a combination thereof. The fair value for trading securities is determined using quoted market prices in active markets. Offering Costs Associated with the Initial Public Offering Offering costs consisted of legal, accounting, and other costs incurred that were directly related to the Initial Public Offering and that were charged to shareholders’ equity upon the completion of the Initial Public Offering. Class A Ordinary Shares Subject to Possible Redemption The Company accounts for its Class A ordinary shares subject to possible redemption in accordance with the guidance in ASC Topic 480 “Distinguishing Liabilities from Equity.” Class A ordinary shares subject to mandatory redemption (if any) are classified as liability instruments and are measured at fair value. Conditionally redeemable Class A ordinary shares (including Class A ordinary shares that feature redemption rights that are either within the control of the holder or subject to redemption upon the occurrence of uncertain events not solely within the Company’s control) are classified as temporary equity. At all other times, Class A ordinary shares are classified as shareholders’ equity. The Company’s Class A ordinary shares feature certain redemption rights that are considered to be outside of the Company’s control and subject to the occurrence of uncertain future events. Accordingly, at March 31, 2021, 13,846,772 Class A ordinary shares subject to possible redemption are presented as temporary equity, outside of the shareholders’ equity section of the Company’s unaudited condensed balance sheet. Income Taxes FASB ASC 740 prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. There were no unrecognized tax benefits as of March 31, 2021. The Company’s management determined that the Cayman Islands is the Company’s only major tax jurisdiction. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as income tax expense. No amounts were accrued for the payment of interest and penalties as of March 31, 2021. The Company is currently not aware of any issues under review that could result in significant payments, accruals or material deviation from its position. The Company is subject to income tax examinations by major taxing authorities since inception. There is currently no taxation imposed on income by the Government of the Cayman Islands. In accordance with Cayman income tax regulations, income taxes are not levied on the Company. Consequently, income taxes are not reflected in the Company’s unaudited condensed financial statements. The Company’s management does not expect that the total amount of unrecognized tax benefits will materially change over the next twelve months. Net Income (Loss) Per Ordinary Share Net income (loss) per share is computed by dividing net income by the weighted-average number of ordinary shares outstanding during the periods. The Company’s unaudited condensed statements of operations include a presentation of income (loss) per share for ordinary shares subject to redemption in a manner similar to the two-class method of income per share. Net income per ordinary share, basic and diluted, for Class A ordinary shares is calculated by dividing the net gain, dividends and interest on investments held in Trust Account, net of applicable taxes available to be withdrawn from the Trust Account, resulting in a net gain of approximately $11,000 for the three months ended March 31, 2021 by the weighted average number of Class A ordinary shares outstanding for the period. Net loss per ordinary share, basic and diluted for Class B ordinary shares is calculated by dividing the net loss, less income attributable to Class A ordinary shares by the weighted average number of Class B ordinary shares outstanding for the period. Recent Accounting Pronouncements Management does not believe that any recently issued, but not yet effective, accounting pronouncement if currently adopted would have a material effect on the Company’s financial statements.	Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements are presented in U.S. dollars in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the SEC. Use of Estimates The preparation of the financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Making estimates requires management to exercise significant judgment. It is at least reasonably possible that the estimate of the effect of a condition, situation or set of circumstances that existed at the date of the financial statements, which management considered in formulating its estimate, could change in the near term due to one or more future confirming events. Accordingly, the actual results could differ from those estimates. Emerging Growth Company The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act, as modified by the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the independent registered public accounting firm attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002, reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. Further, Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Exchange Act) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that an emerging growth company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. The Company has elected not to opt out of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of the Company’s financial statements with another public company that is neither an emerging growth company nor an emerging growth company that has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used. Cash and Cash Equivalents The Company considers all short-term investments with an original maturity of three months or less when purchased to be cash equivalents. The Company had $1,926 in cash equivalents as of December 31, 2020 held in the Trust Account. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash accounts in a financial institution, which, at times, may exceed the Federal Depository Insurance Coverage of $250,000, and investments held in Trust Account. At December 31, 2020, the Company has not experienced losses on these accounts and management believes the Company is not exposed to significant risks on such accounts. Investment Securities Held in Trust Account Upon the closing of the Initial Public Offering and the Private Placement, the Company was required to place net proceeds of the Initial Public Offering and certain of the proceeds of the Private Placement in a Trust Account, which may be invested in U.S. government securities, within the meaning set forth in Section 2(a)(16) of the Investment Company Act, with a maturity of 185 days or less, or in money market funds meeting certain conditions under Rule 2a-7 promulgated under the Investment Company Act which invest only in direct U.S. government treasury obligations, as determined by management of the Company, until the earlier of: (i) the completion of a Business Combination and (ii) the distribution of the Trust Account. Investments held in Trust Account are classified as trading securities, which are presented on the balance sheet at fair value at the end of the reporting period. Gains and losses resulting from the change in fair value of trading securities is included in investment income on Trust Account in the accompanying statement of operations. The estimated fair values of investments held in Trust Account are determined using available market information, other than for investments in open-ended money market funds with published daily net asset values (“NAV”), in which case the Company uses NAV as a practical expedient to fair value. The NAV on these investments is typically held constant at $1.00 per unit. Fair Value Measurements Fair value is defined as the price that would be received for sale of an asset or paid for transfer of a liability, in an orderly transaction between market participants at the measurement date. GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). These tiers include: •Level 1, defined as observable inputs such as quoted prices (unadjusted) for identical instruments in active markets; •Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable such as quoted prices for similar instruments in active markets or quoted prices for identical or similar instruments in markets that are not active; and •Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions, such as valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. In some circumstances, the inputs used to measure fair value might be categorized within different levels of the fair value hierarchy. In those instances, the fair value measurement is categorized in its entirety in the fair value hierarchy based on the lowest level input that is significant to the fair value measurement. As of December 31, 2020, the carrying values of cash, prepaid expenses and accrued expenses approximate their fair values due to the short-term nature of the instruments. The Company’s investments held in Trust Account is comprised of investments in U.S. Treasury securities with an original maturity of 180 days or less and are recognized at fair value. The fair value of investments held in Trust Account is determined using quoted prices in active markets. Offering Costs Associated with the Initial Public Offering Offering costs consisted of underwriters' commissions, legal, accounting, and other costs incurred that were directly related to the Initial Public Offering and that were charged to shareholders’ equity upon the completion of the Initial Public Offering. Class A Ordinary Shares subject to possible redemption The Company accounts for its Class A ordinary shares subject to possible redemption in accordance with the guidance in ASC Topic 480 “Distinguishing Liabilities from Equity.” Class A ordinary shares subject to mandatory redemption (if any) are classified as liability instruments and are measured at fair value. Conditionally redeemable Class A ordinary shares (including Class A ordinary shares that feature redemption rights that are either within the control of the holder or subject to redemption upon the occurrence of uncertain events not solely within the Company’s control) are classified as temporary equity. At all other times, Class A ordinary shares are classified as shareholders’ equity. The Company’s Class A ordinary shares feature certain redemption rights that are considered to be outside of the Company’s control and subject to the occurrence of uncertain future events. Accordingly, at December 31, 2020, 14,023,673 Class A ordinary shares subject to possible redemption are presented as temporary equity, outside of the shareholders’ equity section of the Company’s balance sheet. Net Income (Loss) Per Ordinary Share Net income (loss) per share is computed by dividing net income by the weighted-average number of ordinary shares outstanding during the period. The Company’s statement of operations includes a presentation of income (loss) per share for ordinary shares subject to redemption in a manner similar to the two-class method of income per share. Net income per ordinary share, basic and diluted, for Class A ordinary shares is calculated by dividing the net gain, dividends and interest on investments held in Trust Account, net of applicable taxes available to be withdrawn from the Trust Account, resulting in net income of approximately $53,000 for the period from March 27, 2020 (inception) through December 31, 2020 by the weighted average number of Class A ordinary shares outstanding for the period. Net loss per ordinary share, basic and diluted for Class B ordinary shares is calculated by dividing the net loss, less income attributable to Class A ordinary shares by the weighted average number of Class B ordinary shares outstanding for the period. Income Taxes The Company follows the asset and liability method of accounting for income taxes under FASB ASC Topic 740, “Income Taxes,” which prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. There were no unrecognized tax benefits as of December 31, 2020. The Company’s management determined that the Cayman Islands is the Company’s only major tax jurisdiction. The Company recognizes accrued interest and penalties related to unrecognized tax benefits as income tax expense. There were no unrecognized tax benefits and no amounts were accrued for interest and penalties for the period from March 27, 2020 (inception) through December 31, 2020. The Company is currently not aware of any issues under review that could result in significant payments, accruals or material deviation from its position. The Company may be subject to potential examination by U.S. federal, U.S. state or foreign taxing authorities in the area of income taxes. These potential examinations may include questioning the timing and amount of deductions, the nexus of income among various tax jurisdictions and compliance with U.S. federal, U.S. state and foreign tax laws. There is currently no taxation imposed on income by the Government of the Cayman Islands. In accordance with Cayman federal income tax regulations, income taxes are not levied on the Company. Consequently, deferred tax assets and income taxes are not reflected in the Company’s financial statements. The Company’s management does not expect that the total amount of unrecognized tax benefits will materially change over the next twelve months. Recent Accounting Pronouncements The Company’s management does not believe that any recently issued, but not yet effective, accounting pronouncements, if currently adopted, would have a material effect on the Company’s financial statements.

Initial Public Offering	3 Months Ended	9 Months Ended
Initial Public Offering	Mar. 31, 2021	Dec. 31, 2020
Arya Sciences Acquisition Corp III
Subsidiary, Sale of Stock [Line Items]
Initial Public Offering	Initial Public OfferingOn August 11, 2020, the Company consummated its Initial Public Offering of 14,950,000 Public Shares, including the 1,950,000 Public Shares as a result of the underwriters’ full exercise of their over-allotment option, at an offering price of $10.00 per Public Share, generating gross proceeds of $149.5 million, and incurring offering costs of approximately $8.8 million, inclusive of approximately $5.2 million in deferred underwriting commissions	Initial Public OfferingOn August 11, 2020, the Company consummated its Initial Public Offering of 14,950,000 Public Shares, including the 1,950,000 Public Shares as a result of the underwriters’ full exercise of their over-allotment option, at an offering price of $10.00 per Public Share, generating gross proceeds of $149.5 million, and incurring offering costs of approximately $8.8 million, inclusive of approximately $5.2 million in deferred underwriting commissions.

Related Party Transactions	3 Months Ended	9 Months Ended
Related Party Transactions	Mar. 31, 2021	Dec. 31, 2020
Arya Sciences Acquisition Corp III
Related Party Transaction [Line Items]
Related Party Transactions	Related Party Transactions Founder Shares On April 2, 2020, the Sponsor paid $25,000 to cover certain offering costs of the Company in consideration of 3,593,750 Class B ordinary shares, par value $0.0001, (the “Founder Shares”). In July 2020, the Sponsor transferred an aggregate of 90,000 Founder Shares to the Company’s independent director nominees. On August 6, 2020, the Company effected a share capitalization resulting in the initial shareholders holding 3,737,500 Founder Shares. All shares and the associated amounts have been retroactively restated to reflect the share capitalization. The Sponsor agreed to forfeit up to 487,500 Founder Shares to the extent that the over-allotment option was not exercised in full by the underwriters, so that the Founder Shares would represent 20.0% of the Company’s issued and outstanding ordinary shares (excluding the Private Placement Shares) after the Initial Public Offering. The underwriters fully exercised the over-allotment option on August 11, 2020; thus, these 487,500 Founder Shares were no longer subject to forfeiture. The initial shareholders agreed, subject to limited exceptions, not to transfer, assign or sell any of their Founder Shares until the earlier to occur of: (A) one year after the completion of the initial Business Combination and (B) subsequent to the initial Business Combination, (x) if the closing price of the Company’s Class A ordinary shares equals or exceeds $12.00 per share (as adjusted for share splits, share capitalizations, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after the initial Business Combination, or (y) the date on which the Company completes a liquidation, merger, share exchange, reorganization or other similar transaction that results in all of the Public Shareholders having the right to exchange their ordinary shares for cash, securities or other property. Private Placement Share Simultaneously with the closing of the Initial Public Offering, the Company consummated the Private Placement of 499,000 Private Placement Shares, at a price of $10.00 per Private Placement Share to the Sponsor, generating gross proceeds of approximately $5.0 million. The Private Placement Shares will not be transferable or salable until 30 days after the completion of the initial Business Combination. A portion of the proceeds from the Private Placement Shares was added to the proceeds from the Initial Public Offering held in the Trust Account. The Sponsor and the Company’s officers and directors agreed, subject to limited exceptions, not to transfer, assign or sell any of their Private Placement Shares until 30 days after the completion of the initial Business Combination. Related Party Loans On April 2, 2020, the Sponsor agreed to loan the Company an aggregate of up to $300,000 to cover for expenses related to the Initial Public Offering pursuant to a Note. This loan was non-interest bearing and payable upon the completion of the Initial Public Offering. The Company borrowed $200,000 under the Note and fully repaid this Note on August 11, 2020. In addition, in order to finance transaction costs in connection with a Business Combination, the Sponsor or an affiliate of the Sponsor, or certain of the Company’s officers and directors may, but are not obligated to, loan the Company funds as may be required (“Working Capital Loans”). If the Company completes a Business Combination, the Company may repay the Working Capital Loans out of the proceeds of the Trust Account released to the Company. Otherwise, the Working Capital Loans may be repaid only out of funds held outside the Trust Account. In the event that a Business Combination does not close, the Company may use a portion of the proceeds held outside the Trust Account to repay the Working Capital Loans but no proceeds held in the Trust Account would be used to repay the Working Capital Loans. Except for the foregoing, the terms of such Working Capital Loans, if any, have not been determined and no written agreements exist with respect to such loans. The Working Capital Loans would either be repaid upon consummation of a Business Combination, without interest, or, at the lender’s discretion, up to $1.5 million of such Working Capital Loans may be convertible into shares of the post Business Combination entity at a price of $10.00 per share. The shares would be identical to the Private Placement Shares. To date, the Company had no outstanding borrowings under the Working Capital Loans. Administrative Support Agreement Commencing on the date that the Company’s securities were first listed on the Nasdaq through the earlier of consummation of the initial Business Combination and the Company’s liquidation, the Company reimburses the Sponsor for office space, secretarial and administrative services provided to the Company in the amount of $10,000 per month. The Company incurred $30,000 in general and administrative expenses in the accompanying unaudited condensed consolidated statements of operations for the three months ended March 31, 2021.	Related Party Transactions Founder Shares On April 2, 2020, the Sponsor paid $25,000 to cover certain offering costs of the Company in consideration of 3,593,750 Class B ordinary shares, par value $0.0001 per share (the “Founder Shares”). In July 2020, the Sponsor transferred an aggregate of 90,000 Founder Shares to the Company’s independent directors. On August 6, 2020, the Company effected a share capitalization resulting in the initial shareholders holding 3,737,500 Founder Shares. All shares and the associated amounts have been retroactively restated to reflect the share capitalization. The Sponsor agreed to forfeit up to 487,500 Founder Shares to the extent that the over-allotment option was not exercised in full by the underwriters, so that the Founder Shares would represent 20.0% of the Company’s issued and outstanding ordinary shares (excluding the Private Placement Shares) after the Initial Public Offering. The underwriters fully exercised the over-allotment option on August 11, 2020; thus, these 487,500 Founder Shares were no longer subject to forfeiture. The initial shareholders agreed, subject to limited exceptions, not to transfer, assign or sell any of their Founder Shares until the earlier to occur of: (A) one year after the completion of the initial Business Combination and (B) subsequent to the initial Business Combination, (x) if the closing price of the Company’s Class A ordinary shares equals or exceeds $12.00 per share (as adjusted for share splits, share capitalizations, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after the initial Business Combination, or (y) the date on which the Company completes a liquidation, merger, share exchange, reorganization or other similar transaction that results in all of the Public Shareholders having the right to exchange their ordinary shares for cash, securities or other property. Private Placement Shares Simultaneously with the closing of the Initial Public Offering, the Company consummated the Private Placement of 499,000 Private Placement Shares, at a price of $10.00 per Private Placement Share to the Sponsor, generating gross proceeds of approximately $5.0 million. The Private Placement Shares will not be transferable or salable until 30 days after the completion of the initial Business Combination. A portion of the proceeds from the Private Placement Shares was added to the proceeds from the Initial Public Offering held in the Trust Account. The Sponsor and the Company’s officers and directors agreed, subject to limited exceptions, not to transfer, assign or sell any of their Private Placement Shares until 30 days after the completion of the initial Business Combination. Related Party Loans On April 2, 2020, the Sponsor agreed to loan the Company an aggregate of up to $300,000 to cover for expenses related to the Initial Public Offering pursuant to a promissory note (the “Note”). This loan was non-interest bearing and payable upon the completion of the Initial Public Offering. The Company borrowed $200,000 under the Note and fully repaid this Note on August 11, 2020. In addition, in order to finance transaction costs in connection with a Business Combination, the Sponsor or an affiliate of the Sponsor, or certain of the Company’s officers and directors may, but are not obligated to, loan the Company funds as may be required (“Working Capital Loans”). If the Company completes a Business Combination, the Company may repay the Working Capital Loans out of the proceeds of the Trust Account released to the Company. Otherwise, the Working Capital Loans may be repaid only out of funds held outside the Trust Account. In the event that a Business Combination does not close, the Company may use a portion of the proceeds held outside the Trust Account to repay the Working Capital Loans but no proceeds held in the Trust Account would be used to repay the Working Capital Loans. Except for the foregoing, the terms of such Working Capital Loans, if any, have not been determined and no written agreements exist with respect to such loans. The Working Capital Loans would either be repaid upon consummation of a Business Combination, without interest, or, at the lender’s discretion, up to $1.5 million of such Working Capital Loans may be convertible into shares of the post Business Combination entity at a price of $10.00 per share. The shares would be identical to the Private Placement Shares. As of December 31, 2020, the Company had no outstanding borrowings under the Working Capital Loans. Administrative Support Agreement Commencing on the date that the Company’s securities were first listed on the Nasdaq through the earlier of consummation of the initial Business Combination and the Company’s liquidation, the Company reimburses the Sponsor for office space, secretarial and administrative services provided to the Company in the amount of $10,000 per month. The Company incurred approximately $48,000 for these services and are in general and administrative expenses in the accompanying statement of operations for the period from March 27, 2020 (inception) through December 31, 2020.

Commitments and Contingencies

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Subsidiary, Sale of Stock [Line Items]

Commitments and Contingencies

Purchase Commitments

Open purchase commitments are for the purchase of goods and services related to, but not limited to, research and development, facilities, and professional services under non-cancellable contracts. They were not recorded as liabilities on the condensed balance sheet as of March 31, 2021 as the Company had not yet received the related goods or services. As of March 31, 2021, the Company had open purchase commitments for goods and services of $1.3 million, which are expected to be received through the next 12 months.

Legal Proceedings

From time to time, the Company may become involved in litigation relating to claims arising from the ordinary course of business. Management believes that there are currently no claims or actions pending against the Company where the ultimate disposition could have a material adverse effect on the Company’s results of operations, financial condition or cash flows.

Leases

The Company is obligated under certain non-cancelable operating leases for office space and laboratory space. This space includes operating leases in Seattle, Washington, Menlo Park, California and San Carlos, California. The operating lease in Seattle, Washington will expire in April 2021 and will be renewed month to month while the Company negotiates on a new lease. The operating lease in San Carlos, California will expire in December 2021. The operating lease in Menlo Park, California expired in February 2020.

In December 2020, the Company entered into a new lease in San Carlos, California for ten years commencing in September 2021 and expiring in September 2031 with total minimum lease payments of $42.1 million. In December 2020, the Company also entered into a temporary office space lease agreement in San Carlos, California commencing in February 2021 and expiring in October 2021 with total minimum lease payments of $1.2 million. The temporary office space lease agreement was recognized as a short-term lease due to the election of the short-term lease measurement and recognition exemption.

The components of lease costs, which were included in operating expenses in condensed statements of operations, were as follows:


	Three Months Ended March 31,
(in thousands)	2021		2020
Fixed operating lease costs	$	501	$	594
Variable operating lease costs	10		56
Short-term lease costs	179		—
Sublease income	—		(77)
Total lease costs	$	690	$	573

For the three months ended March 31, 2021 and 2020, cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities was $0.3 million and $0.6 million, respectively.

As of March 31, 2021, the weighted-average remaining lease term and weighted-average discount rate for operating leases is 0.8 years and 10.0% respectively.

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of March 31, 2021:


(in thousands)	Lease Obligations
Year Ended December 31,
2021	$	2,272


Total future minimum lease payments	2,272
Less: Imputed interest	(40)
Total operating lease liabilities	$	2,232

Total future principal contractual obligations for operating lease commitments exceeded the undiscounted lease liability by $1.0 million as of March 31, 2021 because the lease liability in the condensed balance sheet excluded short-term lease payments.

Guarantees and Indemnifications

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnifications will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions.

The Company has also agreed to indemnify its directors and executive officers for costs associated with any fees, expenses, judgments, fines and settlement amounts incurred by them in any action or proceeding to which any of them are, or are threatened to be, made a party by reason of their service as a director or officer. The Company maintains director and officer insurance coverage that would generally enable it to recover a portion of any future amounts paid. The Company may be subject to indemnification obligation by law with respect to the actions of its employees under certain circumstances and in certain jurisdictions.

Letter of Credit

In conjunction with the San Carlos lease agreement, the Company issued a cash-collateralized letter of credit in lieu of security deposit of $0.6 million. The cash amount is recorded as restricted cash under Other long-term assets on the Company’s condensed balance sheet.

Commitments & Contingencies

Registration Rights

The holders of Founder Shares, Private Placement Shares and Private Placement Shares that may be issued upon conversion of Working Capital Loans, will be entitled to registration rights pursuant to a registration and shareholder rights agreement. The holders of these securities are entitled to make up to three demands, excluding short form demands, that the Company registers such securities. In addition, the holders have certain “piggy-back” registration rights with respect to registration statements filed subsequent to the Company’s completion of its Business Combination. However, the registration and shareholder rights agreement provides that the Company will not permit any registration statement filed under the Securities Act to become effective until termination of the applicable lock-up period, which occurs (i) in the case of the Founder Shares, in accordance with the letter agreement the Company’s initial shareholders entered into and (ii) in the case of the Private Placement Shares, 30 days after the completion of the Company’s Business Combination. The Company will bear the expenses incurred in connection with the filing of any such registration statements.

Underwriting Agreement

The Company granted the underwriters a 45-day option from the final prospectus relating to the Initial Public Offering to purchase up to 1,950,000 additional Public Shares to cover over-allotments, at the Initial Public Offering price less the underwriting discounts and commissions. On August 11, 2020, the underwriters fully exercised the over-allotment option.

The underwriters were entitled to an underwriting discount of $0.20 per Public Share, or approximately $3.0 million in the aggregate, paid upon the closing of the Initial Public Offering. In addition, $0.35 per Public Share, or approximately $5.2 million in the aggregate will be payable to the underwriters for deferred underwriting commissions. The deferred fee will become payable to the underwriters from the amounts held in the Trust Account solely in the event that the Company completes a Business Combination, subject to the terms of the underwriting agreement.

Commitments and Contingencies

Purchase Commitments

Open purchase commitments are for the purchase of goods and services related to, but not limited to, research and development, facilities, and professional services under non-cancellable contracts. They were not recorded as liabilities on the balance sheet as of December 31, 2020 as the Company had not yet received the related goods or services. As of December 31, 2020, the Company had open purchase commitments for goods and services of $0.5 million, all of which are expected to be received by December 31, 2021.

Legal Proceedings

Leases

The Company is obligated under certain non-cancelable operating leases for office space and laboratory space. This space includes three operating leases in Seattle, Washington, Menlo Park, California and San Carlos, California. The operating leases in Seattle, Washington and San Carlos, California will expire in April 2021 and September 2023, respectively. The operating lease in Menlo Park, California expired in February 2020.

For the year ended December 31, 2020, the Company incurred $2.1 million in fixed operating lease expense, $0.1 million in variable operating lease expense, and earned $0.1 million in sublease income offset against fixed and variable operating lease expenses, which are included in operating expenses in the statement of operations.

For the year ended December 31, 2020, cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities was $2.0 million.

As of December 31, 2020, the weighted-average remaining lease term and weighted-average discount rate for operating leases is 2.7 years and 8.0% respectively.

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of December 31, 2020:


(in thousands)
Year Ended December 31,	Lease Obligations
2021	$	1,791
2022	1,988
2023	1,525
Total future minimum lease payments	5,304
Less: Imputed interest	(529)
Total operating lease liabilities	$	4,775

As of December 31, 2019, prior to the adoption of the new lease accounting guidance, the Company’s future principal contractual obligations for operating lease commitments were as follows:


(in thousands)
Year Ended December 31,	Lease Obligations
2020	$	2,034
2021	2,107
2022	1,988
2023	1,525
Total future minimum lease payments	$	7,654

Guarantees and Indemnifications

Letter of Credit

Arya Sciences Acquisition Corp III

Subsidiary, Sale of Stock [Line Items]

Commitments and Contingencies

Registration Rights

The holders of Founder Shares, Private Placement Shares and Private Placement Shares that may be issued upon conversion of Working Capital Loans, will be entitled to registration rights pursuant to a registration and shareholder rights agreement signed upon the consummation of the Initial Public Offering. The holders of these securities are entitled to make up to three demands, excluding short form demands, that the Company registers such securities. In addition, the holders have certain “piggy-back” registration rights with respect to registration statements filed

subsequent to the Company’s completion of its Business Combination. However, the registration and shareholder rights agreement provides that the Company will not permit any registration statement filed under the Securities Act to become effective until termination of the applicable lock-up period, which occurs (i) in the case of the Founder Shares, in accordance with the letter agreement the Company’s initial shareholders entered into and (ii) in the case of the Private Placement Shares, 30 days after the completion of the Company’s Business Combination. The Company will bear the expenses incurred in connection with the filing of any such registration statements.

Underwriting Agreement

Shareholders' Equity

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Class of Stock [Line Items]

Shareholders' Equity

Common Stock

The Company’s certificate of incorporation, as amended, authorizes the Company to issue 19,189,462 shares of common stock with a par value of $0.0001 per share as of December 31, 2019. In April 2020, the Company amended its certificate of incorporation to increase the number of authorized common stock shares to 26,710,255. In May 2020, the Company further amended its certificate of incorporation to increase the number of authorized common stock shares to 27,196,999 shares. There were 9,114,904 shares issued and outstanding as of March 31, 2021.

The holders of common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the stockholders. The holders of common stock are not entitled to cumulative voting rights with respect to the election of directors, and as a consequence, minority stockholders are not able to elect directors on the basis of their votes alone. Subject to preferences that may be applicable to any shares of redeemable convertible preferred stock currently outstanding or issued in the future, holders of common stock are entitled to receive ratably such dividends as may be declared by the Company’s board of directors out of funds legally available therefor. In the event of the Company’s liquidation, dissolution, or winding up, holders of the Company’s common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preference of any then outstanding redeemable convertible preferred stock. Holders of common stock have no preemptive rights and no right to convert their common stock into any other securities. There are no redemption or sinking fund provisions applicable to the common stock.

Common Stock Warrants

In connection with a term loan that the Company entered into during fiscal year 2017, 17,500 common stock warrants were issued to the lender, and recorded at fair value within additional paid-in capital in stockholders’ deficit. Fair value was determined using the Black-Scholes Option Pricing Model. There were no common stock warrants issued during the three months ended March 31, 2021 and 2020.

Common stock warrants as of March 31, 2021 and December 31, 2020 were as follows:

March 31, 2021 and December 31, 2020

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	March 31, 2021	December 31, 2020
Convertible preferred stock	14,381,190	14,381,190
Stock options issued and outstanding	1,982,839	1,418,267
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	83,065	647,637
Total shares of common stock reserved	16,464,594	16,464,594

Common Stock

their votes alone. Subject to preferences that may be applicable to any shares of redeemable convertible preferred stock currently outstanding or issued in the future, holders of common stock are entitled to receive ratably such dividends as may be declared by the Company’s board of directors out of funds legally available therefor. In the event of the Company’s liquidation, dissolution, or winding up, holders of the Company’s common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preference of any then outstanding redeemable convertible preferred stock. Holders of common stock have no preemptive rights and no right to convert their common stock into any other securities. There are no redemption or sinking fund provisions applicable to the common stock.

Common Stock Warrants

Common stock warrants as of December 31, 2020 and 2019 were as follows:

December 31, 2020 and 2019

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	December 31, 2020	December 31, 2019
Conversion of convertible preferred stock	14,381,190	8,271,958
Stock options issued and outstanding	1,418,267	457,150
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	647,637	465,788
Total shares of common stock reserved	16,464,594	9,212,396

Arya Sciences Acquisition Corp III

Class of Stock [Line Items]

Shareholders' Equity

Shareholders’ Equity

Class A Ordinary Shares — The Company is authorized to issue 479,000,000 Class A ordinary shares with a par value of $0.0001 per share. As of March 31, 2021, there were 15,449,000 Class A common shares outstanding, including 13,846,772 Class A common stock subject to possible redemption that were classified as temporary equity in the accompanying unaudited condensed balance sheet.

Class B Ordinary Shares — The Company is authorized to issue 20,000,000 Class B ordinary shares with a par value of $0.0001 per share. On April 2, 2020, the Company issued 3,593,750 Class B ordinary shares. On August 6, 2020, the Company effected a share capitalization resulting in the initial shareholders holding 3,737,500 Founder Shares, of which up to 487,500 shares were subject to forfeiture to the Company by the Sponsor for no consideration to the extent that the underwriter’s over-allotment option is not exercised in full or in part, so that the initial shareholders would collectively own 20% of the Company’s issued and outstanding ordinary shares (excluding the Private Placement Shares). All shares and the associated amounts have been retroactively restated to reflect the share capitalization. The underwriters fully exercised the over-allotment option on August 11, 2020; thus, the 487,500 Founder Shares were no longer subject to forfeiture.

Holders of the Class A ordinary shares and holders of the Class B ordinary shares will vote together as a single class on all matters submitted to a vote of our shareholders, except as required by law or stock exchange rule; provided that only holders of the Class B ordinary shares have the right to vote on the election of the Company’s directors prior to the initial Business Combination and holders of a majority of the Company’s Class B ordinary shares may remove a member of the board of directors for any reason.

The Class B ordinary shares will automatically convert into Class A ordinary shares on the first business day following the consummation of the initial Business Combination at a ratio such that the number of Class A ordinary shares issuable upon conversion of all Founder Shares will equal, in the aggregate, on an as-converted basis, 20% of the sum of (i) the total number of ordinary shares issued and outstanding (excluding the Private Placement Shares) upon the consummation of the Initial Public Offering, plus (ii) the sum of the total number of Class A ordinary shares issued or deemed issued or issuable upon conversion or exercise of any equity-linked securities or rights issued or deemed issued, by the Company in connection with or in relation to the consummation of the initial Business Combination, excluding any Class A ordinary shares or equity-linked securities exercisable for or convertible into Class A ordinary shares issued, deemed issued, or to be issued, to any seller in the initial Business Combination and any Private Placement Shares issued to the Sponsor, members of the Company’s management team or any of their affiliates upon conversion of Working Capital Loans. In no event will the Class B ordinary shares convert into Class A ordinary shares at a rate of less than one-to one.

Preference Shares — The Company is authorized to issue 1,000,000 preference shares with a par value of $0.0001 per share and with such designations, voting and other rights and preferences as may be determined from time to time by the Company’s board of directors. As of March 31, 2021, there were no preference shares issued or outstanding.

Shareholders’ Equity

Class A Ordinary Shares — The Company is authorized to issue 479,000,000 Class A ordinary shares with a par value of $0.0001 per share. As of December 31, 2020, there were 15,449,000 Class A common shares outstanding, including 14,023,673 Class A ordinary shares common stock subject to possible redemption that were classified as temporary equity in the accompanying balance sheet.

2020, the Company effected a share capitalization resulting in the initial shareholders holding 3,737,500 Founder Shares, of which up to 487,500 shares were subject to forfeiture to the Company by the Sponsor for no consideration to the extent that the underwriter’s over-allotment option is not exercised in full or in part, so that the initial shareholders would collectively own 20% of the Company’s issued and outstanding ordinary shares (excluding the Private Placement Shares). All shares and the associated amounts have been retroactively restated to reflect the share capitalization. The underwriters fully exercised the over-allotment option on August 11, 2020; thus, the 487,500 Founder Shares were no longer subject to forfeiture.

Preference Shares — The Company is authorized to issue 1,000,000 preference shares with a par value of $0.0001 per share and with such designations, voting and other rights and preferences as may be determined from time to time by the Company’s board of directors. As of December 31, 2020, there were no preference shares issued or outstanding.

Fair Value Measurements

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurements

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of March 31, 2021 and December 31, 2020:


(in thousands)			Gross Unrealized						Reported as:
March 31, 2021	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	51,803	$	—	$	—	$	51,803	$	51,803	$	—
U.S. treasury bills	16,032		2		—		16,034		—		16,034
Total	$	67,835	$	2	$	—	$	67,837	$	51,803	$	16,034


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135

Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135

All contractual maturities at the date of purchase are due in one year or less.

Fair Value Measurements

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of December 31, 2020 and 2019:


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135
Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


(in thousands)			Gross Unrealized						Reported as:
December 31, 2019	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	221	$	—	$	—	$	221	$	221	$	—
U.S. treasury bills	16,057		8		(1)		16,064		—		16,064

Total	$	16,278	$	8	$	(1)	$	16,285	$	221	$	16,064

All contractual maturities at the date of purchase are due in one year or less.

Arya Sciences Acquisition Corp III

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurements

The following table presents information about the Company’s assets that are measured at fair value on a recurring basis as of March 31, 2021 and December 31, 2020, respectively, and indicates the fair value hierarchy of the valuation techniques that the Company utilized to determine such fair value.

March 31, 2021


Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Assets held in Trust Account:
U.S. Treasury Securities	$	149,563,934	$	—	$	—
	$	149,563,934	$	—	$	—

December 31, 2020


Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Assets held in Trust Account:
U.S. Treasury Securities	$	149,551,026	$	—	$	—
Cash equivalents – money market funds	1,926		—		—
	$	149,552,952	$	—	$	—

Transfers to/from Levels 1, 2, and 3 are recognized at the end of the reporting period. There were no transfers between levels for the three months ended March 31, 2021 and December 31, 2020, respectively.

Level 1 instruments include investments in money market funds and U.S. Treasury securities. The Company uses inputs such as actual trade data, benchmark yields, quoted market prices from dealers or brokers, and other similar sources to determine the fair value of its investments.

Fair Value Measurements

The following table presents information about the Company’s assets that are measured at fair value on a recurring basis as of December 31, 2020 and indicates the fair value hierarchy of the valuation techniques that the Company utilized to determine such fair value.


December 31, 2020
Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Investments held in Trust Account:
U.S. Treasury Securities	$	149,551,026	$	—	$	—
Cash equivalents – money market funds	1,926		—		—
	$	149,552,952	$	—	$	—

Transfers to/from Levels 1, 2, and 3 are recognized at the end of the reporting period. There were no transfers between levels for the period from March 27, 2020 (inception) through December 31, 2020.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Description of Business and Basis of Presentation

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business and Basis of Presentation

Nautilus Biotechnology, Inc. (the “Company”) is a biotechnology company incorporated in 2016 and based in Seattle, Washington with laboratory operations in San Carlos, California. Since the Company’s incorporation in 2016, the Company has devoted substantially all of its resources to research and development activities, including with respect to its proteomics platform, business planning, establishing and maintaining its intellectual property portfolio, hiring personnel, raising capital and providing general and administrative support for these operations.

The Company is subject to risks similar to those of other pre-clinical stage companies in the biopharmaceutical industry, including dependence on key individuals, the need to develop commercially viable products, competition from other companies, many of whom are larger and better capitalized, the impact of the COVID-19 pandemic and the need to obtain adequate additional financing to fund the development of its products. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be maintained, that any products developed will obtain required regulatory approval or that any approved products will be commercially viable. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from the sale of its products.

On February 7, 2021, the Company executed a definitive business combination (the “Business Combination”) agreement with ARYA Sciences Acquisition Corp. III (“ARYA”). As a result of the Business Combination, ARYA will be renamed to Nautilus Biotechnology, Inc. (“New Nautilus”), and the Company will become a wholly owned subsidiary of New Nautilus. Upon the completion of the Business Combination, the stockholders of the Company will exchange their interests in the Company for shares of common stock of New Nautilus and awards issued under the Company’s existing equity incentive plans will be exchanged for comparable options to purchase shares of common stock of New Nautilus. In addition, immediately after the completion of the Business Combination, certain investors have agreed to subscribe for the purchase of an aggregate of $200 million of common stock of New Nautilus (“PIPE Investors”).

On June 9, 2021 (the “Closing Date”), the Company consummated the Business Combination with ARYA. ARYA was renamed to Nautilus Biotechnology, Inc. and the Company became a wholly owned subsidiary of New Nautilus. In addition, concurrently with the Closing Date and pursuant to the subscription agreement, PIPE Investors purchased an aggregate of 20,000,000 shares of New Nautilus Common Stock at a price of $10.00 per share, for aggregate gross proceeds of $200 million and the Company received gross proceeds of approximately $145 million from the Business Combination.

Basis of Presentation

The condensed financial statements and accompanying notes are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and regulations of the U.S. Securities and Exchange Commission for interim financial reporting. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these condensed financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2020 and the related notes which provide a more complete discussion of the Company’s accounting policies and certain other information. The information as of December 31, 2020 included on the condensed balance sheets was derived from the Company’s audited financial statements. The condensed financial statements were prepared on the same basis as the audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for a fair statement of the Company’s financial position as of March 31, 2021 and the results of operations and cash flows for the three months ended March 31, 2021 and 2020. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. The Company’s reporting currency is the U.S. dollar.

Revision to previously issued financial statements

Subsequent to the issuance of the Company’s unaudited condensed financial statements as of March 31, 2021 and for the three months ended March 31, 2021 and 2020, the Company determined that an amendment of its San Carlos facility lease contract which was executed in February 2021 to shorten the remaining term of the lease and reduce monthly lease payments should have been accounted for as a modification. The impact of this modification reduces the operating lease right-of-use asset and lease liability balance as a $3.3 million non-cash adjustment during the quarter ended March 31, 2021. Additionally as a result of the remaining lease term being less than a year, a $0.3 million deposit balance was reclassified from long term to short term and the total remaining operating lease liability balance was classified as current. The Company assessed the materiality of the error on the previously issued financial statements during the quarter ended March 31, 2021 in accordance with SEC Staff Accounting Bulletin (“SAB”) No. 99, Materiality, codified in Accounting Standards Codification (“ASC”) 250, Presentation of Financial Statements, and concluded that the misstatement was not material to the previously issued financial statements. Accordingly, in accordance with ASC 250 (SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements), the amounts have been revised in the applicable Condensed Balance Sheet, Condensed Statement of Cash Flows and related footnote disclosures only as all other impacts to the Condensed Statement of Operations and Condensed Statement of Comprehensive Loss were negligible. The following tables summarize the effect of the correction to selected line items in previously issued financial statements for the quarter ended March 31, 2021 (in thousands):

Revised Condensed Balance Sheet Line Items


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Assets
Prepaid expenses and other current assets	$	1,293	$	315	$	1,608
Total current assets	69,130		315		69,445
Operating lease right-of-use assets	4,429		(3,254)		1,175
Other long term assets	4,129		(315)		3,814
Total assets	79,402		(3,254)		76,148
Liabilities, Redeemable Convertible Preferred Stock and Stockholders’ Deficit
Current portion of operating lease liability	1,670		(395)		1,275
Total current liabilities	4,920		(395)		4,525
Operating lease liability, net of current portion	2,859		(2,859)		—
Total liabilities	7,779		(3,254)		4,525
Total liabilities, redeemable convertible preferred stock and stockholders' deficit	79,402		(3,254)		76,148

Revised Condensed Statement of Cash Flows Line Item


	Three Months Ended March 31, 2021
	As Previously Reported		Adjustment		As Revised
Supplemental cash flow information on non-cash activities
Modification to reduce right-of-use assets and lease liability	$	—	$	3,254	$	3,254

Revised Footnote Disclosure Line Items

Other Long Term Assets


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Deposits	$	315	$	(315)	$	—

Commitments and Contingencies

Future principal contractual obligations for operating lease commitments as of March 31, 2021


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Year Ended December 31,
2021	$	2,413	$	(141)	$	2,272
2022	1,988		(1,988)		—
2023	1,525		(1,525)		—
Total operating lease payments	5,926		(3,654)		2,272
Less: Imputed interest	(440)		400		(40)
Total operating lease liabilities	$	5,486	$	(3,254)	$	2,232

Going Concern

The Company’s condensed financial statements have been prepared on the basis of continuity of operations, the realization of assets, and the satisfaction of liabilities in the ordinary course of business. Since inception, the Company has been engaged in developing its technology, raising capital, and recruiting personnel. The Company’s operating plan may change as a result of many factors currently unknown and there can be no assurance that the current operating plan will be achieved in the time frame anticipated by the Company, and it may need to seek additional funds sooner than planned. If adequate funds are not available to the Company on a timely basis, it may be required to delay, limit, reduce, or terminate certain commercial efforts, or pursue merger or acquisition strategies, all of which could adversely affect the holdings or the rights of the Company’s stockholders. The Company has incurred net operating losses and negative cash flows from operations in every year since inception and expects this to continue for the foreseeable future. As of March 31, 2021, the Company had an accumulated deficit of $38.7 million.

The Company has funded its operations primarily with proceeds from the issuance of redeemable convertible preferred stock and common stock. The Company had cash, cash equivalents, and short-term investments of $67.8 million as of March 31, 2021. In June 2021, the Company received gross proceeds of approximately $345 million from PIPE Investors and the Business Combination, offset by approximately $18 million of transaction costs and underwriters’ fees relating to the closing of the Business Combination. As of the date on which these condensed financial statements were available to be issued, the Company believes that its cash, cash equivalents, and short-term investments will be sufficient to fund its operations for the next twelve months following the issuance of the condensed financial statements. The Company’s assessment of the period of time through which its financial

resources will be adequate to support its operations is a forward-looking statement and involves risks and uncertainties. The Company’s actual results could vary as a result of, and its near and long-term future capital requirements will depend on many factors, including its growth rate and the timing and extent of spending to support its research and development efforts. The Company has based its estimates on assumptions that may prove to be wrong, and it could use its available capital resources sooner than it currently expects. The Company may be required to seek additional equity or debt financing. Future liquidity and cash requirements will depend on numerous factors. In the event that additional financing is required from outside sources, the Company may not be able to raise in on acceptable terms or at all. If the Company is unable to raise additional capital when desired, or if it cannot expand its operations or otherwise capitalize on its business opportunities because it lacks sufficient capital, its business, operating results, and financial condition would be adversely affected.

Impact of the COVID-19 Coronavirus

In December 2019, COVID-19 was first reported to the World Health Organization (“WHO”), and in January 2020, the WHO declared the outbreak to be a public health emergency. In March 2020, the WHO characterized COVID-19 as a pandemic. Since then, the COVID-19 pandemic and efforts to control its spread have significantly curtailed the movement of people, goods, and services worldwide. As a result, the Company has taken certain measures in response to COVID-19.

While the duration and extent of the COVID-19 pandemic depends on future developments that cannot accurately predicted at this time, such as the extent and effectiveness of containment and mitigation actions, it has already had an adverse effect on the global economy, and the ultimate societal and economic impact of the COVID-19 pandemic remains unknown. Additionally, concerns over the economic impact of COVID-19 have caused extreme volatility in financial and other capital markets, which may adversely affect the Company’s ability to access capital markets in the future. Furthermore, the impact of the COVID-19 pandemic could adversely impact the Company’s cash flows and operations and delay clinical trial activity.

While the Company has developed and continues to develop plans to help mitigate the potential negative impact of COVID-19, these efforts may not be effective, and any protracted economic downturn will likely limit the effectiveness of its efforts. Accordingly, it is not possible for the Company to predict the duration and ultimate extent to which this will affect its business, future results of operations, and financial condition at this time.

Description of Business and Basis of Presentation

Basis of Presentation

The financial statements and accompanying notes were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The Company’s reporting currency is the U.S. dollar.

Going Concern

The Company’s financial statements have been prepared on the basis of continuity of operations, the realization of assets, and the satisfaction of liabilities in the ordinary course of business. Since inception, the Company has been engaged in developing its technology, raising capital, and recruiting personnel. The Company’s operating plan may change as a result of many factors currently unknown and there can be no assurance that the current operating plan will be achieved in the time frame anticipated by the Company, and it may need to seek additional funds sooner than planned. If adequate funds are not available to the Company on a timely basis, it may be required to delay, limit, reduce, or terminate certain commercial efforts, or pursue merger or acquisition strategies, all of which could adversely affect the holdings or the rights of the Company’s stockholders. The Company has incurred net operating losses and negative cash flows from operations in every year since inception and expects this to continue for the foreseeable future. As of December 31, 2020, the Company had an accumulated deficit of $30.3 million.

The Company has funded its operations primarily with proceeds from the issuance of redeemable convertible preferred stock and common stock. The Company had cash, cash equivalents, and short-term investments of $76.7 million as of December 31, 2020. As of the date on which these financial statements were available to be issued, the Company believes that its cash, cash equivalents, and short-term investments will be sufficient to fund its operations for the next twelve months following the issuance of the financial statements. The Company’s assessment of the period of time through which its financial resources will be adequate to support its operations is a forward-looking statement and involves risks and uncertainties. The Company’s actual results could vary as a result of, and its near and long-term future capital requirements will depend on many factors, including its growth rate and the timing and extent of spending to support its research and development efforts. The Company has based its estimates on assumptions that may prove to be wrong, and it could use its available capital resources sooner than it currently expects. The Company may be required to seek additional equity or debt financing. Future liquidity and cash requirements will depend on numerous factors. In the event that additional financing is required from outside sources, the Company may not be able to raise in on acceptable terms or at all. If the Company is unable to raise additional capital when desired, or if it cannot expand its operations or otherwise capitalize on its business opportunities because it lacks sufficient capital, its business, operating results, and financial condition would be adversely affected.

Impact of the COVID-19 Coronavirus

Significant Accounting Policies	3 Months Ended	12 Months Ended
Significant Accounting Policies	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Use of Estimates The preparation of the condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the condensed financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include determining the estimated lives of property and equipment, stock-based compensation including the estimated fair value per share of common stock, and the valuation allowance for deferred tax assets. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. As future events and their effects cannot be determined with precision, actual results could materially differ from those estimates and assumptions. Concentrations of Credit Risk and Other Risks and Uncertainties Credit risk represents the accounting loss that would be recognized as of the reporting date if counterparties failed completely to perform as contracted. Financial instruments, which potentially subject the Company to concentration of credit risk, consist of cash balances maintained in excess of federal depository insurance limits and investments in U.S. Treasury securities that are not federally insured. The Company has not experienced any losses in such accounts and believes it is not exposed to significant credit risk on cash or investments. The Company relies, and expects to continue to rely, on a small number of vendors to provide services, supplies and materials related to its research and development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials. Segment Reporting Operating segments are defined as components of an entity where discrete financial information is evaluated regularly by the chief operating decision market (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s Chief Executive Officer is its CODM. The Company’s CODM reviews financial information presented on a consolidated basis for the purposes of making operating decisions, allocating resources and evaluating financial performance. As such, the Company has determined that it operates in one operating and one reportable segment. The Company’s long-lived assets are entirely based in the United States. Cash and Cash Equivalents The Company considers all highly-liquid investments with an original maturity of three months or less as of the date of acquisition to be cash equivalents. Short-term Investments The Company considers investments with an original maturity greater than three months and remaining maturities less than one year to be short-term investments. The Company’s short-term investments consist of debt securities and are classified as available for sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). For short-term investments sold prior to maturity, the cost of investments sold is based on the specific identification method. Realized gains and losses on the sale of short-term investments are recorded in other income (expense), net in the condensed statement of operations. Other-than-temporary Impairment The Company evaluates its short-term investments with unrealized losses for other-than-temporary impairment. When assessing short-term investments for other-than-temporary declines in value, the Company considers factors such as, among other things, the extent and length of time the investment’s fair value has been lower than its cost basis, the financial condition and near-term prospects of the investment, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value, and the expected cash flows from the security. If any adjustments to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the condensed statement of operations and condensed statement of comprehensive loss. No such adjustments were necessary during the periods presented. Offering Costs Specific incremental costs (i.e. consisting of legal, accounting and other fees and costs) directly attributable to a proposed or actual offering of securities are deferred and charged against the gross proceeds of the offering. In the event of a significant delay or cancellation of a planned offering of securities, all of the costs are expensed. Offering costs capitalized as of March 31, 2021 and December 31, 2020 were $3.2 million and $0.2 million, respectively, and is included within Other long term assets on the Company’s condensed balance sheets. Leases The Company determines if an arrangement includes a lease at inception by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. Operating leases with a term of more than one year are included in operating lease right-of-use ("ROU") assets and operating lease liabilities on the Company's condensed balance sheets. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments. Operating lease ROU assets and liabilities are recognized on the lease commencement date based on the present value of the future minimum lease payments over the lease term. The Company uses the incremental borrowing rate commensurate with the lease term based on the information available at the lease commencement date in determining the present value of the lease payments as the Company's leases generally do not provide an implicit rate. ROU assets initially equal the lease liability, adjusted for any prepaid lease payments and initial direct costs incurred, less any lease incentives received. Certain of the Company's leases include renewal options which allow the Company to, at its election, renew or extend the lease for a fixed or indefinite period of time. These renewal periods are included in the lease terms when the Company is reasonably certain the options will be exercised. Lease expense is recognized on a straight-line basis over the lease term when leases are operating leases. If finance lease, expense is recognized over the lease term within interest expense and amortization in the Company’s condensed statements of operations. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company's facility leases and to account for the lease and non-lease components as a single lease component. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less. Comprehensive Loss Comprehensive loss consists of net loss and other gains or losses affecting stockholders’ deficit that, under U.S. GAAP are excluded from net loss. For the three months ended March 31, 2021 and December 31, 2020, unrealized gains and losses on debt securities were included as components of comprehensive loss. Accounting Pronouncements The Company is provided the option to adopt new or revised accounting guidance as an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) either (1) within the same periods as those otherwise applicable to public business entities, or (2) within the same time periods as non-public business entities, including early adoption when permissible. With the exception of standards the Company elected to early adopt, when permissible, the Company has elected to adopt new or revised accounting guidance within the same time period as non-public business entities, as indicated below. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement,” to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The ASU will become effective for annual periods beginning after December 15, 2020. The Company adopted this guidance effective January 1, 2021 using prospective method, which did not have a material impact on the Company’s condensed financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which amends existing guidance on the impairment of financial assets and adds an impairment model that is based on expected losses rather than incurred losses and requires an entity to recognize as an allowance its estimate of expected credit losses for its financial assets. An entity will apply this guidance through a cumulative-effect adjustment to retained earnings upon adoption (a modified-retrospective approach) while a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. For SEC filers that are eligible to be smaller reporting companies and non-public entities, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as the elimination of exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, the recognition of deferred tax liabilities for outside basis differences, ownership changes in investments, and tax basis step-up in goodwill obtained in a transaction that is not a business combination. The guidance will be effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848).” The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements.	Significant Accounting Policies Use of Estimates The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include determining the estimated lives of property and equipment, stock-based compensation including the estimated fair value per share of common stock, and the valuation allowance for deferred tax assets. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. As future events and their effects cannot be determined with precision, actual results could materially differ from those estimates and assumptions. Concentrations of Credit Risk and Other Risks and Uncertainties Credit risk represents the accounting loss that would be recognized as of the reporting date if counterparties failed completely to perform as contracted. Financial instruments, which potentially subject the Company to concentration of credit risk, consist of cash balances maintained in excess of federal depository insurance limits and investments in U.S. Treasury securities that and are not federally insured. The Company has not experienced any losses in such accounts and believes it is not exposed to significant credit risk on cash or investments. The Company relies, and expects to continue to rely, on a small number of vendors to provide services, supplies and materials related to its research and development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials. Segment Reporting Operating segments are defined as components of an entity where discrete financial information is evaluated regularly by the chief operating decision market (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s Chief Executive Officer is its CODM. The Company’s CODM reviews financial information presented on a consolidated basis for the purposes of making operating decisions, allocating resources and evaluating financial performance. As such, the Company has determined that it operates in one operating and one reportable segment. The Company’s long-lived assets are entirely based in the United States. Cash and Cash Equivalents The Company considers all highly-liquid investments with an original maturity of three months or less as of the date of acquisition to be cash equivalents. Short-term Investments The Company considers investments with an original maturity greater than three months and remaining maturities less than one year to be short-term investments. The Company’s short-term investments consist of debt securities and are classified as available sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). For short-term investments sold prior to maturity, the cost of investments sold is based on the specific identification method. Realized gains and losses on the sale of short-term investments are recorded in other income (expense), net in the statement of operations. Other-than-temporary Impairment The Company evaluates its short-term investments with unrealized losses for other-than-temporary impairment. When assessing short-term investments for other-than-temporary declines in value, the Company considers factors such as, among other things, the extent and length of time the investment’s fair value has been lower than its cost basis, the financial condition and near-term prospects of the investment, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value, and the expected cash flows from the security. If any adjustments to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and statement of comprehensive loss. No such adjustments were necessary during the periods presented. Offering Costs Specific incremental costs (i.e. consisting of legal, accounting and other fees and costs) directly attributable to a proposed or actual offering of securities are deferred and charged against the gross proceeds of the offering. In the event of a planned offering of securities does not occur or is significantly delayed, all of the costs are expensed. Offering costs capitalized as of December 31, 2020 was $0.2 million and is included within Other long term assets on the Company's balance sheet. No offering costs were capitalized as of December 31, 2019. Property and Equipment, net Property and equipment, net, consisting primarily of laboratory equipment, computers, furniture and fixtures, and office equipment are recorded at cost and are depreciated on a straight-line basis over their estimated useful lives of three to five years. Leasehold improvements are amortized over the shorter of the remaining term of the applicable lease or the useful life of the asset. When assets are retired or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is recognized as income or loss for the period. Maintenance and repairs are charged to operating expense in the period incurred. Impairment of Long-Lived Assets The Company periodically reviews its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. With respect to property and equipment subject to depreciation, the Company compares the carrying value of the long-lived assets with the estimated future net undiscounted cash flows expected to result from the use and eventual disposition of the asset (or asset group). Should the sum of the estimated future net undiscounted cash flows be less than the carrying value, the Company would recognize an impairment loss as of that date. An impairment loss would be measured by comparing the amount by which the carrying value exceeds the fair value of the long-lived assets. No impairment of long-lived assets was recorded during the years ended December 31, 2020 and 2019. Leases The Company determines if an arrangement includes a lease at inception by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. Operating leases with a term of more than one year are included in operating lease right-of-use ("ROU") assets and operating lease liabilities on the Company's balance sheet. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments. Operating lease ROU assets and liabilities are recognized on the lease commencement date based on the present value of the future minimum lease payments over the lease term. The Company uses the incremental borrowing rate commensurate with the lease term based on the information available at the lease commencement date in determining the present value of the lease payments as the Company's leases generally do not provide an implicit rate. ROU assets initially equal the lease liability, adjusted for any prepaid lease payments and initial direct costs incurred, less any lease incentives received. Certain of the Company's leases include renewal options which allow the Company to, at its election, renew or extend the lease for a fixed or indefinite period of time. These renewal periods are included in the lease terms when the Company is reasonably certain the options will be exercised. Lease expense is recognized on a straight-line basis over the lease term when leases are operating leases. If finance lease, expense is recognized over the lease term within interest expense and amortization in the Company’s statements of operations. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company's facility leases and to account for the lease and non-lease components as a single lease component. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less. Income Taxes The Company accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the net deferred tax assets will not be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and recent results of operations, primarily over the most recent three-year period. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon an audit. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being recognized. Changes in recognition or measurement are reflected in the period in which the change in judgement occurs. Research and Development Costs for research and development activities are expensed in the period in which they are incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation and amortization, external costs of vendors engaged to conduct research and development activities. As part of the process of preparing its financial statements, the Company estimates its accrued expenses. This process involves reviewing quotations and contracts, identifying services that have been performed on the Company’s behalf and estimating the level of services performed and the associated cost incurred for services for which the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses at the end of each reporting period based on the facts and circumstances known to the Company at that time. The significant estimates in the Company’s accrued research and development expenses relate to expenses incurred with respect to academic research centers and other vendors in connection with research and development activities for which the Company has not yet been invoiced. Fair Value of Common Stock The fair value of the Company’s common stock is determined by its Board of Directors with input from management and third-party valuation specialists. The Company’s approach to estimate the fair value of the Company’s common stock is consistent with the methods outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Determining the best estimated fair value of the Company’s common stock requires significant judgement and management considers several factors, including the Company’s stage of development, equity market conditions affecting comparable public companies, significant milestones and progress of research and development efforts. Stock-based Compensation The Company accounts for stock-based compensation expense by calculating the estimated fair value of each employee and nonemployee award at the grant date or modification date by applying the Black-Scholes option pricing model (the “model”). The model utilizes the estimated value of the Company’s underlying common stock at the measurement date, the expected or contractual term of the option, the expected stock price volatility, risk-free interest rates, and expected dividend yield of the common stock. Stock-based compensation expense is recognized on a straight-line basis over the requisite service period, which is generally the vesting period. Forfeitures are recognized in the period in which the forfeiture occurs. The Company classifies stock-based compensation expense in its statement of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award’s recipient’s service payments are classified. The Company calculates the expected term as the mid-point between the requisite service period and the contractual term of the award. The Company bases its estimate of expected volatility on the historical volatility of comparable companies from a representative peer group selected based on industry, financial, and market capitalization data. The Company has not declared nor paid any dividends during the years ended December 31, 2020 and 2019 and does not currently expect to do so in the future. The risk-free interest rate used in the model is based on the implied yield currently available in the U.S. Treasury securities at maturity with an equivalent term. Fair Value of Financial Instruments The Company holds financial instruments that are measured at fair value which is determined according to a fair value hierarchy that prioritizes the inputs and assumptions used, and the valuation techniques used to measure fair value. The three levels of the fair value hierarchy are described as follows: Level 1Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2Inputs are quoted prices for similar assets and liabilities in active markets or quoted prices for identical or similar instruments in markets that are not active and model- derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3Inputs are unobservable inputs based on the Company’s assumptions and valuation techniques used to measure assets and liabilities at fair value. The inputs require significant management judgment or estimation. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The Company establishes the fair value of its assets and liabilities using the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date and established a fair value hierarchy based on the inputs used to measure fair value. The recorded amounts of certain financial instruments, including cash and cash equivalents, prepaid expenses and other assets accounts, accounts payable, and accrued expenses and other liabilities approximate fair value due to their relatively short maturities. Comprehensive Loss Comprehensive loss consists of net loss and other gains or losses affecting stockholders’ deficit that, under U.S. GAAP are excluded from net loss. For the years ended December 31, 2020 and 2019, unrealized gains and losses on debt securities were included as components of comprehensive loss. Net Loss per Share Attributable to Common Stockholders Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For the purposes of the diluted net loss per share calculation, the redeemable convertible preferred stock, common stock subject to repurchase, stock options and common stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock and early exercised stock options are considered to be participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income (loss) available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in undistributed earnings as if all income (loss) for the period had been distributed. The Company’s redeemable convertible preferred stock does not have a contractual obligation to share in the Company’s losses. As such, the net loss is attributed entirely to common stockholders. Since the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods. Accounting Pronouncements The Company is provided the option to adopt new or revised accounting guidance as an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) either (1) within the same periods as those otherwise applicable to public business entities, or (2) within the same time periods as non-public business entities, including early adoption when permissible. With the exception of standards the Company elected to early adopt, when permissible, the Company has elected to adopt new or revised accounting guidance within the same time period as non-public business entities, as indicated below. Recently Adopted Accounting Standards The Company adopted ASU 2016-02, Leases (Topic 842), and the related amendments ("ASC 842") on January 1, 2020. ASU 2016-02 supersedes ASC Topic 840, Leases, and is intended to increase transparency and comparability among entities by requiring the recognition of right-of-use ("ROU") assets and lease liabilities by lessees for those leases classified as operating leases. The Company adopted the new standard using a modified retrospective transition approach by applying the new standard to all leases existing as of the date of initial application of January 1, 2020. The Company elected the package of practical expedients including (1) to not reassess whether any expired or existing contract are or contain leases; (2) to maintain existing lease classifications for expired or existing leases; and (3) to not reassess whether previously capitalized initial direct costs qualify for capitalization under Topic ASC 842. Upon adoption, the Company recognized a right-of-use asset and lease liability on the Company's balance sheet of $6.5 million and $6.4 million, respectively. There was no material impact on the Company's statements of operations. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement. This ASU amends the disclosure requirement in ASC 820, Fair Value Measurement, by adding, changing, or removing certain disclosures. It applies to all entities that are required under this guidance to provide disclosure about recurring or nonrecurring fair value measurements. This ASU is effective for all entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. The adoption of ASU 2018-13 did not have a material impact on the Company’s financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which amends existing guidance on the impairment of financial assets and adds an impairment model that is based on expected losses rather than incurred losses and requires an entity to recognize as an allowance its estimate of expected credit losses for its financial assets. An entity will apply this guidance through a cumulative-effect adjustment to retained earnings upon adoption (a modified-retrospective approach) while a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. For SEC filers that are eligible to be smaller reporting companies and non-public entities, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement,” to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The ASU will become effective for annual periods beginning after December 15, 2020. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as the elimination of exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, the recognition of deferred tax liabilities for outside basis differences, ownership changes in investments, and tax basis step-up in goodwill obtained in a transaction that is not a business combination. The guidance will be effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848).” The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements.

Fair Value Measurements

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value Measurements

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of March 31, 2021 and December 31, 2020:


(in thousands)			Gross Unrealized						Reported as:
March 31, 2021	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	51,803	$	—	$	—	$	51,803	$	51,803	$	—
U.S. treasury bills	16,032		2		—		16,034		—		16,034
Total	$	67,835	$	2	$	—	$	67,837	$	51,803	$	16,034


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135

Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135

All contractual maturities at the date of purchase are due in one year or less.

Fair Value Measurements

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of December 31, 2020 and 2019:


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135
Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


(in thousands)			Gross Unrealized						Reported as:
December 31, 2019	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	221	$	—	$	—	$	221	$	221	$	—
U.S. treasury bills	16,057		8		(1)		16,064		—		16,064

Total	$	16,278	$	8	$	(1)	$	16,285	$	221	$	16,064

All contractual maturities at the date of purchase are due in one year or less.

- Definition

+ References + Details

Composition of Certain Financial Statement Line Items

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Composition of Certain Financial Statement Line Items

Composition of Certain Condensed Financial Statement Line Items

Property and Equipment, Net

Property and equipment consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Laboratory equipment	$	2,711	$	2,256
Leasehold improvements	169		169
Furniture, fixtures and office equipment	126		126
Computer hardware	114		105
	3,120		2,656
Less: Accumulated depreciation	(1,499)		(1,285)
Total	1,621		1,371
Construction in progress	93		—
Property and equipment, net	$	1,714	$	1,371

The Company recorded $0.2 million of depreciation expense for the three months ended March 31, 2021 and 2020, which was primarily allocated to research and development expense.

Other Long Term Assets

Other long term assets consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Deferred offering costs	$	3,202	$	212
Restricted cash	612		612
Deposits	—		315
Total	$	3,814	$	1,139

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Accrued professional and consulting fees	$	469	$	452
Employee compensation	459		484
Use tax	74		49

Other	128		84
Total	$	1,130	$	1,069

Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Cash and cash equivalents	$	51,803	$	36,607
Restricted cash included in other long term assets	612		612
Total	$	52,415	$	37,219

Composition of Certain Financial Statement Line Items

Property and Equipment, Net

Property and equipment consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Laboratory equipment	$	2,256	$	1,444
Leasehold improvements	169		226
Computer hardware	105		98
Furniture, fixtures and office equipment	126		100
	2,656		1,868
Less: Accumulated depreciation	(1,285)		(749)
Total	$	1,371	$	1,119

The Company recorded $0.7 million and $0.5 million of depreciation expense for the year ended December 31, 2020 and 2019, respectively, which was primarily allocated to research and development expense.

Other Long Term Assets

Other long term assets consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Restricted cash	$	612	$	—
Deposits	315		459
Deferred offering costs	212		—
Total	$	1,139	$	459

Accrued Expenses and Other Liabilities

Accrued expenses and other liabilities consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Employee compensation	$	484	$	61
Accrued professional and consulting fees	452		21
Use tax	49		42
Deferred rent	—		30
Other	84		47
Total	$	1,069	$	201

Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Cash and cash equivalents	$	36,607	$	595
Restricted cash included in other long term assets	612		—
Total	$	37,219	$	595

Redeemable Convertible Preferred Stock

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Temporary Equity [Abstract]

Redeemable Convertible Preferred Stock


(in thousands, except share and per share information)
	March 31, 2021 and December 31, 2020
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,604	4,640,604	$	5.86	27,200		27,067
Series B	6,209,233	6,109,232	$	12.45	76,070		75,857
	14,481,191	14,381,190			$	110,533	$	108,418

Series Seed Redeemable Convertible Preferred Stock

In 2017, the Company completed a private placement authorizing the issuance and sale of 3,631,354 shares of Series Seed redeemable convertible preferred stock. Of the shares authorized, 2,500,000 shares were issued at $2.00 per share and 1,131,354 shares were issued in exchange for the surrender of a convertible promissory note plus interest, in the amount of $0.5 million.

Series A Redeemable Convertible Preferred Stock

In 2018, the Company completed a private placement authorizing the issuance and sale of 4,640,608 shares of Series A redeemable convertible preferred stock. Of the shares authorized, 4,640,604 were issued at $5.86 per share, net of issuance costs of $0.1 million.

Series B Redeemable Convertible Preferred Stock

In April 2020, the Company increased the total number of authorized shares of preferred stock to issue 5,722,489 shares of Series B redeemable convertible preferred stock. In May 2020, the Company increased the number of shares of Series B redeemable convertible preferred stock authorized for issuance to a total of 6,209,233 shares.

In April and May 2020, the Company completed private placements of 6,109,232 shares of Series B redeemable convertible preferred stock which were issued at $12.45 per share for total proceeds of $76.1 million, net of issuance costs of $0.2 million.

Dividends

The holders of Series Seed redeemable convertible preferred stock, Series A redeemable convertible preferred stock and Series B redeemable convertible preferred stock are entitled to receive noncumulative dividends in an amount equal to $0.12 per share, $0.35 per share and $0.75 per share, respectively, payable annually when, as and if, declared by the Board of Directors. Seniority with respect to the payment of dividends shall be Series B redeemable convertible preferred stock, Series A redeemable convertible preferred stock, Series Seed redeemable convertible preferred stock, and common stock. Payment of any dividends to the holders of redeemable convertible preferred stock shall be on a pro rata, pari passu basis in proportion to the dividend rates for Series Seed redeemable

convertible preferred stock, Series A redeemable convertible preferred stock and Series B redeemable convertible preferred stock. As of March 31, 2021, no dividends have been declared or paid by the Company.

Conversion

Each share of redeemable convertible preferred stock is convertible, at the option of the holder, into the number of fully-paid and non-assessable shares of common stock that result from dividing the applicable original issue price per share by the applicable conversion price per share at the time of conversion, as adjusted for recapitalizations. If, after the issuance date of the Series B redeemable convertible preferred stock, the Company issues or sells, or is deemed to have sold, additional shares of common stock without consideration or for consideration per share less than the conversion price for a particular series of preferred stock in effect immediately prior to the issuance of such additional shares of common stock, except for certain exceptions allowed, the conversion price of the redeemable convertible preferred stock would be adjusted. As of March 31, 2021, each series of the Company’s redeemable convertible preferred stock was convertible into the Company’s shares of common stock on a one-for-one basis.

Each share of redeemable convertible preferred stock is convertible into common stock automatically immediately upon the earlier of (i) immediately prior to the closing of a firm commitment underwritten initial public offering pursuant to an effective registration statement filed under the Securities Act of 1933, as amended (the “Securities Act”) covering the offer and sale of the Company’s common stock, provided that the aggregate gross proceeds before payment of underwriters’ commissions and expenses to the Company are not less than $50.0 million or (ii) upon the receipt by the Company of a written request for such conversion from the holders of a majority of the redeemable convertible preferred stock then outstanding voting as a single class and on an as-converted basis, or, if later, the effective date for conversion specified in such requests, provided, however, that solely with respect to (ii), the consent of the holders of at least a majority of the outstanding shares of Series B redeemable convertible preferred stock shall be required to convert the Series B redeemable convertible preferred stock in connection with any financing transaction in which the pre-money valuation of the Company is less than $1,000,000,000 or in connection with a Liquidation Event in which the gross proceeds (including the maximum amount of any additional consideration in such Liquidation Event) available for distribution to the holders of the Company’s equity securities are less than $1,000,000,000.

Liquidation Event

In the event of any Liquidation Event (as defined below), before any payment shall be made to common stockholders, redeemable convertible preferred stockholders shall be paid, on an amount per share for each share of redeemable convertible preferred stock held by the them equal to the sum of (i) the liquidation rate of $2.00 per share for Series Seed redeemable convertible preferred stock, $5.86 per share for Series A redeemable convertible preferred stock and $12.45 per share for Series B redeemable convertible preferred stock, and (ii) all declared but unpaid dividends (if any) on such shares of redeemable convertible preferred stock, or such lesser amount as may be approved by the holders of a majority of the redeemable convertible preferred stock then outstanding voting as a single class and on an as-converted basis.

A Liquidation Event is (i) the acquisition of the Company by another entity by means, (ii) a sale, lease transfer, exclusive license or other disposition of substantially all of the assets of the Company, or (iii) any liquidation, dissolution, or winding up of the Company unless the holders of a majority of the redeemable convertible preferred stock then outstanding voting as a single class and on an as-converted basis and the holders of a majority of the outstanding shares of Series B redeemable convertible preferred stock, elect otherwise.

The preferred stock agreements contain a provision that, in the event of a Liquidation Event of the Company, would give the holders of the redeemable convertible preferred stock the right to receive a cash distribution equal to the liquidation preference on the redeemable convertible preferred stock. Due to these redemption characteristics, the redeemable convertible preferred stock has been presented within the mezzanine section on the condensed balance sheets.

Voting Rights

Holders of Series Seed redeemable convertible preferred stock, Series A redeemable convertible preferred stock and Series B redeemable convertible preferred stock are entitled to the number of votes equal to the number of shares of common stock into which their stock could be converted and have voting rights equal to holders of common stock.

Redeemable Convertible Preferred Stock


(in thousands, except share and per share information)
	December 31, 2020
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed-1	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,604	4,640,604	$	5.86	27,200		27,067
Series B	6,209,233	6,109,232	$	12.45	76,060		75,857
	14,481,191	14,381,190			$	110,523	$	108,418


(in thousands, except share and per share information)
	December 31, 2019
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed-1	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,608	4,640,604	$	5.86	27,200		27,067
	8,271,962	8,271,958			$	34,463	$	32,561

Series Seed Redeemable Convertible Preferred Stock

Series A Redeemable Convertible Preferred Stock

Series B Redeemable Convertible Preferred Stock

Dividends

Conversion

Each share of redeemable convertible preferred stock is convertible, at the option of the holder, into the number of fully-paid and non-assessable shares of common stock that result from dividing the applicable original issue price per share by the applicable conversion price per share at the time of conversion, as adjusted for recapitalizations. If, after the issuance date of the Series B redeemable convertible preferred stock, the Company issues or sells, or is deemed to have sold, additional shares of common stock without consideration or for consideration per share less than the conversion price for a particular series of preferred stock in effect immediately prior to the issuance of such additional shares of common stock, except for certain exceptions allowed, the conversion price of the redeemable convertible preferred stock would be adjusted. As of December 31, 2020, each series of the Company’s redeemable convertible preferred stock was convertible into the Company’s shares of common stock on a one-for-one basis.

Liquidation Event

Voting Rights

Common Stock

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Equity [Abstract]

Common Stock

Common Stock Warrants

Common stock warrants as of March 31, 2021 and December 31, 2020 were as follows:

March 31, 2021 and December 31, 2020

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	March 31, 2021	December 31, 2020
Convertible preferred stock	14,381,190	14,381,190
Stock options issued and outstanding	1,982,839	1,418,267
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	83,065	647,637
Total shares of common stock reserved	16,464,594	16,464,594

Common Stock

Common Stock Warrants

Common stock warrants as of December 31, 2020 and 2019 were as follows:

December 31, 2020 and 2019

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	December 31, 2020	December 31, 2019
Conversion of convertible preferred stock	14,381,190	8,271,958
Stock options issued and outstanding	1,418,267	457,150
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	647,637	465,788
Total shares of common stock reserved	16,464,594	9,212,396

Income Taxes

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Taxes

The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. For the three months ended March 31, 2021 and 2020, no income tax expense or benefit was recognized, primarily due to a full valuation allowance recorded against its deferred tax asset.

The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by the relevant taxing authorities. Assessing an uncertain tax position begins with the initial determination of the position’s sustainability and is measured at the largest amount of benefit that is greater than fifty percent likely of being realized upon ultimate settlement. At each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company determines whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit might change as new information becomes available.

Income Taxes The Company is liable for income taxes in the United States. For the year ended December 31, 2020 and 2019, the Company did not have any income for income tax purposes and therefore, no tax liability or expense has been recorded in these financial statements. The difference between the tax at the statutory federal tax rate and no tax

provision recorded by the Company is primarily due to the Company’s full valuation allowance against its deferred tax assets.

A reconciliation between the expected income tax provision at the federal statutory rate and the reported income tax provision is approximately as follows:


(in thousands)	Year Ended December 31, 2020		Year Ended December 31, 2019
Federal income tax at statutory rate	$	(3,280)	$	(2,020)
State income tax, net of federal benefit	(960)		(671)
Permanent differences	226		122
Tax credits generated in current year	(628)		(432)
Valuation allowance change	4,506		3,001
Other	$	136	$	—
Total	$	—	$	—

As of December 31, 2020, the Company had federal net operating loss carryforwards of $0.5 million that begin to expire in 2037 and federal net operating loss carryforwards of $13.1 million that arose after the 2017 tax year that will carryforward indefinitely. The Company has state net operating loss carryforwards of $7.7 million that will begin to expire in 2037.

As of December 31, 2020, the Company had research and development tax credit carryover of $0.8 million and $0.9 million for federal and state tax purposes, respectively. If not utilized, the federal carryforward will expire in various amounts beginning in 2039. The California credits can be carried forward indefinitely.

The Company has evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets. Management has considered the Company’s history of cumulative net losses incurred since inception and its lack of revenue since inception and has concluded that it is more likely than not that the Company will not realize the benefits of the deferred tax assets. Accordingly, the Company has provided a full valuation allowance against the net deferred tax assets. The valuation allowance increased by $4.5 million during the year ended December 31, 2020. Management reevaluates the positive and negative evidence at each reporting period.

Deferred income taxes reflect the net tax effects of loss and credit carryforwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Components of the Company’s deferred tax assets are as follows:


(in thousands)	December 31, 2020		December 31, 2019
Deferred tax assets
Depreciation and amortization	$	4,414	$	2,030
Loss carryforwards	3,348		1,887
Lease liabilities	1,296		—
Tax credit carryforwards	1,183		556
Equity-based compensation	64		12
Total deferred tax assets	10,305		4,485
Valuation allowance for deferred tax assets	(8,991)		(4,485)
Total deferred tax assets, net of valuation allowance	$	1,314	$	—

Deferred tax liability
Right-of-use assets	(1,314)		—
Net deferred tax assets (liability)	$	—	$	—

The Company began to file income tax returns in the United States in 2017. All tax years are open to examination.

As of December 31, 2020, the Company had an unrecognized tax benefit balance of $0.4 million related to research and development credits and California net operating loss carryforward. No amount of unrecognized tax benefits as of December 31, 2020, if recognized, would reduce the Company’s effective tax rate because the benefits would be in the form of tax credit carryforwards, which would attract a full valuation allowance. There are no provisions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within 12 months of the reporting date. Because the statute of limitations does not expire until after the net operating loss and credit carryforwards and actually used, the statutes are still open on calendars years ending 2017 forward for federal and state purposes.

A reconciliation of the beginning and ending amount of the liability for uncertain tax positions, excluding potential interest and penalties, is as follows:


(in thousands)	December 31, 2020
Balance as of December 31, 2019	$	—
Increase based on current year tax positions	204
Increase for prior year tax positions	187

Balance as of December 31, 2020	$	391

Net operating loss and tax credit carry-forwards are subject to review and possible adjustment by the Internal Revenue Service (the “IRS”) and may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50% as defined under Sections 382 and 383 in the Code, which could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the Company’s value immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has not, as yet, conducted a study to determine if any such changes have occurred that could limit its ability to use the net operating loss and tax credit carryforwards.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Stock Option Plan and Stock-based Compensation

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock Option Plan and Stock-based Compensation

In 2017, the Board of Directors adopted the 2017 Equity Incentive Plan (the “Plan”). Under the Plan, up to 1,000,000 shares of the Company’s common stock, in the form of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock and restricted stock units may be issued to employees, directors and consultants. In April 2020, shares of Company’s common stock authorized for issuance under the Plan increased to 2,180,808. The Board of Directors has the authority to determine to whom options will be granted, the number of shares, the term, and the exercise price, which cannot be less than the fair market value at the date of grant for incentive stock options. Options generally vest with respect to 25% of the shares one year after the options’ commencement date and the remainder ratably on a monthly basis over the following three years. Options granted under the Plan have a maximum term of 10 years. Vested options can be exercised at any time. As of March 31, 2021, 83,065 options were available for grant under the 2017 Equity Incentive Plan.

The 2017 Plan allows for the early exercise of stock options for certain individuals as determined by the Company’s board of directors. Stock options that are early exercised are subject to a repurchase option that allows the Company to repurchase any unvested shares. Early exercises of stock options are not deemed to be outstanding shares for accounting purposes until those shares vest according to their respective vesting schedules.

In determining the compensation cost of the option awards, the fair value for each option award has been estimated using the Black Scholes model. The significant assumptions used in these calculations are summarized as follows:


	Three Months Ended March 31,
	2021	2020
Expected term (in years)	5.5 - 6.6	6.0 - 6.1
Expected volatility	92.0% - 94.2%	96.4% - 96.5%
Expected dividend rate	0.0%	0.0%
Risk free interest rate	0.53% - 0.73%	1.4%
Stock price	$27.42 - $36.28	$1.66

Expected term: The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. The Company does not have sufficient historical exercise and post-vesting termination activity to provide accurate data for estimating the expected term of options and has opted to use the “simplified method,” whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option.

Expected volatility: As the Company is not publicly traded, the expected volatility for the Company’s stock options was determined by using an average of historical volatilities of selected industry peers deemed to be comparable to the Company’s business corresponding to the expected term of the awards.

Expected dividend yield: The expected dividend rate is zero as the Company currently has no history or expectation of declaring dividends on its common stock.

Risk-free interest rate: The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities corresponding to the expected term of the awards.

Fair value of common stock: The fair value of the shares of common stock underlying the stock options has historically been determined by the Company’s Board of Directors. Because there has been no public market for the common stock, the Board of Directors has determined the fair value of the common stock at the time of grant of the option by contemporaneous valuations performed by an unrelated third-party valuation firm as well as a number of objective and subjective factors including valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the implied equity value of the Company as contemplated by the Business Combination, the lack of liquidity of capital stock and general and industry specific economic outlook, among other factors. The fair value of common stock was determined in accordance with applicable elements of the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation.

For awards granted in late January 2021, these were granted at the grant date fair value on the date of grant. The Company’s board of directors made a determination of the fair market value of our common stock which contemplated the implied equity value of the Company per the Business Combination agreement that was executed on February 7, 2021. For the period following execution of the Business Combination agreement through March 31, 2021, no additional equity awards were granted.

The following table summarizes option award activity during the three months ended March 31, 2021:


	Number of Stock Option Awards	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2020	1,418,267	$	3.05
Granted	578,572	$	35.62
Exercised	—	$	—
Forfeited	(14,000)	$	4.12
Outstanding as of March 31, 2021	1,982,839	$	12.55	9.2	$	69,289,358
Options vested and expected to vest as of March 31, 2021	1,982,839	$	12.55
Vested and exercisable at March 31, 2021	299,720	$	1.44	7.7	$	13,803,431

As of March 31, 2021, there was $22.5 million of total unrecognized compensation expense expected to be recognized over a weighted average-period of 3.63 years. Aggregate intrinsic value represents the difference between the fair market value of the common stock and the exercise price of outstanding, in-the-money options.

Restricted Stock

In January 2017, the Company granted 9.0 million shares of restricted common stock to founders for future services that vest over four years from the date of grant.

Activity with respect to restricted stock during the three months ended March 31, 2021 was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted- Average Grant Date Fair Value
Unvested, December 31, 2020	157,031	$	0.0001
Vested	(157,031)	$	0.0001
Unvested, March 31, 2021	—

Stock-based Compensation Expense

The following sets forth the total stock-based compensation expense for the Company’s stock options included in the Company’s condensed statement of operations:


	Three Months Ended March 31,
(in thousands)	2021		2020
Research and development	$	497	$	5
General and administrative	839		14
Total stock-based compensation expense	$	1,336	$	19

Stock Option Plan and Stock-based Compensation

In 2017, the Board of Directors adopted the 2017 Equity Incentive Plan (the “Plan”). Under the Plan, up to 1,000,000 shares of the Company’s common stock, in the form of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock and restricted stock units may be issued to employees, directors and consultants. In April 2020, shares of Company’s common stock authorized for issuance under the Plan increased to 2,180,808. The Board of Directors has the authority to determine to whom options will be granted, the number of shares, the term, and the exercise price, which cannot be less than the fair market value at the date of grant for incentive stock options. Options generally vest with respect to 25% of the shares one year after the options’ commencement date and the remainder ratably on a monthly basis over the following three years. Options granted under the Plan have a maximum term of 10 years. Vested options can be exercised at any time. As of December 31, 2020, 647,637 options were available for grant under the 2017 Equity Incentive Plan.


	Year Ended December 31, 2020		Year Ended December 31, 2019
Expected term (in years)	5.1 - 6.4		5.7 - 6.1
Expected volatility	91.0% - 96.5%		86.7% - 101.1%
Expected dividend rate	0.0	%	0.0	%
Risk free interest rate	0.3% - 1.4%		1.6% - 2.6%
Stock price	$1.66 - $16.21		$1.53 - $1.66

Expected dividend yield: The expected dividend rate is zero as the Company currently has no history or expectation of declaring dividends on its common stock.

Fair value of common stock: The fair value of the shares of common stock underlying the stock options has historically been determined by the Company’s Board of Directors. Because there has been no public market for the common stock, the Board of Directors has determined the fair value of the common stock at the time of grant of the option by contemporaneous valuations performed by an unrelated third-party valuation firm as well as a number of objective and subjective factors including valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock and general and industry specific economic outlook, among other factors. The fair value of common stock was determined in accordance with applicable elements of the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation.

The following table summarizes option award activity for the year ended December 31, 2020 and 2019:


	Number of Stock Option Awards	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2018	354,212	$	0.64
Granted	295,500	$	1.59
Exercised	(77,062)	$	0.46
Forfeited	(115,500)	$	0.83
Outstanding as of December 31, 2019	457,150	$	1.24
Granted	1,018,950	$	3.76
Exercised	(37,842)	$	1.11
Forfeited	(19,991)	$	1.58
Outstanding as of December 31, 2020	1,418,267	$	3.05	9.2	$	34,562,932
Options vested and expected to vest as of December 31, 2020	1,418,267	$	3.05
Vested and exercisable at December 31, 2020	227,126	$	1.11	7.6	$	5,975,399

The total intrinsic value of options exercised during the year ended December 31, 2020 and 2019 was $0.1 million. Aggregate intrinsic value represents the difference between the fair market value of the common stock and the exercise price of outstanding, in-the-money options.

The weighted-average grant-date fair value of options granted during the years ended December 31, 2020 and December 31, 2019 was $8.30 and $1.23 per share, respectively.

As of December 31, 2020, there was $8.4 million of total unrecognized compensation expense expected to be recognized over a weighted average-period of 3.9 years.

Restricted Stock

In January 2017, the Company granted 9.0 million shares of restricted common stock to founders for future services that vest over 4 years from the date of grant.

Activity with respect to restricted stock for the year ended December 31, 2020 and 2019 was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted- Average Grant Date Fair Value
Unvested, January 1, 2019	3,925,781	$	0.0001
Vested	(1,884,375)	$	0.0001
Unvested, December 31, 2019	2,041,406	$	0.0001
Vested	(1,884,375)	$	0.0001
Unvested, December 31, 2020	157,031	$	0.0001

Stock-based Compensation Expense

The following sets forth the total stock-based compensation expense for the Company’s stock options included in the Company’s statement of operations:


(in thousands)	Year Ended December 31, 2020		Year Ended December 31, 2019
Research and development	$	174	$	75
General and administrative	195		35
Total stock-based compensation expense	$	369	$	110

Commitment and Contingencies

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Purchase Commitments

Legal Proceedings

Leases

The components of lease costs, which were included in operating expenses in condensed statements of operations, were as follows:


	Three Months Ended March 31,
(in thousands)	2021		2020
Fixed operating lease costs	$	501	$	594
Variable operating lease costs	10		56
Short-term lease costs	179		—
Sublease income	—		(77)
Total lease costs	$	690	$	573

As of March 31, 2021, the weighted-average remaining lease term and weighted-average discount rate for operating leases is 0.8 years and 10.0% respectively.

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of March 31, 2021:


(in thousands)	Lease Obligations
Year Ended December 31,
2021	$	2,272


Total future minimum lease payments	2,272
Less: Imputed interest	(40)
Total operating lease liabilities	$	2,232

Guarantees and Indemnifications

Letter of Credit

Commitments & Contingencies

Registration Rights

Underwriting Agreement

Commitments and Contingencies

Purchase Commitments

Open purchase commitments are for the purchase of goods and services related to, but not limited to, research and development, facilities, and professional services under non-cancellable contracts. They were not recorded as liabilities on the balance sheet as of December 31, 2020 as the Company had not yet received the related goods or services. As of December 31, 2020, the Company had open purchase commitments for goods and services of $0.5 million, all of which are expected to be received by December 31, 2021.

Legal Proceedings

Leases

For the year ended December 31, 2020, cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities was $2.0 million.

As of December 31, 2020, the weighted-average remaining lease term and weighted-average discount rate for operating leases is 2.7 years and 8.0% respectively.

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of December 31, 2020:


(in thousands)
Year Ended December 31,	Lease Obligations
2021	$	1,791
2022	1,988
2023	1,525
Total future minimum lease payments	5,304
Less: Imputed interest	(529)
Total operating lease liabilities	$	4,775

As of December 31, 2019, prior to the adoption of the new lease accounting guidance, the Company’s future principal contractual obligations for operating lease commitments were as follows:


(in thousands)
Year Ended December 31,	Lease Obligations
2020	$	2,034
2021	2,107
2022	1,988
2023	1,525
Total future minimum lease payments	$	7,654

Guarantees and Indemnifications

Letter of Credit

Basic and Diluted Net Loss per Share

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Earnings Per Share [Abstract]

Basic and Diluted Net Loss per Share

The following tables set forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders for the three months ended March 31, 2021 and 2020:


	Three Months Ended March 31,
(in thousands, except share and per share amounts)	2021		2020
Numerator:
Net loss attributable to common stockholders	$	(8,409)	$	(2,934)
Denominator:
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted	9,095,711		7,292,773
Net loss per share attributable to common stockholders, basic and diluted:	$	(0.92)	$	(0.40)

The potential shares of common stock that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have had an antidilutive effect were as follows:


	Three Months Ended March 31,
	2021	2020
Convertible preferred stock (on an as-converted basis)	14,381,190	8,271,958
Options to purchase common stock	1,982,839	598,181
Common stock warrants	17,500	17,500
Unvested restricted common stock	—	1,570,313
Total potentially dilutive common share equivalents	16,381,529	10,457,952

Basic and Diluted Net Loss per Share

The following tables set forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders for the years ended December 31, 2020 and 2019:


(in thousands, except share and per share data)	Year Ended December 31, 2020		Year Ended December 31, 2019
Numerator:
Net loss attributable to common stockholders	$	(15,619)	$	(9,618)
Denominator:
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted	8,017,976		6,066,928
Net loss per share attributable to common stockholders, basic and diluted:	$	(1.95)	$	(1.59)


	Year Ended December 31, 2020	Year Ended December 31, 2019
Convertible preferred stock (on an as-converted basis)	14,381,190	8,271,958
Options to purchase common stock	1,418,267	457,150
Unvested restricted common stock	157,031	2,041,406
Common stock warrants	17,500	17,500
Total potentially dilutive common share equivalents	15,973,988	10,788,014

Subsequent Events	3 Months Ended	12 Months Ended
Subsequent Events	Mar. 31, 2021	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated subsequent events through June 9, 2021, the date on which the condensed financial statements were available to be issued. On June 9, 2021, the Company consummated the Business Combination with ARYA. ARYA was renamed to Nautilus Biotechnology, Inc. and the Company became a wholly owned subsidiary of New Nautilus. In addition, concurrently with the Closing Date and pursuant to the subscription agreement, PIPE Investors purchased an aggregate of 20,000,000 shares of New Nautilus Common Stock at a price of $10.00 per share, for aggregate gross proceeds of $200 million and the Company received gross proceeds of approximately $145 million from ARYA, offset by approximately $18 million of transaction costs and underwriters’ fees relating to the closing of the Business Combination.	Subsequent Events The Company has evaluated subsequent events through March 26, 2021, the date on which the financial statements were available to be issued. In January and February 2021, the Company granted a total of $0.6 million stock option awards to employees under the 2017 Equity Incentive Plan. Generally, the stock option awards will vest over four years from the date of grant 25% of the award vesting after the first year with subsequent monthly vesting over the remaining period. These stock options for the fiscal year 2021 have a weighted average exercise price of $35.62 per share. On February 7, 2021, the Company executed a definitive business combination (the “Business Combination”) agreement with ARYA Sciences Acquisition Corp. III (“ARYA”). As a result of the Business Combination, ARYA will be renamed to Nautilus Biotechnology, Inc. (“New Nautilus”), and the Company will become a wholly owned subsidiary of New Nautilus. Upon the completion of the Business Combination, the stockholders of the Company will exchange their interests in the Company for shares of common stock of New Nautilus and awards issued under the Company’s existing equity incentive plans will be exchanged for awards issued under a new equity incentive plan to be adopted by New Nautilus. In addition, immediately after the completion of the Business Combination, certain investors have agreed to subscribe for the purchase an aggregate of $200 million of common stock of New Nautilus. The board of directors of both ARYA and the Company have approved the proposed transaction. Completion of the transaction, which is expected by the second quarter of 2021, is subject to approval of ARYA’s shareholders and the satisfaction or waiver of certain other customary closing conditions.

Significant Accounting Policies (Policies)	3 Months Ended	12 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	The condensed financial statements and accompanying notes are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and regulations of the U.S. Securities and Exchange Commission for interim financial reporting. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these condensed financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2020 and the related notes which provide a more complete discussion of the Company’s accounting policies and certain other information. The information as of December 31, 2020 included on the condensed balance sheets was derived from the Company’s audited financial statements. The condensed financial statements were prepared on the same basis as the audited financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for a fair statement of the Company’s financial position as of March 31, 2021 and the results of operations and cash flows for the three months ended March 31, 2021 and 2020. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. The Company’s reporting currency is the U.S. dollar.	The financial statements and accompanying notes were prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The Company’s reporting currency is the U.S. dollar.
Use of Estimates	The preparation of the condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the condensed financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include determining the estimated lives of property and equipment, stock-based compensation including the estimated fair value per share of common stock, and the valuation allowance for deferred tax assets. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. As future events and their effects cannot be determined with precision, actual results could materially differ from those estimates and assumptions.	The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include determining the estimated lives of property and equipment, stock-based compensation including the estimated fair value per share of common stock, and the valuation allowance for deferred tax assets. These estimates and assumptions are based on management’s best estimates and judgment. Management evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors, including the current economic environment, which management believes to be reasonable under the circumstances. The Company adjusts such estimates and assumptions when facts and circumstances dictate. Changes in those estimates resulting from continuing changes in the economic environment will be reflected in the financial statements in future periods. As future events and their effects cannot be determined with precision, actual results could materially differ from those estimates and assumptions.
Concentrations of Credit Risk and Other Risks and Uncertainties	Credit risk represents the accounting loss that would be recognized as of the reporting date if counterparties failed completely to perform as contracted. Financial instruments, which potentially subject the Company to concentration of credit risk, consist of cash balances maintained in excess of federal depository insurance limits and investments in U.S. Treasury securities that are not federally insured. The Company has not experienced any losses in such accounts and believes it is not exposed to significant credit risk on cash or investments. The Company relies, and expects to continue to rely, on a small number of vendors to provide services, supplies and materials related to its research and development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials.	Credit risk represents the accounting loss that would be recognized as of the reporting date if counterparties failed completely to perform as contracted. Financial instruments, which potentially subject the Company to concentration of credit risk, consist of cash balances maintained in excess of federal depository insurance limits and investments in U.S. Treasury securities that and are not federally insured. The Company has not experienced any losses in such accounts and believes it is not exposed to significant credit risk on cash or investments. The Company relies, and expects to continue to rely, on a small number of vendors to provide services, supplies and materials related to its research and development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials.
Segment Reporting	Operating segments are defined as components of an entity where discrete financial information is evaluated regularly by the chief operating decision market (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s Chief Executive Officer is its CODM. The Company’s CODM reviews financial information presented on a consolidated basis for the purposes of making operating decisions, allocating resources and evaluating financial performance. As such, the Company has determined that it operates in one operating and one reportable segment. The Company’s long-lived assets are entirely based in the United States.	Operating segments are defined as components of an entity where discrete financial information is evaluated regularly by the chief operating decision market (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s Chief Executive Officer is its CODM. The Company’s CODM reviews financial information presented on a consolidated basis for the purposes of making operating decisions, allocating resources and evaluating financial performance. As such, the Company has determined that it operates in one operating and one reportable segment. The Company’s long-lived assets are entirely based in the United States.
Cash and Cash Equivalents	The Company considers all highly-liquid investments with an original maturity of three months or less as of the date of acquisition to be cash equivalents.	The Company considers all highly-liquid investments with an original maturity of three months or less as of the date of acquisition to be cash equivalents.
Short-term Investments	The Company considers investments with an original maturity greater than three months and remaining maturities less than one year to be short-term investments. The Company’s short-term investments consist of debt securities and are classified as available for sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). For short-term investments sold prior to maturity, the cost of investments sold is based on the specific identification method. Realized gains and losses on the sale of short-term investments are recorded in other income (expense), net in the condensed statement of operations. Other-than-temporary Impairment The Company evaluates its short-term investments with unrealized losses for other-than-temporary impairment. When assessing short-term investments for other-than-temporary declines in value, the Company considers factors such as, among other things, the extent and length of time the investment’s fair value has been lower than its cost basis, the financial condition and near-term prospects of the investment, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value, and the expected cash flows from the security. If any adjustments to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the condensed statement of operations and condensed statement of comprehensive loss. No such adjustments were necessary during the periods presented.	The Company considers investments with an original maturity greater than three months and remaining maturities less than one year to be short-term investments. The Company’s short-term investments consist of debt securities and are classified as available sale and reported at fair value, with unrealized gains and losses recorded in accumulated other comprehensive income (loss). For short-term investments sold prior to maturity, the cost of investments sold is based on the specific identification method. Realized gains and losses on the sale of short-term investments are recorded in other income (expense), net in the statement of operations. Other-than-temporary Impairment The Company evaluates its short-term investments with unrealized losses for other-than-temporary impairment. When assessing short-term investments for other-than-temporary declines in value, the Company considers factors such as, among other things, the extent and length of time the investment’s fair value has been lower than its cost basis, the financial condition and near-term prospects of the investment, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value, and the expected cash flows from the security. If any adjustments to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations and statement of comprehensive loss. No such adjustments were necessary during the periods presented.
Offering Costs	Specific incremental costs (i.e. consisting of legal, accounting and other fees and costs) directly attributable to a proposed or actual offering of securities are deferred and charged against the gross proceeds of the offering. In the event of a significant delay or cancellation of a planned offering of securities, all of the costs are expensed. Offering costs capitalized as of March 31, 2021 and December 31, 2020 were $3.2 million and $0.2 million, respectively, and is included within Other long term assets on the Company’s condensed balance sheets.	Specific incremental costs (i.e. consisting of legal, accounting and other fees and costs) directly attributable to a proposed or actual offering of securities are deferred and charged against the gross proceeds of the offering. In the event of a planned offering of securities does not occur or is significantly delayed, all of the costs are expensed. Offering costs capitalized as of December 31, 2020 was $0.2 million and is included within Other long term assets on the Company's balance sheet. No offering costs were capitalized as of December 31, 2019.
Property and Equipment, net		Property and equipment, net, consisting primarily of laboratory equipment, computers, furniture and fixtures, and office equipment are recorded at cost and are depreciated on a straight-line basis over their estimated useful lives of three to five years. Leasehold improvements are amortized over the shorter of the remaining term of the applicable lease or the useful life of the asset. When assets are retired or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is recognized as income or loss for the period. Maintenance and repairs are charged to operating expense in the period incurred.
Impairment of Long-Lived Assets		The Company periodically reviews its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. With respect to property and equipment subject to depreciation, the Company compares the carrying value of the long-lived assets with the estimated future net undiscounted cash flows expected to result from the use and eventual disposition of the asset (or asset group). Should the sum of the estimated future net undiscounted cash flows be less than the carrying value, the Company would recognize an impairment loss as of that date. An impairment loss would be measured by comparing the amount by which the carrying value exceeds the fair value of the long-lived assets.
Leases	The Company determines if an arrangement includes a lease at inception by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. Operating leases with a term of more than one year are included in operating lease right-of-use ("ROU") assets and operating lease liabilities on the Company's condensed balance sheets. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments. Operating lease ROU assets and liabilities are recognized on the lease commencement date based on the present value of the future minimum lease payments over the lease term. The Company uses the incremental borrowing rate commensurate with the lease term based on the information available at the lease commencement date in determining the present value of the lease payments as the Company's leases generally do not provide an implicit rate. ROU assets initially equal the lease liability, adjusted for any prepaid lease payments and initial direct costs incurred, less any lease incentives received. Certain of the Company's leases include renewal options which allow the Company to, at its election, renew or extend the lease for a fixed or indefinite period of time. These renewal periods are included in the lease terms when the Company is reasonably certain the options will be exercised. Lease expense is recognized on a straight-line basis over the lease term when leases are operating leases. If finance lease, expense is recognized over the lease term within interest expense and amortization in the Company’s condensed statements of operations. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company's facility leases and to account for the lease and non-lease components as a single lease component. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less.	The Company determines if an arrangement includes a lease at inception by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. Operating leases with a term of more than one year are included in operating lease right-of-use ("ROU") assets and operating lease liabilities on the Company's balance sheet. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments. Operating lease ROU assets and liabilities are recognized on the lease commencement date based on the present value of the future minimum lease payments over the lease term. The Company uses the incremental borrowing rate commensurate with the lease term based on the information available at the lease commencement date in determining the present value of the lease payments as the Company's leases generally do not provide an implicit rate. ROU assets initially equal the lease liability, adjusted for any prepaid lease payments and initial direct costs incurred, less any lease incentives received. Certain of the Company's leases include renewal options which allow the Company to, at its election, renew or extend the lease for a fixed or indefinite period of time. These renewal periods are included in the lease terms when the Company is reasonably certain the options will be exercised. Lease expense is recognized on a straight-line basis over the lease term when leases are operating leases. If finance lease, expense is recognized over the lease term within interest expense and amortization in the Company’s statements of operations. The Company also has lease arrangements with lease and non-lease components. The Company elected the practical expedient not to separate non-lease components from lease components for the Company's facility leases and to account for the lease and non-lease components as a single lease component. The Company also elected to apply the short-term lease measurement and recognition exemption in which ROU assets and lease liabilities are not recognized for leases with terms of 12 months or less.
Income Taxes		The Company accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the net deferred tax assets will not be realized. In making such a determination, the Company considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and recent results of operations, primarily over the most recent three-year period. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon an audit. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being recognized. Changes in recognition or measurement are reflected in the period in which the change in judgement occurs.
Research and Development		Costs for research and development activities are expensed in the period in which they are incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries and bonuses, stock-based compensation, employee benefits, facilities costs, laboratory supplies, depreciation and amortization, external costs of vendors engaged to conduct research and development activities.As part of the process of preparing its financial statements, the Company estimates its accrued expenses. This process involves reviewing quotations and contracts, identifying services that have been performed on the Company’s behalf and estimating the level of services performed and the associated cost incurred for services for which the Company has not yet been invoiced or otherwise notified of the actual cost. The majority of the Company’s service providers invoice monthly in arrears for services performed or when contractual milestones are met. The Company makes estimates of its accrued expenses at the end of each reporting period based on the facts and circumstances known to the Company at that time. The significant estimates in the Company’s accrued research and development expenses relate to expenses incurred with respect to academic research centers and other vendors in connection with research and development activities for which the Company has not yet been invoiced.
Fair Value of Common Stock		The fair value of the Company’s common stock is determined by its Board of Directors with input from management and third-party valuation specialists. The Company’s approach to estimate the fair value of the Company’s common stock is consistent with the methods outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Determining the best estimated fair value of the Company’s common stock requires significant judgement and management considers several factors, including the Company’s stage of development, equity market conditions affecting comparable public companies, significant milestones and progress of research and development efforts.
Stock-based Compensation		The Company accounts for stock-based compensation expense by calculating the estimated fair value of each employee and nonemployee award at the grant date or modification date by applying the Black-Scholes option pricing model (the “model”). The model utilizes the estimated value of the Company’s underlying common stock at the measurement date, the expected or contractual term of the option, the expected stock price volatility, risk-free interest rates, and expected dividend yield of the common stock. Stock-based compensation expense is recognized on a straight-line basis over the requisite service period, which is generally the vesting period. Forfeitures are recognized in the period in which the forfeiture occurs. The Company classifies stock-based compensation expense in its statement of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award’s recipient’s service payments are classified. The Company calculates the expected term as the mid-point between the requisite service period and the contractual term of the award. The Company bases its estimate of expected volatility on the historical volatility of comparable companies from a representative peer group selected based on industry, financial, and market capitalization data. The Company has not declared nor paid any dividends during the years ended December 31, 2020 and 2019 and does not currently expect to do so in the future. The risk-free interest rate used in the model is based on the implied yield currently available in the U.S. Treasury securities at maturity with an equivalent term.
Fair Value of Financial Instruments		The Company holds financial instruments that are measured at fair value which is determined according to a fair value hierarchy that prioritizes the inputs and assumptions used, and the valuation techniques used to measure fair value. The three levels of the fair value hierarchy are described as follows: Level 1Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2Inputs are quoted prices for similar assets and liabilities in active markets or quoted prices for identical or similar instruments in markets that are not active and model- derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3Inputs are unobservable inputs based on the Company’s assumptions and valuation techniques used to measure assets and liabilities at fair value. The inputs require significant management judgment or estimation. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The Company establishes the fair value of its assets and liabilities using the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date and established a fair value hierarchy based on the inputs used to measure fair value. The recorded amounts of certain financial instruments, including cash and cash equivalents, prepaid expenses and other assets accounts, accounts payable, and accrued expenses and other liabilities approximate fair value due to their relatively short maturities.
Comprehensive loss	Comprehensive loss consists of net loss and other gains or losses affecting stockholders’ deficit that, under U.S. GAAP are excluded from net loss. For the three months ended March 31, 2021 and December 31, 2020, unrealized gains and losses on debt securities were included as components of comprehensive loss.	Comprehensive loss consists of net loss and other gains or losses affecting stockholders’ deficit that, under U.S. GAAP are excluded from net loss. For the years ended December 31, 2020 and 2019, unrealized gains and losses on debt securities were included as components of comprehensive loss.
Net Loss per Share Attributable to Common Stockholders		Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For the purposes of the diluted net loss per share calculation, the redeemable convertible preferred stock, common stock subject to repurchase, stock options and common stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities as the redeemable convertible preferred stock and early exercised stock options are considered to be participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income (loss) available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to share in undistributed earnings as if all income (loss) for the period had been distributed. The Company’s redeemable convertible preferred stock does not have a contractual obligation to share in the Company’s losses. As such, the net loss is attributed entirely to common stockholders. Since the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.
Accounting Pronouncements	The Company is provided the option to adopt new or revised accounting guidance as an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) either (1) within the same periods as those otherwise applicable to public business entities, or (2) within the same time periods as non-public business entities, including early adoption when permissible. With the exception of standards the Company elected to early adopt, when permissible, the Company has elected to adopt new or revised accounting guidance within the same time period as non-public business entities, as indicated below. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement,” to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The ASU will become effective for annual periods beginning after December 15, 2020. The Company adopted this guidance effective January 1, 2021 using prospective method, which did not have a material impact on the Company’s condensed financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which amends existing guidance on the impairment of financial assets and adds an impairment model that is based on expected losses rather than incurred losses and requires an entity to recognize as an allowance its estimate of expected credit losses for its financial assets. An entity will apply this guidance through a cumulative-effect adjustment to retained earnings upon adoption (a modified-retrospective approach) while a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. For SEC filers that are eligible to be smaller reporting companies and non-public entities, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as the elimination of exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, the recognition of deferred tax liabilities for outside basis differences, ownership changes in investments, and tax basis step-up in goodwill obtained in a transaction that is not a business combination. The guidance will be effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848).” The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company is in the process of evaluating the impact of the adoption of this ASU on its condensed financial statements and related disclosures and does not anticipate adoption to have a material impact on its condensed financial statements.	The Company is provided the option to adopt new or revised accounting guidance as an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) either (1) within the same periods as those otherwise applicable to public business entities, or (2) within the same time periods as non-public business entities, including early adoption when permissible. With the exception of standards the Company elected to early adopt, when permissible, the Company has elected to adopt new or revised accounting guidance within the same time period as non-public business entities, as indicated below. Recently Adopted Accounting Standards The Company adopted ASU 2016-02, Leases (Topic 842), and the related amendments ("ASC 842") on January 1, 2020. ASU 2016-02 supersedes ASC Topic 840, Leases, and is intended to increase transparency and comparability among entities by requiring the recognition of right-of-use ("ROU") assets and lease liabilities by lessees for those leases classified as operating leases. The Company adopted the new standard using a modified retrospective transition approach by applying the new standard to all leases existing as of the date of initial application of January 1, 2020. The Company elected the package of practical expedients including (1) to not reassess whether any expired or existing contract are or contain leases; (2) to maintain existing lease classifications for expired or existing leases; and (3) to not reassess whether previously capitalized initial direct costs qualify for capitalization under Topic ASC 842. Upon adoption, the Company recognized a right-of-use asset and lease liability on the Company's balance sheet of $6.5 million and $6.4 million, respectively. There was no material impact on the Company's statements of operations. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework- Changes to the Disclosure Requirements for Fair Value Measurement. This ASU amends the disclosure requirement in ASC 820, Fair Value Measurement, by adding, changing, or removing certain disclosures. It applies to all entities that are required under this guidance to provide disclosure about recurring or nonrecurring fair value measurements. This ASU is effective for all entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted. The adoption of ASU 2018-13 did not have a material impact on the Company’s financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which amends existing guidance on the impairment of financial assets and adds an impairment model that is based on expected losses rather than incurred losses and requires an entity to recognize as an allowance its estimate of expected credit losses for its financial assets. An entity will apply this guidance through a cumulative-effect adjustment to retained earnings upon adoption (a modified-retrospective approach) while a prospective transition approach is required for debt securities for which an other-than-temporary impairment had been recognized before the effective date. For SEC filers that are eligible to be smaller reporting companies and non-public entities, this ASU is effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement,” to help entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (hosting arrangement) by providing guidance for determining when the arrangement includes a software license. The ASU will become effective for annual periods beginning after December 15, 2020. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes”, which enhances and simplifies various aspects of the income tax accounting guidance, including requirements such as the elimination of exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, the recognition of deferred tax liabilities for outside basis differences, ownership changes in investments, and tax basis step-up in goodwill obtained in a transaction that is not a business combination. The guidance will be effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848).” The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in this ASU are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company is in the process of evaluating the impact of the adoption of this ASU on its financial statements and related disclosures and does not anticipate adoption to have a material impact on its financial statements.

Fair Value Measurements (Tables)

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value, Assets Measured on Recurring Basis

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of March 31, 2021 and December 31, 2020:


(in thousands)			Gross Unrealized						Reported as:
March 31, 2021	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	51,803	$	—	$	—	$	51,803	$	51,803	$	—
U.S. treasury bills	16,032		2		—		16,034		—		16,034
Total	$	67,835	$	2	$	—	$	67,837	$	51,803	$	16,034


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135

Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


December 31, 2020
Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Investments held in Trust Account:
U.S. Treasury Securities	$	149,551,026	$	—	$	—
Cash equivalents – money market funds	1,926		—		—
	$	149,552,952	$	—	$	—

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of December 31, 2020 and 2019:


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135
Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


(in thousands)			Gross Unrealized						Reported as:
December 31, 2019	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	221	$	—	$	—	$	221	$	221	$	—
U.S. treasury bills	16,057		8		(1)		16,064		—		16,064

Total	$	16,278	$	8	$	(1)	$	16,285	$	221	$	16,064

Arya Sciences Acquisition Corp III

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value, Assets Measured on Recurring Basis

March 31, 2021


Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Assets held in Trust Account:
U.S. Treasury Securities	$	149,563,934	$	—	$	—
	$	149,563,934	$	—	$	—

December 31, 2020


Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Assets held in Trust Account:
U.S. Treasury Securities	$	149,551,026	$	—	$	—
Cash equivalents – money market funds	1,926		—		—
	$	149,552,952	$	—	$	—

Description of Business and Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Error Corrections and Prior Period Adjustments

The following tables summarize the effect of the correction to selected line items in previously issued financial statements for the quarter ended March 31, 2021 (in thousands):

Revised Condensed Balance Sheet Line Items


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Assets
Prepaid expenses and other current assets	$	1,293	$	315	$	1,608
Total current assets	69,130		315		69,445
Operating lease right-of-use assets	4,429		(3,254)		1,175
Other long term assets	4,129		(315)		3,814
Total assets	79,402		(3,254)		76,148
Liabilities, Redeemable Convertible Preferred Stock and Stockholders’ Deficit
Current portion of operating lease liability	1,670		(395)		1,275
Total current liabilities	4,920		(395)		4,525
Operating lease liability, net of current portion	2,859		(2,859)		—
Total liabilities	7,779		(3,254)		4,525
Total liabilities, redeemable convertible preferred stock and stockholders' deficit	79,402		(3,254)		76,148

Revised Condensed Statement of Cash Flows Line Item


	Three Months Ended March 31, 2021
	As Previously Reported		Adjustment		As Revised
Supplemental cash flow information on non-cash activities
Modification to reduce right-of-use assets and lease liability	$	—	$	3,254	$	3,254

Revised Footnote Disclosure Line Items

Other Long Term Assets


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Deposits	$	315	$	(315)	$	—

Commitments and Contingencies

Future principal contractual obligations for operating lease commitments as of March 31, 2021


	As of March 31, 2021
	As Previously Reported		Adjustment		As Revised
Year Ended December 31,
2021	$	2,413	$	(141)	$	2,272
2022	1,988		(1,988)		—
2023	1,525		(1,525)		—
Total operating lease payments	5,926		(3,654)		2,272
Less: Imputed interest	(440)		400		(40)
Total operating lease liabilities	$	5,486	$	(3,254)	$	2,232

Fair Value Measurements (Tables)

3 Months Ended

9 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of March 31, 2021 and December 31, 2020:


(in thousands)			Gross Unrealized						Reported as:
March 31, 2021	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	51,803	$	—	$	—	$	51,803	$	51,803	$	—
U.S. treasury bills	16,032		2		—		16,034		—		16,034
Total	$	67,835	$	2	$	—	$	67,837	$	51,803	$	16,034


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135

Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


December 31, 2020
Description	Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)
Investments held in Trust Account:
U.S. Treasury Securities	$	149,551,026	$	—	$	—
Cash equivalents – money market funds	1,926		—		—
	$	149,552,952	$	—	$	—

The following table details the assets carried at fair value and measured on a recurring basis within the three levels of fair value as of December 31, 2020 and 2019:


(in thousands)			Gross Unrealized						Reported as:
December 31, 2020	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	36,607	$	—	$	—	$	36,607	$	36,607	$	—
U.S. treasury bills	40,132		4		(1)		40,135		—		40,135
Total	$	76,739	$	4	$	(1)	$	76,742	$	36,607	$	40,135


(in thousands)			Gross Unrealized						Reported as:
December 31, 2019	Amortized Cost		Gains		Losses		Fair Value		Cash and cash equivalents		Short-term investments
Level 1
Mutual funds	$	221	$	—	$	—	$	221	$	221	$	—
U.S. treasury bills	16,057		8		(1)		16,064		—		16,064

Total	$	16,278	$	8	$	(1)	$	16,285	$	221	$	16,064

Composition of Certain Financial Statement Line Items (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Property, Plant and Equipment

Property and equipment consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Laboratory equipment	$	2,711	$	2,256
Leasehold improvements	169		169
Furniture, fixtures and office equipment	126		126
Computer hardware	114		105
	3,120		2,656
Less: Accumulated depreciation	(1,499)		(1,285)
Total	1,621		1,371
Construction in progress	93		—
Property and equipment, net	$	1,714	$	1,371

Property and equipment consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Laboratory equipment	$	2,256	$	1,444
Leasehold improvements	169		226
Computer hardware	105		98
Furniture, fixtures and office equipment	126		100
	2,656		1,868
Less: Accumulated depreciation	(1,285)		(749)
Total	$	1,371	$	1,119

Schedule of Other Assets, Noncurrent

Other long term assets consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Deferred offering costs	$	3,202	$	212
Restricted cash	612		612
Deposits	—		315
Total	$	3,814	$	1,139

Other long term assets consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Restricted cash	$	612	$	—
Deposits	315		459
Deferred offering costs	212		—
Total	$	1,139	$	459

Schedule of Accrued Liabilities

Accrued expenses and other liabilities consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Accrued professional and consulting fees	$	469	$	452
Employee compensation	459		484
Use tax	74		49

Other	128		84
Total	$	1,130	$	1,069

Accrued expenses and other liabilities consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Employee compensation	$	484	$	61
Accrued professional and consulting fees	452		21
Use tax	49		42
Deferred rent	—		30
Other	84		47
Total	$	1,069	$	201

Other Current Liabilities

Accrued expenses and other liabilities consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Accrued professional and consulting fees	$	469	$	452
Employee compensation	459		484
Use tax	74		49

Other	128		84
Total	$	1,130	$	1,069

Accrued expenses and other liabilities consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Employee compensation	$	484	$	61
Accrued professional and consulting fees	452		21
Use tax	49		42
Deferred rent	—		30
Other	84		47
Total	$	1,069	$	201

Schedule of Cash and Cash Equivalents

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Cash and cash equivalents	$	51,803	$	36,607
Restricted cash included in other long term assets	612		612
Total	$	52,415	$	37,219

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Cash and cash equivalents	$	36,607	$	595
Restricted cash included in other long term assets	612		—
Total	$	37,219	$	595

Restrictions on Cash and Cash Equivalents

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	March 31, 2021		December 31, 2020
Cash and cash equivalents	$	51,803	$	36,607
Restricted cash included in other long term assets	612		612
Total	$	52,415	$	37,219

Cash, cash equivalents and restricted cash consisted of the following:


(in thousands)	December 31, 2020		December 31, 2019
Cash and cash equivalents	$	36,607	$	595
Restricted cash included in other long term assets	612		—
Total	$	37,219	$	595

Redeemable Convertible Preferred Stock (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Temporary Equity [Abstract]

Schedule of Redeemable Convertible Preferred Stock


(in thousands, except share and per share information)
	March 31, 2021 and December 31, 2020
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,604	4,640,604	$	5.86	27,200		27,067
Series B	6,209,233	6,109,232	$	12.45	76,070		75,857
	14,481,191	14,381,190			$	110,533	$	108,418

Redeemable Convertible Preferred Stock


(in thousands, except share and per share information)
	December 31, 2020
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed-1	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,604	4,640,604	$	5.86	27,200		27,067
Series B	6,209,233	6,109,232	$	12.45	76,060		75,857
	14,481,191	14,381,190			$	110,523	$	108,418


(in thousands, except share and per share information)
	December 31, 2019
	Shares		Original Issue Price per Share		Liquidation Preference		Carrying Value
	Authorized	Outstanding
Series Seed-1	3,631,354	3,631,354	$	2.00	$	7,263	$	5,494
Series A	4,640,608	4,640,604	$	5.86	27,200		27,067
	8,271,962	8,271,958			$	34,463	$	32,561

Common Stock (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Equity [Abstract]

Schedule of Warrants or Rights

Common stock warrants as of March 31, 2021 and December 31, 2020 were as follows:

March 31, 2021 and December 31, 2020

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Common stock warrants as of December 31, 2020 and 2019 were as follows:

December 31, 2020 and 2019

Outstanding Warrants

Number of Warrants

Exercise Price

Expiration Date

Common stock

17,500

0.42

9/7/2027

Total outstanding common stock warrants

17,500

Schedule of Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	March 31, 2021	December 31, 2020
Convertible preferred stock	14,381,190	14,381,190
Stock options issued and outstanding	1,982,839	1,418,267
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	83,065	647,637
Total shares of common stock reserved	16,464,594	16,464,594

Shares of common stock reserved for future issuance on an as-if converted basis, were as follows:


	December 31, 2020	December 31, 2019
Conversion of convertible preferred stock	14,381,190	8,271,958
Stock options issued and outstanding	1,418,267	457,150
Common stock warrants outstanding	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan	647,637	465,788
Total shares of common stock reserved	16,464,594	9,212,396

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation between the expected income tax provision at the federal statutory rate and the reported income tax provision is approximately as follows:


(in thousands)	Year Ended December 31, 2020		Year Ended December 31, 2019
Federal income tax at statutory rate	$	(3,280)	$	(2,020)
State income tax, net of federal benefit	(960)		(671)
Permanent differences	226		122
Tax credits generated in current year	(628)		(432)
Valuation allowance change	4,506		3,001
Other	$	136	$	—
Total	$	—	$	—

Schedule of Deferred Tax Assets and Liabilities

Components of the Company’s deferred tax assets are as follows:


(in thousands)	December 31, 2020		December 31, 2019
Deferred tax assets
Depreciation and amortization	$	4,414	$	2,030
Loss carryforwards	3,348		1,887
Lease liabilities	1,296		—
Tax credit carryforwards	1,183		556
Equity-based compensation	64		12
Total deferred tax assets	10,305		4,485
Valuation allowance for deferred tax assets	(8,991)		(4,485)
Total deferred tax assets, net of valuation allowance	$	1,314	$	—

Deferred tax liability
Right-of-use assets	(1,314)		—
Net deferred tax assets (liability)	$	—	$	—

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amount of the liability for uncertain tax positions, excluding potential interest and penalties, is as follows:


(in thousands)	December 31, 2020
Balance as of December 31, 2019	$	—
Increase based on current year tax positions	204
Increase for prior year tax positions	187

Balance as of December 31, 2020	$	391

Stock Option Plan and Stock-based Compensation (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Significant Assumptions

The significant assumptions used in these calculations are summarized as follows:


	Three Months Ended March 31,
	2021	2020
Expected term (in years)	5.5 - 6.6	6.0 - 6.1
Expected volatility	92.0% - 94.2%	96.4% - 96.5%
Expected dividend rate	0.0%	0.0%
Risk free interest rate	0.53% - 0.73%	1.4%
Stock price	$27.42 - $36.28	$1.66

The significant assumptions used in these calculations are summarized as follows:


	Year Ended December 31, 2020		Year Ended December 31, 2019
Expected term (in years)	5.1 - 6.4		5.7 - 6.1
Expected volatility	91.0% - 96.5%		86.7% - 101.1%
Expected dividend rate	0.0	%	0.0	%
Risk free interest rate	0.3% - 1.4%		1.6% - 2.6%
Stock price	$1.66 - $16.21		$1.53 - $1.66

Schedule of Stock Option Activity

The following table summarizes option award activity during the three months ended March 31, 2021:


	Number of Stock Option Awards	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2020	1,418,267	$	3.05
Granted	578,572	$	35.62
Exercised	—	$	—
Forfeited	(14,000)	$	4.12
Outstanding as of March 31, 2021	1,982,839	$	12.55	9.2	$	69,289,358
Options vested and expected to vest as of March 31, 2021	1,982,839	$	12.55
Vested and exercisable at March 31, 2021	299,720	$	1.44	7.7	$	13,803,431

The following table summarizes option award activity for the year ended December 31, 2020 and 2019:


	Number of Stock Option Awards	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding at December 31, 2018	354,212	$	0.64
Granted	295,500	$	1.59
Exercised	(77,062)	$	0.46
Forfeited	(115,500)	$	0.83
Outstanding as of December 31, 2019	457,150	$	1.24
Granted	1,018,950	$	3.76
Exercised	(37,842)	$	1.11
Forfeited	(19,991)	$	1.58
Outstanding as of December 31, 2020	1,418,267	$	3.05	9.2	$	34,562,932
Options vested and expected to vest as of December 31, 2020	1,418,267	$	3.05
Vested and exercisable at December 31, 2020	227,126	$	1.11	7.6	$	5,975,399

Schedule of Restricted Stock Activity

Activity with respect to restricted stock during the three months ended March 31, 2021 was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted- Average Grant Date Fair Value
Unvested, December 31, 2020	157,031	$	0.0001
Vested	(157,031)	$	0.0001
Unvested, March 31, 2021	—

Activity with respect to restricted stock for the year ended December 31, 2020 and 2019 was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted- Average Grant Date Fair Value
Unvested, January 1, 2019	3,925,781	$	0.0001
Vested	(1,884,375)	$	0.0001
Unvested, December 31, 2019	2,041,406	$	0.0001
Vested	(1,884,375)	$	0.0001
Unvested, December 31, 2020	157,031	$	0.0001

Schedule of Stock Based Compensation Expense

The following sets forth the total stock-based compensation expense for the Company’s stock options included in the Company’s condensed statement of operations:


	Three Months Ended March 31,
(in thousands)	2021		2020
Research and development	$	497	$	5
General and administrative	839		14
Total stock-based compensation expense	$	1,336	$	19

The following sets forth the total stock-based compensation expense for the Company’s stock options included in the Company’s statement of operations:


(in thousands)	Year Ended December 31, 2020		Year Ended December 31, 2019
Research and development	$	174	$	75
General and administrative	195		35
Total stock-based compensation expense	$	369	$	110

Commitment and Contingencies (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Commitments and Contingencies Disclosure [Abstract]

Lessee, Operating Lease, Liability, Maturity

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of March 31, 2021:


(in thousands)	Lease Obligations
Year Ended December 31,
2021	$	2,272


Total future minimum lease payments	2,272
Less: Imputed interest	(40)
Total operating lease liabilities	$	2,232

The following table summarizes the Company's future principal contractual obligations for operating lease commitments as of December 31, 2020:


(in thousands)
Year Ended December 31,	Lease Obligations
2021	$	1,791
2022	1,988
2023	1,525
Total future minimum lease payments	5,304
Less: Imputed interest	(529)
Total operating lease liabilities	$	4,775

Schedule of Future Minimum Lease Payments for Capital Leases

As of December 31, 2019, prior to the adoption of the new lease accounting guidance, the Company’s future principal contractual obligations for operating lease commitments were as follows:


(in thousands)
Year Ended December 31,	Lease Obligations
2020	$	2,034
2021	2,107
2022	1,988
2023	1,525
Total future minimum lease payments	$	7,654

Components of Lease Cost

The components of lease costs, which were included in operating expenses in condensed statements of operations, were as follows:


	Three Months Ended March 31,
(in thousands)	2021		2020
Fixed operating lease costs	$	501	$	594
Variable operating lease costs	10		56
Short-term lease costs	179		—
Sublease income	—		(77)
Total lease costs	$	690	$	573

Basic and Diluted Net Loss per Share (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following tables set forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders for the three months ended March 31, 2021 and 2020:


	Three Months Ended March 31,
(in thousands, except share and per share amounts)	2021		2020
Numerator:
Net loss attributable to common stockholders	$	(8,409)	$	(2,934)
Denominator:
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted	9,095,711		7,292,773
Net loss per share attributable to common stockholders, basic and diluted:	$	(0.92)	$	(0.40)

The following tables set forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders for the years ended December 31, 2020 and 2019:


(in thousands, except share and per share data)	Year Ended December 31, 2020		Year Ended December 31, 2019
Numerator:
Net loss attributable to common stockholders	$	(15,619)	$	(9,618)
Denominator:
Weighted average shares used in computing net loss per share attributable to common stockholders, basic and diluted	8,017,976		6,066,928
Net loss per share attributable to common stockholders, basic and diluted:	$	(1.95)	$	(1.59)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share


	Three Months Ended March 31,
	2021	2020
Convertible preferred stock (on an as-converted basis)	14,381,190	8,271,958
Options to purchase common stock	1,982,839	598,181
Common stock warrants	17,500	17,500
Unvested restricted common stock	—	1,570,313
Total potentially dilutive common share equivalents	16,381,529	10,457,952


	Year Ended December 31, 2020	Year Ended December 31, 2019
Convertible preferred stock (on an as-converted basis)	14,381,190	8,271,958
Options to purchase common stock	1,418,267	457,150
Unvested restricted common stock	157,031	2,041,406
Common stock warrants	17,500	17,500
Total potentially dilutive common share equivalents	15,973,988	10,788,014

Description of Organization, Business Operations and Basis of Presentation (Details) - USD ($)				9 Months Ended
	Feb. 07, 2021	Aug. 11, 2020	Apr. 02, 2020	Dec. 31, 2020	Mar. 31, 2021	Dec. 31, 2019
Sponsor and Initial Public Offering [Abstract]
Deferred offering costs				$ 200,000	$ 3,200,000	$ 0
Trust Account [Abstract]
Unrecognized tax benefits				391,000		$ 0
Arya Sciences Acquisition Corp III
Sponsor and Initial Public Offering [Abstract]
Gross proceeds from initial public offering		$ 149,500,000		149,500,000
Deferred offering costs		8,800,000
Deferred underwriting commissions		5,200,000
Gross proceeds from private placement				4,990,000
Trust Account [Abstract]
Assets Held-in-trust, Noncurrent				149,552,952	149,563,934
Cash				1,001,032	682,010
Working capital				916,000	864,000
Deferred Offering Costs Paid by Sponsor in Exchange for Issuance of Ordinary Shares				25,000
Proceeds from Related Party Debt				136,590
Unrecognized tax benefits				0	0
Accrued interest and penalties				0	0
Arya Sciences Acquisition Corp III \| Nautilus Biotechnology, Inc. [Member]
Sponsor and Initial Public Offering [Abstract]
Share price (in dollars per share)	$ 10.00
Trust Account [Abstract]
Stock Issued During Period, Shares, Acquisitions	20,000,000
Proceeds from Issuance of Common Stock	$ 200,000,000
Business combination share conversion (in shares)	1
Implied equity value	$ 900,000,000
Investor [Member] \| Arya Sciences Acquisition Corp III
Trust Account [Abstract]
Deferred Offering Costs Paid by Sponsor in Exchange for Issuance of Ordinary Shares			$ 25,000
Investor [Member] \| Promissory Note [Member] \| Arya Sciences Acquisition Corp III
Trust Account [Abstract]
Proceeds from Related Party Debt			$ 200,000
Notes Payable, Related Parties, Current				$ 0	0
Maximum
Trust Account [Abstract]
Interest from Trust Account that can be held to pay dissolution expenses					$ 100,000
Maximum \| Arya Sciences Acquisition Corp III
Trust Account [Abstract]
Interest from Trust Account that can be held to pay dissolution expenses		$ 100,000
Private Placement Units [Member] \| Arya Sciences Acquisition Corp III
Sponsor and Initial Public Offering [Abstract]
Shares issued (in shares)		499,000
Share price (in dollars per share)		$ 10.00
Gross proceeds from private placement		$ 5,000,000.0
Trust Account [Abstract]
Units Issued During Period, Shares, New Issues		499,000
Initial Public Offering [Member] \| Public Shares [Member] \| Arya Sciences Acquisition Corp III
Sponsor and Initial Public Offering [Abstract]
Shares issued (in shares)		14,950,000
Share price (in dollars per share)		$ 10.00
Gross proceeds from initial public offering		$ 149,500,000
Trust Account [Abstract]
Units Issued During Period, Shares, New Issues		14,950,000
Over-Allotment Option [Member] \| Arya Sciences Acquisition Corp III
Sponsor and Initial Public Offering [Abstract]
Shares issued (in shares)		1,950,000
Trust Account [Abstract]
Units Issued During Period, Shares, New Issues		1,950,000
Over-Allotment Option [Member] \| Public Shares [Member] \| Arya Sciences Acquisition Corp III
Sponsor and Initial Public Offering [Abstract]
Shares issued (in shares)		1,950,000
Share price (in dollars per share)		$ 10.00
Trust Account [Abstract]
Units Issued During Period, Shares, New Issues		1,950,000

Summary of Significant Accounting Policies (Details) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investment Securities Held In Trust Account [Abstract]
Net Asset Value Per Share	$ 1.00
Other Liabilities and Financial Instruments Subject to Mandatory Redemption [Abstract]
Outstanding (in shares)	14,381,190	14,381,190	8,271,958
Net Asset Value Per Share	$ 1.00
Unrecognized tax benefits		$ 391,000	$ 0
Income Taxes [Abstract]
Unrecognized tax benefits		391,000	$ 0
Arya Sciences Acquisition Corp III
Cash and Cash Equivalents, at Carrying Value [Abstract]
Cash equivalents	$ 0	$ 1,926
Investment Securities Held In Trust Account [Abstract]
Net Asset Value Per Share		$ 1.00
Other Liabilities and Financial Instruments Subject to Mandatory Redemption [Abstract]
Cash equivalents	0	$ 1,926
Net Asset Value Per Share		$ 1.00
Unrecognized tax benefits	0	$ 0
Accrued interest and penalties	0	0
Income Taxes [Abstract]
Unrecognized tax benefits	0	0
Accrued interest and penalties	0	0
Earnings Per Share [Abstract]
Net income on investments	$ 10,982	$ 52,952
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Other Liabilities and Financial Instruments Subject to Mandatory Redemption [Abstract]
Outstanding (in shares)	13,846,772	14,023,673

Initial Public Offering (Details) - USD ($)		9 Months Ended
Initial Public Offering (Details) - USD ($)	Aug. 11, 2020	Dec. 31, 2020	Mar. 31, 2021	Dec. 31, 2019
Initial Public Offering [Abstract]
Deferred offering costs		$ 200,000	$ 3,200,000	$ 0
Arya Sciences Acquisition Corp III
Initial Public Offering [Abstract]
Gross proceeds from initial public offering	$ 149,500,000	$ 149,500,000
Deferred offering costs	8,800,000
Deferred underwriting commissions	$ 5,200,000
Initial Public Offering [Member] \| Public Shares [Member] \| Arya Sciences Acquisition Corp III
Initial Public Offering [Abstract]
Units Issued During Period, Shares, New Issues	14,950,000
Shares issued (in shares)	14,950,000
Share price (in dollars per share)	$ 10.00
Gross proceeds from initial public offering	$ 149,500,000
Over-Allotment Option [Member] \| Arya Sciences Acquisition Corp III
Initial Public Offering [Abstract]
Units Issued During Period, Shares, New Issues	1,950,000
Shares issued (in shares)	1,950,000
Over-Allotment Option [Member] \| Public Shares [Member] \| Arya Sciences Acquisition Corp III
Initial Public Offering [Abstract]
Units Issued During Period, Shares, New Issues	1,950,000
Shares issued (in shares)	1,950,000
Share price (in dollars per share)	$ 10.00

Related Party Transactions, Founder Shares (Details) - USD ($)			1 Months Ended	3 Months Ended	9 Months Ended
	Aug. 11, 2020	Apr. 02, 2020	Jul. 31, 2020	Mar. 31, 2021	Dec. 31, 2020	Aug. 06, 2020	Dec. 31, 2019
Founder Shares [Abstract]
Common stock, par value (in dollars per share)				$ 0.0001	$ 0.0001		$ 0.0001
Common stock, shares outstanding (in shares)				9,114,904	9,114,904		9,077,062
Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Common stock, par value (in dollars per share)				$ 0.0001	$ 0.0001
Private Placement [Abstract]
Gross proceeds from private placement					$ 4,990,000
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Common stock, par value (in dollars per share)				$ 0.0001	$ 0.0001
Common stock, shares outstanding (in shares)				1,602,228	1,425,327
Common Class B [Member] \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Common stock, par value (in dollars per share)				$ 0.0001	$ 0.0001
Common stock, shares outstanding (in shares)				3,737,500	3,737,500	487,500
Investor [Member] \| Private Placement \| Arya Sciences Acquisition Corp III
Private Placement [Abstract]
Gross proceeds from private placement	$ 5,000,000.0
Shares issued (in shares)	499,000
Share price (in dollars per share)	$ 10.00
Units Issued During Period, Shares, New Issues	499,000
Investor [Member] \| Common Class A [Member] \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Number of trading days				20 days	20 days
Trading Days Threshold				30 days	30 days
Investor [Member] \| Common Class A [Member] \| Minimum \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Stock price (in dollars per share)				$ 12.00	$ 12.00
Threshold period after initial Business Combination				150 days	150 days
Investor [Member] \| Common Class B [Member] \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Proceeds from Issuance of Common Stock		$ 25,000
Shares issued (in shares)		3,593,750
Common stock, par value (in dollars per share)		$ 0.0001
Common stock, shares outstanding (in shares)	487,500					3,737,500
Ownership interest, as converted percentage		20.00%		20.00%
Shares no longer subject to forfeiture (in shares)	487,500
Period to not transfer, assign or sell Founder Shares				1 year	1 year
Private Placement [Abstract]
Shares issued (in shares)		3,593,750
Investor [Member] \| Common Class B [Member] \| Maximum \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Shares subject to forfeiture (in shares)	487,500					487,500
Independent Director Nominees [Member] \| Arya Sciences Acquisition Corp III
Founder Shares [Abstract]
Shares issued (in shares)			90,000
Private Placement [Abstract]
Shares issued (in shares)			90,000

Related Party Transactions, Promissory Note, Related Party Loans and Administrative Support Agreement (Details) - USD ($)			3 Months Ended		9 Months Ended	12 Months Ended
	Aug. 11, 2020	Apr. 02, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Administrative Support Agreement [Abstract]
General and administrative			$ 3,582,000	$ 527,000		$ 3,312,000	$ 1,622,000
Arya Sciences Acquisition Corp III
Related Party Transaction, Due from (to) Related Party [Abstract]
Proceeds from Related Party Debt					$ 136,590
Repayments of Related Party Debt					200,000
Administrative Support Agreement [Abstract]
General and administrative			1,779,993		576,035
Investor [Member] \| Promissory Note [Member] \| Arya Sciences Acquisition Corp III
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transaction, Amounts of Transaction		$ 300,000
Proceeds from Related Party Debt		$ 200,000
Repayments of Related Party Debt	$ 200,000
Investor [Member] \| Administrative Support Agreement [Member] \| Arya Sciences Acquisition Corp III
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transaction, Amounts of Transaction			10,000
Administrative Support Agreement [Abstract]
Monthly fee					10,000
General and administrative			30,000		48,000
Sponsor Affiliate of Sponsor or Certain Company Officers and Directors [Member] \| Working Capital Loans [Member] \| Arya Sciences Acquisition Corp III
Related Party Transaction, Due from (to) Related Party [Abstract]
Conversion of Stock, Amount Converted			1,500,000		$ 1,500,000
Debt Instrument, Convertible, Conversion Price					$ 10.00	$ 10.00
Notes Payable, Related Parties			$ 0		$ 0	$ 0
Private Placement \| Investor [Member] \| Arya Sciences Acquisition Corp III
Related Party Transaction, Due from (to) Related Party [Abstract]
Original Issue Price per Share (in dollars per share)	$ 10.00

Commitments and Contingencies (Details) - Arya Sciences Acquisition Corp III - USD ($)	Aug. 11, 2020	Mar. 31, 2021	Dec. 31, 2020
Underwriting Agreement [Abstract]
Underwriting discount (in dollars per share)	$ 0.20
Payments for Underwriting Expense	$ 3,000,000.0
Deferred underwriting discount (in dollars per share)	$ 0.35
Deferred underwriting commissions	$ 5,200,000	$ 5,232,500	$ 5,232,500
Over-Allotment Option [Member]
Underwriting Agreement [Abstract]
Sale of stock underwriter option term	45 days
Units Issued During Period, Shares, New Issues	1,950,000
Shares issued (in shares)	1,950,000

Shareholders' Equity (Details)	9 Months Ended
Shareholders' Equity (Details)	Dec. 31, 2020 $ / shares shares	Mar. 31, 2021 $ / shares shares	Aug. 11, 2020 shares	Aug. 06, 2020 shares	May 31, 2020 shares	Apr. 30, 2020 shares	Apr. 02, 2020 $ / shares shares	Dec. 31, 2019 $ / shares shares
Stockholders' Equity Note [Abstract]
Common stock, shares authorized (in shares)	27,196,999	27,196,999			27,196,999	26,710,255		19,189,462
Common stock, par value (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001						$ 0.0001
Common stock, shares issued (in shares)	9,114,904	9,114,904						9,077,062
Common stock, shares outstanding (in shares)	9,114,904	9,114,904						9,077,062
Outstanding (in shares)	14,381,190	14,381,190						8,271,958
Arya Sciences Acquisition Corp III
Stockholders' Equity Note [Abstract]
Common stock, shares authorized (in shares)	479,000,000	479,000,000
Common stock, par value (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001
Stock conversion percentage threshold	20.00%	20.00%		20.00%
Stock conversion basis at time of business combination	1
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock, Par or Stated Value Per Share \| $ / shares	$ 0.0001	$ 0.0001
Shares issued (in shares)	0	0
Preferred Stock, Shares Outstanding	0	0
Common Class A [Member] \| Arya Sciences Acquisition Corp III
Stockholders' Equity Note [Abstract]
Common stock, shares authorized (in shares)	479,000,000	479,000,000
Common stock, par value (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	1,425,327	1,602,228
Ordinary shares including common stock subject to possible redemption shares, Outstanding (in shares)	15,449,000	15,449,000
Common stock, shares outstanding (in shares)	1,425,327	1,602,228
Outstanding (in shares)	14,023,673	13,846,772
Common Class B [Member] \| Arya Sciences Acquisition Corp III
Stockholders' Equity Note [Abstract]
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, par value (in dollars per share) \| $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	3,737,500	3,737,500					3,593,750
Common stock, shares outstanding (in shares)	3,737,500	3,737,500		487,500
Stock conversion percentage threshold		20.00%
Investor [Member] \| Common Class B [Member] \| Arya Sciences Acquisition Corp III
Stockholders' Equity Note [Abstract]
Common stock, par value (in dollars per share) \| $ / shares							$ 0.0001
Common stock, shares issued (in shares)				3,737,500
Common stock, shares outstanding (in shares)			487,500	3,737,500
Investor [Member] \| Common Class B [Member] \| Maximum \| Arya Sciences Acquisition Corp III
Stockholders' Equity Note [Abstract]
Shares subject to forfeiture (in shares)			487,500	487,500

Fair Value Measurements - Arya (Details) - Arya Sciences Acquisition Corp III - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Investments held in Trust Account [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0
Fair Value, Recurring \| Level 1
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	149,563,934	$ 149,552,952
Fair Value, Recurring \| Level 1 \| U.S. treasury bills
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	149,563,934	149,551,026
Fair Value, Recurring \| Level 1 \| Money Market Funds [Member]
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure		1,926
Fair Value, Recurring \| Fair Value, Inputs, Level 2 [Member]
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Recurring \| Fair Value, Inputs, Level 2 [Member] \| U.S. treasury bills
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Recurring \| Fair Value, Inputs, Level 2 [Member] \| Money Market Funds [Member]
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure		0
Fair Value, Recurring \| Fair Value, Inputs, Level 3 [Member]
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Recurring \| Fair Value, Inputs, Level 3 [Member] \| U.S. treasury bills
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure	$ 0	0
Fair Value, Recurring \| Fair Value, Inputs, Level 3 [Member] \| Money Market Funds [Member]
Investments held in Trust Account [Abstract]
Investments, Fair Value Disclosure		$ 0

Description of Business and Basis of Presentation - Narrative (Details) - USD ($)			1 Months Ended
	Jun. 09, 2021	Feb. 07, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsidiary, Sale of Stock [Line Items]
Operating lease right-of-use assets				$ (1,175,000)	$ (4,842,000)	$ 0
Other long term assets				(3,814,000)	(1,139,000)	(459,000)
Accumulated deficit				38,734,000	30,325,000	$ 14,706,000
Cash, cash equivalents, and short-term investments				67,800,000	$ 76,700,000
Adjustment
Subsidiary, Sale of Stock [Line Items]
Operating lease right-of-use assets				3,254,000
Other long term assets				$ 315,000
Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Proceeds from reverse recapitalization transaction	$ 145,000,000
Proceeds from sale of stock and reverse recapitalization transaction			$ 345,000,000
Payments of transaction costs	18,000,000		$ 18,000,000
Private Placement \| Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Consideration received on transaction	$ 200,000,000	$ 200,000,000
Shares issued in transaction (in shares)	20,000,000
Price per share (in dollars per share)	$ 10.00

Description of Business and Basis of Presentation - Corrected Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Assets
Prepaid expenses and other current assets	$ 1,608		$ 917	$ 305
Total current assets	69,445		77,659	16,964
Operating lease right-of-use assets	1,175		4,842	0
Other long term assets	3,814		1,139	459
Total assets	76,148		85,011	18,542
Liabilities, Redeemable Convertible Preferred Stock, and Stockholders’ Deficit
Current portion of operating lease liability	1,275		1,479	0
Total current liabilities	4,525		3,018	490
Operating lease liability, net of current portion	0		3,296	0
Total liabilities	4,525		6,314	490
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	76,148		85,011	18,542
Modification to reduce right-of-use assets and lease liability	3,254	$ 0
Deposits	0		315	$ 459
Remainder of fiscal year	2,272
Year one	0		1,791
Year two	0		1,988
Total future minimum lease payments	2,272		5,304
Less: Imputed interest	(40)		(529)
Total operating lease liabilities	2,232		$ 4,775
As Previously Reported
Assets
Prepaid expenses and other current assets	1,293
Total current assets	69,130
Operating lease right-of-use assets	4,429
Other long term assets	4,129
Total assets	79,402
Liabilities, Redeemable Convertible Preferred Stock, and Stockholders’ Deficit
Current portion of operating lease liability	1,670
Total current liabilities	4,920
Operating lease liability, net of current portion	2,859
Total liabilities	7,779
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	79,402
Modification to reduce right-of-use assets and lease liability	0
Deposits	315
Remainder of fiscal year	2,413
Year one	1,988
Year two	1,525
Total future minimum lease payments	5,926
Less: Imputed interest	(440)
Total operating lease liabilities	5,486
Adjustment
Assets
Prepaid expenses and other current assets	315
Total current assets	315
Operating lease right-of-use assets	(3,254)
Other long term assets	(315)
Total assets	(3,254)
Liabilities, Redeemable Convertible Preferred Stock, and Stockholders’ Deficit
Current portion of operating lease liability	(395)
Total current liabilities	(395)
Operating lease liability, net of current portion	(2,859)
Total liabilities	(3,254)
Total liabilities, redeemable convertible preferred stock and stockholders’ deficit	(3,254)
Modification to reduce right-of-use assets and lease liability	3,254
Deposits	(315)
Remainder of fiscal year	(141)
Year one	(1,988)
Year two	(1,525)
Total future minimum lease payments	(3,654)
Less: Imputed interest	400
Total operating lease liabilities	$ (3,254)

Significant Accounting Policies (Details) - USD ($)	12 Months Ended
Significant Accounting Policies (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2021	Jan. 01, 2020
Property, Plant and Equipment [Line Items]
Deferred offering costs	$ 200,000	$ 0	$ 3,200,000
Impairment of long-lived assets	0	0
Operating lease right-of-use assets	4,842,000	$ 0	1,175,000
Total operating lease liabilities	$ 4,775,000		$ 2,232,000
Cumulative Effect, Period of Adoption, Adjustment
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets				$ 6,500,000
Total operating lease liabilities				$ 6,400,000
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years

Fair Value Measurements - Nautilus (Details) - Fair Value, Recurring - Level 1 - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 67,835	$ 76,739	$ 16,278
Gains	2	4	8
Losses	0	(1)	(1)
Fair Value	67,837	76,742	16,285
Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	51,803	36,607	221
Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	16,034	40,135	16,064
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	51,803	36,607	221
Gains	0	0	0
Losses	0	0	0
Fair Value	51,803	36,607	221
Mutual funds \| Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	51,803	36,607	221
Mutual funds \| Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0	0
U.S. treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	16,032	40,132	16,057
Gains	2	4	8
Losses	0	(1)	(1)
Fair Value	16,034	40,135	16,064
U.S. treasury bills \| Cash and cash equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0	0
U.S. treasury bills \| Short-term investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 16,034	$ 40,135	$ 16,064

Composition of Certain Financial Statement Line Items - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross			$ 2,656	$ 1,868
Less: Accumulated depreciation	$ (1,499)		(1,285)	(749)
Property and equipment, net	1,714		1,371	1,119
Depreciation	214	$ 158	710	548
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,711		2,256	1,444
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	169		169	226
Computer hardware
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	114		105	98
Furniture, fixtures and office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	126		126	$ 100
Depreciable Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,120		2,656
Property and equipment, net	1,621		1,371
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 93		$ 0

Composition of Certain Financial Statement Line Items - Other Long-term Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 612	$ 612	$ 0
Deposits	0	315	459
Deferred offering costs	3,202	212	0
Total	$ 3,814	$ 1,139	$ 459

Composition of Certain Financial Statement Line Items - Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Employee compensation	$ 459	$ 484	$ 61
Accrued professional and consulting fees	469	452	21
Use tax	74	49	42
Deferred rent			30
Other	128	84	47
Total	$ 1,130	$ 1,069	$ 201

Composition of Certain Financial Statement Line Items - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 51,803	$ 36,607		$ 595
Restricted cash included in other long term assets	612	612		0
Total	$ 52,415	$ 37,219	$ 5,860	$ 595	$ 6,171

Redeemable Convertible Preferred Stock - Schedule of Redeemable Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	May 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Temporary Equity [Line Items]
Authorized (in shares)	14,481,191	14,481,191				8,271,962
Outstanding (in shares)	14,381,190	14,381,190				8,271,958
Liquidation Preference	$ 110,533	$ 110,523				$ 34,463
Carrying Value	$ 108,418	$ 108,418				$ 32,561
Series Seed
Temporary Equity [Line Items]
Authorized (in shares)	3,631,354	3,631,354				3,631,354		3,631,354
Outstanding (in shares)	3,631,354	3,631,354			3,631,354	3,631,354	3,631,354
Original Issue Price per Share (in dollars per share)	$ 2.00	$ 2.00				$ 2.00		$ 2.00
Liquidation Preference	$ 7,263	$ 7,263				$ 7,263
Carrying Value	$ 5,494	$ 5,494			$ 5,494	$ 5,494	$ 5,494
Series A
Temporary Equity [Line Items]
Authorized (in shares)	4,640,604	4,640,604				4,640,608	4,640,608
Outstanding (in shares)	4,640,604	4,640,604			4,640,604	4,640,604	4,640,604
Original Issue Price per Share (in dollars per share)	$ 5.86	$ 5.86				$ 5.86	$ 5.86
Liquidation Preference	$ 27,200	$ 27,200				$ 27,200
Carrying Value	$ 27,067	$ 27,067			$ 27,067	$ 27,067	$ 27,067
Series B
Temporary Equity [Line Items]
Authorized (in shares)	6,209,233	6,209,233	6,209,233	5,722,489		0
Outstanding (in shares)	6,109,232	6,109,232				0
Original Issue Price per Share (in dollars per share)	$ 12.45	$ 12.45	$ 12.45
Liquidation Preference	$ 76,070	$ 76,060				$ 0
Carrying Value	$ 75,857	$ 75,857				$ 0

Redeemable Convertible Preferred Stock - Narrative (Details) - USD ($)	2 Months Ended	3 Months Ended		12 Months Ended
	May 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2017	Apr. 30, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized (in shares)		14,481,191		14,481,191				8,271,962
Payments of stock issuance costs		$ 2,069,000	$ 0
Minimum gross proceeds from sale of common stock		50,000,000.0		$ 50,000,000.0
Maximum pre-money valuation requiring consent		1,000,000,000		1,000,000,000
Maximum liquidation event proceeds requiring consent to convert		$ 1,000,000,000		$ 1,000,000,000
Series Seed
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized (in shares)		3,631,354		3,631,354		3,631,354		3,631,354
Redeemable convertible preferred stock, shares issued (in shares)		3,631,354		3,631,354		2,500,000		3,631,354
Original Issue Price per Share (in dollars per share)		$ 2.00		$ 2.00		$ 2.00		$ 2.00
Dividend rate (in dollars per share)		0.12		0.12
Liquidation rate (in dollars per share)		$ 2.00		$ 2.00
Series Seed 1 Preferred Stock Issued For Convertible Note
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares issued (in shares)						1,131,354
Proceeds from issuance of convertible preferred stock, net of issuance costs						$ 500,000
Series A
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized (in shares)		4,640,604		4,640,604	4,640,608			4,640,608
Redeemable convertible preferred stock, shares issued (in shares)		4,640,604		4,640,604	4,640,604			4,640,604
Original Issue Price per Share (in dollars per share)		$ 5.86		$ 5.86	$ 5.86			$ 5.86
Payments of stock issuance costs					$ 100,000
Dividend rate (in dollars per share)		0.35		0.35
Liquidation rate (in dollars per share)		$ 5.86		$ 5.86
Series B
Temporary Equity [Line Items]
Redeemable convertible preferred stock, shares authorized (in shares)	6,209,233	6,209,233		6,209,233			5,722,489	0
Redeemable convertible preferred stock, shares issued (in shares)	6,109,232	6,109,232		6,109,232				0
Original Issue Price per Share (in dollars per share)	$ 12.45	$ 12.45		$ 12.45
Proceeds from issuance of convertible preferred stock, net of issuance costs	$ 76,100,000
Payments of stock issuance costs	$ 200,000
Dividend rate (in dollars per share)		0.75		0.75
Liquidation rate (in dollars per share)		$ 12.45		$ 12.45

Common Stock - Narrative (Details) - $ / shares	Mar. 31, 2021	Dec. 31, 2020	May 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Equity [Abstract]
Common stock, shares authorized (in shares)	27,196,999	27,196,999	27,196,999	26,710,255		19,189,462
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001				$ 0.0001
Common stock, shares issued (in shares)	9,114,904	9,114,904				9,077,062
Common stock, shares outstanding (in shares)	9,114,904	9,114,904				9,077,062
Warrants issued (in shares)	0	0			0	0	17,500

Common Stock - Warrants (Details) - $ / shares	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Equity [Abstract]
Number of Warrants Outstanding (in shares)	17,500	17,500	17,500
Exercise Price (in dollars per share)	$ 0.42	$ 0.42	$ 0.42

Common Stock - Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Conversion of convertible preferred stock (in shares)	14,381,190	14,381,190	8,271,958
Stock options issued and outstanding (in shares)	1,982,839	1,418,267	457,150	354,212
Common stock warrants outstanding (in shares)	17,500	17,500	17,500
Shares available for grant under 2017 Equity Incentive Plan (in shares)	83,065	647,637	465,788
Total shares of common stock reserved (in shares)	16,464,594	16,464,594	9,212,396

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
Income Taxes - Narrative (Details) - USD ($)	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Tax liability			$ 0	$ 0
Income tax expense	$ 0	$ 0	0	0
Increase in valuation allowance			4,500,000
Unrecognized tax benefits			391,000	$ 0
Unrecognized tax benefits that would impact effective tax rate			0
Decrease in unrecognized tax benefits is reasonably possible			0
Increase in unrecognized tax benefits is reasonably possible			0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, subject to expiration			500,000
Operating loss carryforwards, not subject to expiration			13,100,000
Domestic Tax Authority \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount			800,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, subject to expiration			7,700,000
State and Local Jurisdiction \| Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount			$ 900,000

Income Taxes - Income Tax Reconciliation (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate			$ (3,280,000)	$ (2,020,000)
State income tax, net of federal benefit			(960,000)	(671,000)
Permanent differences			226,000	122,000
Tax credits generated in current year			(628,000)	(432,000)
Valuation allowance change			4,506,000	3,001,000
Other			136,000	0
Total	$ 0	$ 0	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets
Depreciation and amortization	$ 4,414	$ 2,030
Loss carryforwards	3,348	1,887
Lease liabilities	1,296	0
Tax credit carryforwards	1,183	556
Equity-based compensation	64	12
Total deferred tax assets	10,305	4,485
Valuation allowance for deferred tax assets	(8,991)	(4,485)
Total deferred tax assets, net of valuation allowance	1,314	0
Deferred tax liability
Right-of-use assets	(1,314)	0
Net deferred tax assets (liability)	$ 0	$ 0

Income Taxes - Uncertain Tax Positions (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 0
Increase based on current year tax positions	204
Increase for prior year tax positions	187
Ending balance	$ 391

Stock Option Plan and Stock-based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2017	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017	Apr. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)					1,000,000	2,180,808
Options available for grant (in shares)		83,065	647,637	465,788
Intrinsic value of options exercised			$ 0.1	$ 0.1
Weighted average grant date fair value (in dollars per share)			$ 8.30	$ 1.23
Unrecognized compensation expense		$ 22.5	$ 8.4
Unrecognized compensation expense, period for recognition		3 years 7 months 17 days	3 years 10 months 24 days
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period					10 years
Options available for grant (in shares)		83,065			647,637
Options \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage					25.00%
Award vesting period					1 year
Options \| Remaining Tranches
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period					3 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Grants (in shares)	9,000,000.0

Stock Option Plan and Stock-based Compensation - Significant Assumptions (Details) - Options - $ / shares	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	92.00%	96.40%	91.00%	86.70%
Expected volatility, maximum	94.20%	96.50%	96.50%	101.10%
Expected dividend rate	0.00%	0.00%	0.00%	0.00%
Risk free interest rate, minimum	0.53%		0.30%	1.60%
Risk free interest rate, maximum	0.73%		1.40%	2.60%
Risk free interest rate		140.00%
Stock price (in dollars per share)		$ 1.66
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	6 years	5 years 1 month 6 days	5 years 8 months 12 days
Stock price (in dollars per share)	$ 27.42		$ 1.66	$ 1.53
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 7 months 6 days	6 years 1 month 6 days	6 years 4 months 24 days	6 years 1 month 6 days
Stock price (in dollars per share)	$ 36.28		$ 16.21	$ 1.66

Stock Option Plan and Stock-based Compensation - Stock Option Activity (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of Stock Option Awards
Outstanding beginning balance (in shares)	1,418,267	457,150	354,212
Granted (in shares)	578,572	1,018,950	295,500
Exercised (in shares)	0	(37,842)	(77,062)
Forfeited (in shares)	(14,000)	(19,991)	(115,500)
Outstanding ending balance (in shares)	1,982,839	1,418,267	457,150
Options vested and expected to vest (in shares)	1,982,839	1,418,267
Vested and exercisable (in shares)	299,720	227,126
Weighted Average Exercise Price
Outstanding beginning balance (in dollars per share)	$ 3.05	$ 1.24	$ 0.64
Granted (in dollars per share)	35.62	3.76	1.59
Exercised (in dollars per share)	0	1.11	0.46
Forfeited (in dollars per share)	4.12	1.58	0.83
Outstanding ending balance (in dollars per share)	12.55	3.05	$ 1.24
Options vested and expected to vest (in dollars per share)	12.55	3.05
Vested and exercisable (in dollars per share)	$ 1.44	$ 1.11
Options outstanding, weighted average remaining contractual life	9 years 2 months 12 days	9 years 2 months 12 days
Vested and exercisable, weighted average remaining contractual life	7 years 8 months 12 days	7 years 7 months 6 days
Options outstanding, aggregate intrinsic value	$ 69,289,358	$ 34,562,932
Vested and exercisable, aggregate intrinsic value	$ 13,803,431	$ 5,975,399

Stock Option Plan and Stock-based Compensation - Restricted Stock Activity (Details) - Restricted Stock - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Number of Shares Underlying Outstanding Restricted Stock
Unvested beginning balance (in shares)	157,031	2,041,406	3,925,781
Vested (in shares)	(157,031)	(1,884,375)	(1,884,375)
Unvested ending balance (in shares)	0	157,031	2,041,406
Weighted- Average Grant Date Fair Value
Unvested beginning balance (in dollars per share)	$ 0.0001	$ 0.0001	$ 0.0001
Vested (in dollars per share)	$ 0.0001	0.0001	0.0001
Unvested ending balance (in dollars per share)		$ 0.0001	$ 0.0001

Stock Option Plan and Stock-based Compensation - Stock Based Compensation Expense (Details) - Options - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,336	$ 19	$ 369	$ 110
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	497	5	174	75
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 839	$ 14	$ 195	$ 35

Commitment and Contingencies - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) lease
Lessee, Lease, Description [Line Items]
Open purchase commitment	$ 1,300		$ 500
Number of Leases \| lease			3
Total minimum lease payments	2,272		$ 5,304
Fixed operating lease costs	501	$ 594	2,100
Variable operating lease costs	10	56	100
Sublease income	0	77	100
Cash paid for lease liabilities included in operating activities	$ 300	$ 600	$ 2,000
Weighted average remaining lease term	9 months 18 days		2 years 8 months 12 days
Weighted average discount rate	10.00%		8.00%
Short-term lease payments	$ 1,000
Letters of credit			$ 600
September 2021 to September 2031
Lessee, Lease, Description [Line Items]
Term of contract			10 years
Total minimum lease payments			$ 42,100
February 2021 to October 2021
Lessee, Lease, Description [Line Items]
Total minimum lease payments			$ 1,200

Commitment and Contingencies - Components of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Fixed operating lease costs	$ 501	$ 594	$ 2,100
Variable operating lease costs	10	56	100
Short-term lease costs	179	0
Sublease income	0	(77)	$ (100)
Total lease costs	$ 690	$ 573

Commitment and Contingencies - Lease Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Remainder of fiscal year	$ 2,272
Year one	0	$ 1,791
Year two	0	1,988
Year three		1,525
Total future minimum lease payments	2,272	5,304
Less: Imputed interest	(40)	(529)
Total operating lease liabilities	$ 2,232	$ 4,775

Commitment and Contingencies - Pre 842 Lease Maturity (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 2,034
2021	2,107
2022	1,988
2023	1,525
Total future minimum lease payments	$ 7,654

Basic and Diluted Net Loss per Share - Basic and Diluted Not Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss attributable to common stockholders, basic	$ (8,409)	$ (2,934)	$ (15,619)	$ (9,618)
Net loss attributable to common stockholders, diluted	$ (8,409)	$ (2,934)	$ (15,619)	$ (9,618)
Weighted average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	9,095,711	7,292,773	8,017,976	6,066,928
Weighted average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	9,095,711	7,292,773	8,017,976	6,066,928
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.92)	$ (0.40)	$ (1.95)	$ (1.59)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.92)	$ (0.40)	$ (1.95)	$ (1.59)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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+ Details

Basic and Diluted Net Loss per Share - Antidilutive Securities (Details) - shares	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	16,381,529	10,457,952	15,973,988	10,788,014
Convertible preferred stock (on an as-converted basis)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	14,381,190	8,271,958	14,381,190	8,271,958
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	1,982,839	598,181	1,418,267	457,150
Unvested restricted common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	0	1,570,313	157,031	2,041,406
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive common share equivalents	17,500	17,500	17,500	17,500

Subsequent Events (Details) - USD ($)			1 Months Ended	2 Months Ended	3 Months Ended	12 Months Ended
Subsequent Events (Details) - USD ($)	Jun. 09, 2021	Feb. 07, 2021	Jun. 30, 2021	Feb. 28, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Subsequent Event [Line Items]
Granted (in shares)					578,572	1,018,950	295,500
Options, grants, weighted average exercise price (in dollars per share)					$ 35.62	$ 3.76	$ 1.59
Subsequent Event
Subsequent Event [Line Items]
Granted (in shares)				600,000
Options, grants, weighted average exercise price (in dollars per share)				$ 35.62
Proceeds from reverse recapitalization transaction	$ 145,000,000
Payments of transaction costs	18,000,000		$ 18,000,000
Subsequent Event \| Private Placement
Subsequent Event [Line Items]
Consideration received on transaction	$ 200,000,000	$ 200,000,000
Shares issued in transaction (in shares)	20,000,000
Price per share (in dollars per share)	$ 10.00
Options \| Subsequent Event
Subsequent Event [Line Items]
Award vesting period				4 years
Options \| Tranche One
Subsequent Event [Line Items]
Award vesting period								1 year
Award vesting rights, percentage								25.00%
Options \| Tranche One \| Subsequent Event
Subsequent Event [Line Items]
Award vesting rights, percentage				25.00%