Forma Therapeutics (FMTX) 10-Q 12 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 09, 2021
Cover [Abstract]
Entity Registrant Name	Forma Therapeutics Holdings, Inc.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		47,404,601
Amendment Flag	false
Entity Central Index Key	0001538927
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-39333
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	37-1657129
Entity Address Address Line1	300 North Beacon Street
Entity Address, Address Line Two	Suite 501
Entity Address City Or Town	Watertown
Entity Address State Or Province	MA
Entity Address Postal Zip Code	02472
City Area Code	617
Local Phone Number	679-1970
Document Quarterly Report	true
Document Transition Report	false
Security12b Title	Common stock, par value $0.001 per share
Trading Symbol	FMTX
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 87,248	$ 282,689
Short-term marketable securities	425,433	350,365
Income tax receivable	14,066	15,273
Prepaid expenses and other current assets	8,139	6,120
Total current assets	534,886	654,447
Property and equipment, net	14,741	1,520
Long-term marketable securities	19,088	12,534
Operating lease right-of-use asset	20,569
Other assets	12,941	12,470
Total assets	602,225	680,971
Current liabilities:
Accounts payable	4,595	4,295
Accrued expenses and other current liabilities	23,453	27,104
Operating lease liability	4,541
Income tax payable	45	301
Total current liabilities	32,634	31,700
Operating lease liability, noncurrent	26,760
Deferred rent, noncurrent		1,027
Total liabilities	59,394	32,727
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $0.001 par value; 150,000,000 shares authorized at September 30, 2021 and December 31, 2020; 47,399,873 and 47,300,231 shares issued at September 30, 2021 and December 31, 2020, respectively; 47,378,041 and 47,248,685 shares outstanding at September 30, 2021 and December 31, 2020, respectively	47	47
Preferred stock, $0.001 par value; 10,000,000 shares authorized and no issued or outstanding at September 30, 2021 and December 31, 2020
Additional paid-in capital	723,033	705,607
Accumulated deficit	(180,249)	(57,410)
Total stockholders’ equity	542,831	648,244
Total liabilities and stockholders’ equity	$ 602,225	$ 680,971

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.001	$ 0.001
Common stock shares authorized	150,000,000	150,000,000
Common stock shares issued	47,399,873	47,300,231
Common stock shares outstanding	47,378,041	47,248,685

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses:
Research and development	$ 30,684	$ 24,780	$ 88,614	$ 68,501
General and administrative	12,749	7,460	35,087	22,841
Restructuring charges				63
Total operating expenses	43,433	32,240	123,701	91,405
Loss from operations	(43,433)	(32,240)	(123,701)	(91,405)
Other income:
Gain on Hit Discovery divestiture				23,312
Interest income	216	870	770	2,406
Other (expense) income, net	(70)	(52)	215	(2,668)
Total other income, net	146	818	985	23,050
Loss before taxes	(43,287)	(31,422)	(122,716)	(68,355)
Income tax expense (benefit)	7	(3,806)	123	(26,529)
Net loss and comprehensive loss	(43,294)	(27,616)	(122,839)	(41,826)
Accretion of cumulative dividends on Series D redeemable convertible preferred stock				(3,736)
Net loss allocable to shares of common stock, basic	(43,294)	(27,616)	(122,839)	(45,562)
Change in fair value attributable to warrants to purchase common stock		(8)		2,597
Net loss allocable to shares of common stock, diluted	$ (43,294)	$ (27,624)	$ (122,839)	$ (45,562)
Net loss per share of common stock:
Basic	$ (0.91)	$ (0.67)	$ (2.60)	$ (2.74)
Diluted	$ (0.91)	$ (0.67)	$ (2.60)	$ (2.74)
Weighted-average shares of common stock outstanding:
Basic	47,365,704	41,088,261	47,333,652	16,616,143
Diluted	47,365,704	41,088,924	47,333,652	16,616,143

Consolidated Statements of Rede

Consolidated Statements of Redeemable Convertible and Convertible Preferred Stock and Stockholders' Equity - USD ($)	Total	Series A Convertible Preferred Stock [Member]	Series B-1 Convertible Preferred Stock [Member]	Series B-2 Convertible Preferred Stock [Member]	Series D Redeemable Convertible Preferred Stock [Member]	Enterprise Junior Stock [Member]	Series C Convertible Preferred Stock [Member]	Common Stock	Additional Paid-In Capital [Member]	(Accumulated Deficit) Retained Earnings [Member]
Balance at Dec. 31, 2019	$ 18,246,000					$ 3,000		$ 2,000	$ 1,116,000	$ 16,740,000
Temporary equity balance, Shares at Dec. 31, 2019		2,304,815	14,921,676	8,790,249	53,593,440		6,452,619
Temporary equity balance, Value at Dec. 31, 2019		$ 4,656,000	$ 20,907,000	$ 12,272,000	$ 100,296,000		$ 385,000
Balance, Shares at Dec. 31, 2019						2,597,091		2,250,696
Accretion of cumulative dividends on Series D redeemable convertible preferred stock	(1,936,000)				$ 1,936,000					(1,936,000)
Exercise of options to purchase common stock	3,000								3,000
Exercise of options to purchase common stock, Shares								496
Exercise of warrant to purchase common stock	12,000								12,000
Exercise of warrant to purchase common stock, Shares								297,241
Equity-based compensation	1,210,000								1,210,000
Equity-based compensation, Shares						38,339
Net income (loss) and comprehensive income (loss)	11,230,000									11,230,000
Balance at Mar. 31, 2020	28,765,000					$ 3,000		$ 2,000	2,341,000	26,034,000
Temporary equity balance, Shares at Mar. 31, 2020		2,304,815	14,921,676	8,790,249	53,593,440		6,452,619
Temporary equity balance, Value at Mar. 31, 2020		$ 4,656,000	$ 20,907,000	$ 12,272,000	$ 102,232,000		$ 385,000
Balance, Shares at Mar. 31, 2020						2,635,430		2,548,433
Balance at Dec. 31, 2019	18,246,000					$ 3,000		$ 2,000	1,116,000	16,740,000
Temporary equity balance, Shares at Dec. 31, 2019		2,304,815	14,921,676	8,790,249	53,593,440		6,452,619
Temporary equity balance, Value at Dec. 31, 2019		$ 4,656,000	$ 20,907,000	$ 12,272,000	$ 100,296,000		$ 385,000
Balance, Shares at Dec. 31, 2019						2,597,091		2,250,696
Net income (loss) and comprehensive income (loss)	(41,826,000)
Balance at Sep. 30, 2020	415,602,000					$ 0		$ 41,000	444,383,000	(28,822,000)
Temporary equity balance, Shares at Sep. 30, 2020		0	0	0	0		0
Temporary equity balance, Value at Sep. 30, 2020		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Sep. 30, 2020						0		41,096,319
Balance at Mar. 31, 2020	28,765,000					$ 3,000		$ 2,000	2,341,000	26,034,000
Temporary equity balance, Shares at Mar. 31, 2020		2,304,815	14,921,676	8,790,249	53,593,440		6,452,619
Temporary equity balance, Value at Mar. 31, 2020		$ 4,656,000	$ 20,907,000	$ 12,272,000	$ 102,232,000		$ 385,000
Balance, Shares at Mar. 31, 2020						2,635,430		2,548,433
Accretion of cumulative dividends on Series D redeemable convertible preferred stock	(1,800,000)				1,800,000					(1,800,000)
Exercise of options to purchase common stock	142,000								142,000
Exercise of options to purchase common stock, Shares								28,051
Equity-based compensation	1,256,000								1,256,000
Equity-based compensation, Shares						25,440
Conversion of redeemable convertible and convertible preferred stock into common stock	141,867,000	$ (4,656,000)	$ (20,907,000)	$ (12,272,000)	$ (104,032,000)		$ (385,000)	$ 21,000	142,231,000
Conversion of redeemable convertible and convertible preferred stock into common stock, Shares		(2,304,815)	(14,921,676)	(8,790,249)	(53,593,440)		(6,452,619)	20,349,223
Conversion of enterprise junior stock into common stock						$ (3,000)		$ 2,000	1,000
Conversion of enterprise junior stock into common stock, Shares						(2,660,870)		2,124,845
Issuance of common stock from initial public offering, net of issuance costs	293,707,000							$ 16,000	293,691,000
Issuance of common stock from initial public offering, net of issuance costs, Shares								15,964,704
Vesting of restricted common stock, Shares								925
Net income (loss) and comprehensive income (loss)	(25,440,000)									(25,440,000)
Balance at Jun. 30, 2020	438,497,000					$ 0		$ 41,000	439,662,000	(1,206,000)
Temporary equity balance, Shares at Jun. 30, 2020		0	0	0	0		0
Temporary equity balance, Value at Jun. 30, 2020		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Jun. 30, 2020						0		41,016,181
Exercise of warrant to purchase common stock	2,961,000								2,961,000
Exercise of warrant to purchase common stock, Shares								62,193
Equity-based compensation	2,129,000								2,129,000
Change In Estimate Of Initial Public Offering Costs	(369,000)								(369,000)
Vesting of restricted common stock, Shares								17,945
Net income (loss) and comprehensive income (loss)	(27,616,000)									(27,616,000)
Balance at Sep. 30, 2020	415,602,000					$ 0		$ 41,000	444,383,000	(28,822,000)
Temporary equity balance, Shares at Sep. 30, 2020		0	0	0	0		0
Temporary equity balance, Value at Sep. 30, 2020		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Sep. 30, 2020						0		41,096,319
Balance at Dec. 31, 2020	648,244,000					$ 0		$ 47,000	705,607,000	(57,410,000)
Temporary equity balance, Shares at Dec. 31, 2020							0
Temporary equity balance, Value at Dec. 31, 2020							$ 0
Balance, Shares at Dec. 31, 2020						0		47,248,685
Exercise of options to purchase common stock	333,000								333,000
Exercise of options to purchase common stock, Shares								68,389
Equity-based compensation	3,848,000								3,848,000
Vesting of restricted common stock, Shares								11,501
Net income (loss) and comprehensive income (loss)	(35,960,000)									(35,960,000)
Balance at Mar. 31, 2021	616,465,000					$ 0		$ 47,000	709,788,000	(93,370,000)
Temporary equity balance, Shares at Mar. 31, 2021		0	0	0	0		0
Temporary equity balance, Value at Mar. 31, 2021		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Mar. 31, 2021						0		47,328,575
Balance at Dec. 31, 2020	$ 648,244,000					$ 0		$ 47,000	705,607,000	(57,410,000)
Temporary equity balance, Shares at Dec. 31, 2020							0
Temporary equity balance, Value at Dec. 31, 2020							$ 0
Balance, Shares at Dec. 31, 2020						0		47,248,685
Exercise of options to purchase common stock, Shares	91,560
Net income (loss) and comprehensive income (loss)	$ (122,839,000)
Balance at Sep. 30, 2021	542,831,000					$ 0		$ 47,000	723,033,000	(180,249,000)
Temporary equity balance, Shares at Sep. 30, 2021		0	0	0	0		0
Temporary equity balance, Value at Sep. 30, 2021		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Sep. 30, 2021						0		47,378,041
Balance at Mar. 31, 2021	616,465,000					$ 0		$ 47,000	709,788,000	(93,370,000)
Temporary equity balance, Shares at Mar. 31, 2021		0	0	0	0		0
Temporary equity balance, Value at Mar. 31, 2021		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Mar. 31, 2021						0		47,328,575
Exercise of options to purchase common stock	92,000							$ 92,000
Exercise of options to purchase common stock, Shares								17,652
Equity-based compensation	6,423,000								6,423,000
Vesting of restricted common stock, Shares								8,652
Net income (loss) and comprehensive income (loss)	(43,585,000)									(43,585,000)
Balance at Jun. 30, 2021	579,395,000					$ 0		$ 47,000	716,303,000	(136,955,000)
Temporary equity balance, Shares at Jun. 30, 2021		0	0	0	0		0
Temporary equity balance, Value at Jun. 30, 2021		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Jun. 30, 2021						0		47,354,879
Exercise of options to purchase common stock	29,000								29,000
Exercise of options to purchase common stock, Shares								5,519
Equity-based compensation	6,701,000								6,701,000
Vesting of restricted common stock, Shares								7,482
Vesting of restricted stock units, shares								10,161
Net income (loss) and comprehensive income (loss)	(43,294,000)									(43,294,000)
Balance at Sep. 30, 2021	$ 542,831,000					$ 0		$ 47,000	$ 723,033,000	$ (180,249,000)
Temporary equity balance, Shares at Sep. 30, 2021		0	0	0	0		0
Temporary equity balance, Value at Sep. 30, 2021		$ 0	$ 0	$ 0	$ 0		$ 0
Balance, Shares at Sep. 30, 2021						0		47,378,041

Consolidated Statements of Re_2

Consolidated Statements of Redeemable Convertible and Convertible Preferred Stock and Stockholders' (Deficit) Equity (Parenthetical) $ in Thousands	3 Months Ended
	Jun. 30, 2020USD ($)
Statement Of Stockholders Equity [Abstract]
Net of Issuance Costs	$ 25,587

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net loss	$ (122,839)	$ (41,826)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	672	1,076
Non-cash operating lease expense	813
Gain on lease modification	(287)
Equity-based compensation	16,972	4,595
Change in fair value of warrant liability		2,597
Amortization (accretion) of marketable securities	1,024	192
Gain on Hit Discovery divestiture		(23,312)
Loss on disposal and sale of property and equipment	121	89
Changes in operating assets and liabilities:
Decrease in accounts receivable		227
Decrease (increase) in income taxes receivable	1,207	(26,555)
(Increase) in prepaid expenses and other current assets	(2,348)	(5,432)
Increase in accounts payable	272	355
(Decrease) in accrued expenses and other current liabilities	(3,029)	6,280
(Decrease) in income taxes payable	(256)	451
(Decrease) in deferred rent, noncurrent		(298)
(Decrease) in operating lease liability	(907)
Net cash used in operating activities	(108,585)	(83,099)
Cash flows from investing activities
Purchases of held-to-maturity marketable securities	(514,121)	(343,320)
Proceeds from maturity and redemption of marketable securities	431,475	38,647
Purchases of property and equipment	(3,721)	(134)
Net proceeds from Hit Discovery divestiture	17,500
Net cash used in investing activities	(86,367)	(301,967)
Cash flows from financing activities
Proceeds from initial public offering of common stock, net of issuance costs		293,707
Proceeds from exercise of warrant to purchase common stock		12
Proceeds from exercise of options to purchase common stock	454	145
Payment of public offering costs	(943)
Net cash (used in) provided by financing activities	(489)	293,605
Net (decrease) increase in cash, cash equivalents and restricted cash	(195,441)	(91,461)
Cash, cash equivalents and restricted cash, beginning of the period	285,159	173,796
Cash, cash equivalents and restricted cash, end of the period	89,718	82,335
Supplemental disclosure of non-cash activities:
Operating lease right-of-use asset recognized upon adoption of Topic 842	7,478
Operating lease right-of-use asset obtained in exchange for operating lease liability	19,312
Accretion of preferred return and cumulative dividends on preferred securities		3,736
Public offering costs included in accounts payable and accrued expenses	28	369
Net exercise of warrants to purchase common stock		2,961
Purchases of property and equipment included in accounts payable	$ 277
Installment Receivable, in prepaid expenses and other current assets (Note 17)		14,131
Equity Consideration in other assets (Note 17)		10,000
Conversion of enterprise junior stock into common stock		3
Conversion of redeemable convertible and convertible preferred stock into common stock		142,252
Series D Redeemable Convertible Preferred Stock [Member]
Cash flows from financing activities
Payment of issuance costs on Series D redeemable convertible preferred stock		(259)
Valo Health [Member]
Adjustments to reconcile net loss to net cash used in operating activities:
Interest income on future cash payments from Valo Health		(1,538)
Hit Discovery Divestiture [Member]
Cash flows from investing activities
Net proceeds from Hit Discovery divestiture		$ 2,840

Organization and Nature of Busi

Organization and Nature of Business	9 Months Ended
	Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Nature of Business	Note 1—Organization and Nature of Business On October 2, 2019, Forma Therapeutics Holdings, LLC, a Delaware limited liability company formed in December 2011 , was reorganized into Forma Therapeutics Holdings, Inc. Forma Therapeutics Holdings, Inc. and its wholly-owned subsidiaries, hereinafter collectively, “the Company”, is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel therapeutics to transform the lives of patients with rare hematologic diseases and cancers. On June 23, 2020, the Company completed an initial public offering (“IPO”) in which the Company issued and sold 15,964,704 shares of its common stock at a public offering price of $ 20.00 per share, including 2,082,352 shares of common stock sold pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock, for aggregate gross proceeds of $ 319.3 million. The Company raised approximately $ 293.3 million in net proceeds after deducting underwriting discounts and commissions and offering expenses payable by the Company. Upon the closing of the IPO, all of the outstanding shares of Series A convertible preferred stock (“Series A Preferred Stock”), Series B-1 convertible preferred stock (“Series B-1 Preferred Stock”), Series B-2 convertible preferred stock (“Series B-2 Preferred Stock”), Series C convertible preferred stock (“Series C Preferred Stock”), and Series D redeemable convertible preferred stock (“Series D Preferred Stock”) automatically converted into 20,349,223 shares of common stock; all issued shares of enterprise junior stock automatically converted into 2,124,845 and 103,007 shares of common stock and restricted common stock, respectively; and warrants to purchase an aggregate of 299,999 shares of Series B-3 convertible preferred stock (“Series B-3 Preferred Stock”, collectively with the Series A, Series B-1, Series B-2, Series C, and Series D Preferred Stock, “Preferred Stock”) with an exercise price of $ 1.20 per share automatically converted into warrants to purchase an aggregate of 70,133 shares of common stock with an exercise price of $ 5.13 per share. Subsequent to the closing of the IPO, there were no shares of preferred stock or enterprise junior stock outstanding. In connection with the closing of the IPO, the Company filed a second amended and restated certificate of incorporation (“Second Amended Certificate of Incorporation”) to change the authorized capital stock to 160,000,000 shares of which 147,494,175 are designated as voting common stock, 2,505,825 are designated as non-voting common stock and 10,000,000 are designated as undesignated preferred stock, all with a par value of $ 0.001 per share. On December 15, 2020, the Company completed a follow-on public offering in which the Company issued and sold 6,095,000 shares of its common stock at a public offering price of $ 45.25 per share, including 795,000 shares of common stock sold pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock, for aggregate gross proceeds of $ 275.8 million. The Company raised approximately $ 258.6 million in net proceeds after deducting underwriting discounts and commissions and offering expenses payable by the Company. On July 26, 2021, the Company filed a Registration Statement on Form S-3ASR ("2021 Shelf") with the SEC, which was automatically declared effective on July 26, 2021 (File No. 333-258174) in relation to the registration of common stock, preferred stock, debt securities, warrants and units or any combination thereof. The Company also simultaneously entered into a Sales Agreement ("Sales Agreement") with SVB Leerink LLC (the "Sales Agent") to provide for the offering, issuance and sale of up to an aggregate amount of $ 200.0 million of common stock from time to time in “at-the-market” offerings under the 2021 Shelf and subject to the limitations thereof. The Company will pay to the Sales Agent cash commissions of up to 3.0 % of the gross proceeds of sales of common stock under the Sales Agreement. As of the date of this Quarterly Report on Form 10-Q, the Company has not made any sales of its common stock under the Sales Agreement. Liquidity The Company is focused on the development and commercialization of novel therapeutics to transform the lives of patients with rare hematologic diseases and cancers. The Company is building a pipeline of therapeutics with a focus on these areas and has devoted substantially all of its resources to the research and development of its drug development efforts, comprised of research and development, manufacturing, conducting clinical trials, protecting its intellectual property and general and administrative functions relating to these operations. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain sustained profitable operations through commercialization of products. The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, the need for additional capital, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval and reimbursement for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development of technological innovations by competitors, reliance on third-party manufacturers and the ability to transition from pilot-scale production to large-scale manufacturing of products. The Company has determined that its cash, cash equivalents and marketable securities of $ 531.8 million as of September 30, 2021 will be sufficient to fund its operations for at least one year from the date these condensed consolidated financial statements are issued. To date, the Company has primarily financed its operations through license and collaboration agreements, the sale of preferred shares and preferred stock to outside investors and the completion of the IPO and follow-on public offering. The Company has experienced significant negative cash flows from operations during the nine months ended September 30, 2021 . The Company does not expect to experience any significant positive cash flows from its existing collaboration agreements and does not expect to have any product revenue in the near term. The Company expects to incur substantial operating losses and negative cash flows from operations for the foreseeable future as it continues to invest significantly in research and development of its programs. Management’s belief with respect to its ability to fund operations is based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, the Company may need to seek additional funding sooner than would otherwise be expected. There can be no assurance that the Company will be able to obtain additional funding on acceptable terms, if at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2—Summary of Significant Accounting Policies Basis of Presentation and Consolidation The condensed consolidated financial statements include the accounts of Forma Therapeutics Holdings, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company has prepared the accompanying condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures generally included in financial statements in conformity with GAAP have been condensed or omitted in accordance with such rules and regulations. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standard Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Significant Accounting Policies These condensed consolidated financial statements should be read in conjunction with the Company’s consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020. Unaudited Interim Condensed Consolidated Financial Statements The accompanying condensed consolidated balance sheet as of September 30, 2021, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2021 and 2020, the condensed consolidated statements of redeemable convertible and convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the nine months ended September 30, 2021 and 2020 are unaudited. The financial data and other information contained in the notes thereto as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 are also unaudited. The condensed consolidated balance sheet data as of December 31, 2020 was derived from the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2020. With the exception of the adoption of ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02” or “Topic 842”), the unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements as of and for the year ended December 31, 2020, and in the opinion of the Company’s management, reflect all adjustments which are necessary to present fairly the Company’s financial position as of September 30, 2021, the results of its operations for the three and nine months ended September 30, 2021 and 2020 and cash flows for the nine months ended September 30, 2021 and 2020. Such adjustments are of a normal and recurring nature. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2020 , and the notes thereto, included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2020. Cash, Cash Equivalents and Restricted Cash The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents. The carrying amounts of the Company’s cash equivalents approximate their fair value due to their short-term nature. Amounts in restricted cash consist of letters of credit to secure the Company’s facilities, including its new lease for office and laboratory space entered into in September 2020 (see Note 7). Restricted cash is included in other assets on the condensed consolidated balance sheets. The following table reconciles cash, cash equivalents and restricted cash as of September 30, 2021 and 2020 to the condensed consolidated statements of cash flows (in thousands): September 30, 2021 2020 Cash and cash equivalents $ 87,248 $ 79,865 Restricted cash 2,470 2,470 Total cash, cash equivalents and restricted cash as shown in the condensed $ 89,718 $ 82,335 Marketable Securities Marketable securities generally consist of U.S. Treasury securities, debt securities of U.S. government agencies and corporate entities and commercial paper. The objectives for holding investments are to invest the Company’s excess cash resources in investment vehicles that provide a better rate of return compared to an interest-bearing bank account with limited risk to the principal invested. Marketable securities with original maturities of greater than 90 days and remaining maturities of less than one year from the balance sheet date are classified as short-term marketable securities. Marketable securities with remaining maturities of greater than one year from the balance sheet date are classified as long-term marketable securities. All investments are classified as held-to-maturity marketable securities as the Company does not have intent to sell these securities and it is more likely than not the Company will not be required to sell such investments before recovery of their amortized cost basis. Held-to-maturity securities are stated at their amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in interest income in the condensed consolidated statements of operations and comprehensive loss. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with the equity holders. There was no difference between net loss and comprehensive loss presented in the accompanying condensed consolidated financial statements for the three and nine months ended September 30, 2021 and 2020 . Equity-Based Compensation The Company accounts for equity awards, including grants of enterprise incentive shares, enterprise junior stock, stock options, restricted stock units and restricted common stock, in accordance with ASC 718, Compensation – Stock Compensation (“Topic 718”). Topic 718 requires all equity-based payments to employees, which includes grants of employee equity awards, to be recognized in the condensed consolidated statements of operations and comprehensive loss based on their grant date fair values. The Company estimates the grant date fair value of stock options using the Black-Scholes option pricing model. The fair value of restricted stock units is based on the fair value of the Company’s common stock on the grant date. The Company recognizes equity-based compensation expense for any non-employee awards consistent with equity awards issued to employees. As it relates to both employee and non-employee equity awards, the Company has elected to account for forfeitures as they occur. Subsequent to the IPO, the fair value of the Company’s common stock underlying its equity awards is based on the quoted market price of the Company’s common stock on the grant date. The Company estimates the fair value of stock options using the Black-Scholes option pricing model, which uses as inputs the fair value of the Company’s common stock, and certain management estimates, including the expected stock price volatility, the expected term of the award, the risk-free rate, and expected dividends. Expected volatility is calculated based on reported volatility data for a representative group of publicly traded companies for which historical information is available. The Company selects companies with comparable characteristics with historical share price information that approximates the expected term of the equity-based awards. The Company computes the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period that approximates the calculated expected term of the stock options. The Company will continue to apply this method until a sufficient amount of historical information regarding the volatility of its stock price becomes available. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. The Company uses the simplified method, under which the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data. The expected dividend yield is assumed to be zero as the Company has no current plans to pay any dividends on common stock. For awards granted in 2020 prior to the Company’s IPO, the Company used a probability-weighted expected returns method (“PWERM”) with four scenarios to value the common stock underlying the awards: an IPO, a delayed IPO, a sale of the Company and a remain private scenario. In the IPO and sale scenarios, the Company estimated an equity value based on the guideline public company method under a market approach. The guideline public companies consisted of biopharmaceutical companies with recently completed initial public offerings. For the remain private scenario, the Company back-solved to the price of a recently issued preferred security. The Company converted its estimated future value in each scenario to present value using a risk-adjusted discount rate. The relative probability of each scenario was determined based on an assessment of then-current market conditions. Where appropriate, the Company applied a discount for lack of marketability to the value indicated for the common stock. The valuation methodology used to value the common stock prior to the IPO included estimates and assumptions that required the Company’s judgment. Significant changes to the key assumptions used in the valuations could have resulted in different fair values of the Company’s common stock at each valuation date. For awards with service-based vesting conditions, the Company recognizes equity-based compensation expense on a straight-line basis over the vesting period. For awards subject to performance conditions, the Company recognizes equity-based compensation expense using an accelerated recognition method over the remaining service period when the Company determines the achievement of the performance condition is probable. The Company classifies equity-based compensation expense in its condensed consolidated statements of operations and comprehensive loss consistent with the classification of the award recipient’s compensation expense. Leases Effective January 1, 2021, the Company adopted Topic 842 using the required modified retrospective approach and utilizing the effective date as its date of initial application. As a result, prior periods are presented in accordance with the previous guidance in ASC 840, Leases (“ASC 840”). The Company evaluates whether an arrangement is or contains a lease at the inception date. If determined to be or contain a lease, the Company determines the classification of the lease at the commencement date, which represents the date at which the lessor makes the underlying asset available for use by the Company. When determining the expected accounting lease term, the Company includes the noncancellable lease term, together with periods covered by (i) an option to extend the lease if the Company is reasonably certain to exercise such option, (ii) an option to terminate the lease if the Company is reasonably certain not to exercise such option and (iii) an option to extend or not terminate the lease where the exercise of such option is controlled by the lessor. The Company has elected the short-term lease exemption, which allows the Company to not recognize lease liabilities and right-of-use assets arising from lease arrangements with original lease terms of twelve months or less. The Company elected the practical expedient to not separate lease and non-lease components for its real estate leases. Right-of-use assets represent the Company’s right to use an underlying asset over the lease term and lease liabilities represent the Company’s obligation to make lease payments under the arrangement. The Company measures its lease liabilities as the present value of the lease payments, discounted using an incremental borrowing rate, as interest rates implicit in lease arrangements are generally not readily determinable. The Company measures its right-of-use assets as the present value of its lease payments at the commencement date, adjusted for prepaid rent payments and tenant incentives. The incremental borrowing rate represents the interest rate at which the Company could borrow an amount equal to the lease payments on a fully collateralized basis, over a similar term, in a similar economic environment. The Company recognizes rent expense for operating leases on a straight-line basis. The Company recognizes variable lease expenses as incurred. The Company remeasures right-of-use assets and lease liabilities when a lease is modified, and the modification is not accounted for as a separate contract. A modification is accounted for as a separate contract if the modification grants the Company an additional right of use not included in the original lease arrangement and the increase in lease payments is commensurate with the additional right of use. The Company assesses its right-of-use assets for impairment in a manner consistent with its assessment for long-lived assets held and used in operations. Recently Adopted Accounting Pronouncements In February 2016, the FASB Topic 842 was issued, which supersedes the existing guidance for lease accounting. The FASB has issued several updates to the standard which: (i) clarify how to apply certain aspects of the new standard; (ii) provide an additional transition method for adoption of the new standard; (iii) provide a practical expedient for certain lessor accounting; and (iv) amend certain narrow aspects of the guidance. Topic 842 requires the identification and classification of arrangements that are or contain a lease. In general, for lease arrangements exceeding a twelve-month term, these arrangements must be recognized as assets and liabilities on the balance sheet of the lessee. Under Topic 842, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of Topic 842 is calculated using the applicable incremental borrowing rate at the date of adoption. Topic 842 is effective for the Company on January 1, 2022, with early adoption permitted. The Company elected to early adopt the new standard and used the modified retrospective approach effective January 1, 2021 as the initial date of application. The Company elected the available package of practical expedients which allowed the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of leases, and the treatment of initial direct costs. As a result of the adoption of Topic 842, the Company recorded (i) an operating lease liability of $ 8.9 million and (ii) an operating lease right-of-use asset of $ 7.5 million, net of the unamortized balance of deferred rent liability and tenant improvement allowances as of the transition date. There was no impact to the Company’s results of operations and cash flows from operations. A summary of the impact of the adoption is as follows (in thousands): December 31, 2020 Impact of Adoption January 1, 2021 Operating lease right-of-use asset $ — $ 7,478 $ 7,478 Accrued expenses and other current liabilities 27,104 ( 399 ) 26,705 Operating lease liability, current — 3,025 3,025 Deferred rent, noncurrent 1,027 ( 1,027 ) — Operating lease liability, noncurrent — 5,879 5,879

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	Note 3—Fair Value of Financial Assets and Liabilities The following tables present information about the Company’s assets that are measured or disclosed at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at the Reporting Date Using September 30, Quoted Prices Significant Significant Assets—Cash equivalents Repurchase agreement $ 25,000 $ — $ 25,000 $ — Money market funds 59,814 59,814 — — Assets—Short-term marketable securities U.S. Government agency securities 41,292 — 41,292 — U.S. Treasury securities 37,062 37,062 — — Commercial paper 299,517 — 299,517 — Corporate debt securities 47,607 — 47,607 — Assets—Long-term marketable securities U.S. Government agency securities 1,999 — 1,999 — U.S. Treasury securities 17,083 17,083 — — Total $ 529,374 $ 113,959 $ 415,415 $ — Fair Value Measurements at the Reporting Date Using December 31, Quoted Prices Significant Significant Assets—Cash equivalents Repurchase agreement $ 12,000 $ — $ 12,000 $ — Commercial paper 22,493 — 22,493 — Money market funds 227,987 227,987 — — Assets—Short-term marketable securities U.S. Government agency securities 55,469 — 55,469 — U.S. Treasury securities 38,294 38,294 — — Commercial paper 237,735 — 237,735 — Corporate debt securities 18,873 — 18,873 — Assets—Long-term marketable securities U.S. Government agency securities 7,049 — 7,049 — Corporate debt securities 5,492 — 5,492 — Total $ 625,392 $ 266,281 $ 359,111 $ — During the nine months ended September 30, 2021 and twelve months ended December 31, 2020 there were no transfers into or out of Level 3. The Company’s Level 2 investments classified as cash equivalents and marketable securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities and other observable inputs. During the nine months ended September 30, 2020, the Company recognized a loss on the remeasurement of the warrant liability. Prior to the IPO, the warrant liability balance was comprised of three warrants to purchase an aggregate of 299,999 shares of Series B-3 Preferred Stock with an exercise price of $ 1.20 per share (“Series B-3 Preferred Warrants”). Upon the closing of the IPO, the Series B-3 Preferred Warrants were automatically converted into warrants to purchase an aggregate of 70,133 shares of common stock with an exercise price of $ 5.13 per share. The remaining terms and provisions of the warrants held immediately prior and subsequent to the conversion were substantially the same, including the provision under which the Company was obligated to pay the holders the greater of (i) five times the exercise price, less the exercise price, or (ii) the excess of the fair market value of a warrant share over the exercise price, in the event of a change in control in which the acquirer did not assume the warrants. As the common stock warrants embodied an obligation to repurchase the Company’s shares in exchange for specified assets that was not within the Company’s control, the Company classified the common stock warrants as a liability. The value for the warrant liability balance was based on a Black-Scholes option pricing model using significant inputs not observable in the market representing a Level 3 measurement within the fair value hierarchy. Gains and losses on remeasurement of Level 3 securities are included in other (expense) income, net on the condensed consolidated statements of operations and comprehensive loss. The warrants were exercised in July 2020 and as of September 30, 2021 , the Company had no outstanding warrants. The following assumptions were used to determine the fair value of the warrants to purchase common stock: July 1, 2020 Risk-free interest rate 0.31 % Expected term (in years) 5.0 Expected volatility 75.8 % Expected dividend yield 0.0 % Fair value per share of underlying common stock $ 46.37 The following table provides a summary of changes in fair value of the Level 3 warrant liability (in thousands): Warrant Balance at December 31, 2019 $ 364 Change in fair value 2,597 Net exercise of warrants to purchase common stock ( 2,961 ) Balance at September 30, 2020 $ -

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2021
Investments Debt And Equity Securities [Abstract]
Marketable Securities	Note 4—Marketable Securities The following table presents the carrying amounts and estimated fair values of financial instruments not measured at fair value in the condensed consolidated balance sheets as they are considered held-to-maturity securities. The Company’s investments by type consisted of the following (in thousands): September 30, 2021 Amortized Gross Gross Estimated Assets U.S. Government agency securities $ 43,284 $ 7 $ — $ 43,291 U.S. Treasury securities 54,144 7 ( 6 ) 54,145 Commercial paper 299,472 45 — 299,517 Corporate debt securities 47,621 — ( 14 ) 47,607 Total $ 444,521 $ 59 $ ( 20 ) $ 444,560 December 31, 2020 Amortized Gross Gross Estimated Assets U.S. Government agency securities $ 62,508 $ 10 $ — $ 62,518 U.S. Treasury securities 38,287 7 — 38,294 Commercial paper 237,733 18 ( 16 ) 237,735 Corporate debt securities 24,371 3 ( 9 ) 24,365 Total $ 362,899 $ 38 $ ( 25 ) $ 362,912 As marketable securities are considered held-to-maturity, the unrealized gains and losses are not recorded within the condensed consolidated financial statements. As of September 30, 2021 and December 31, 2020, the Company held 17 and 16 investments, respectively, in an unrealized loss position with an aggregate fair value of $ 92.7 million and $ 93.7 million, respectively. These investments were in a loss position for less than 12 months and the Company considered the loss to be temporary in nature. The aggregate of individual unrealized losses as of September 30, 2021 and December 31, 2020 was not significant.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	9 Months Ended
	Sep. 30, 2021
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Note 5—Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2021 2020 Manufacturing and clinical prepaid expenses $ 3,187 $ 3,068 Other prepaid expenses 4,485 1,725 Other non-trade receivables 467 1,327 $ 8,139 $ 6,120

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Property and Equipment, Net	Note 6—Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2021 2020 Computer and office equipment $ 1,735 $ 2,253 Software 514 2,473 Lab equipment 3,599 4,560 Furniture and fixtures 840 377 Leasehold improvements 14,888 3,402 Construction in process 851 — 22,427 13,065 Less: Accumulated depreciation ( 7,686 ) ( 11,545 ) $ 14,741 $ 1,520 Depreciation and amortization expense related to property and equipment for the three months ended September 30, 2021 and 2020 totaled $ 0.3 million and $ 0.3 million, respectively. For the nine months ended September 30, 2021 and 2020 , depreciation and amortization expense related to property and equipment totaled $ 0.7 million and $ 1.1 million, respectively.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	Note 7—Leases The Company’s operating lease activity is primarily comprised of noncancelable facilities leases for office and laboratory space in Watertown, MA and Branford, CT. North Beacon Street Lease In September 2020 , the Company entered into a lease for office and laboratory space in Watertown, MA (the “Beacon Street Lease”). The Beacon Street Lease is with a landlord who is an investor and related party of the Company. The Beacon Street Lease, which commenced in September 2021, is subject to base rent of $ 0.3 million per month, plus the Company's ratable share of taxes, maintenance and other operating expenses. Base rent is subject to a 3.0 % annual increase over the 10-year lease term. In addition, the Beacon Street Lease provides an extension option for one additional five-year term at then-market rates and includes a tenant improvement allowance of $ 10.0 million. The Company paid first month’s rent of $0.3 million upon execution of the Beacon Street Lease agreement. The Beacon Street Lease is secured by a letter of credit of $ 2.0 million and is classified in other assets on the condensed consolidated balance sheets. The Beacon Street Lease required the landlord to perform a scope of work to build-out the base building prior to the construction of the Company’s premises. The Company concluded the accounting commencement date occurred when the landlord completed the build-out of the base building and control passed to the Company, which occurred in early September 2021. The Company assessed the classification of the Beacon Street Lease at the accounting commencement date and concluded the lease should be accounted for as an operating lease. The Company recorded an operating lease liability of $ 29.3 million, measured as the present value of the remaining lease payments discounted using the incremental borrowing as of the accounting commencement date. The Company recorded an operating lease right-of-use asset of $ 19.3 million, measured as the present value of the remaining lease payments, plus prepaid rent, net of the tenant incentives. The operating lease right-of-use asset was reduced by the difference between the right-of-use asset and lease liability of the Arsenal Street Lease measured upon accounting commencement of the Beacon Street Lease. The Company determined the appropriate incremental borrowing rate using a synthetic credit rating based on the interest coverage ratio, factoring in adjustments for additional risks based on an analysis of comparable companies with similar credit and financial profiles. The Company concluded the improvements paid for by the tenant improvement allowance represent lessee assets and therefore recorded $ 10.0 million of leasehold improvements from the tenant improvement allowance in property and equipment. The Company recorded an additional $ 1.6 million of leasehold improvements in excess of the tenant improvement allowance, all of which were placed in service in September 2021. Arsenal Street Lease The Company previously leased office and laboratory space in Watertown, MA (the “Arsenal Street Lease”) prior to occupying the Beacon Street Lease. The Arsenal Street Lease was with the same landlord as the Company’s Beacon Street Lease. The Arsenal Street Lease included annual increases to base rent over the lease term and included monthly rental payments payable by the Company based on its proportionate share of operating expenses. The Arsenal Street Lease included a tenant improvement allowance of $ 0.5 million, of which the Company used the entire allowance. The Arsenal Street Lease was secured by a letter of credit of $ 0.5 million. In May 2021, the Company amended the Arsenal Street Lease to reduce the rentable square feet by approximately 50 %. Pursuant to the amendment, annual base rent and the Company’s share of operating expenses were reduced in proportion to the reduction in rentable square feet. There was no change to the lease term for the remaining space. The Company determined that the amendment did not grant an additional right-of-use asset and as such was accounted for as a modification to the existing operating lease. The operating lease right-of-use asset and operating lease liability were remeasured at the date of modification which resulted in a reduction of the operating lease right-of-use asset of $ 2.6 million and a reduction in the operating lease liability of $ 2.9 million. The Company recorded the resulting gain on the modification of $ 0.3 million in other (expense) income, net on the condensed consolidated statements of operations and comprehensive loss. In September 2021, concurrent with the execution of the Beacon Street Lease, the Arsenal Street Lease was further amended to expire 30 days following the lease commencement date of the Beacon Street Lease during which time rent would be fully abated. The Company concluded the Beacon Street Lease and amended Arsenal Street Lease should be combined for accounting purposes given that the amendment of the Arsenal Street Lease and the Beacon Street Lease were negotiated with both the same commercial objective and landlord. Upon lease commencement of the Beacon Street Lease in September 2021, the Company derecognized the operating lease right-of-use asset and operating lease liability for the Arsenal Street Lease. The difference between the right-of-use asset and lease liability was $ 0.3 million and was recorded as a reduction to the operating lease right-of-use asset for the Beacon Street Lease. The letter of credit securing the Arsenal Street Lease remains classified in other assets on the condensed consolidated balance sheets and the Company anticipates the restriction to be released in the fourth quarter of 2021. Branford, CT Lease As amended on January 1, 2018, the Company’s Branford, CT lease is subject to annual increases to base rent over a term expiring in December 2023 . The lease included a tenant improvement allowance of $ 1.0 million, of which $ 0.1 million remains unused. In addition to base rent, monthly rental payments include the Company’s proportionate share of operating expenses. The lease terms provide for one five-year extension term with base rent calculated on a discounted then-market rate . Pursuant to the Hit Discovery divestiture, the Company’s Branford, CT lease was assigned to and assumed by Valo Health. Valo Health will pay the landlord rental amounts due under the lease including minimum lease payments of $ 0.2 million, $ 0.8 million and $ 0.8 million for the three months ended December 31, 2021, and years ended December 31, 2022 and 2023, respectively. The Company remains jointly and severally liable for the remaining lease payments under the lease. In the event Valo Health does not make payments under the lease, the Company would be expected to pursue available remedies under the Asset Purchase Agreement (the “Agreement”) executed pursuant to the sale (see Note 17). During the three and nine months ended September 30, 2021 , the Company recorded rent expense under the head lease of $ 0.2 million and $ 0.6 million, respectively, offset by sublease income of $ 0.2 million and $ 0.6 million, respectively, both of which are included as components of operating lease cost in the table below. The components of operating lease expense were as follows (in thousands): Three Months Ended Nine Months Ended Operating lease cost $ 312 $ 1,112 Variable lease cost 255 738 $ 567 $ 1,850 Supplemental cash flow information related to operating leases was as follows (in thousands): Three Months Ended Nine Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows related to operating leases $ 220 $ 1,258 Future minimum lease payments under noncancellable leases as of September 30, 2021 were as follows (in thousands): Operating Leases 2021 (excluding the nine months ended September 30, 2021) $ 1,110 2022 4,843 2023 4,986 2024 4,222 2025 4,349 Thereafter 27,645 Total lease payments 47,155 Present value adjustment ( 15,854 ) Present value of operating lease liabilities $ 31,301 As of September 30, 2021 , the Company’s operating leases were measured using a weighted-average incremental borrowing rate of 8.7 % over a weighted-average remaining lease term of 9.5 years.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2021
Payables And Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Note 8—Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2021 2020 Manufacturing and clinical accruals $ 12,922 $ 17,952 Employee compensation 6,898 6,834 Other research and development related accruals 1,567 338 Professional and consulting services 967 1,008 Other current liabilities 1,099 972 $ 23,453 $ 27,104

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 9—Commitments and Contingencies Guarantees and Indemnification Obligations The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to these agreements, the Company indemnifies and agrees to reimburse the indemnified party for losses and costs incurred by the indemnified party, generally the Company’s customers, in connection with any patent, copyright, trade secret or other intellectual property or personal right infringement claim by any third party with respect to the Company’s technology. The term of these indemnification agreements is generally perpetual after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. Based on historical experience and information known as of September 30, 2021 and December 31, 2020 , the Company had no t incurred any costs for the above guarantees and indemnities.

Restructuring Charges

Restructuring Charges	9 Months Ended
	Sep. 30, 2021
Restructuring And Related Activities [Abstract]
Restructuring Charges	Note 10—Restructuring Charges In January 2019, the Company undertook an organization realignment to reduce the Company’s cost base and simplify its business goals to focus on a wholly owned pipeline. To achieve this cost reduction, the Company reduced its headcount by approximately 40 %. The total restructuring charges incurred of $ 5.4 million were comprised of termination benefits including expenses for severance, health benefits and outplacement services. There were no restructuring activities during the nine months ended September 30, 2021 . The following table summarizes the restructuring activity incurred during the nine months ended September 30, 2020 (in thousands): Accrued Balance at December 31, 2019 $ 325 Restructuring costs incurred 63 Termination benefits paid ( 388 ) Balance at September 30, 2020 $ —

Redeemable Convertible and Conv

Redeemable Convertible and Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2021
Temporary Equity [Abstract]
Redeemable Convertible and Convertible Preferred Stock	Note 11—Redeemable Convertible and Convertible Preferred Stock Immediately prior to the closing of the IPO, the Company had an aggregate of 86,062,799 shares of redeemable convertible and convertible preferred stock issued and outstanding which automatically converted into 20,349,223 shares of common stock. Subsequent to the closing of the IPO, no shares of preferred stock were issued or outstanding. Upon the closing of the IPO, the Company filed the Second Amended Certificate of Incorporation to authorize 10,000,000 shares of preferred stock which were designated as undesignated preferred stock. As of September 30, 2021 , no shares of preferred stock were issued or outstanding.

Stockholder's Equity

Stockholder's Equity	9 Months Ended
	Sep. 30, 2021
Stockholders Equity Note [Abstract]
Stockholders' Equity	Note 12—Stockholders’ Equity Common Stock Reserved for Future Issuances As of September 30, 2021, the Company had reserved for future issuance the following number of shares of common stock: Stock For exercise of stock options under the 2019 Stock Incentive Plan 3,898,584 For exercise of stock options under the 2020 Stock Option and Incentive Plan 2,262,682 For restricted stock units granted under the 2020 Stock Option and Incentive Plan 800,209 For future issuance under the 2020 Stock Option and Incentive Plan 2,381,767 For future issuance under the 2020 Employee Stock Purchase Plan 840,032 10,183,274

Equity-Based Compensation

Equity-Based Compensation	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity-Based Compensation	Note 13—Equity-Based Compensation 2020 Stock Option and Incentive Plan The Company grants stock-based awards under the 2020 Stock Option and Incentive Plan (“2020 Plan”). All shares of common stock underlying any awards that are forfeited, cancelled, expired, repurchased, or otherwise terminated under the 2020 and 2019 Plans are added back to the shares of common stock available for issuance under the 2020 Plan, while all unvested shares under the 2012 Plan that are forfeited, cancelled or are otherwise terminated that are reserved under the 2012 Plan are automatically retired. The Company also has stock options and restricted common stock outstanding under the 2019 Stock Incentive Plan (“2019 Plan”) and 2012 Equity Incentive Plan, as Amended and Restated, (“2012 Plan”) respectively, but is no longer granting awards under such plans. On January 1, 2021, the number of shares of common stock available for issuance under the 2020 Plan increased by 1,892,009 shares as a result of the automatic increase provision of the 2020 Plan. As of September 30, 2021, there were 2,381,767 shares available for future issuance under the 2020 Plan. Equity-Based Compensation Expense Equity-based compensation expense was as follows (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development $ 2,747 $ 659 $ 6,756 $ 1,431 General and administrative 3,954 1,470 10,216 3,164 $ 6,701 $ 2,129 $ 16,972 $ 4,595 Enterprise junior stock — — — 365 Restricted common stock 54 181 230 217 Restricted stock units 2,848 29 6,496 29 Stock options 3,799 1,919 10,246 3,984 $ 6,701 $ 2,129 $ 16,972 $ 4,595 Stock Options The following table summarizes the Company’s stock option activity under the 2019 and 2020 Plans: Number Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 4,941,537 $ 8.62 9.1 $ 130,802 Granted 1,363,220 34.92 Exercised ( 91,560 ) 5.14 Forfeited ( 51,931 ) 8.73 Outstanding as of September 30, 2021 6,161,266 $ 14.49 8.5 $ 72,281 Exercisable as of September 30, 2021 2,173,996 $ 8.08 8.1 $ 33,742 Vested and expected to vest as of September 30, 2021 6,161,266 $ 14.49 8.5 $ 72,281 The weighted-average grant date fair value per share of stock options granted during the nine months ended September 30, 2021 and 2020 was $ 23.45 and $ 6.62 , respectively. The aggregate intrinsic value of stock options exercised during the nine months ended September 30, 2021 was $ 2.8 million. As of September 30, 2021 , there was approximately $ 42.7 million of unrecognized equity-based compensation expense related to stock options that is expected to be recognized over a weighted-average period of approximately 2.6 years. Stock Options Valuation The following assumptions were used in determining the fair value of stock options, presented on a weighted average basis: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Risk-free interest rate 0.98 % 0.36 % 0.96 % 1.09 % Expected term (in years) 6.1 5.9 6.0 6.0 Expected volatility 77.5 % 76.1 % 77.9 % 74.8 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 % Fair value per share of common stock $ 23.38 $ 40.82 $ 34.92 $ 10.13 Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity under the 2020 Plan: Number of Shares Weighted Unvested as of December 31, 2020 42,100 $ 42.26 Granted 772,760 $ 35.15 Vested ( 10,161 ) $ 44.29 Forfeited ( 4,490 ) $ 32.12 Unvested as of September 30, 2021 800,209 $ 35.42 The aggregate fair value of restricted stock units that vested during the nine months ended September 30, 2021 was $ 0.5 million. The weighted-average grant date fair value of restricted stock units granted during the nine months ended September 30, 2020 was $ 44.02 per share. As of September 30, 2021 , there was approximately $ 22.2 million of unrecognized equity-based compensation expense related to the restricted stock units that is expected to be recognized over a weighted-average period of approximately 2.9 years. Restricted Common Stock The following table summarizes the Company’s restricted common stock activity under the 2012 Plan: Number of Shares Weighted Issued and unvested as of December 31, 2020 51,546 $ 7.44 Vested ( 27,635 ) $ 9.35 Forfeited ( 2,079 ) $ 14.88 Issued and unvested as of September 30, 2021 21,832 $ 4.25 The aggregate fair value of restricted common stock that vested during the nine months ended September 30, 2021 and 2020 was $ 0.3 million and $ 0.2 million, respectively. As of September 30, 2021 , there was approximately $ 0.1 million of unrecognized equity-based compensation expense related to the restricted common stock that is expected to be recognized over a weighted-average period of approximately 1.0 year. 2020 Employee Stock Purchase Plan The 2020 Employee Stock Purchase Plan (“ESPP”) became effective June 2020. On January 1, 2021, the number of shares of common stock available for issuance under the ESPP increased by 472,487 shares as a result of the automatic increase provision of the ESPP. As of September 30, 2021 , no shares have been issued under the ESPP and 840,032 shares remain available for issuance.

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss per Share	Note 14—Net Loss per Share The following is a reconciliation of weighted-average common stock outstanding used in calculating basic net loss per share to weighted-average common stock outstanding used in calculating diluted net loss per share: Three Months Ended 2020 Weighted-average common stock outstanding, basic 41,088,261 Add: Effect of dilutive securities Warrants to purchase shares of common stock (as converted from 663 Weighted-average common stock outstanding, diluted 41,088,924 The following table sets forth the outstanding shares of common stock equivalents, presented based on amounts outstanding at each period end, which were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Stock options 6,161,266 4,947,106 6,161,266 4,947,106 Restricted common stock 21,832 66,073 21,832 66,073 Restricted stock units 800,209 18,200 800,209 18,200

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 15—Income Taxes Income taxes for the three months ended September 30, 2021 and 2020 have been calculated based on an estimated annual effective tax rate and certain discrete items. For the nine months ended September 30, 2021 and 2020 , the Company recorded an income tax expense of $ 0.1 million and an income tax benefit of $ 26.5 million, respectively. The Company’s income tax expense for the nine months ended September 30, 2021 was related to the provision to return adjustment and a reduction to the income tax refund arising from the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). The income tax benefit for the nine months ended September 30, 2020 was related to refunds arising from the CARES Act. On March 27, 2020, the CARES Act was enacted in response to the COVID-19 pandemic. Among other things, the CARES Act permits corporate taxpayers to carryback net operating losses (“NOLs”) originating in 2018 through 2020 to each of the five preceding tax years. Further, the CARES Act removed the 80 % taxable income limitation on utilization of those NOLs allowing corporate taxpayers to fully utilize NOL carryforwards to offset taxable income in 2018, 2019 or 2020. Such changes resulted in the generation of refunds of previously paid income taxes for which some refunds have been received in 2020 through September 30, 2021 and some refunds are expected to be received over the next twelve months. The Company has filed refund claims related to its 2018, 2019 and 2020 tax years to carryback NOLs to its 2015, 2016, 2017 and 2018 tax years for federal tax purposes which will result in anticipated refunds of $ 29.6 million, of which $ 16.6 million has been received through September 30, 2021 .

Collaboration Agreements

Collaboration Agreements	9 Months Ended
	Sep. 30, 2021
Collaboration And License Agreements Disclosure [Abstract]
Collaboration Agreements	Note 16—Collaboration Agreements In November 2010, the Company entered into an arrangement with a partner to deliver a compound library. Included in the arrangement were certain options to exclusive licenses for a defined number of library compounds. The Company determined the options represented material rights as they were exercisable for no additional consideration over the ten-year contract term. As of December 31, 2019, the Company had $ 1.2 million of deferred revenue related to the options. Pursuant to the Hit Discovery divestiture, the contract was assigned to and assumed by Valo Health and therefore the Company’s obligation relative to the options were released and assumed by Valo Health (see Note 17) during the nine months ended September 30, 2020. Summary of Contract Assets and Liabilities The following table presents changes in the Company’s balances of contract liabilities (in thousands): Beginning Additions Deductions End of Nine months ended September 30, 2020 Deferred revenue $ 1,239 $ — $ 1,239 $ — Deferred revenue, noncurrent $ — $ — $ — $ — During the nine months ended September 30, 2021 and 2020, the Company recognized no revenue. The Company had no contract asset balances as of September 30, 2021 and 2020 .

Hit Discovery Divestiture

Hit Discovery Divestiture	9 Months Ended
	Sep. 30, 2021
Discontinued Operations And Disposal Groups [Abstract]
Hit Discovery Divestiture	Note 17—Hit Discovery Divestiture On March 16, 2020, the Company and Valo Health, Inc. (“Valo Health”, previously disclosed as “Integral Health, Inc.” and “NewCo”) executed an Agreement to divest select hit discovery capabilities (“Hit Discovery”, previously disclosed as “Early Discovery”). Valo Health purchased certain assets, including specified intellectual property, contracts and equipment used to conduct early stage hit identification and hit to lead discovery activities related to the identification, screening, and validation of compounds in early stage drug discovery from the Company. Additionally, certain of the Company’s employees terminated their employment with the Company and became employees of Valo Health. In exchange, the Company was entitled to receive: $ 17.5 million in cash, of which $ 2.5 million was paid at closing, and $ 15.0 million was payable in installments through June 1, 2021 (the “Installment Receivable”); $ 0.5 million of reimbursements for expenses prepaid by the Company, the benefit of which was transferred to Valo Health; and equity consideration equal to $ 10.0 million of equity in Valo Health’s next financing round or, if Valo Health’s next equity financing did not occur prior to the one-year anniversary of the closing of the Agreement, a number of shares of preferred stock issued in Valo Health’s previous round of equity financing prior to this Agreement equal to $10.0 million divided by the price per share paid by investors in that previous equity financing (the “Equity Consideration”). Further, if Valo Health closed a financing that met certain minimum thresholds prior to June 1, 2021, Valo Health would pay the Company the balance of the unpaid Installment Receivable. The Company is also eligible to receive low single digit future royalties on the aggregate net sales of any products that bind to a target in certain identified target classes, on a product-by-product and country-by-country basis during the periods of time commencing at the time of the first commercial sale of such product in such country, until the later of (i) the expiration of certain related patents and (ii) ten years after such first commercial sale (“Contingent Royalty Income”). The Company concluded that substantially all of the fair value of the gross assets sold was not concentrated in a single identifiable asset or group of similar identifiable assets based on the value of the identifiable tangible and intangible assets sold and the employees transferred as part of the transaction. The Company concluded that the asset group transferred to Valo Health constituted a business as the Company transferred inputs and processes that are capable of producing outputs. Further, the Company concluded it no longer had a controlling interest in the divested business subsequent to the transaction. The Company recognized a gain representing the difference between the fair value of the consideration received and the carrying amount of the net assets sold. The Company concluded the Equity Consideration was not a derivative instrument pursuant to ASC 815, Derivatives and Hedging, (“ASC 815”) as it could not be net settled. The Company did not have a significant influence on the operating and financial policies of Valo Health. As a result, the Equity Consideration was accounted for under ASC 321, Equity Securities , (“ASC 321”). The Company recorded the equity instrument at fair value and applied the measurement alternative under ASC 321 such that the Company would not change the amount recorded for the equity instrument unless the Company identified observable price changes in orderly transactions for the identical or similar investment of the same issuer or the equity instrument was otherwise deemed to be impaired. The Company initially concluded the fair value of the Equity Consideration was $ 10.0 million based on the expected value of the equity to be received. The fair value of the Installment Receivable was initially calculated as the present value of the then future cash payments to be received from Valo Health using a discount rate of 19.0 % which factored in the risks associated with an early-stage development company. The Company used the effective interest rate to accrete the present value of the then future payments to the total amount of payments that were received from Valo Health. The fair value of the Contingent Royalty Income was determined to be de minimis given the remote likelihood the Company will receive any significant future payments. The fair value of the total consideration received, as of the transaction date, used in calculating the gain on Hit Discovery divestiture is summarized as follows (in thousands): Fair Value Cash consideration: Cash due at closing $ 2,961 Installment Receivable 12,593 Non-cash consideration: Equity Consideration $ 10,000 Total fair value of consideration $ 25,554 The carrying value of the assets and liabilities included in the sale to Valo Health were as follows (in thousands): Carrying Assets: Prepaid expenses and other current assets $ 1,117 Property and equipment, net 2,398 Other assets 125 $ 3,640 Liabilities: Accounts payable $ 159 Deferred revenue 1,239 $ 1,398 Net assets sold $ 2,242 The Company recognized a gain on Hit Discovery divestiture of $ 23.3 million which is presented as a separate component of other (expense) income, net on the Company’s condensed consolidated statement of operations and comprehensive loss for the nine months ended September 30, 2020. For the three and nine months ended September 30, 2020 , the Company recorded interest income of approximately $ 0.7 million and $ 1.5 million, respectively, related to the accretion of the Installment Receivable. Upon the execution of the Agreement, the Company accelerated the vesting of 23,317 stock options, 18,818 of which were held by employees who terminated employment with the Company as part of the transaction, in accordance with the respective award agreements. In addition, the Company modified 19,981 stock options to increase the exercise period from 90 days to one year from the date of termination for certain employees terminated in relation to the transaction. The incremental compensation expense associated with the modification was deemed immaterial. Separately, the Company recognized $ 0.5 million of research and development expense in the condensed consolidated statement of operations and comprehensive loss for the nine months ended September 30, 2020 related to a cash bonus payable as a result of the transaction. During the fourth quarter of 2020, Valo Health closed on their equity financing round. In connection with the closing, the Company received preferred shares in Valo Health in an amount equal to $ 10.0 million and the remaining balance of the Installment Receivable. The Company concluded the fair value of the equity interest received in Valo Health was equal to $ 10.0 million and continues to record the equity interest in other assets on the Company’s consolidated balance sheet as of September 30, 2021 . No gain or loss was recorded by the Company in connection with the closing of Valo Health’s equity financing round as the carrying value of the Equity Consideration immediately prior to the closing was equal to the fair value of the equity interest that was received in Valo Health as part of the equity financing. As the Company does not have a significant influence on the operating and financial policies of Valo Health, the Company accounted for the equity interest received in Valo Health by applying the measurement alternative under ASC 321. As of September 30, 2021 and December 31, 2020, no impairments, nor any upward or downward adjustments have been recognized on the equity interest in Valo Health as a result of the application of the measurement alternative as there have been no observable price changes.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Liquidity	Liquidity The Company is focused on the development and commercialization of novel therapeutics to transform the lives of patients with rare hematologic diseases and cancers. The Company is building a pipeline of therapeutics with a focus on these areas and has devoted substantially all of its resources to the research and development of its drug development efforts, comprised of research and development, manufacturing, conducting clinical trials, protecting its intellectual property and general and administrative functions relating to these operations. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain sustained profitable operations through commercialization of products. The Company is subject to risks common to companies in the biotechnology industry, including but not limited to, the need for additional capital, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval and reimbursement for any drug product candidate that it may identify and develop, the need to successfully commercialize and gain market acceptance of its product candidates, dependence on key personnel, protection of proprietary technology, compliance with government regulations, development of technological innovations by competitors, reliance on third-party manufacturers and the ability to transition from pilot-scale production to large-scale manufacturing of products. The Company has determined that its cash, cash equivalents and marketable securities of $ 531.8 million as of September 30, 2021 will be sufficient to fund its operations for at least one year from the date these condensed consolidated financial statements are issued. To date, the Company has primarily financed its operations through license and collaboration agreements, the sale of preferred shares and preferred stock to outside investors and the completion of the IPO and follow-on public offering. The Company has experienced significant negative cash flows from operations during the nine months ended September 30, 2021 . The Company does not expect to experience any significant positive cash flows from its existing collaboration agreements and does not expect to have any product revenue in the near term. The Company expects to incur substantial operating losses and negative cash flows from operations for the foreseeable future as it continues to invest significantly in research and development of its programs. Management’s belief with respect to its ability to fund operations is based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, the Company may need to seek additional funding sooner than would otherwise be expected. There can be no assurance that the Company will be able to obtain additional funding on acceptable terms, if at all.
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The condensed consolidated financial statements include the accounts of Forma Therapeutics Holdings, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company has prepared the accompanying condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures generally included in financial statements in conformity with GAAP have been condensed or omitted in accordance with such rules and regulations. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standard Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Unaudited Interim Condensed Consolidated Financial Statements	Unaudited Interim Condensed Consolidated Financial Statements The accompanying condensed consolidated balance sheet as of September 30, 2021, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2021 and 2020, the condensed consolidated statements of redeemable convertible and convertible preferred stock and stockholders’ equity for the three and nine months ended September 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the nine months ended September 30, 2021 and 2020 are unaudited. The financial data and other information contained in the notes thereto as of September 30, 2021 and for the three and nine months ended September 30, 2021 and 2020 are also unaudited. The condensed consolidated balance sheet data as of December 31, 2020 was derived from the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2020. With the exception of the adoption of ASU No. 2016-02, Leases (Topic 842) (“ASU 2016-02” or “Topic 842”), the unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements as of and for the year ended December 31, 2020, and in the opinion of the Company’s management, reflect all adjustments which are necessary to present fairly the Company’s financial position as of September 30, 2021, the results of its operations for the three and nine months ended September 30, 2021 and 2020 and cash flows for the nine months ended September 30, 2021 and 2020. Such adjustments are of a normal and recurring nature. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2020 , and the notes thereto, included in the Annual Report on Form 10-K for the fiscal year ended December 31, 2020.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents. The carrying amounts of the Company’s cash equivalents approximate their fair value due to their short-term nature. Amounts in restricted cash consist of letters of credit to secure the Company’s facilities, including its new lease for office and laboratory space entered into in September 2020 (see Note 7). Restricted cash is included in other assets on the condensed consolidated balance sheets. The following table reconciles cash, cash equivalents and restricted cash as of September 30, 2021 and 2020 to the condensed consolidated statements of cash flows (in thousands): September 30, 2021 2020 Cash and cash equivalents $ 87,248 $ 79,865 Restricted cash 2,470 2,470 Total cash, cash equivalents and restricted cash as shown in the condensed $ 89,718 $ 82,335
Marketable Securities	Marketable Securities Marketable securities generally consist of U.S. Treasury securities, debt securities of U.S. government agencies and corporate entities and commercial paper. The objectives for holding investments are to invest the Company’s excess cash resources in investment vehicles that provide a better rate of return compared to an interest-bearing bank account with limited risk to the principal invested. Marketable securities with original maturities of greater than 90 days and remaining maturities of less than one year from the balance sheet date are classified as short-term marketable securities. Marketable securities with remaining maturities of greater than one year from the balance sheet date are classified as long-term marketable securities. All investments are classified as held-to-maturity marketable securities as the Company does not have intent to sell these securities and it is more likely than not the Company will not be required to sell such investments before recovery of their amortized cost basis. Held-to-maturity securities are stated at their amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion is included in interest income in the condensed consolidated statements of operations and comprehensive loss.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with the equity holders. There was no difference between net loss and comprehensive loss presented in the accompanying condensed consolidated financial statements for the three and nine months ended September 30, 2021 and 2020 .
Equity-Based Compensation	Equity-Based Compensation The Company accounts for equity awards, including grants of enterprise incentive shares, enterprise junior stock, stock options, restricted stock units and restricted common stock, in accordance with ASC 718, Compensation – Stock Compensation (“Topic 718”). Topic 718 requires all equity-based payments to employees, which includes grants of employee equity awards, to be recognized in the condensed consolidated statements of operations and comprehensive loss based on their grant date fair values. The Company estimates the grant date fair value of stock options using the Black-Scholes option pricing model. The fair value of restricted stock units is based on the fair value of the Company’s common stock on the grant date. The Company recognizes equity-based compensation expense for any non-employee awards consistent with equity awards issued to employees. As it relates to both employee and non-employee equity awards, the Company has elected to account for forfeitures as they occur. Subsequent to the IPO, the fair value of the Company’s common stock underlying its equity awards is based on the quoted market price of the Company’s common stock on the grant date. The Company estimates the fair value of stock options using the Black-Scholes option pricing model, which uses as inputs the fair value of the Company’s common stock, and certain management estimates, including the expected stock price volatility, the expected term of the award, the risk-free rate, and expected dividends. Expected volatility is calculated based on reported volatility data for a representative group of publicly traded companies for which historical information is available. The Company selects companies with comparable characteristics with historical share price information that approximates the expected term of the equity-based awards. The Company computes the historical volatility data using the daily closing prices for the selected companies’ shares during the equivalent period that approximates the calculated expected term of the stock options. The Company will continue to apply this method until a sufficient amount of historical information regarding the volatility of its stock price becomes available. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected term assumption. The Company uses the simplified method, under which the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data. The expected dividend yield is assumed to be zero as the Company has no current plans to pay any dividends on common stock. For awards granted in 2020 prior to the Company’s IPO, the Company used a probability-weighted expected returns method (“PWERM”) with four scenarios to value the common stock underlying the awards: an IPO, a delayed IPO, a sale of the Company and a remain private scenario. In the IPO and sale scenarios, the Company estimated an equity value based on the guideline public company method under a market approach. The guideline public companies consisted of biopharmaceutical companies with recently completed initial public offerings. For the remain private scenario, the Company back-solved to the price of a recently issued preferred security. The Company converted its estimated future value in each scenario to present value using a risk-adjusted discount rate. The relative probability of each scenario was determined based on an assessment of then-current market conditions. Where appropriate, the Company applied a discount for lack of marketability to the value indicated for the common stock. The valuation methodology used to value the common stock prior to the IPO included estimates and assumptions that required the Company’s judgment. Significant changes to the key assumptions used in the valuations could have resulted in different fair values of the Company’s common stock at each valuation date. For awards with service-based vesting conditions, the Company recognizes equity-based compensation expense on a straight-line basis over the vesting period. For awards subject to performance conditions, the Company recognizes equity-based compensation expense using an accelerated recognition method over the remaining service period when the Company determines the achievement of the performance condition is probable. The Company classifies equity-based compensation expense in its condensed consolidated statements of operations and comprehensive loss consistent with the classification of the award recipient’s compensation expense.
Leases	Leases Effective January 1, 2021, the Company adopted Topic 842 using the required modified retrospective approach and utilizing the effective date as its date of initial application. As a result, prior periods are presented in accordance with the previous guidance in ASC 840, Leases (“ASC 840”). The Company evaluates whether an arrangement is or contains a lease at the inception date. If determined to be or contain a lease, the Company determines the classification of the lease at the commencement date, which represents the date at which the lessor makes the underlying asset available for use by the Company. When determining the expected accounting lease term, the Company includes the noncancellable lease term, together with periods covered by (i) an option to extend the lease if the Company is reasonably certain to exercise such option, (ii) an option to terminate the lease if the Company is reasonably certain not to exercise such option and (iii) an option to extend or not terminate the lease where the exercise of such option is controlled by the lessor. The Company has elected the short-term lease exemption, which allows the Company to not recognize lease liabilities and right-of-use assets arising from lease arrangements with original lease terms of twelve months or less. The Company elected the practical expedient to not separate lease and non-lease components for its real estate leases. Right-of-use assets represent the Company’s right to use an underlying asset over the lease term and lease liabilities represent the Company’s obligation to make lease payments under the arrangement. The Company measures its lease liabilities as the present value of the lease payments, discounted using an incremental borrowing rate, as interest rates implicit in lease arrangements are generally not readily determinable. The Company measures its right-of-use assets as the present value of its lease payments at the commencement date, adjusted for prepaid rent payments and tenant incentives. The incremental borrowing rate represents the interest rate at which the Company could borrow an amount equal to the lease payments on a fully collateralized basis, over a similar term, in a similar economic environment. The Company recognizes rent expense for operating leases on a straight-line basis. The Company recognizes variable lease expenses as incurred. The Company remeasures right-of-use assets and lease liabilities when a lease is modified, and the modification is not accounted for as a separate contract. A modification is accounted for as a separate contract if the modification grants the Company an additional right of use not included in the original lease arrangement and the increase in lease payments is commensurate with the additional right of use. The Company assesses its right-of-use assets for impairment in a manner consistent with its assessment for long-lived assets held and used in operations.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the FASB Topic 842 was issued, which supersedes the existing guidance for lease accounting. The FASB has issued several updates to the standard which: (i) clarify how to apply certain aspects of the new standard; (ii) provide an additional transition method for adoption of the new standard; (iii) provide a practical expedient for certain lessor accounting; and (iv) amend certain narrow aspects of the guidance. Topic 842 requires the identification and classification of arrangements that are or contain a lease. In general, for lease arrangements exceeding a twelve-month term, these arrangements must be recognized as assets and liabilities on the balance sheet of the lessee. Under Topic 842, a right-of-use asset and lease obligation will be recorded for all leases, whether operating or financing, while the income statement will reflect lease expense for operating leases and amortization/interest expense for financing leases. The balance sheet amount recorded for existing leases at the date of adoption of Topic 842 is calculated using the applicable incremental borrowing rate at the date of adoption. Topic 842 is effective for the Company on January 1, 2022, with early adoption permitted. The Company elected to early adopt the new standard and used the modified retrospective approach effective January 1, 2021 as the initial date of application. The Company elected the available package of practical expedients which allowed the Company to not reassess previous accounting conclusions around whether arrangements are or contain leases, the classification of leases, and the treatment of initial direct costs. As a result of the adoption of Topic 842, the Company recorded (i) an operating lease liability of $ 8.9 million and (ii) an operating lease right-of-use asset of $ 7.5 million, net of the unamortized balance of deferred rent liability and tenant improvement allowances as of the transition date. There was no impact to the Company’s results of operations and cash flows from operations. A summary of the impact of the adoption is as follows (in thousands): December 31, 2020 Impact of Adoption January 1, 2021 Operating lease right-of-use asset $ — $ 7,478 $ 7,478 Accrued expenses and other current liabilities 27,104 ( 399 ) 26,705 Operating lease liability, current — 3,025 3,025 Deferred rent, noncurrent 1,027 ( 1,027 ) — Operating lease liability, noncurrent — 5,879 5,879

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Reconciles Cash, Cash equivalents and Restricted Cash	The following table reconciles cash, cash equivalents and restricted cash as of September 30, 2021 and 2020 to the condensed consolidated statements of cash flows (in thousands): September 30, 2021 2020 Cash and cash equivalents $ 87,248 $ 79,865 Restricted cash 2,470 2,470 Total cash, cash equivalents and restricted cash as shown in the condensed $ 89,718 $ 82,335
Summary of the impact of the adoption	A summary of the impact of the adoption is as follows (in thousands): December 31, 2020 Impact of Adoption January 1, 2021 Operating lease right-of-use asset $ — $ 7,478 $ 7,478 Accrued expenses and other current liabilities 27,104 ( 399 ) 26,705 Operating lease liability, current — 3,025 3,025 Deferred rent, noncurrent 1,027 ( 1,027 ) — Operating lease liability, noncurrent — 5,879 5,879

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets Measured at Fair Value on a Recurring Basis	The following tables present information about the Company’s assets that are measured or disclosed at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at the Reporting Date Using September 30, Quoted Prices Significant Significant Assets—Cash equivalents Repurchase agreement $ 25,000 $ — $ 25,000 $ — Money market funds 59,814 59,814 — — Assets—Short-term marketable securities U.S. Government agency securities 41,292 — 41,292 — U.S. Treasury securities 37,062 37,062 — — Commercial paper 299,517 — 299,517 — Corporate debt securities 47,607 — 47,607 — Assets—Long-term marketable securities U.S. Government agency securities 1,999 — 1,999 — U.S. Treasury securities 17,083 17,083 — — Total $ 529,374 $ 113,959 $ 415,415 $ — Fair Value Measurements at the Reporting Date Using December 31, Quoted Prices Significant Significant Assets—Cash equivalents Repurchase agreement $ 12,000 $ — $ 12,000 $ — Commercial paper 22,493 — 22,493 — Money market funds 227,987 227,987 — — Assets—Short-term marketable securities U.S. Government agency securities 55,469 — 55,469 — U.S. Treasury securities 38,294 38,294 — — Commercial paper 237,735 — 237,735 — Corporate debt securities 18,873 — 18,873 — Assets—Long-term marketable securities U.S. Government agency securities 7,049 — 7,049 — Corporate debt securities 5,492 — 5,492 — Total $ 625,392 $ 266,281 $ 359,111 $ —
Schedule of Assumptions Used to Determine the Fair Value of Warrants to Purchase Common Stock	The following assumptions were used to determine the fair value of the warrants to purchase common stock: July 1, 2020 Risk-free interest rate 0.31 % Expected term (in years) 5.0 Expected volatility 75.8 % Expected dividend yield 0.0 % Fair value per share of underlying common stock $ 46.37
Summary of Changes in Fair Value of the Level 3 Warrant Liability	The following table provides a summary of changes in fair value of the Level 3 warrant liability (in thousands): Warrant Balance at December 31, 2019 $ 364 Change in fair value 2,597 Net exercise of warrants to purchase common stock ( 2,961 ) Balance at September 30, 2020 $ -

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Investments Debt And Equity Securities [Abstract]
Held-to-maturity Securities	The Company’s investments by type consisted of the following (in thousands): September 30, 2021 Amortized Gross Gross Estimated Assets U.S. Government agency securities $ 43,284 $ 7 $ — $ 43,291 U.S. Treasury securities 54,144 7 ( 6 ) 54,145 Commercial paper 299,472 45 — 299,517 Corporate debt securities 47,621 — ( 14 ) 47,607 Total $ 444,521 $ 59 $ ( 20 ) $ 444,560 December 31, 2020 Amortized Gross Gross Estimated Assets U.S. Government agency securities $ 62,508 $ 10 $ — $ 62,518 U.S. Treasury securities 38,287 7 — 38,294 Commercial paper 237,733 18 ( 16 ) 237,735 Corporate debt securities 24,371 3 ( 9 ) 24,365 Total $ 362,899 $ 38 $ ( 25 ) $ 362,912

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, 2021 2020 Manufacturing and clinical prepaid expenses $ 3,187 $ 3,068 Other prepaid expenses 4,485 1,725 Other non-trade receivables 467 1,327 $ 8,139 $ 6,120

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2021 2020 Computer and office equipment $ 1,735 $ 2,253 Software 514 2,473 Lab equipment 3,599 4,560 Furniture and fixtures 840 377 Leasehold improvements 14,888 3,402 Construction in process 851 — 22,427 13,065 Less: Accumulated depreciation ( 7,686 ) ( 11,545 ) $ 14,741 $ 1,520

Leases (Table)

Leases (Table)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Component of Operating Lease Expenses	The components of operating lease expense were as follows (in thousands): Three Months Ended Nine Months Ended Operating lease cost $ 312 $ 1,112 Variable lease cost 255 738 $ 567 $ 1,850
Summary of Supplemental Cash Flow Information Related to Operating Lease	Supplemental cash flow information related to operating leases was as follows (in thousands): Three Months Ended Nine Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows related to operating leases $ 220 $ 1,258
Schedule of Future Minimum Payments Under Noncancelable Operating Leases	Future minimum lease payments under noncancellable leases as of September 30, 2021 were as follows (in thousands): Operating Leases 2021 (excluding the nine months ended September 30, 2021) $ 1,110 2022 4,843 2023 4,986 2024 4,222 2025 4,349 Thereafter 27,645 Total lease payments 47,155 Present value adjustment ( 15,854 ) Present value of operating lease liabilities $ 31,301

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables And Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, December 31, 2021 2020 Manufacturing and clinical accruals $ 12,922 $ 17,952 Employee compensation 6,898 6,834 Other research and development related accruals 1,567 338 Professional and consulting services 967 1,008 Other current liabilities 1,099 972 $ 23,453 $ 27,104

Restructuring Charges (Tables)

Restructuring Charges (Tables)	9 Months Ended
	Sep. 30, 2021
Restructuring And Related Activities [Abstract]
Restructuring and Related Costs	The following table summarizes the restructuring activity incurred during the nine months ended September 30, 2020 (in thousands): Accrued Balance at December 31, 2019 $ 325 Restructuring costs incurred 63 Termination benefits paid ( 388 ) Balance at September 30, 2020 $ —

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Stockholders Equity Note [Abstract]
Schedule of Reserved Common Stock for Warrants to Purchase Common Stock and Future Issuance	As of September 30, 2021, the Company had reserved for future issuance the following number of shares of common stock: Stock For exercise of stock options under the 2019 Stock Incentive Plan 3,898,584 For exercise of stock options under the 2020 Stock Option and Incentive Plan 2,262,682 For restricted stock units granted under the 2020 Stock Option and Incentive Plan 800,209 For future issuance under the 2020 Stock Option and Incentive Plan 2,381,767 For future issuance under the 2020 Employee Stock Purchase Plan 840,032 10,183,274

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-Based Compensation Expense	Equity-based compensation expense was as follows (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Research and development $ 2,747 $ 659 $ 6,756 $ 1,431 General and administrative 3,954 1,470 10,216 3,164 $ 6,701 $ 2,129 $ 16,972 $ 4,595 Enterprise junior stock — — — 365 Restricted common stock 54 181 230 217 Restricted stock units 2,848 29 6,496 29 Stock options 3,799 1,919 10,246 3,984 $ 6,701 $ 2,129 $ 16,972 $ 4,595
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity under the 2019 and 2020 Plans: Number Weighted Weighted Aggregate (in years) (in thousands) Outstanding as of December 31, 2020 4,941,537 $ 8.62 9.1 $ 130,802 Granted 1,363,220 34.92 Exercised ( 91,560 ) 5.14 Forfeited ( 51,931 ) 8.73 Outstanding as of September 30, 2021 6,161,266 $ 14.49 8.5 $ 72,281 Exercisable as of September 30, 2021 2,173,996 $ 8.08 8.1 $ 33,742 Vested and expected to vest as of September 30, 2021 6,161,266 $ 14.49 8.5 $ 72,281 The following table summarizes the Company’s restricted stock unit activity under the 2020 Plan: Number of Shares Weighted Unvested as of December 31, 2020 42,100 $ 42.26 Granted 772,760 $ 35.15 Vested ( 10,161 ) $ 44.29 Forfeited ( 4,490 ) $ 32.12 Unvested as of September 30, 2021 800,209 $ 35.42 The following table summarizes the Company’s restricted common stock activity under the 2012 Plan: Number of Shares Weighted Issued and unvested as of December 31, 2020 51,546 $ 7.44 Vested ( 27,635 ) $ 9.35 Forfeited ( 2,079 ) $ 14.88 Issued and unvested as of September 30, 2021 21,832 $ 4.25
Schedule of Assumptions to Estimate Fair Value of Stock Options, Presented on a Weighted Average Basis	The following assumptions were used in determining the fair value of stock options, presented on a weighted average basis: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Risk-free interest rate 0.98 % 0.36 % 0.96 % 1.09 % Expected term (in years) 6.1 5.9 6.0 6.0 Expected volatility 77.5 % 76.1 % 77.9 % 74.8 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 % Fair value per share of common stock $ 23.38 $ 40.82 $ 34.92 $ 10.13

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Weighted-Average Common Shares Outstanding used in Calculating Basic and Diluted Net Income Per Share	The following is a reconciliation of weighted-average common stock outstanding used in calculating basic net loss per share to weighted-average common stock outstanding used in calculating diluted net loss per share: Three Months Ended 2020 Weighted-average common stock outstanding, basic 41,088,261 Add: Effect of dilutive securities Warrants to purchase shares of common stock (as converted from 663 Weighted-average common stock outstanding, diluted 41,088,924
Summary of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) per Share	The following table sets forth the outstanding shares of common stock equivalents, presented based on amounts outstanding at each period end, which were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended Nine Months Ended 2021 2020 2021 2020 Stock options 6,161,266 4,947,106 6,161,266 4,947,106 Restricted common stock 21,832 66,073 21,832 66,073 Restricted stock units 800,209 18,200 800,209 18,200

Collaboration Agreements (Table

Collaboration Agreements (Tables)	9 Months Ended
	Sep. 30, 2021
Collaboration And License Agreements Disclosure [Abstract]
Summary of Contract Assets and Liabilities	The following table presents changes in the Company’s balances of contract liabilities (in thousands): Beginning Additions Deductions End of Nine months ended September 30, 2020 Deferred revenue $ 1,239 $ — $ 1,239 $ — Deferred revenue, noncurrent $ — $ — $ — $ —

Hit Discovery Divestiture (Tabl

Hit Discovery Divestiture (Tables)	9 Months Ended
	Sep. 30, 2021
Discontinued Operations And Disposal Groups [Abstract]
Schedule Of Fair Value Of The Consideration To Be Received Used In Calculating The Gain On Divestiture Table [Text Block]	The fair value of the total consideration received, as of the transaction date, used in calculating the gain on Hit Discovery divestiture is summarized as follows (in thousands): Fair Value Cash consideration: Cash due at closing $ 2,961 Installment Receivable 12,593 Non-cash consideration: Equity Consideration $ 10,000 Total fair value of consideration $ 25,554
Carrying Value of Assets and Liabilities included in Sale to Valo Health	The carrying value of the assets and liabilities included in the sale to Valo Health were as follows (in thousands): Carrying Assets: Prepaid expenses and other current assets $ 1,117 Property and equipment, net 2,398 Other assets 125 $ 3,640 Liabilities: Accounts payable $ 159 Deferred revenue 1,239 $ 1,398 Net assets sold $ 2,242

Organization and Nature of Bu_2

Organization and Nature of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 26, 2021	Dec. 15, 2020	Jun. 23, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Class Of Stock [Line Items]
Entity Incorporation, Date of Incorporation				Dec. 31, 2011
Issuance of common stock from initial public offering, net of issuance costs, Shares		795,000
Shares issued and sold, public offering price | $ / shares		$ 45.25
Proceeds from initial public offering of common stock, net of issuance costs		$ 258,600			$ 293,707
Aggregate Amount of Issuance and Offering Cost	$ 200,000
Preferred stock shares outstanding			0	0		0
Authorized capital stock			160,000,000
Common stock shares authorized				150,000,000		150,000,000
Preferred stock shares authorized			10,000,000	10,000,000		10,000,000
Preferred stock par value			$ 0.001	$ 0.001		$ 0.001
Gross proceeds from follow on public offering		$ 275,800
Cash, cash equivalents and marketable securities				$ 531,800
Sales Agent cash commissions	3.00%
Enterprise Junior Stock [Member]
Class Of Stock [Line Items]
Temporary equity shares issued			103,007
Common Stock
Class Of Stock [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares		6,095,000	2,082,352
Gross Proceeds From Initial Public Offering			$ 319,300
Proceeds from initial public offering of common stock, net of issuance costs			$ 293,300
Temporary equity shares outstanding			20,349,223
Common Stock | Enterprise Junior Stock [Member]
Class Of Stock [Line Items]
Temporary equity shares issued			2,124,845
Common Stock | Voting Common Stock [Member]
Class Of Stock [Line Items]
Common stock shares authorized			147,494,175
Common Stock | Non Voting Common Stock [Member]
Class Of Stock [Line Items]
Common stock shares authorized			2,505,825
Warrant
Class Of Stock [Line Items]
Number of warrants issued to purchase common stock | shares			70,133
Warrants exercise price, per share | $ / shares			$ 5.13
Warrant | Series B3 Preferred Stock [Member]
Class Of Stock [Line Items]
Number of warrants issued to purchase common stock | shares			299,999
Warrants exercise price, per share | $ / shares			$ 1.20
IPO [Member] | Common Stock
Class Of Stock [Line Items]
Issuance of common stock from initial public offering, net of issuance costs, Shares			15,964,704
Shares issued and sold, public offering price | $ / shares			$ 20

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)shares	Jan. 01, 2021USD ($)
Summary Of Significant Accounting Policies [Line Items]
Short-term, highly liquid investments with original maturities	90 days or less
Operating Lease, Liability	$ 31,301	$ 8,900
Operating lease right-of-use asset	$ 20,569	$ 7,478
Measurement Input, Expected Dividend Rate [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected dividend yield | shares	0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Reconciles Cash, Cash equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 87,248	$ 282,689	$ 79,865
Restricted cash	2,470		2,470
Total cash, cash equivalents and restricted cash as shown in the condensed consolidated statements of cash flows	$ 89,718	$ 285,159	$ 82,335	$ 173,796

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of the impact of the adoption (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jan. 01, 2021	Dec. 31, 2020
Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use asset	$ 20,569	$ 7,478
Accrued expenses and other current liabilities	23,453	26,705	$ 27,104
Operating lease liability	4,541	3,025
Deferred rent, noncurrent			$ 1,027
Operating lease liability, noncurrent	$ 26,760	5,879
Impact of Adoption [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating lease right-of-use asset		7,478
Accrued expenses and other current liabilities		(399)
Operating lease liability		3,025
Deferred rent, noncurrent		(1,027)
Operating lease liability, noncurrent		$ 5,879

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets, Fair Value Disclosure
Assets	$ 529,374	$ 625,392
Quoted Prices in Active Markets Using Identical Assets (Level 1)
Assets, Fair Value Disclosure
Assets	113,959	266,281
Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure
Assets	415,415	359,111
Repurchase agreements
Assets, Fair Value Disclosure
Assets	25,000	12,000
Repurchase agreements | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure
Assets	25,000	12,000
Money market funds
Assets, Fair Value Disclosure
Assets	59,814	227,987
Money market funds | Quoted Prices in Active Markets Using Identical Assets (Level 1)
Assets, Fair Value Disclosure
Assets	59,814	227,987
US Government Corporations and Agencies Securities | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	41,292	55,469
US Government Corporations and Agencies Securities | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets	1,999	7,049
US Government Corporations and Agencies Securities | Significant Other Observable Inputs (Level 2) | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	41,292	55,469
US Government Corporations and Agencies Securities | Significant Other Observable Inputs (Level 2) | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets	1,999	7,049
US Treasury Securities | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	37,062	38,294
US Treasury Securities | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets	17,083
US Treasury Securities | Quoted Prices in Active Markets Using Identical Assets (Level 1) | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	37,062	38,294
US Treasury Securities | Quoted Prices in Active Markets Using Identical Assets (Level 1) | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets	17,083
Commercial Paper
Assets, Fair Value Disclosure
Assets		22,493
Commercial Paper | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	299,517	237,735
Commercial Paper | Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure
Assets		22,493
Commercial Paper | Significant Other Observable Inputs (Level 2) | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	299,517	237,735
Corporate Debt Securities | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	47,607	18,873
Corporate Debt Securities | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets		5,492
Corporate Debt Securities | Significant Other Observable Inputs (Level 2) | Short Term Marketable Securities
Assets, Fair Value Disclosure
Assets	$ 47,607	18,873
Corporate Debt Securities | Significant Other Observable Inputs (Level 2) | Long Term Marketable Securities
Assets, Fair Value Disclosure
Assets		$ 5,492

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Additional Information (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)Warrant$ / sharesshares	Dec. 31, 2020USD ($)	Jun. 23, 2020$ / sharesshares
Warrant
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrant outstanding	0
Number of warrants issued to purchase common stock | shares			70,133
Warrants exercise price, per share | $ / shares | $ / shares			$ 5.13
Series B-3 Convertible Preferred Stock | Warrant
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of warrants issued to purchase common stock | shares	70,133
Warrants exercise price, per share | $ / shares | $ / shares	$ 5.13
IPO [Member] | Series B-3 Convertible Preferred Stock | Warrant
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of warrants to purchase | Warrant	3
Convertible preferred stock warrant purchased	299,999
Exercise price per share | $ / shares	$ 1.20
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers into out of Level 3 | $	$ 0	$ 0

Fair Value of Financial Asset_5

Fair Value of Financial Assets and Liabilities - Schedule of Assumptions Used to Determine the Fair Value of Warrants to Purchase Common Stock (Details)	Jul. 01, 2021	Jul. 01, 2020shares
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value per share of underlying common stock		46.37
Series B-3 Convertible Preferred Stock | Risk-free interest rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative liability, measurement input		0.31
Series B-3 Convertible Preferred Stock | Expected term (in years)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Expected term (in years)	5 years
Series B-3 Convertible Preferred Stock | Expected volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative liability, measurement input		75.8
Series B-3 Convertible Preferred Stock | Expected Dividend yield
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative liability, measurement input		0

Fair Value of Financial Asset_6

Fair Value of Financial Assets and Liabilities - Summary of Changes in Fair Value of the Level 3 Warrant Liability (Details) - Significant Unobservable Inputs (Level 3) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 364
Change in fair value	2,597
Ending Balance	0
Common Stock
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Net exercise of warrant to purchase shares	$ (2,961)

Marketable Securities - Held-to

Marketable Securities - Held-to-maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Amortized Cost	$ 444,521	$ 362,899
Gross Unrealized Gains	59	38
Gross Unrealized Losses	(20)	(25)
Estimated Fair Value	444,560	362,912
US Treasury Securities
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Amortized Cost	54,144	38,287
Gross Unrealized Gains	7	7
Gross Unrealized Losses	(6)
Estimated Fair Value	54,145	38,294
Commercial Paper
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Amortized Cost	299,472	237,733
Gross Unrealized Gains	45	18
Gross Unrealized Losses	0	(16)
Estimated Fair Value	299,517	237,735
US Government Debt Securities
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Amortized Cost	43,284	62,508
Gross Unrealized Gains	7	10
Gross Unrealized Losses	0
Estimated Fair Value	43,291	62,518
Corporate Debt Securities
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Amortized Cost	47,621	24,371
Gross Unrealized Gains	0	3
Gross Unrealized Losses	(14)	(9)
Estimated Fair Value	$ 47,607	$ 24,365

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Unrealized loss position with an aggregate fair value	$ 92.7	$ 93.7

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Manufacturing and clinical prepaid expenses	$ 3,187	$ 3,068
Other prepaid expenses	4,485	1,725
Other non-trade receivables	467	1,327
Prepaid and other current assets	$ 8,139	$ 6,120

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 22,427	$ 13,065
Less: Accumulated depreciation	(7,686)	(11,545)
Property and equipment, net	14,741	1,520
Computer and office equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,735	2,253
Software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	514	2,473
Lab equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,599	4,560
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	840	377
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	14,888	$ 3,402
Construction in process [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 851

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property Plant And Equipment [Abstract]
Depreciation and amortization	$ 300	$ 300	$ 672	$ 1,076

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Thousands	Jan. 01, 2018	May 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021
Lessee Lease Description [Line Items]
Operating lease right-of-use asset			$ 20,569		$ 20,569					$ 7,478
Other income (expense), gain on modification			(70)	$ (52)	215	$ (2,668)
Future minimum rental payments due			$ 47,155		$ 47,155
Weighted average remaining lease term			9 years 6 months		9 years 6 months
Weighted average incremental borrowing rate percent					8.70%
Operating Lease, Liability			$ 31,301		$ 31,301					$ 8,900
North Beacon Street Lease [Member]
Lessee Lease Description [Line Items]
Tenant Improvement Allowance					$ 10,000
Option to extend lease term					The Beacon Street Lease, which commenced in September 2021, is subject to base rent of $0.3 million per month, plus the Company's ratable share of taxes, maintenance and other operating expenses. Base rent is subject to a 3.0% annual increase over the 10-year lease term. In addition, the Beacon Street Lease provides an extension option for one additional five-year term at then-market rates and includes a tenant improvement allowance of $10.0 million.
Operating lease right-of-use asset			19,300		$ 19,300
Leasehold improvements in excess of tenant improvement allowance			1,600		1,600
Operating lease right-of-use asset , reduction					$ 300
Aggregate tenant improvements of the premises						$ 10,000
Lease agreement date					2020-09
Lessee operating lease discount rate				3.00%		3.00%
Operating Lease, Liability			29,300	$ 300	$ 29,300	$ 300
Letters of credit outstanding amount				$ 2,000		$ 2,000
Arsenal Street Lease [Member]
Lessee Lease Description [Line Items]
Tenant Improvement Allowance					500
Percentage of reduction in leased area		50.00%
Operating lease right-of-use asset , reduction		$ 2,600
Operating lease liability , reduction		2,900
Other income (expense), gain on modification		$ 300
Letters of credit outstanding amount			500		500
Branford, CT Lease [Member]
Lessee Lease Description [Line Items]
Tenant Improvement Allowance	$ 1,000
Lease Expiration Date	Dec. 31, 2023
Option to extend lease term	The lease terms provide for one five-year extension term with base rent calculated on a discounted then-market rate
Aggregate tenant improvements of the premises, unused	$ 100
Operating Leases, Rent Expense			200		600
Sublease Income			$ 200		$ 600
Forecast | Branford, CT Lease [Member]
Lessee Lease Description [Line Items]
Future minimum rental payments due							$ 800	$ 800	$ 200

Leases - Components of Lease Co

Leases - Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Leases [Abstract]
Operating lease cost	$ 312	$ 1,112
Variable lease cost	255	738
Lease cost	$ 567	$ 1,850

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information Related to Operating Lease (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows related to operating leases	$ 220	$ 1,258

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments Under Noncancelable Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jan. 01, 2021
Leases [Abstract]
2021 (excluding the nine months ended September 30, 2021)	$ 1,110
2022	4,843
2023	4,986
2024	4,222
2025	4,349
Thereafter	27,645
Total lease payments	47,155
Present value adjustment	(15,854)
Present value of operating lease liabilities	$ 31,301	$ 8,900

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Manufacturing and clinical accruals	$ 12,922	$ 17,952
Employee compensation	6,898	6,834
Other research and development related accruals	1,567	338
Professional and consulting services	967	1,008
Other current liabilities	1,099	972
Accrued Expenses And Other Liabilities Current Net	$ 23,453	$ 27,104

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Cost for guarantees and indemnities	$ 0	$ 0

Restructuring Charges - Additio

Restructuring Charges - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2019	Sep. 30, 2021	Sep. 30, 2020
Restructuring And Related Activities [Abstract]
Percentage of reduction in head count for cost reduction	40.00%
Restructuring charges	$ 5,400		$ 63
Restructuring Charges, Description		There were no restructuring activities during the nine months ended September 30, 2021

Restructuring Charges - Summary

Restructuring Charges - Summary of the Restructuring Activity (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jan. 31, 2019	Sep. 30, 2020
Restructuring And Related Activities [Abstract]
Balance at December 31, 2019		$ 325
Restructuring costs incurred	$ 5,400	63
Termination benefits paid		$ (388)

Redeemable Convertible and Co_2

Redeemable Convertible and Convertible Preferred Stock - Additional Information (Details) - shares	Sep. 30, 2021	Dec. 31, 2020	Jun. 23, 2020
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0	0
Conversion of redeemable convertible and convertible preferred stock into common stock			20,349,223
Preferred stock shares authorized	10,000,000	10,000,000	10,000,000
Series B-3 Convertible Preferred Stock
Preferred stock shares issued			86,062,799
Preferred stock shares outstanding			86,062,799
Redeemable Convertible Preferred Stock
Preferred stock shares issued			86,062,799
Preferred stock shares outstanding			86,062,799

Stockholder's Equity - Schedule

Stockholder's Equity - Schedule of Reserved Common Stock for Warrants to Purchase Common Stock and Future Issuance (Details)	Sep. 30, 2021shares
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	10,183,274
2019 Stock Incentive Plan Exercised [Member]
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	3,898,584
2020 Stock Option and Incentive Plan Exercised [Member]
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	2,262,682
2020 Stock Option and Incentive Plan Restricted [Member]
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	800,209
2020 Stock Option and Incentive Plan Future Issuance [Member]
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	2,381,767
2020 Employee Stock Option Purchase Plan Future Issuance [Member]
Schedule Of Capitalization [Line Items]
Common Stock, Capital Stock Reserved for Future Issuance	840,032

Equity-Based Compensation - Add

Equity-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares outstanding	47,378,041		47,378,041		47,248,685
Aggregate Intrinsic Value, Exercisable	$ 33,742		$ 33,742
Equity based compensation expense	6,701	$ 2,129	$ 16,972	$ 4,595
Weighted Average Remaining Contractual Term, Outstanding			8 years 6 months		9 years 1 month 6 days
Number of Shares, Granted			1,363,220
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value			$ 35.15	$ 44.02
Equity based compensation expense			$ 22,200
Weighted Average Remaining Contractual Term, Outstanding			2 years 10 months 24 days
Number of Shares, Granted			772,760
Aggregate fair value of restricted common stock vested			$ 500
Restricted Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense			$ 100
Weighted Average Remaining Contractual Term, Outstanding			1 year
Aggregate fair value of restricted common stock vested			$ 300	$ 200
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value			$ 23.45	$ 6.62
Aggregate Intrinsic Value, Exercisable	$ 2,800		$ 2,800
Equity based compensation expense			$ 42,700
Weighted Average Remaining Contractual Term, Outstanding			2 years 7 months 6 days
2020 Stock Option And Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares outstanding	1,892,009		1,892,009
Annual increase common stock issuance			2,381,767
2020 Employee stock purchase plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares outstanding	840,032		840,032
Annual increase common stock issuance			472,487
Shares issued under ESPP			0

Equity-Based Compensation - Sum

Equity-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	$ 6,701	$ 2,129	$ 16,972	$ 4,595
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	2,747	659	6,756	1,431
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	3,954	1,470	10,216	3,164
Enterprise Junior Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense		0		365
Restricted Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	54	181	230	217
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	2,848	29	6,496	29
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity based compensation expense	$ 3,799	$ 1,919	$ 10,246	$ 3,984

Equity-Based Compensation - S_2

Equity-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding beginning balance | shares	4,941,537
Number of Shares, Granted | shares	1,363,220
Number of Shares, Exercised | shares	(91,560)
Number of Shares, Forfeited | shares	(51,931)
Number of Shares, Outstanding ending balance | shares	6,161,266	4,941,537
Number of Shares, Exercisable | shares	2,173,996
Number of Shares, Vested and expected to vest | shares	6,161,266
Weighted Average Exercise Price Per share, Outstanding beginning balance | $ / shares	$ 8.62
Weighted Average Exercise Price Per share, Granted | $ / shares	34.92
Weighted Average Exercise Price Per share, Exercised | $ / shares	5.14
Weighted Average Exercise Price Per share, Forfeited | $ / shares	8.73
Weighted Average Exercise Price Per share, Outstanding ending balance | $ / shares	14.49	$ 8.62
Weighted Average Exercise Price Per share, Exercisable | $ / shares	8.08
Weighted Average Exercise Price Per share, Vested and expected to vest | $ / shares	$ 14.49
Weighted Average Remaining Contractual Term, Outstanding	8 years 6 months	9 years 1 month 6 days
Weighted Average Remaining Contractual Term, Outstanding	8 years 6 months
Weighted Average Remaining Contractual Term, Exercisable	8 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding | $	$ 72,281	$ 130,802
Aggregate Intrinsic Value, Exercisable | $	33,742
Aggregate Intrinsic Value, Vested and expected to vest | $	$ 72,281

Equity-Based Compensation - Sch

Equity-Based Compensation - Schedule of Assumptions to Estimate Fair Value of Stock Options, Presented on a Weighted Average Basis (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.98%	0.36%	0.96%	1.09%
Expected term (in years)	6 years 1 month 6 days	5 years 10 months 24 days	6 years	6 years
Expected volatility	77.50%	76.10%	77.90%	74.80%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Fair value per share of common stock	$ 23.38	$ 40.82	$ 34.92	$ 10.13

Equity-Based Compensation - S_3

Equity-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted	1,363,220
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning balance	42,100
Number of Shares, Granted	772,760
Number of Shares, Vested	(10,161)
Number of Shares, Forfeited	(4,490)
Number of Shares, Ending balance	800,209
Weighted Average Grant Date Fair Value, Beginning period	$ 42.26
Weighted-average grant date fair value	35.15	$ 44.02
Weighted average fair value of options vested (in dollars per share)	44.29
Weighted average fair value of options forfeited (in dollars per share)	32.12
Weighted Average Grant Date Fair Value, Ending period	$ 35.42

Equity-Based Compensation - S_4

Equity-Based Compensation - Summary of Restricted Common Stock Activity (Details) - Restricted Common Stock [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning balance | shares	51,546
Number of Shares, Vested | shares	(27,635)
Number of Shares, Forfeited | shares	(2,079)
Number of Shares, Ending balance | shares	21,832
Weighted Average Grant Date Fair Value, Beginning period | $ / shares	$ 7.44
Weighted Average Grant Date Fair Value, Vested | $ / shares	9.35
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	14.88
Weighted Average Grant Date Fair Value, Ending period | $ / shares	$ 4.25

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Weighted-Average Common Shares Outstanding used in Calculating Basic and Diluted Net Income Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock outstanding, basic	47,365,704	41,088,261	47,333,652	16,616,143
Add: Effect of dilutive securities
Weighted-average common stock outstanding, diluted	47,365,704	41,088,924	47,333,652	16,616,143
Warrants to Purchase Series B3 Preferred Shares [Member]
Add: Effect of dilutive securities
Warrants to purchase shares of common stock (as converted from warrants to purchase Series B-3 Preferred Stock in connection with the closing of the IPO)		663

Net Loss per Share - Summary of

Net Loss per Share - Summary of Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	6,161,266	4,947,106	6,161,266	4,947,106
Restricted Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	21,832	66,073	21,832	66,073
Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	800,209	18,200	800,209	18,200

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	Mar. 27, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Line Items]
Income tax expense (benefit)		$ 7	$ (3,806)	$ 123	$ (26,529)
Federal tax anticipated refund				$ 29,600	$ 16,600
Cares Act [Member]
Income Tax Disclosure [Line Items]
Percentage of removal on taxable income On non operating losses	80.00%

Collaboration Agreements - Addi

Collaboration Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Nov. 30, 2010	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue		$ 0	$ 0
Contract asset balances		$ 0	$ 0
Other Collaboration Agreements | Stock Option [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contract term	10 years
Deferred revenue				$ 1,200

Collaboration Agreements - Summ

Collaboration Agreements - Summary of Contract Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Collaboration And License Agreements Disclosure [Abstract]
Deferred revenue, Beginning of Period	$ 1,239
Deferred revenue, Deductions	$ 1,239

Hit Discovery Divestiture - Add

Hit Discovery Divestiture - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net proceeds from Hit Discovery divestiture			$ 17,500
Installment receivable	$ 12,593		12,593
Prepaid of reimbursement expense	500		500
Equity consideration	10,000		10,000
Research and development	30,684	$ 24,780	88,614	$ 68,501
Impairment to equity consideration			$ 0		$ 0
Fair Value Discount Rate
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Discount Rate Percent			19.00%
Hit Discovery Divestiture [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Fair value of equity consideration	10,000		$ 10,000
Gain on hit discovery divestiture				23,300
Interest income		$ 700		$ 1,500
Number of Shares, Vested				23,317
Number of stock options vested, held by terminated employees				18,818
Number of stock options, modified				19,981
Stock options, modification terms				the Company modified 19,981 stock options to increase the exercise period from 90 days to one year from the date of termination for certain employees terminated in relation to the transaction.
Research and development				$ 500
Valo Health [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash received			2,500
Installment receivable	15,000		15,000
Valo Health [Member] | Hit Discovery Divestiture [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain on hit discovery divestiture			0
Preferred shares in Valo Health	$ 10,000		10,000
Fair value of the equity interest received			$ 10,000

Hit Discovery Divestiture - Sch

Hit Discovery Divestiture - Schedule of Fair Value of Total Consideration to be Received Used in Calculating the Gain on Hit Discovery Divestiture (Details) $ in Thousands	Sep. 30, 2021USD ($)
Fair Value Cash consideration:
Fair Value Cash due at closing	$ 2,961
Fair Value Installment Receivable	12,593
Fair Value Non-cash consideration:
Fair Value Equity Consideration	10,000
Total fair value of consideration	$ 25,554

Hit Discovery Divestiture - Car

Hit Discovery Divestiture - Carrying Value of Assets and Liabilities included in Sale to Value Health (Details) $ in Thousands	Sep. 30, 2021USD ($)
Assets:
Prepaid expenses and other current assets	$ 1,117
Property and equipment, net	2,398
Other assets	125
Disposal Group, Including Discontinued Operation, Assets	3,640
Liabilities:
Accounts payable	159
Deferred revenue	1,239
Disposal Group, Including Discontinued Operation, Liabilities	1,398
Net assets sold	$ 2,242