Relay Therapeutics (RLAY) 10-K 23 Feb 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2022	Feb. 17, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Registrant Name	RELAY THERAPEUTICS, INC.
Entity Central Index Key	0001812364
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 1.8
ICFR Auditor Attestation Flag	true
Entity Common Stock, Shares Outstanding		121,384,719
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	RLAY
Security Exchange Name	NASDAQ
Entity File Number	001-39385
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-3923475
Entity Address, Address Line One	399 Binney Street
Entity Address, Address Line Two	2nd Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	370-8837
Document Annual Report	true
Document Transition Report	false
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE The Registrant intends to file a definitive proxy statement pursuant to Regulation 14A relating to the 2023 Annual Meeting of Stockholders within 120 days of the end of the registrant’s fiscal year ended December 31, 2022 . Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.
Auditor Firm ID	42
Auditor Name	Ernst & Young
Auditor Location	Boston, Massachusetts

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 151,794	$ 280,119
Investments	847,123	677,954
Accounts receivable	306	403
Contract asset	4,913	4,537
Prepaid expenses	12,110	11,465
Other current assets	3,259	1,764
Total current assets	1,019,505	976,242
Property and equipment, net	11,634	6,543
Operating lease assets	63,754	20,780
Restricted cash	2,578	2,578
Intangible asset	2,300	2,300
Total assets	1,099,771	1,008,443
Current liabilities:
Accounts payable	10,578	8,276
Accrued expenses	22,703	13,557
Operating lease liabilities	4,276	1,844
Deferred revenue		248
Other current liabilities	26,152	396
Total current liabilities	63,709	24,321
Operating lease liabilities, net of current portion	53,466	21,056
Contingent consideration liability	32,378	50,258
Other liabilities		15,000
Total liabilities	149,553	110,635
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 and 150,000,000 shares authorized at December 31, 2022 and December 31, 2021, respectively; 121,112,234 and 108,210,318 shares issued and outstanding at December 31, 2022 and December31, 2021, respectively	121	109
Additional paid-in capital	2,019,126	1,666,887
Accumulated other comprehensive loss	(10,420)	(1,088)
Accumulated deficit	(1,058,609)	(768,100)
Total stockholders' equity	950,218	897,808
Total liabilities and stockholders' equity	$ 1,099,771	$ 1,008,443

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Common stock par value	$ 0.001	$ 0.001
Common stock shares authorized	300,000,000	150,000,000
Common stock shares issued	121,112,234	108,210,318
Common stock shares outstanding	121,112,234	108,210,318
Undesignated Preferred Stock [Member]
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

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue:
License and other revenue	$ 1,381	$ 3,029	$ 82,654
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember	us-gaap:LicenseAndServiceMember
Total revenue	$ 1,381	$ 3,029	$ 82,654
Operating expenses:
Research and development expenses	246,355	172,650	99,862
In-process research and development expenses		123,000
Loss on initial consolidation of variable interest entity		11,855
Change in fair value of contingent consideration liability	(11,677)	2,836
General and administrative expenses	65,978	57,386	38,588
Total operating expenses	300,656	367,727	138,450
Loss from operations	(299,275)	(364,698)	(55,796)
Other income:
Interest income	8,786	830	3,400
Other income (expense)	(20)	(4)	(16)
Total other income, net	8,766	826	3,384
Net loss	(290,509)	(363,872)	(52,412)
Dividend upon extinguishment of Series C Preferred Stock (Note 9)	0		(177,789)
Net loss attributable to common stockholders	$ (290,509)	$ (363,872)	$ (230,201)
Net loss attributable to common stockholders per share, basic	$ (2.59)	$ (3.82)	$ (5.40)
Net loss attributable to common stockholders per share, diluted	$ (2.59)	$ (3.82)	$ (5.40)
Weighted average shares of common stock, basic	112,233,649	95,136,719	42,619,582
Weighted average shares of common stock, diluted	112,233,649	95,136,719	42,619,582
Other comprehensive loss:
Unrealized holding loss	$ (9,332)	$ (1,152)	$ (261)
Total other comprehensive loss	(9,332)	(1,152)	(261)
Total comprehensive loss	$ (299,841)	$ (365,024)	$ (52,673)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Preferred Stock [Member] Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2019	$ (180,438)	$ 537,781	$ 4	$ 8,715	$ 325	$ (189,482)
Beginning balance, shares at Dec. 31, 2019		212,642,857	4,037,476
Extinguisment upon modification of Series C Preferred Stock (Note 9)	(177,789)	$ 177,789		(15,455)	(162,334)
Conversion of convertible preferred stock into common stock upon initial public offering	715,570	$ (715,570)	$ 62	715,508
Conversion of convertible preferred stock into common stock upon initial public offering, shares		(212,642,857)	61,992,534
Issuance of common stock in initial public offering/follow-on offering, net	425,293		$ 23	425,270
Issuance of common stock in initial public offering/follow-on offering, net, Shares			23,000,000
Issuance of common stock upon exercise of stock options	1,216			1,216
Issuance of common stock upon exercise of stock options, shares			297,000
Vesting of restricted common stock	154		$ 1	153
Vesting of restricted common stock ,shares			579,825
Stock-based compensation expense	31,960			31,960
Unrealized loss on investments	(261)				(261)
Net loss	(52,412)					(52,412)
Ending balance at Dec. 31, 2020	763,293		$ 90	1,167,367	64	(404,228)
Ending balance, shares at Dec. 31, 2020			89,906,835
Extinguisment upon modification of Series C Preferred Stock (Note 9)
Issuance of common stock in follow-on offering, net, shares			15,188,679
Issuance of common stock upon exercise of stock options	4,739		$ 1	4,738
Issuance of common stock upon exercise of stock options, shares			996,536
Shares issued in connection with acquisition of ZebiAI	62,992		$ 2	62,990
Shares issued in connection with acquisition, shares			1,914,219
Issuance of common stock in follow-on offering, net	382,210		$ 15	382,195
Purchase of common stock under ESPP	1,141		$ 1	1,140
Purchase of common stock under ESPP, shares			43,685
Vesting of restricted common stock	3			3
Vesting of restricted common stock ,shares			84,489
Vesting of restricted stock units, Shares			75,875
Stock-based compensation expense	48,454			48,454
Unrealized loss on investments	(1,152)				(1,152)
Net loss	(363,872)					(363,872)
Ending balance at Dec. 31, 2021	897,808		$ 109	1,666,887	(1,088)	(768,100)
Ending balance, shares at Dec. 31, 2021			108,210,318
Extinguisment upon modification of Series C Preferred Stock (Note 9)	0
Issuance of common stock in follow-on offering, net, shares			11,320,755
Issuance of common stock upon exercise of stock options	3,480		$ 1	3,479
Issuance of common stock upon exercise of stock options, shares			757,873
Issuance of common stock upon milestone achievement	6,203			6,203
Issuance of common stock upon milestone achievement,shares			301,939
Issuance of common stock in follow-on offering, net	284,744		$ 11	284,733
Purchase of common stock under ESPP	1,686			1,686
Purchase of common stock under ESPP, shares			123,019
Vesting of restricted stock units, Shares			398,330
Stock-based compensation expense	56,138			56,138
Unrealized loss on investments	(9,332)				(9,332)
Net loss	(290,509)					(290,509)
Ending balance at Dec. 31, 2022	$ 950,218		$ 121	$ 2,019,126	$ (10,420)	$ (1,058,609)
Ending balance, shares at Dec. 31, 2022			121,112,234

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (290,509)	$ (363,872)	$ (52,412)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	56,138	48,454	31,960
Depreciation expense	4,130	3,925	3,549
Net amortization of premiums and discounts on investments	1,182	2,052	(416)
Acquired in-process research and development		123,000
Loss on initial consolidation of variable interest entity		11,855
Change in fair value of contingent consideration liability	(11,677)	2,836
Changes in assets and liabilities:
Accounts receivable	97	74,677	(75,000)
Contract asset	(376)	3,117	(7,654)
Prepaid expenses and other current assets	(2,140)	(2,681)	(4,665)
Operating lease assets and liabilities, net	(8,132)	277	571
Other assets		22	(22)
Accounts payable	1,989	930	(410)
Accrued expenses and other liabilities	20,056	21,002	2,010
Deferred revenue	(248)
Net cash used in operating activities	(229,490)	(74,406)	(102,489)
Cash flows from investing activities:
Purchases of property and equipment	(9,062)	(3,471)	(1,931)
Purchases of investments	(535,419)	(980,665)	(266,455)
Proceeds from maturities of investments	355,736	529,923	350,058
Cash paid for acquisition of ZebiAI, net of cash acquired		(25,298)
Net cash (used in) provided by investing activities	(188,745)	(479,511)	81,672
Cash flows from financing activities:
Proceeds from issuance of common stock in initial public offering, net			425,293
Proceeds from issuance of common stock in follow-on offering, net	284,744	382,210
Proceeds from issuance of common stock upon exercise of stock options	3,480	4,739	1,216
Proceeds from issuance of common stock under ESPP	1,686	1,141
Net cash provided by financing activities	289,910	388,090	426,509
Net (decrease) increase in cash, cash equivalents, and restricted cash	(128,325)	(165,827)	405,692
Cash, cash equivalents and restricted cash at beginning of period	282,697	448,524	42,832
Cash, cash equivalents and restricted cash at end of period	154,372	282,697	448,524
Supplemental disclosure of non-cash activities:
Extinguisment upon modification of Series C Preferred Stock (Note 9)	0		(177,789)
Conversion of preferred stock into common stock upon initial public offering			715,508
Additions of property and equipment in accounts payable and accrued expenses	159	1,010	519
Reclassification of restricted stock liability to additional paid-in capital		3	153
Assets obtained in asset acquisition of ZebiAI		662
Liabilities assumed in asset acquisition of ZebiAI		2,330
Fair value of common stock issued in asset acquisition of ZebiAI		$ 62,990
Issuance of common stock upon milestone achievement	6,203
Operating lease assets obtained in exchange for operating lease liabilities	$ 46,626		$ 819

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Restricted Cash And Cash Equivalents At Carrying Value [Abstract]
Cash and cash equivalents	$ 151,794	$ 280,119	$ 447,646
Restricted cash	2,578	2,578	878
Cash, cash equivalents, and restricted cash per statements of cash flows	$ 154,372	$ 282,697	$ 448,524

Nature of Business and Basis of

Nature of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2022
Text Block [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Relay Therapeutics, Inc. (the “Company”) was incorporated in Delaware on May 4, 2015 and is headquartered in Cambridge, Massachusetts. The Company is a clinical-stage, precision medicine company transforming the drug discovery process by combining leading-edge computational and experimental technologies with the goal of bringing life-changing therapies to patients. As the Company believes it is among the first of a new breed of biotech created at the intersection of complementary techniques and technologies, the Company aims to push the boundaries of what’s possible in drug discovery. The Company’s Dynamo™ platform integrates an array of leading-edge computational and experimental approaches designed to drug protein targets that have previously been intractable or inadequately addressed . The Company’s initial focus is on enhancing small molecule therapeutic discovery in targeted oncology and genetic disease indications. The Company’s lead product candidates, RLY-4008, RLY-2608, and GDC-1971 (formerly known as RLY-1971), are in clinical development. In addition, the Company has three discovery stage programs as part of its HR+/HER2- breast cancer franchise, including a selective cyclin dependent kinase 2 inhibitor, a rationally designed estrogen receptor alpha degrader and a selective and chemically distinct pan-mutant PI3Kα inhibitor, RLY-5836. The Company also has five additional discovery stage programs across both precision oncology and genetic disease indications. The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, new technological innovations, protection of proprietary technology, dependence on key personnel, compliance with government regulations, and the need to obtain additional financing. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure, and extensive compliance-reporting capabilities. The Company’s product candidates are in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval, or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees and consultants. The Company has devoted substantially all of its resources to developing its product candidates, including RLY-4008, RLY-2608, and GDC-1971 (formerly known as RLY-1971), by developing its computation and experimental approaches, building its intellectual property portfolio, business planning, raising capital and providing general and administrative support for these operations. The Company has incurred net operating losses since inception and had an accumulated deficit of $ 1.1 billion as of December 31, 2022. The Company expects that its existing cash, cash equivalents, and investments as of December 31, 2022 will enable it to fund its planned operating expenses and capital expenditure requirements for at least one year from the date of the issuance of these consolidated financial statements. The future viability of the Company is dependent on its ability to generate cash from operating activities or to raise additional capital to finance its operations. The Company’s failure to raise capital as and when needed could have a material adverse effect on its financial condition and ability to pursue its business strategies. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into license or collaboration arrangements or obtain government grants. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce, or eliminate its research and development programs, product portfolio expansion, or commercialization efforts, which could adversely affect its business prospects. In the event the Company requires additional funding, there can be no assurance that it will be successful in obtaining sufficient funding on terms acceptable to the Company to fund its continuing operations, if at all.

Significant Accounting Policie

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for reporting on Form 10-K. The Company’s consolidated financial statements include the accounts of Relay Therapeutics, Inc. and its wholly-owned subsidiaries, Relay Securities Corporation and Relay ML Discovery, LLC. All intercompany balances and transactions have been eliminated. Certain prior period amounts, limited to (a) prepaid expenses and other current assets and (b) accrued expenses and other current liabilities, have been reclassified to conform to current period presentation. Such reclassifications have no impact on the Company’s consolidated statements of operations and comprehensive loss, as previously reported. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the fair value of contingent milestone payments in connection with the acquisition of ZebiAI Therapeutics, Inc. (“ZebiAI”), the determination of the transaction price and standalone selling price of performance obligations under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers ("ASC 606"), the accrual of research and development and manufacturing expenses, the valuation of equity instruments, and the incremental borrowing rate for determining operating lease assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Segment Information The Company manages its operations as a single segment for purposes of assessing performance and making operating decisions. The Company’s singular focus is on using innovative experimental and computational approaches on protein motion for making medicines to drug protein targets that have previously been intractable or inadequately addressed. The Company operates in the United States and all tangible assets are held in the United States. Cash Equivalents The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents. Cash equivalents, which consist of money market funds, are stated at fair value. Restricted Cash The Company had restricted cash of $ 2.6 million as of December 31, 2022 and 2021, specifically to secure letters of credit in connection with operating leases of the Company’s facilities, as detailed in Note 13, Leases . The Company classified the restricted cash as a noncurrent asset on its consolidated balance sheets, consistent with the terms of the lease agreements. Investments Investments in marketable securities are classified as available-for-sale. Available-for-sale securities are measured and reported at fair value using quoted prices in active markets for similar securities. Premiums or discounts from par value are amortized to investment income over the life of the underlying investment. In June 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). Certain amendments thereto were also issued by the FASB. The Company adopted ASU 2016-13, as well as the related amendments thereto, on January 1, 2022, pursuant to which the Company reviews investments whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. In connection therewith, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors, considering the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security is compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded on the consolidated balance sheet, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that is not related to credit is recognized in other comprehensive loss as a separate component of stockholders' equity. Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense in general and administrative expenses within the consolidated statements of operations and comprehensive loss. Losses are charged against the allowance when the Company believes the uncollectability of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. All of the Company’s available-for-sale securities are available to the Company for use in current operations. As a result, the Company classified all such securities as current assets as of December 31, 2022 and 2021, even though the stated maturity of some individual securities may be one year or more beyond the balance sheet dates. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in other income (expense) within the consolidated statements of operations and comprehensive loss. Concentration of Credit Risk and Significant Suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents, and investments. From time to time, the Company has maintained all of its cash, cash equivalents, and investments at certain accredited financial institutions in amounts that exceed federally insured limits. The Company generally invests its excess capital in money market funds, U.S. treasury bonds, U.S. treasury bills, and agency bonds, all of which are subject to minimal credit and market risk. Management has established guidelines relative to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. The investment portfolio is maintained in accordance with the Company’s investment policy, which defines allowable investments, specifies credit quality standards, and limits the credit exposure of any single issuer. The Company is dependent on third-party suppliers for research and development activities of its programs, including preclinical and clinical testing. In particular, the Company relies and expects to continue to rely on a small number of these suppliers, including D. E. Shaw Research, LLC, as discussed in Note 12, Commitments and Contingencies , to meet its requirements for its programs. These programs could be adversely affected by a significant interruption in preclinical and clinical testing, as well as the supply of active pharmaceutical ingredients and formulated drugs. Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies, and similar techniques. Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the useful life of the asset. Laboratory and computer equipment are depreciated over three years . Furniture and fixtures are depreciated over five years . Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the underlying asset. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations. Impairment of Long-Lived Assets The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured in an amount by which the book values of the assets exceed their fair value. The Company did no t recognize any impairment losses for the years ended December 31, 2022, 2021, and 2020 . Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include salaries, stock-based compensation and benefits of employees, third-party license fees, and other operational costs related to the Company’s research and development activities, including allocated facility-related expenses and external costs of outside vendors engaged to conduct both preclinical studies and clinical trials. Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. Stock-Based Compensation The Company measures stock options and other stock-based awards granted to employees, directors, and other consultants based on their fair value on the date of grant and recognizes compensation expense for such awards over the requisite service period, which is generally the vesting period of the respective award. The Company recognizes the impact of forfeitures on stock-based compensation expense as they occur. The Company estimates the fair value of each stock option grant on the date of grant using the Black-Scholes option pricing model, which uses as inputs the fair value of the Company’s common stock and assumptions the Company makes for the expected term of the stock options, the risk-free interest rate and volatility of its common stock for a period that approximates the expected term of the stock options, and the expected dividend yield. Prior to the Company’s initial public offering of common stock in 2020, the estimated fair value of its common stock was determined by the board of directors, or compensation committee thereof, as of the date of each option grant, with input from management, considering the most recently available third-party valuations of common stock and the board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent valuation through the date of the grant. Historically, such independent third-party valuations of the Company’s equity instruments were performed contemporaneously with identified value inflection points. Furthermore, such third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation (the “Practice Aid”). The Practice Aid identifies various available methods for allocating the enterprise value across classes of series of capital stock in determining the fair value of the Company’s common stock at each valuation date. Following the Company’s initial public offering of common stock in 2020 , in connection with the accounting for stock options and other awards the Company may grant, the fair value of the Company’s common stock is determined based on the quoted market price of its common stock. Revenue Recognition The Company accounts for revenue recognition in accordance with ASC 606, pursuant to which an entity recognizes revenue when its customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with customer(s); (ii) identify the performance obligation(s) in the contract(s); (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligation(s) in the contract(s); and (v) recognize revenue when (or as) the entity satisfies a performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract and determines those that are performance obligations. The Company then determines the transaction price and allocates it to the performance obligations. As part of the accounting for such arrangements, the Company must use judgment to determine: (a) the number of performance obligations based on the determination under step (ii) above; (b) the transaction price under step (iii) above, including the determination of whether milestones or other variable consideration should be included in the transaction price; and (c) the stand-alone selling price for each performance obligation identified in the contract for the allocation of the transaction price in step (iv) above. The Company utilizes key assumptions and judgments in (a) determining the stand-alone selling price for each performance obligation, which may include discounted cash flow models, evaluation of comparable transactions, and pricing considered in negotiating the transaction and estimated costs, and (b) determining how the transaction price is allocated amongst the performance obligations. The Company also uses judgment to determine whether milestones or other variable consideration should be included in the transaction price. As part of management’s evaluation of the transaction price, the Company considers numerous factors, including whether the achievement of the milestones is outside of the Company's control, contingent upon the efforts of others, or subject to scientific risks of success. If the Company concludes it is probable that a significant revenue reversal would not occur, the associated milestone payment is included in the transaction price. Milestone payments that are not within the Company's control, such as regulatory approvals, are generally not considered probable until those milestones are achieved. The Company re-evaluates the transaction price, including estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. For revenue-based royalties, including milestone payments based on the level of sales, the Company will include royalties in the transaction price at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty is allocated has been satisfied (or partially satisfied). Once the performance obligations are identified, the transaction price is allocated to each performance obligation based on the relative stand-alone selling price. The Company then recognizes as revenue the amount of the transaction price allocated to the respective performance obligation when (or as) it is satisfied, either at a point in time or over time. If the performance obligation is satisfied over time, the Company recognizes revenue based on the use of either an output or input method. Collaboration Agreements The Company enters into collaborative agreements with third parties to research, develop, and commercialize drug candidates, pursuant to which the risks and rewards for such activities are shared between the parties. Such arrangements also provide for cost sharing between the parties during the research and development phase, as well as potential future profit share payments during the commercialization phase. In general, such contracts are evaluated under the provisions of FASB ASC 808, Collaborative Arrangements (“ASC 808”). The amounts receivable and payable for research and development activities are presented net within research and development expense on the consolidated statements of operations and comprehensive loss. As such, the net costs reflect the Company’s share of the ongoing research and development efforts. The amounts receivable and payable for commercialization activities are presented net as either collaboration revenue, separate from revenue from contracts with customers, or collaboration expense on the consolidated statements of operations, as appropriate. Research and Manufacturing Contracts The Company has entered into various research and development contracts with research institutions and other companies whose costs are included in research and development expense in the accompanying consolidated statements of operations and comprehensive loss. These agreements are generally cancelable and related payments are recorded as research and development expenses as the underlying services are performed. When evaluating the adequacy of the expense recognized, the Company analyzes progress of the services, including the phase or completion of events, invoices received, and contracted costs. Judgments and estimates are made in determining the expense recognized and the related prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical estimates have not been materially different from the actual costs. Lease Agreements Pursuant to ASC 842, Leases , the Company determines if an arrangement is or contains a lease at inception. For leases with a term of 12 months or less, the Company does not recognize a right-of-use asset or lease liability. The Company’s operating leases are recognized on its consolidated balance sheets as other noncurrent assets, other current liabilities, and other noncurrent liabilities. The Company does not have any finance leases. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As the Company’s leases typically do not provide an implicit rate, the Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Operating lease right-of-use assets also include the effect of any lease payments made prior to commencement and exclude lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are accounted for as a combined element. Acquired In-Process Research and Development In an asset acquisition, the cost allocated to acquire in-process research and development (“IPR&D”) with no alternative future use is charged to expense at the acquisition date. Please refer to Note 10, Acquisition of ZebiAI , for a more detailed description of the accounting policies applied to the Company's only asset acquisition during the three years ended December 31, 2022 . Comprehensive Loss Comprehensive loss includes net loss, as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the years ended December 31, 2022, 2021, and 2020 , other comprehensive income (loss) consisted of changes in unrealized gains and losses from available-for-sale investments. Net Loss per Common Share Basic net loss per share is computed using the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the sum of the weighted-average number of common shares outstanding during the period and the effect of any dilutive securities. The Company applies the two-class method to calculate its basic and diluted net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. The Company’s participating securities contractually entitle the holders of such shares to participate in dividends, but do not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. Additionally, in periods in which the Company reports a net loss, diluted net loss per share is the same as basic net loss per share, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. For additional discussion of net loss per common share, please refer to Note 9, Net Loss per Share. Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on differences between the financial statement carrying amounts and the tax bases of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Recently Adopted Accounting Pronouncements As noted above, the Company adopted ASU 2016-13, as well as the related amendments thereto, on January 1, 2022. The adoption of ASU 2016-13, as well as the related amendments thereto, did not have a material impact on the Company’s consolidated financial statements or disclosures. Recently Issued Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. The Company does not believe that the adoption of any recently issued standards have or may have a material impact on its consolidated financial statements and disclosures.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair Value Measurements as of Level 1 Level 2 Level 3 Total (in thousands) Assets Cash equivalents: Money market funds $ 118,446 $ — $ — $ 118,446 U.S. treasury bills — 9,950 — 9,950 Total cash equivalents 118,446 9,950 — 128,396 Investments: U.S. treasury bills — 466,603 — 466,603 U.S. agency securities — 380,520 — 380,520 Total investments — 847,123 — 847,123 Total assets $ 118,446 $ 857,073 $ — $ 975,519 Liabilities Contingent Milestone Payments $ — $ — $ 27,378 $ 27,378 Total liabilities $ — $ — $ 27,378 $ 27,378 Fair Value Measurements as of Level 1 Level 2 Level 3 Total (in thousands) Assets Cash equivalents: Money market funds $ 251,891 $ — $ — $ 251,891 Total cash equivalents 251,891 — — 251,891 Investments: U.S. treasury bills — 469,386 — 469,386 U.S. agency securities — 208,568 — 208,568 Total investments — 677,954 — 677,954 Total assets $ 251,891 $ 677,954 $ — $ 929,845 Liabilities Contingent Milestone Payments $ — $ — $ 45,258 $ 45,258 Total liabilities $ — $ — $ 45,258 $ 45,258 In determining the fair value of its investments at each date presented above, the Company relied on quoted prices for similar securities in active markets or using other inputs that are observable or can be corroborated by observable market data. Fair Value of Contingent Consideration In April 2021, the Company acquired ZebiAI, as detailed further in Note 10, Acquisition of ZebiAI . The Company’s Level 3 contingent consideration liability is related to $ 85.0 million of platform and program milestones (“Contingent Milestone Payments”) payable to ZebiAI’s former equity holders upon achievement. The contingent consideration liability for the Contingent Milestone Payments is measured at fair value at each reporting date pursuant to FASB ASC Topic 480, Distinguishing Liabilities from Equity (“ASC 480”). The Company determines the fair value of the Contingent Milestone Payments based on the probability of achieving the milestones, the related timing, and, to a lesser extent, an appropriate discount rate. Significant judgment is used in determining the underlying assumptions. Due to the uncertainties associated with the development of platforms and drug candidates in the pharmaceutical industry and the effects of changes in assumptions, including probability of success and related timing, the Company expects its estimates regarding the fair value of Contingent Milestone Payments to continue to change in the future, resulting in adjustments to the fair value of the Company’s Contingent Milestone Payments. The effect of any such adjustments could be material. The Company also has a contingent consideration liability related to the fair value of $ 100.0 million in earnout payments (“Contingent Earnout Payments”). Because the Contingent Earnout Payments were not accounted for as derivatives under FASB ASC Topic 815, Derivatives and Hedging ("ASC 815"), they were only measured at fair value as of the acquisition date and are not re-assessed at fair value at each reporting period. The Contingent Earnout Payments will be adjusted when the contingency is resolved and the consideration is paid or becomes payable. The following table reconciles the change in the contingent consideration liability: Year Ended December 31, 2022 2021 2020 (in thousands) Balance at beginning of period $ 50,258 $ — $ — Fair value of contingent consideration upon acquisition — 47,422 — Change in fair value of Contingent Milestone Payments ( 11,677 ) 2,836 — Common stock issued upon milestone achievement ( 6,203 ) — — $ 32,378 $ 50,258 $ — The "Fair value of contingent consideration upon acquisition" in the table above represents the fair value of the Contingent Milestone Payments and Contingent Earnout Payments upon acquisition of ZebiAI in 2021. The “Change in fair value of Contingent Milestone Payments” in the table above was attributable to changes in the assumptions noted above during the periods specified. The “Common stock issued upon milestone achievement” in the table above was attributable to 301,939 shares of common stock issued to ZebiAI's former equity holders upon achievement of one of the platform milestones during the year ended December 31, 2022. The outstanding Contingent Milestone Payments are payable in shares of common stock based on a fixed amount assigned to each milestone and the average closing price of the Company’s common stock for the 5-day period prior to the milestone achievement. Accordingly, the number of shares of common stock to be issued upon a milestone achievement vary dependent on the Company’s common stock price. If the outstanding milestones were achieved in full on December 31, 2022 , the number of shares of common stock to be issued would be 4,954,739 based on an average closing price of the Company's common stock of $ 14.58 for the 5-day period prior to December 31, 2022 .

Investments

Investments	12 Months Ended
	Dec. 31, 2022
Schedule of Investments [Abstract]
Investments	4. Investments The fair value of available-for-sale investments by type of security was as follows: December 31, 2022 Amortized Unrealized Unrealized Fair (in thousands) Investments: U.S. treasury bills $ 356,728 $ 9 $ ( 5,523 ) $ 351,214 U.S. agency securities 236,483 49 ( 3,104 ) 233,428 Total investments with a maturity of one year or less 593,211 58 ( 8,627 ) 584,642 U.S. treasury bills 116,290 14 ( 915 ) 115,389 U.S. agency securities 148,042 36 ( 986 ) 147,092 Total investments with a maturity of one to two years 264,332 50 ( 1,901 ) 262,481 Total investments $ 857,543 $ 108 $ ( 10,528 ) $ 847,123 December 31, 2021 Amortized Unrealized Unrealized Fair (in thousands) Investments: U.S. treasury bills $ 189,406 $ — $ ( 228 ) $ 189,178 U.S. agency securities 108,895 — ( 138 ) 108,757 Total investments with a maturity of one year or less 298,301 — ( 366 ) 297,935 U.S. treasury bills 280,743 — ( 535 ) 280,208 U.S. agency securities 99,998 — ( 187 ) 99,811 Total investments with a maturity of one to two years 380,741 — ( 722 ) 380,019 Total investments $ 679,042 $ — $ ( 1,088 ) $ 677,954 The following table summarizes the Company's available-for-sale debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded at December 31, 2022, aggregated by major security type and length of time in a continuous unrealized loss position: Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized (in thousands) U.S. treasury bills $ 143,089 $ ( 1,860 ) $ 275,445 $ ( 4,578 ) $ 418,534 $ ( 6,438 ) U.S. agency securities 190,468 ( 1,649 ) 97,305 ( 2,441 ) 287,773 ( 4,090 ) Total $ 333,557 $ ( 3,509 ) $ 372,750 $ ( 7,019 ) $ 706,307 $ ( 10,528 ) The following table summarizes our available-for-sale debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded at December 31, 2021, aggregated by major security type and length of time in a continuous unrealized loss position: Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized (in thousands) U.S. treasury bills $ 469,386 $ ( 763 ) $ — $ — $ 469,386 $ ( 763 ) U.S. agency securities 208,568 ( 325 ) — — 208,568 ( 325 ) Total $ 677,954 $ ( 1,088 ) $ — $ — $ 677,954 $ ( 1,088 ) As summarized in the tables immediately above, the Company held 126 and 88 debt securities that were in an unrealized loss position as of December 31, 2022 and 2021, respectively. The unrealized losses at December 31, 2022 and 2021 were attributable to changes in interest rates and the unrealized losses do not represent credit losses. The Company does not intend to sell these securities and it is not more likely than not that it will be required to sell them before recovery of their amortized cost basis.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment, net consisted of the following: December 31, 2022 2021 (in thousands) Property and equipment: Laboratory equipment $ 21,472 $ 15,797 Leasehold improvements 3,826 2,897 Computer equipment 1,743 1,093 Furniture and fixtures 1,762 989 Construction in process 1,220 134 30,023 20,910 Less: accumulated depreciation ( 18,389 ) ( 14,367 ) Total property and equipment, net $ 11,634 $ 6,543 The Company recorded $ 4.1 million, $ 3.9 million, and $ 3.5 million of depreciation expense for the years ended December 31, 2022, 2021, and 2020 , respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses	6. Accrued Expenses Accrued expenses consisted of the following: December 31, 2022 2021 (in thousands) External research and development costs $ 19,276 $ 9,353 Consulting and professional services 831 1,109 Compensation costs 1,043 593 Other 1,553 2,502 Total accrued expenses $ 22,703 $ 13,557

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Common Stock	7. Common Stock Each share of common stock entitles the stockholder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the Company’s board of directors. As of December 31, 2022 , no dividends had been declared. Restricted Common Stock In prior years, the Company issued restricted shares of common stock to its founders and consultants. The Company also issued restricted shares of common stock upon the early exercise of stock options under the Company’s 2016 Stock Option and Grant Plan (the “2016 Stock Plan”). The restrictions on the common shares generally lapsed over vesting terms of four years . The Company included the proceeds from the issuance of the restricted shares of common stock as a restricted stock liability on the accompanying consolidated balance sheets. Amounts were reclassified to additional paid-in capital as the restrictions lapsed. The Company had the right to repurchase any unvested shares of restricted common stock at the original cost upon termination. As of December 31, 2021, the restrictions had lapsed on each share of restricted common stock issued in prior years. At-the-Market Offering In August 2021, the Company entered into a sales agreement, (the “Sales Agreement”), with Cowen and Company, LLC ("Cowen"), pursuant to which the Company may offer and sell shares of its common stock having aggregate gross proceeds of up to $ 300.0 million from time to time in “at-the-market” offerings through Cowen, as the Company’s sales agent. The Company agreed to pay Cowen a commission of up to 3.0 % of the gross proceeds of any shares sold by Cowen under the Sales Agreement. There have been no shares of common stock sold under the Sales Agreement through December 31, 2022. Follow-On Offerings In October 2021, the Company completed a public offering of 15,188,679 shares of common stock, including the exercise in full of the underwriters’ option to purchase an additional 1,981,132 shares, at an offering price of $ 26.50 per share. The Company received proceeds of $ 382.2 million, which was net of $ 20.3 million in underwriting discounts and commissions, as well as other offering expenses. In September 2022, the Company completed a public offering of 11,320,755 shares of common stock at an offering price of $ 26.50 per share. The Company received proceeds of $ 284.7 million, which was net of $ 15.3 million in underwriting discounts and commissions, as well as other offering expenses.

Stock Compensation

Stock Compensation	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock Compensation	8. Stock Compensation In 2016, the Company adopted the 2016 Stock Plan. Subsequent to July 2020, no further awards have been granted under the 2016 Stock Plan and all equity-based awards have been and will continue to be granted under the 2020 Stock Option and Incentive Plan (the “2020 Stock Plan”). To the extent outstanding options granted under the 2016 Stock Plan are cancelled, forfeited, or otherwise terminated without being exercised and would otherwise have been returned to the share reserve under the 2016 Stock Plan, the number of shares underlying such awards will be available for future grant under the 2020 Stock Plan. In 2020, the Company’s stockholders approved the 2020 Stock Plan. All of the Company’s employees, officers, directors, and consultants are eligible to be granted options, restricted stock units, and other stock-based awards under the terms of the 2020 Stock Plan, which originally provided for the issuance of up to 8,376,080 of stock-based awards. The 2020 Stock Plan is also subject to annual increases to be added on the first day of each fiscal year, commencing on January 1, 2021, equal to 5 % of the number of outstanding shares on the immediately preceding December 31 or such lesser number of shares approved by the Company’s board of directors or compensation committee of the board of directors. On January 1, 2022, the number of shares available for issuance under the 2020 Stock Plan was increased by 5,410,515 shares of common stock. There were 10,783,577 stock-based awards available for grant at December 31, 2022 under the 2020 Stock Plan. In 2020, the Company adopted an Employee Stock Purchase Plan (“ESPP”) that permits eligible employees to enroll in six-month offering periods. Participants may purchase shares of the Company’s common stock, through payroll deductions, at a price equal to 85 % of the fair market value of the common stock on the first or last day of the applicable six-month offering period, whichever is lower. Purchase dates under the ESPP occur on or about June 30 and December 31 each year, with the initial purchase date under the ESPP on December 31, 2021. The Company’s stockholders originally authorized 1,092,532 shares for issuance pursuant to the ESPP, which is subject to annual increases to be added on the first day of each fiscal year, commencing on January 1, 2021, equal to the lesser of 2,185,064 shares of the Company’s common stock, 1 % of the number of outstanding shares on the immediately preceding December 31, or an amount determined by the Company’s board of directors. On January 1, 2022, the number of shares available for issuance under the ESPP was increased by 1,082,103 shares of common stock. There were 2,906,999 shares available for grant at December 31, 2022 under the ESPP. In connection with all stock-based payments, total stock-based compensation expense recognized was as follows: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 30,671 $ 24,922 $ 14,691 General and administrative expenses 25,467 23,532 17,269 $ 56,138 $ 48,454 $ 31,960 Time-Based Stock Options The Company has historically granted stock options to employees, directors, and consultants with vesting conditions based on continued service over time. Accordingly, stock-based compensation expense for such awards is recognized using a straight-line attribution model over the vesting term of each option. The following table summarizes activity for time-based stock options under the 2016 Stock Plan and the 2020 Stock Plan for the year ended December 31, 2022: Number of Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2021 6,906,367 $ 16.80 7.90 $ 111,021 Granted 3,658,461 20.58 Exercised ( 737,144 ) 4.47 Cancelled ( 551,132 ) 32.60 Outstanding at December 31, 2022 9,276,552 $ 18.33 7.85 $ 34,647 Vested at December 31, 2022 4,415,876 $ 13.49 6.94 $ 29,401 Unvested at December 31, 2022 4,860,676 $ 22.73 8.67 $ 5,246 The total intrinsic value of time-based stock options exercised was $ 15.5 million, $ 32.4 million, and $ 2.4 million for the years ended December 31, 2022, 2021, and 2020, respectively. The fair value of each time-based stock option granted is estimated on the date of grant using the Black-Scholes option pricing model, pursuant to which the weighted-average grant date fair values were $ 13.67 , $ 22.95 , and $ 14.77 during the years ended December 31, 2022, 2021, and 2020 , respectively. The following table summarizes the assumptions used in calculating the fair value of the time-based stock options granted. Year Ended December 31, 2022 2021 2020 Expected term (in years) 6.25 6.25 6.25 Risk-free interest rate 1.6 % to 4.2 % 0.6 % to 1.6 % 0.4 % to 1.8 % Expected volatility 72.7 % to 76.2 % 74.7 % to 76.6 % 73.5 % to 77.6 % Expected dividend yield 0.0 % 0.0 % 0.0 % The Company uses the simplified method to calculate the expected term, as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term for time-based stock options granted. The expected term is applied to the time-based stock option grant group as a whole, as the Company does not expect substantially different exercise or post-vesting termination behavior among the Company’s employees, directors, and consultants. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected term of the stock options. The Company’s stock price volatility assumption is based on historical volatility of a group of companies with similar characteristics to the Company and who have similar risk profiles and positions within the industry. The Company accounts for forfeitures as they occur. As of December 31, 2022 , the total unrecognized stock-based compensation related to unvested time-based stock options was $ 66.7 million, which the Company expects to recognize over a weighted-average period of approximately 1.47 years. Performance-Based Stock Options In March 2020 and September 2021, the Company granted options to certain employees with performance-based vesting conditions. In both instances, the commencement of vesting is based on the achievement of various scientific and operational milestones during specified periods, subject to the discretion and approval of either the Company’s board of directors or President and Chief Executive Officer. For the performance-based stock options, the Company applies variable accounting until the performance criteria are determined to be achieved, at which time vesting commences over contractual service periods. Furthermore, because (a) the awards were authorized prior to the accounting grant date in the context of ASC 718, Stock Compensation , (b) the recipients were providing service prior to the accounting grant date, and (c) there were performance conditions that, if not met by the accounting grant date, would have resulted in the forfeiture of the award, the service inception dates preceded the accounting grant date. Ultimately, the stock-based compensation expense for the options is determined based on the fair value of the awards on the accounting grant date, which is then recognized using an accelerated attribution model over the vesting term commencing upon the actual or expected accounting grant date. For the performance-based stock options granted in March 2020, all performance conditions have been resolved and the grant date was set at or prior to December 31, 2020. For the performance-based stock options granted in September 2021, all performance conditions have been resolved and the grant date was set at or prior to December 31, 2022. The following table summarizes activity for performance-based stock options for the year ended December 31, 2022: Number of Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2021 1,813,260 $ 5.41 8.11 $ 45,912 Exercised ( 20,729 ) 5.22 Cancelled ( 18,348 ) 5.22 Outstanding at December 31, 2022 1,774,183 $ 5.41 7.18 $ 17,128 Vested at December 31, 2022 927,394 $ 5.22 7.17 $ 9,014 Unvested at December 31, 2022 846,789 $ 5.62 7.19 $ 8,114 The total intrinsic value of performance-based stock options exercised was $ 0.4 million, $ 1.1 million, and immaterial for the years ended December 31, 2022, 2021, and 2020, respectively. The fair value of each performance-based stock option granted is estimated on the accounting grant date, or at the end of each reporting period if variable accounting is applied, using the Black-Scholes option-pricing model, pursuant to which the grant date fair values were $ 20.28 and $ 37.48 during the years ended December 31, 2021 and 2020 , respectively. There were no performance-based stock options granted during the year ended December 31, 2022. The assumptions and methodologies used in calculating the fair value of performance-based stock options was similar to the assumptions and methodologies used in calculating the fair value of time-based stock options granted during the years ended December 31, 2021 and 2020. As of December 31, 2022 , the total unrecognized stock-based compensation related to unvested performance-based stock options was $ 8.5 million, which the Company expects to recognize over a weighted-average period of approximately 0.79 years. Restricted Stock Units Starting in 2021, the Company granted restricted stock units (“RSUs”) to employees, directors, and consultants under the 2020 Stock Plan. Each of the RSUs represents the right to receive one share of the Company’s common stock upon vesting. The majority of RSUs granted to date have vesting conditions based on continued service over time. Accordingly, stock-based compensation expense for the majority of such awards is recognized using a straight-line attribution model over the vesting term of each RSU. The fair value of each RSU is based on the closing price of the Company’s common stock on the date of grant. The following table summarizes activity for RSUs under the 2020 Stock Plan for the year ended December 31, 2022: Number of Shares Underlying RSUs Weighted-Average Unvested at December 31, 2021 691,205 $ 34.51 Granted 1,389,696 20.85 Vested ( 398,330 ) 27.75 Cancelled ( 115,811 ) 27.59 Unvested at December 31, 2022 1,566,760 24.62 The fair value of restricted shares that vested during the year ended December 31, 2022 was $ 8.6 million. As of December 31, 2022 , the total unrecognized compensation related to unvested RSUs granted was $ 35.0 million, which the Company expects to recognize over a weighted-average period of approximately 1.55 years. Employee Stock Purchase Plan The following table summarizes activity under the Company's ESPP from the initial offering period, or July 1, 2021 through December 31, 2021, through December 31, 2022, including (a) after-tax contributions from employees, (b) shares purchased, and (c) assumptions underlying the Black-Scholes option pricing model to estimate the fair value of the option component of the shares purchased under the ESPP in each period. July 1, 2022 to January 1, 2022 to July 1, 2021 to December 31, 2022 June 30, 2022 December 31, 2021 Purchase date December 31, 2022 June 30, 2022 December 31, 2021 After-tax contributions (in thousands) $ 549 $ 1,137 $ 1,141 Shares of common stock purchased 43,160 79,859 43,685 Expected term (in years) 0.50 0.50 0.50 Risk-free interest rate 2.5 % 0.2 % 0.1 % Expected volatility 89.6 % 66.2 % 65.1 % Expected dividend yield 0.0 % 0.0 % 0.0 % As of December 31, 2022, there was no unrecognized stock-based compensation expense related to ESPP, since the purchase for the offering period between July 1, 2022 and December 31, 2022 was transacted on December 31, 2022 .

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	9. Net Loss per Share The following table summarizes the computation of basic and diluted net loss per share of the Company: Year Ended December 31, 2022 2021 2020 (in thousands, except share and per share data) Net loss $ ( 290,509 ) $ ( 363,872 ) $ ( 52,412 ) Dividend upon extinguishment of Series C Preferred Stock — — ( 177,789 ) Net loss attributable to common stockholders $ ( 290,509 ) $ ( 363,872 ) $ ( 230,201 ) Net loss attributable to common stockholders per share, basic and diluted $ ( 2.59 ) $ ( 3.82 ) $ ( 5.40 ) Weighted average shares of common stock, basic and diluted 112,233,649 95,136,719 42,619,582 On July 8, 2020, the Company’s board of directors and its Series C preferred stockholders approved an amendment to the conversion preferences and rights of the Company's Series C preferred stock, which, among other changes, resulted in a reduction in the conversion price of the Series C preferred stock from $ 3.21 to $ 3.027603 . The changes to the conversion feature were considered to be a significant change to the substantive contractual terms of the Company's Series C preferred stock and, therefore, the Company accounted for the change as an extinguishment and reissuance of the Company's Series C preferred stock. In accordance with SEC staff guidance codified in ASC 260-10-S99-2, when equity classified preferred shares are extinguished, the difference between (1) the fair value of the consideration transferred to the holders of the preferred shares and (2) the carrying amount of the preferred shares, net of issuance costs, is subtracted from (or added back to) net income to arrive at income available to common stockholders in the calculation of earnings per share. This difference between the fair value of consideration transferred and carrying amount of the preferred shares, also referred to as a deemed dividend, was, therefore, added back to net loss above to derive net loss attributable to common stockholders. T he Company excluded the following potentially dilutive securities, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the years ended December 31, 2022, 2021, and 2020 , as the effect would be anti-dilutive and reduce the net loss per share calculated for each period. Therefore, the weighted-average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share is the same. Year Ended December 31, 2022 2021 2020 Options to purchase common stock 11,050,735 8,719,627 7,697,058 Unvested restricted stock — — 84,489 Unvested restricted stock units 1,566,760 691,205 — 12,617,495 9,410,832 7,781,547

Acquisition of ZebiAI

Acquisition of ZebiAI	12 Months Ended
	Dec. 31, 2022
Business Combination, Description [Abstract]
Acquisition of ZebiAI	10. Acquisition of ZebiAI On April 22, 2021 (the “Acquisition Date”), the Company acquired ZebiAI, a privately held company focused on using machine learning combined with DNA encoded library data sets for drug discovery. Pursuant to the Agreement and Plan of Merger (the “Merger Agreement”), upfront consideration included (a) payment of approximately $ 20.0 million in cash and (b) issuance of 1,914,219 shares of the Company’s common stock at an aggregate fair value of $ 61.8 million, both transferred to ZebiAI’s former stockholders, option holders, and warrant holders (the "ZebiAI Holders"), upon closing. In addition, (i) the ZebiAI Holders are eligible to receive up to $ 85.0 million in other payments upon the achievement of certain platform or program milestones, payable in shares of the Company's common stock (the "Contingent Milestone Payments"), a portion of which was paid to the ZebiAI Holders in 2022 , and (ii) the Company will pay 10 % of payments it receives within three years of the closing date of the Merger Agreement from partnering, collaboration, or other agreements related to ZebiAI’s platform, up to an aggregate maximum amount of $ 100.0 million, payable in cash (the "Contingent Earnout Payments"), to the ZebiAI Holders. In accounting for the transaction, the Company assessed if ZebiAI represented an asset or business under ASC 805, Business Combinations (“ASC 805”), as amended by ASU 2017-01. Pursuant to the guidance noted, the Company concluded ZebiAI did not constitute a business, since substantially all of the fair value of the gross assets acquired was concentrated in a single asset, which was the intellectual property for the AI platform and the related data sets in development by ZebiAI. The intellectual property acquired from ZebiAI was at an early stage of development and continues to require a significant investment of time and capital for development. There is no assurance the Company will be successful in completing the additional research and development activities. The Company also concluded the acquisition represented an initial consolidation of a variable interest entity that does not constitute a business in accordance with ASC 810, Consolidation (“ASC 810”). In connection therewith, the Company determined ZebiAI was considered to be a variable interest entity, as it did not have sufficient equity to finance its activities without additional subordinated financial support. Prior to the Acquisition Date, the primary source of funding for ZebiAl had been preferred stock financings and convertible notes. The Company acquired all of the outstanding shares of ZebiAI and, therefore, is the sole equity holder. The Company will absorb the losses of ZebiAI, has the rights to the benefits derived from the ZebiAI platform, and the power to direct all activities. Therefore, the Company is the primary beneficiary. The net assets acquired and liabilities assumed in connection with the ZebiAI acquisition were recorded at their estimated fair values as of the Acquisition Date. Total consideration transferred of $ 135.5 million included the cash and shares of the Company's common stock issued to ZebiAI Holders, the fair value of the Contingent Milestone Payments, and the fair value of the Contingent Earnout Payments, as well as an insignificant amount attributed to the replacement of stock options to ZebiAI Holders. The Contingent Milestone Payments were determined to be liabilities pursuant to ASC 480 and, therefore, included in consideration transferred. The Contingent Earnout Payments were required to be included in total consideration transferred as a result of the guidance under ASC 810. The difference between total consideration transferred and the fair value of net assets acquired and liabilities assumed of $ 11.9 million was recorded as loss on initial consolidation of a variable interest entity pursuant to ASC 810. The following table summarizes net assets acquired based on their estimated fair values as of the Acquisition Date: Amount (in thousands) Acquired IPR&D asset $ 123,000 Loss on initial consolidation of VIE 11,855 Assets obtained in asset acquisition 662 Liabilities assumed in asset acquisition ( 2,330 ) Intangible asset 2,300 Net acquired assets $ 135,487 In estimating the fair value of the acquired tangible assets and liabilities assumed, the Company used the carrying value of the net working capital balances as the most reliable indicator of fair value based on the associated short-term nature of the balances. The remaining fair value was attributable to the acquired IPR&D and an intangible asset. The fair value attributable to the IPR&D asset was determined using an Avoided Cost Method, which includes all costs to develop the IPR&D asset, including appropriate mark-ups on the cost estimate and an expected return related to developing the IPR&D asset over a period of time. The fair value of the IPR&D asset was expensed in the Company’s consolidated statements of operations and comprehensive loss for the year ended December 31, 2021, as the acquired IPR&D had no alternative future use, which was determined by the Company in accordance with U.S. GAAP, including ASC 730, Research and Development ("ASC 730"). The intangible asset represents the assembled workforce, for which the Company concluded there were no indicators of impairment through December 31, 2022 . The Company recognized stock-based compensation expense of $ 4.6 million associated with accelerated vesting for certain stock options in connection with the acquisition within the consolidated statements of operations and comprehensive loss for the year ended December 31, 2021, with no incremental charges in connection therewith for the year ended December 31, 2022 . Finally, the Company recognized other acquisition costs of $ 0.9 million within general and administrative expenses in the consolidated statements of operations and comprehensive loss for the year ended December 31, 2021. For the Contingent Milestone Payments and Contingent Earnout Payments, the Company recorded contingent consideration liabilities of $ 42.4 million and $ 5.0 million, respectively, representing the fair value of the payment provisions noted as of the Acquisition Date. The Company is required to re-assess the fair value of the Contingent Milestone Payments at each reporting period pursuant to ASC 480, as summarized within Note 3, Fair Value Measurements . However, the Contingent Earnout Payments were not accounted for as derivatives under ASC 815 and, therefore, are not re-assessed at fair value at each reporting period. The Contingent Earnout Payments will be adjusted when the contingency is resolved and the consideration is paid or becomes payable.

Collaboration and License Arran

Collaboration and License Arrangements	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and License Agreement with Genentech, Inc.	11. Collaboration and License Agreement with Genentech, Inc. In December 2020, the Company and Genentech, Inc. ("Genentech") entered into the Collaboration and License Agreement ("Genentech Agreement"), which granted Genentech a license to develop and commercialize GDC-1971 (formerly known as RLY-1971). In 2022, the Company completed enrollment of a Phase 1a dose escalation study of GDC-1971 as a monotherapy in patients with advanced or metastatic solid tumors ("Phase 1a Trial for GDC-1971"). The Company is also responsible for the one-time transfer of the active pharmaceutical ingredient (“API”) and other materials related to GDC-1971 to Genentech. Genentech will be responsible for conducting any additional clinical development of GDC-1971, including in any combination trials with Genentech’s compound, GDC-6036, that directly binds to and inhibits KRAS G12C, or other compounds. Genentech initiated the cohort of GDC-1971 in combination with GDC-6036 in a Phase 1b trial in July 2021, and a Phase 1b trial of GDC-1971 in combination with atezolizumab, its PD-L1 antibody, in August 2022. Under the Genentech Agreement, the Company was entitled to a non-refundable upfront payment of $ 75.0 million, which was due upon completion of certain technology transfer activities and was reflected as accounts receivable on the consolidated balance sheet at December 31, 2020 . The Company collected this amount in January 2021. In April 2021, the Company completed the transfer of the Investigational New Drug (“IND”) application for GDC-1971 to Genentech, upon which the Company received payment for the associated non-refundable milestone payment of $ 5.0 million in May 2021. The Company received further milestone payments of $ 15.0 million and $ 10.0 million in December 2021 and October 2022, respectively, which are refundable if the Company opts into the collaboration with Genentech, as discussed below. The Company is eligible to receive up to $ 5.0 million in other near-term milestone payments. The Company is also eligible to receive up to an aggregate of an additional $ 685.0 million upon the achievement of specified development, commercialization, and sales-based milestones for GDC-1971 worldwide, as well as tiered royalties ranging from low-to-mid teens on annual worldwide net sales of GDC-1971, on a country-by-country basis, subject to reduction in certain circumstances. The Company has the option, exercisable one time at the Company’s sole discretion, to (a) fund half of the development costs of GDC-1971 in the U.S., (b) share half of the net profits or net losses of commercializing GDC-1971 in the U.S. (the “Profit/Cost Share”), and (c) be eligible to receive up to an aggregate of an additional $ 410.0 million upon the achievement of specified commercialization and sales-based milestones for GDC-1971 outside of the U.S and tiered royalties ranging from low-to-mid teens on annual net sales of GDC-1971 outside of the U.S., on a country-by-country basis, subject to reduction in certain circumstances. The Company may elect to opt-out of further participation in the Profit/Cost Share at any time prior to the third anniversary of the first commercial sale of GDC-1971 in the U.S, in which case the financial terms would revert to the terms applicable as if Company had not opted into the Profit/Cost Share as of the effective opt-out date. Genentech may terminate the Genentech Agreement for convenience and the Company may terminate the Genentech Agreement under certain limited circumstances. Unless otherwise terminated, the Genentech Agreement will remain in effect until the expiration of all Genentech’s royalty payment obligations to the Company. Accounting Analysis Identification of the Contract The Company concluded Genentech is a customer in this arrangement and, as such, the arrangement falls within the scope of the revenue recognition guidance in ASC 606. Identification of Performance Obligations At the commencement of the Genentech Agreement, the Company identified the following performance obligations: • License to develop and commercialize GDC-1971 and the related know-how; • Research and development services to complete the Phase 1a Trial for GDC-1971; and • Transfer of API and other materials related to GDC-1971. The Company concluded the performance obligations outlined above are both capable of being distinct and distinct within the context of the contract, given such rights and activities are independent of each other. The license can be used by Genentech without the research and development services or API outlined above. Similarly, such services and inventory provide distinct benefit to Genentech within the context of the contract, separate from the license. Determination of Transaction Price As of December 31, 2022 , the Company concluded the transaction price for the Genentech Agreement was $ 86.8 million, which includes both fixed and variable consideration. The total transaction price of $ 86.8 million is comprised of (i) the $ 75.0 million fixed, non-refundable upfront payment, (ii) a $ 5.0 million non-refundable milestone payment due upon the transfer of the IND application to Genentech, (iii) a $ 5.0 million non-refundable milestone payment due upon delivery of certain data relating to the completion of the Phase 1a Trial for GDC-1971, and (iv) $ 1.8 million of estimated variable consideration related to reimbursements due from Genentech for research and development services. No (a) other development milestone payments, including the $ 15.0 million and $ 10.0 million milestone payments received in December 2021 and October 2022, respectively, and (b) regulatory milestone payments are included in the transaction price, as such payments are variable consideration fully constrained as of December 31, 2022 . As part of management’s evaluation of the constraint, the Company considered numerous factors, including consideration of the fact that achievement of the milestones is outside of the Company’s control, contingent upon Genentech’s efforts, the receipt of regulatory approval, and subject to scientific risks of success, as well as the Company’s option to participate in the Profit/Cost Share. Allocation of Transaction Price to Performance Obligations The Company allocated the transaction price of $ 86.8 million based on the stand-alone selling prices (“SSP”) of each of the performance obligations as follows: • $ 83.6 million for the transfer of the license; • $ 2.9 million for research and development services; and • $ 0.3 million for the transfer of API. The SSP for the license was determined using an approach that considered discounted, probability-weighted cash flows related to the license transferred. The Company also reviewed comparable market transactions in determining the SSP of the license. The SSP for the research and development services and the transfer of API were based on estimates of the associated effort and cost of these services and cost to manufacture API, adjusted for a reasonable profit margin that would be expected to be realized under similar contracts. Recognition of Revenue The Company is recognizing revenue for each of the three performance obligations as follows. • The Company recognized revenue related to the license at a point in time upon transfer of the license to Genentech. The Company recognized the full amount allocated to the license and related know-how in 2020, because the Company had transferred the license upon execution of the Genentech Agreement. • The Company is satisfying the research and development performance obligation for GDC-1971 as the research and development services are performed. The research and development services performance obligation consists of the Company completing the Phase 1a clinical trial initiated in 2020. The Company recognizes revenue related to the research and development services over time using a cost-based input method by calculating actual costs incurred to date at each period end relative to total estimated costs expected to be incurred to fulfill the performance obligation. Revenue recognized related to this performance obligation during the years ended December 31, 2022, 2021, and 2020 was $ 0.7 million, $ 1.7 million, and $ 0 , respectively. • The Company recognized the full amount of revenue related to the transfer of API in 2021 upon transfer to Genentech in the amount of $ 0.3 million. There was no revenue recognized related to this performance obligation during the years ended December 31, 2022 and 2020. During the years ended December 31, 2022, 2021, and 2020 , the Company recognized an aggregate of $ 1.0 million, $ 2.6 million, and $ 82.7 million, respectively, of revenue from the Genentech Agreement. As of December 31, 2022 and 2021, the Company recorded a contract asset of $ 4.9 million and $ 4.5 million, respectively, both of which are classified as current assets on the consolidated balance sheets. The contract asset relates to the amount of revenue recognized for which the right to payment is contingent upon conditions other than the passage of time, such as the completion of future milestone activities. The Company recorded an other current liability of $ 25.0 million and an other liability of $ 15.0 million as of of December 31, 2022 and 2021, respectively, representing the amount of certain development milestones achieved as of such dates under the Genentech Agreement. The amounts have been excluded from the transaction price at both December 31, 2022 and 2021 and, therefore, excluded from amounts recognized as revenue to date, since they are subject to repayment to Genentech if the Company exercises its option to participate in the Profit/Cost Share under the Genentech Agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Intellectual Property License The Company has a Collaboration and License Agreement with D. E. Shaw Research, LLC (“D. E. Shaw Research”), which held 9,999,999 shares of Series A preferred stock and 1,557,875 shares of Series C preferred stock at December 31, 2019. In conjunction with the Company's initial public offering in 2020 , such shares were converted into 3,281,253 shares of common stock of the Company, which are outstanding at December 31, 2022 . The contract provides that the parties will jointly conduct research efforts with the goal of identifying and developing product candidates. The original term of the contract was three years and required the Company to pay an annual fee of $ 1.0 million. On June 15, 2020, the Company and D. E. Shaw Research agreed to amend the Collaboration and License Agreement (the “DESRES Agreement”). The DESRES Agreement extended the term of the agreement to August 16, 2025 and increased the annual fee from $ 1.0 million to $ 9.9 million. The DESRES Agreement also automatically renews for successive one-year periods, unless either party provides at least one year notice of non-renewal. The annual fee during each of the one-year renewal terms is subject to mutual agreement of the Company and D. E. Shaw Research. The Company is obligated to pay potential development milestone payments under the terms of the DESRES Agreement up to $ 7.3 million per target, plus sales milestones and royalties, upon the achievement of certain specified contingent events. Such payments for achievement of development and regulatory milestones total up to $ 7.3 million in the aggregate for each of the first three products the Company develops and up to $ 6.3 million, in the aggregate, for each product the Company develops after the first three. The Company assessed the milestone and royalty events under the DESRES Agreement as of December 31, 2022 and 2021, concluding no such payments were due. For the years ended December 31, 2022, 2021, and 2020 , the Company recorded research and development expenses of $ 9.4 million, $ 9.5 million, and $ 6.4 million, respectively, under the DESRES Agreement on its consolidated statements of operations and comprehensive loss. As of December 31, 2022 and 2021 , the Company had prepaid balances of $ 4.9 million and $ 4.4 million, respectively, under the DESRES Agreement on its consolidated balance sheets. As of December 31, 2022 and 2021 , the Company had no accrued expense and accounts payable balances under the DESRES Agreement on its consolidated balance sheets. Other Research Arrangements The Company has certain other research and license arrangements with third parties, which provide the Company with research services with the goal of identifying and developing product candidates. The Company is obligated to pay certain development milestone payments pursuant to such arrangements upon the achievement of certain specified contingent events. The Company assessed such milestones at December 31, 2022 and 2021 , concluding $ 0 was due as of December 31, 2022 and $ 0.5 million was due as of December 31, 2021 . The Company incurred approximately $ 2.9 million, $ 5.4 million, and $ 2.7 million of research and development expenses under such agreements for the years ended December 31, 2022, 2021, and 2020 , respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	13. Leases 399 Binney Street In December 2017, the Company entered into an operating lease agreement for 44,336 square feet of office and laboratory space at 399 Binney Street, Cambridge, Massachusetts, which was increased to 44,807 square feet in January 2018. The Company gained control of the leased space in January 2019 and, accordingly, recorded an operating lease right-of-use asset and liability at such time. The operating lease expires in April 2029 , subject to certain renewal options, which have not been included in the Company’s operating lease right-of-use asset and liability, as the Company is not reasonably certain to exercise such options as of December 31, 2022. In September 2020, the Company entered into an amendment to its operating lease agreement to expand the leased area by 1,824 square feet of office space at 399 Binney Street, Cambridge, Massachusetts. The amendment to the operating lease agreement met the criteria to be accounted for as a separate operating lease. The Company gained control of the leased space in October 2020 and, accordingly, recorded an operating lease right-of-use asset and liability at such time. The operating lease right-of-use asset and lease liability recorded in connection with the amendment were not material. The amended operating lease expires in April 2029, subject to certain renewal options. As discussed in Note 2, Significant Accounting Policies , the Company provided a letter of credit in the amount of $ 0.9 million with a financial institution, which expires commensurate with the lease in April 2029 . The following table summarizes the presentation of amounts recorded on the Company’s consolidated balance sheets for the operating lease at 399 Binney Street as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 18,828 $ 20,780 Liabilities: Operating lease liabilities $ 2,170 $ 1,844 Operating lease liabilities, net of current portion 18,886 21,056 Total operating lease liabilities $ 21,056 $ 22,900 The following table summarizes the effect of lease costs for the Company's operating lease at 399 Binney Street on the Company’s condensed consolidated statements of operations and comprehensive loss for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 3,350 $ 3,262 $ 3,273 General and administrative expenses 893 1,002 899 $ 4,243 $ 4,264 $ 4,172 The Company made cash payments of $ 4.1 million, $ 4.0 million, and $ 3.8 million under the operating lease agreement for 399 Binney Street during the years ended December 31, 2022, 2021, and 2020, respectively. The minimum lease payments for the Company’s operating lease at 399 Binney Street as of December 31, 2022 for the next five years and thereafter are expected to be as follows: Year Ending December 31, Amount (in thousands) 2023 $ 4,254 2024 4,377 2025 4,503 2026 4,634 2027 4,768 Thereafter 6,557 Total lease payments 29,093 Less: interest ( 8,037 ) Present value of operating lease liabilities $ 21,056 The weighted-average remaining lease term and weighted-average discount rate of the Company's operating lease at 399 Binney Street were 6.33 years and 10.4 %, respectively, at December 31, 2022. The weighted-average remaining lease term and weighted-average discount rate of the Company's operating lease at 399 Binney Street were 7.33 years and 10.4 %, respectively, at December 31, 2021. 60 Hampshire Street In May 2021, the Company entered into an operating lease agreement for 41,474 square feet of office and laboratory space at 60 Hampshire Street, Cambridge, Massachusetts. The Company gained control of the leased space in July 2022 and, accordingly, recorded an operating lease right-of-use asset and liability at such time. The operating lease expires in June 2032 and there are no renewal options. As discussed in Note 2, Significant Accounting Policies , the Company provided a letter of credit in the amount of $ 1.7 million with a financial institution, which expires commensurate with the lease in June 2032 . The following table summarizes the presentation of amounts recorded on the Company’s consolidated balance sheets for the operating lease at 60 Hampshire Street as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 44,926 $ — Liabilities: Current operating lease liabilities $ 2,106 $ — Operating lease liabilities, net of current portion 34,580 — Total operating lease liabilities $ 36,686 $ — The following table summarizes the effect of lease costs for the Company's operating lease at 60 Hampshire Street on the Company’s condensed consolidated statements of operations and comprehensive loss for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 2,675 $ — $ — General and administrative expenses 564 — — $ 3,239 $ — $ — The Company made cash payments of $ 11.5 million, $ 0 , and $ 0 under the operating lease agreement for 60 Hampshire Street during the years ended December 31, 2022, 2021, and 2020, respectively. The minimum lease payments for the Company’s operating lease at 60 Hampshire Street as of December 31, 2022 for the next five years and thereafter are expected to be as follows: Year Ending December 31, Amount (in thousands) 2023 $ 4,966 2024 5,109 2025 5,257 2026 5,409 2027 5,565 Thereafter 27,084 Total lease payments 53,390 Less: interest ( 16,704 ) Present value of operating lease liabilities $ 36,686 The weighted-average remaining lease term and weighted-average discount rate of the Company's operating lease at 60 Hampshire Street were 9.50 years and 8.0 %, respectively, at December 31, 2022 .

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes During the years ended December 31, 2022, 2021, and 2020 , the Company recorded no income tax benefits due to losses incurred and the uncertainty of future taxable income. A reconciliation of the expected income tax (benefit) computed using the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2022, 2021, and 2020: December 31, 2022 2021 2020 Income tax computed at federal statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.5 % 5.7 % 5.7 % Change in valuation allowance ( 30.2 )% ( 20.5 )% ( 27.3 )% IPR&D — ( 7.0 )% — R&D credit carryovers 4.2 % 2.2 % 7.6 % Stock-based compensation ( 2.1 )% ( 0.4 )% ( 6.7 )% Permanent differences ( 0.6 )% ( 1.0 )% ( 0.3 )% Total 0.0 % 0.0 % 0.0 % The Company’s deferred tax assets and liabilities at December 31, 2022 and 2021, consist of the following: December 31, 2022 2021 (in thousands) Deferred tax assets: Net operating losses $ 119,688 $ 108,800 Tax credit carryforwards 30,593 18,288 Capitalized R&D 55,303 — Lease liability 18,307 6,010 Stock-based compensation 14,510 8,374 Intangibles 1,875 1,859 Depreciation and amortization 568 477 Other 7,270 4,304 Total gross deferred tax assets 248,114 148,112 Valuation allowance ( 230,518 ) ( 142,674 ) Net deferred tax assets 17,596 5,438 Deferred tax liabilities Operating lease assets ( 17,596 ) ( 5,438 ) Total deferred tax liabilities ( 17,596 ) ( 5,438 ) $ — $ — The Company has incurred net operating losses (“NOLs”) since inception. As of December 31, 2022 and 2021 , the Company had federal NOL carryforwards of $ 412.0 million and $ 371.4 million, respectively, available to reduce taxable income, of which $ 43.1 million expire beginning in 2035 and $ 368.9 million do not expire. The Company also has state NOL carryforwards of $ 501.7 million and $ 466.2 million as of December 31, 2022 and 2021 , respectively, available to reduce future state taxable income, which expire at various dates beginning in 2035 . As of December 31, 2022 and 2021 , the Company also had available federal research and development tax credit carryforwards of $ 25.9 million and $ 14.9 million, respectively, available to reduce future tax liabilities, which begin to expire beginning in 2035 . The Company also has state research and development tax credit carryforwards of $ 5.6 million and $ 4.2 million as of December 31, 2022 and 2021 , respectively, available to reduce future state tax liabilities, which expire at various dates beginning in 2030 . Utilization of NOL and research and development credit carryforwards may generally be subject to limitation under Sections 382 and 383 of the Internal Revenue Code of 1986 (“Sections 382 and 383”) due to ownership changes that have occurred previously or could occur in the future. Such ownership changes may limit the amount of NOL and research and development credit carryforwards that can be utilized annually to offset any post-ownership change in taxable income and tax, respectively. The most recent Section 382 study was performed by the Company up to December 31, 2022, through which it was noted that a historic ownership change has likely occurred. Nonetheless, the Company has concluded that, as of December 31, 2022, the prospective utilization of NOL and research and development credit carryforwards from inception through December 31, 2022 (and, therefore, the corresponding Federal and state deferred tax assets) should not be restricted by Sections 382 and 383, although ownership changes after December 31, 2022 could impact the Company’s ability to utilize such tax attributes in the future. The Company recorded a valuation allowance against its deferred tax assets for the years ended December 31, 2022 and 2021 , because the Company’s management believes it is more likely than not that these assets will not be realized. The valuation allowance increased by approximately $ 87.8 million and $ 76.9 million for the years ended December 31, 2022 and 2021, respectively, primarily as a result of operating losses generated with no corresponding financial statement benefit. The Company had no unrecognized tax benefits as of December 31, 2022 and 2021. The Company files tax returns, as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by Federal and state jurisdictions, where applicable. There are currently no pending tax examinations. The Company’s tax years are still open under statute from inception to the present. In 2017, the Tax Cuts and Jobs Act of 2017 (“2017 Tax Act”) was signed into law. Amongst other provisions, the 2017 Tax Act requires taxpayers to capitalize and amortize research and experimental (R&D) expenditures under Section 174 for tax years beginning after December 31, 2021. As such, the rule noted became effective for the Company during the year ended December 31, 2022 and resulted in the capitalization of certain R&D costs within its tax provision. The Company will amortize such costs for tax purposes over 5 years if the R&D was performed in the United States and over 15 years if the R&D was performed outside the United States. In 2020, the Coronavirus Aid, Relief and Economic Security Act (“CARES Act” ) was signed into law. The CARES Act lifts certain deduction limitations originally imposed by the 2017 Tax Act. Corporate taxpayers may carryback NOLs originating during 2018 through 2020 for up to five years , which was not previously allowed under the 2017 Tax Act. The CARES Act also eliminates the 80 % of taxable income limitations by allowing corporate entities to fully utilize NOL carryforwards to offset taxable income in 2018, 2019, or 2020. Taxpayers may generally deduct interest up to the sum of 50 % of adjusted taxable income plus business interest income ( 30 % limit under the 2017 Tax Act) for tax years beginning January 1, 2019 and 2020. The CARES Act allows taxpayers with alternative minimum tax credits to claim a refund in 2020 for the entire amount of the credits instead of recovering the credits through refunds over a period of years, as originally enacted by the 2017 Tax Act. In addition, the CARES Act raises the corporate charitable deduction limit to 25 % of taxable income and makes qualified improvement property generally eligible for 15-year cost-recovery and 100 % bonus depreciation. The enactment of the CARES Act did not result in any adjustments to the Company’s income tax provision for the years ended December 31, 2022, 2021, and 2020, or to the Company’s net deferred tax assets as of December 31, 2022 and 2021 , since the Company has no t recorded any U.S. Federal or state income tax benefits for the net losses incurred in any year due to the uncertainty of realizing a benefit from such items.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2022
Postemployment Benefits [Abstract]
Retirement Benefits	15. Employee Benefits In 2016, the Company established a defined-contribution plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. The Company made matching contributions to the 401(k) Plan of $ 2.3 million and $ 1.2 million for the years ended December 31, 2022 and 2021. The Company was not required to make and did not make any matching contributions to the 401(k) Plan for the year ended December 31, 2020 .

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events In preparing the consolidated financial statements as of December 31, 2022 , the Company evaluated subsequent events for recognition and measurement purposes through the filing date of this Annual Report on Form 10-K. The Company concluded that no events or transactions have occurred that require disclosure in the accompanying consolidated financial statements.

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for reporting on Form 10-K. The Company’s consolidated financial statements include the accounts of Relay Therapeutics, Inc. and its wholly-owned subsidiaries, Relay Securities Corporation and Relay ML Discovery, LLC. All intercompany balances and transactions have been eliminated. Certain prior period amounts, limited to (a) prepaid expenses and other current assets and (b) accrued expenses and other current liabilities, have been reclassified to conform to current period presentation. Such reclassifications have no impact on the Company’s consolidated statements of operations and comprehensive loss, as previously reported.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the fair value of contingent milestone payments in connection with the acquisition of ZebiAI Therapeutics, Inc. (“ZebiAI”), the determination of the transaction price and standalone selling price of performance obligations under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers ("ASC 606"), the accrual of research and development and manufacturing expenses, the valuation of equity instruments, and the incremental borrowing rate for determining operating lease assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience.
Segment Information	Segment Information The Company manages its operations as a single segment for purposes of assessing performance and making operating decisions. The Company’s singular focus is on using innovative experimental and computational approaches on protein motion for making medicines to drug protein targets that have previously been intractable or inadequately addressed. The Company operates in the United States and all tangible assets are held in the United States.
Cash Equivalents	Cash Equivalents The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents. Cash equivalents, which consist of money market funds, are stated at fair value.
Restricted Cash	Restricted Cash The Company had restricted cash of $ 2.6 million as of December 31, 2022 and 2021, specifically to secure letters of credit in connection with operating leases of the Company’s facilities, as detailed in Note 13, Leases . The Company classified the restricted cash as a noncurrent asset on its consolidated balance sheets, consistent with the terms of the lease agreements.
Investments	Investments Investments in marketable securities are classified as available-for-sale. Available-for-sale securities are measured and reported at fair value using quoted prices in active markets for similar securities. Premiums or discounts from par value are amortized to investment income over the life of the underlying investment. In June 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). Certain amendments thereto were also issued by the FASB. The Company adopted ASU 2016-13, as well as the related amendments thereto, on January 1, 2022, pursuant to which the Company reviews investments whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. In connection therewith, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors, considering the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security is compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded on the consolidated balance sheet, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that is not related to credit is recognized in other comprehensive loss as a separate component of stockholders' equity. Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense in general and administrative expenses within the consolidated statements of operations and comprehensive loss. Losses are charged against the allowance when the Company believes the uncollectability of an available-for-sale security is confirmed or when either of the criteria regarding intent or requirement to sell is met. All of the Company’s available-for-sale securities are available to the Company for use in current operations. As a result, the Company classified all such securities as current assets as of December 31, 2022 and 2021, even though the stated maturity of some individual securities may be one year or more beyond the balance sheet dates. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in other income (expense) within the consolidated statements of operations and comprehensive loss.
Concentration of Credit Risk and Significant Suppliers	Concentration of Credit Risk and Significant Suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash, cash equivalents, and investments. From time to time, the Company has maintained all of its cash, cash equivalents, and investments at certain accredited financial institutions in amounts that exceed federally insured limits. The Company generally invests its excess capital in money market funds, U.S. treasury bonds, U.S. treasury bills, and agency bonds, all of which are subject to minimal credit and market risk. Management has established guidelines relative to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. The investment portfolio is maintained in accordance with the Company’s investment policy, which defines allowable investments, specifies credit quality standards, and limits the credit exposure of any single issuer. The Company is dependent on third-party suppliers for research and development activities of its programs, including preclinical and clinical testing. In particular, the Company relies and expects to continue to rely on a small number of these suppliers, including D. E. Shaw Research, LLC, as discussed in Note 12, Commitments and Contingencies , to meet its requirements for its programs. These programs could be adversely affected by a significant interruption in preclinical and clinical testing, as well as the supply of active pharmaceutical ingredients and formulated drugs.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies, and similar techniques.
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation. Depreciation expense is recognized using the straight-line method over the useful life of the asset. Laboratory and computer equipment are depreciated over three years . Furniture and fixtures are depreciated over five years . Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the underlying asset. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Upon retirement or sale, the cost and related accumulated depreciation of assets disposed of are removed from the accounts and any resulting gain or loss is included in loss from operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured in an amount by which the book values of the assets exceed their fair value. The Company did no t recognize any impairment losses for the years ended December 31, 2022, 2021, and 2020 .
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include salaries, stock-based compensation and benefits of employees, third-party license fees, and other operational costs related to the Company’s research and development activities, including allocated facility-related expenses and external costs of outside vendors engaged to conduct both preclinical studies and clinical trials. Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made.
Patent Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses.
Stock-Based Compensation	Stock-Based Compensation The Company measures stock options and other stock-based awards granted to employees, directors, and other consultants based on their fair value on the date of grant and recognizes compensation expense for such awards over the requisite service period, which is generally the vesting period of the respective award. The Company recognizes the impact of forfeitures on stock-based compensation expense as they occur. The Company estimates the fair value of each stock option grant on the date of grant using the Black-Scholes option pricing model, which uses as inputs the fair value of the Company’s common stock and assumptions the Company makes for the expected term of the stock options, the risk-free interest rate and volatility of its common stock for a period that approximates the expected term of the stock options, and the expected dividend yield. Prior to the Company’s initial public offering of common stock in 2020, the estimated fair value of its common stock was determined by the board of directors, or compensation committee thereof, as of the date of each option grant, with input from management, considering the most recently available third-party valuations of common stock and the board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent valuation through the date of the grant. Historically, such independent third-party valuations of the Company’s equity instruments were performed contemporaneously with identified value inflection points. Furthermore, such third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation (the “Practice Aid”). The Practice Aid identifies various available methods for allocating the enterprise value across classes of series of capital stock in determining the fair value of the Company’s common stock at each valuation date. Following the Company’s initial public offering of common stock in 2020 , in connection with the accounting for stock options and other awards the Company may grant, the fair value of the Company’s common stock is determined based on the quoted market price of its common stock.
Revenue Recognition	Revenue Recognition The Company accounts for revenue recognition in accordance with ASC 606, pursuant to which an entity recognizes revenue when its customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, the entity performs the following five steps: (i) identify the contract(s) with customer(s); (ii) identify the performance obligation(s) in the contract(s); (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligation(s) in the contract(s); and (v) recognize revenue when (or as) the entity satisfies a performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within the contract and determines those that are performance obligations. The Company then determines the transaction price and allocates it to the performance obligations. As part of the accounting for such arrangements, the Company must use judgment to determine: (a) the number of performance obligations based on the determination under step (ii) above; (b) the transaction price under step (iii) above, including the determination of whether milestones or other variable consideration should be included in the transaction price; and (c) the stand-alone selling price for each performance obligation identified in the contract for the allocation of the transaction price in step (iv) above. The Company utilizes key assumptions and judgments in (a) determining the stand-alone selling price for each performance obligation, which may include discounted cash flow models, evaluation of comparable transactions, and pricing considered in negotiating the transaction and estimated costs, and (b) determining how the transaction price is allocated amongst the performance obligations. The Company also uses judgment to determine whether milestones or other variable consideration should be included in the transaction price. As part of management’s evaluation of the transaction price, the Company considers numerous factors, including whether the achievement of the milestones is outside of the Company's control, contingent upon the efforts of others, or subject to scientific risks of success. If the Company concludes it is probable that a significant revenue reversal would not occur, the associated milestone payment is included in the transaction price. Milestone payments that are not within the Company's control, such as regulatory approvals, are generally not considered probable until those milestones are achieved. The Company re-evaluates the transaction price, including estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. For revenue-based royalties, including milestone payments based on the level of sales, the Company will include royalties in the transaction price at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty is allocated has been satisfied (or partially satisfied). Once the performance obligations are identified, the transaction price is allocated to each performance obligation based on the relative stand-alone selling price. The Company then recognizes as revenue the amount of the transaction price allocated to the respective performance obligation when (or as) it is satisfied, either at a point in time or over time. If the performance obligation is satisfied over time, the Company recognizes revenue based on the use of either an output or input method.
Collaboration Agreements	Collaboration Agreements The Company enters into collaborative agreements with third parties to research, develop, and commercialize drug candidates, pursuant to which the risks and rewards for such activities are shared between the parties. Such arrangements also provide for cost sharing between the parties during the research and development phase, as well as potential future profit share payments during the commercialization phase. In general, such contracts are evaluated under the provisions of FASB ASC 808, Collaborative Arrangements (“ASC 808”). The amounts receivable and payable for research and development activities are presented net within research and development expense on the consolidated statements of operations and comprehensive loss. As such, the net costs reflect the Company’s share of the ongoing research and development efforts. The amounts receivable and payable for commercialization activities are presented net as either collaboration revenue, separate from revenue from contracts with customers, or collaboration expense on the consolidated statements of operations, as appropriate.
Research and Manufacturing Contracts	Research and Manufacturing Contracts The Company has entered into various research and development contracts with research institutions and other companies whose costs are included in research and development expense in the accompanying consolidated statements of operations and comprehensive loss. These agreements are generally cancelable and related payments are recorded as research and development expenses as the underlying services are performed. When evaluating the adequacy of the expense recognized, the Company analyzes progress of the services, including the phase or completion of events, invoices received, and contracted costs. Judgments and estimates are made in determining the expense recognized and the related prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical estimates have not been materially different from the actual costs.
Lease Agreements	Lease Agreements Pursuant to ASC 842, Leases , the Company determines if an arrangement is or contains a lease at inception. For leases with a term of 12 months or less, the Company does not recognize a right-of-use asset or lease liability. The Company’s operating leases are recognized on its consolidated balance sheets as other noncurrent assets, other current liabilities, and other noncurrent liabilities. The Company does not have any finance leases. Right-of-use assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As the Company’s leases typically do not provide an implicit rate, the Company uses an estimate of its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Operating lease right-of-use assets also include the effect of any lease payments made prior to commencement and exclude lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are accounted for as a combined element.
Acquired In-Process Research and Development	Acquired In-Process Research and Development In an asset acquisition, the cost allocated to acquire in-process research and development (“IPR&D”) with no alternative future use is charged to expense at the acquisition date. Please refer to Note 10, Acquisition of ZebiAI , for a more detailed description of the accounting policies applied to the Company's only asset acquisition during the three years ended December 31, 2022 .
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss, as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. For the years ended December 31, 2022, 2021, and 2020 , other comprehensive income (loss) consisted of changes in unrealized gains and losses from available-for-sale investments.
Net Loss Per Common Share	Net Loss per Common Share Basic net loss per share is computed using the weighted-average number of common shares outstanding during the period. Diluted net loss per share is computed using the sum of the weighted-average number of common shares outstanding during the period and the effect of any dilutive securities. The Company applies the two-class method to calculate its basic and diluted net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. The Company’s participating securities contractually entitle the holders of such shares to participate in dividends, but do not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss, such losses are not allocated to such participating securities. Additionally, in periods in which the Company reports a net loss, diluted net loss per share is the same as basic net loss per share, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. For additional discussion of net loss per common share, please refer to Note 9, Net Loss per Share.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on differences between the financial statement carrying amounts and the tax bases of the assets and liabilities using the enacted tax rates in effect in the years in which the differences are expected to reverse. A valuation allowance against deferred tax assets is recorded if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements As noted above, the Company adopted ASU 2016-13, as well as the related amendments thereto, on January 1, 2022. The adoption of ASU 2016-13, as well as the related amendments thereto, did not have a material impact on the Company’s consolidated financial statements or disclosures.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. The Company does not believe that the adoption of any recently issued standards have or may have a material impact on its consolidated financial statements and disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis and Level of the Fair Value Hierarchy	The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair Value Measurements as of Level 1 Level 2 Level 3 Total (in thousands) Assets Cash equivalents: Money market funds $ 118,446 $ — $ — $ 118,446 U.S. treasury bills — 9,950 — 9,950 Total cash equivalents 118,446 9,950 — 128,396 Investments: U.S. treasury bills — 466,603 — 466,603 U.S. agency securities — 380,520 — 380,520 Total investments — 847,123 — 847,123 Total assets $ 118,446 $ 857,073 $ — $ 975,519 Liabilities Contingent Milestone Payments $ — $ — $ 27,378 $ 27,378 Total liabilities $ — $ — $ 27,378 $ 27,378 Fair Value Measurements as of Level 1 Level 2 Level 3 Total (in thousands) Assets Cash equivalents: Money market funds $ 251,891 $ — $ — $ 251,891 Total cash equivalents 251,891 — — 251,891 Investments: U.S. treasury bills — 469,386 — 469,386 U.S. agency securities — 208,568 — 208,568 Total investments — 677,954 — 677,954 Total assets $ 251,891 $ 677,954 $ — $ 929,845 Liabilities Contingent Milestone Payments $ — $ — $ 45,258 $ 45,258 Total liabilities $ — $ — $ 45,258 $ 45,258
Schedule of Changes in Contingent Consideration Liability	The following table reconciles the change in the contingent consideration liability: Year Ended December 31, 2022 2021 2020 (in thousands) Balance at beginning of period $ 50,258 $ — $ — Fair value of contingent consideration upon acquisition — 47,422 — Change in fair value of Contingent Milestone Payments ( 11,677 ) 2,836 — Common stock issued upon milestone achievement ( 6,203 ) — — $ 32,378 $ 50,258 $ —

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2022
Schedule of Investments [Abstract]
Summary of Fair Value of Available-for-Sale Investments by Type of Security	The fair value of available-for-sale investments by type of security was as follows: December 31, 2022 Amortized Unrealized Unrealized Fair (in thousands) Investments: U.S. treasury bills $ 356,728 $ 9 $ ( 5,523 ) $ 351,214 U.S. agency securities 236,483 49 ( 3,104 ) 233,428 Total investments with a maturity of one year or less 593,211 58 ( 8,627 ) 584,642 U.S. treasury bills 116,290 14 ( 915 ) 115,389 U.S. agency securities 148,042 36 ( 986 ) 147,092 Total investments with a maturity of one to two years 264,332 50 ( 1,901 ) 262,481 Total investments $ 857,543 $ 108 $ ( 10,528 ) $ 847,123 December 31, 2021 Amortized Unrealized Unrealized Fair (in thousands) Investments: U.S. treasury bills $ 189,406 $ — $ ( 228 ) $ 189,178 U.S. agency securities 108,895 — ( 138 ) 108,757 Total investments with a maturity of one year or less 298,301 — ( 366 ) 297,935 U.S. treasury bills 280,743 — ( 535 ) 280,208 U.S. agency securities 99,998 — ( 187 ) 99,811 Total investments with a maturity of one to two years 380,741 — ( 722 ) 380,019 Total investments $ 679,042 $ — $ ( 1,088 ) $ 677,954
Available-for-sale Debt Securities in an Unrealized Loss Position	The following table summarizes the Company's available-for-sale debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded at December 31, 2022, aggregated by major security type and length of time in a continuous unrealized loss position: Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized (in thousands) U.S. treasury bills $ 143,089 $ ( 1,860 ) $ 275,445 $ ( 4,578 ) $ 418,534 $ ( 6,438 ) U.S. agency securities 190,468 ( 1,649 ) 97,305 ( 2,441 ) 287,773 ( 4,090 ) Total $ 333,557 $ ( 3,509 ) $ 372,750 $ ( 7,019 ) $ 706,307 $ ( 10,528 ) The following table summarizes our available-for-sale debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded at December 31, 2021, aggregated by major security type and length of time in a continuous unrealized loss position: Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Fair Value Unrealized Fair Value Unrealized (in thousands) U.S. treasury bills $ 469,386 $ ( 763 ) $ — $ — $ 469,386 $ ( 763 ) U.S. agency securities 208,568 ( 325 ) — — 208,568 ( 325 ) Total $ 677,954 $ ( 1,088 ) $ — $ — $ 677,954 $ ( 1,088 ) As summarized in the tables immediately above, the Company held 126 and 88 debt securities that were in an unrealized loss position as of December 31, 2022 and 2021, respectively. The unrealized losses at December 31, 2022 and 2021 were attributable to changes in interest rates and the unrealized losses do not represent credit losses. The Company does not intend to sell these securities and it is not more likely than not that it will be required to sell them before recovery of their amortized cost basis.

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following: December 31, 2022 2021 (in thousands) Property and equipment: Laboratory equipment $ 21,472 $ 15,797 Leasehold improvements 3,826 2,897 Computer equipment 1,743 1,093 Furniture and fixtures 1,762 989 Construction in process 1,220 134 30,023 20,910 Less: accumulated depreciation ( 18,389 ) ( 14,367 ) Total property and equipment, net $ 11,634 $ 6,543

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following: December 31, 2022 2021 (in thousands) External research and development costs $ 19,276 $ 9,353 Consulting and professional services 831 1,109 Compensation costs 1,043 593 Other 1,553 2,502 Total accrued expenses $ 22,703 $ 13,557

Stock Compensation (Tables)

Stock Compensation (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Schedule of Total Stock-based Compensation Expense Recognized	In connection with all stock-based payments, total stock-based compensation expense recognized was as follows: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 30,671 $ 24,922 $ 14,691 General and administrative expenses 25,467 23,532 17,269 $ 56,138 $ 48,454 $ 31,960
Schedule of Restricted Stock Units Activity	The following table summarizes activity for RSUs under the 2020 Stock Plan for the year ended December 31, 2022: Number of Shares Underlying RSUs Weighted-Average Unvested at December 31, 2021 691,205 $ 34.51 Granted 1,389,696 20.85 Vested ( 398,330 ) 27.75 Cancelled ( 115,811 ) 27.59 Unvested at December 31, 2022 1,566,760 24.62
Schedule of Estimated Fair Value of Employee Stock Purchase Plan	The following table summarizes activity under the Company's ESPP from the initial offering period, or July 1, 2021 through December 31, 2021, through December 31, 2022, including (a) after-tax contributions from employees, (b) shares purchased, and (c) assumptions underlying the Black-Scholes option pricing model to estimate the fair value of the option component of the shares purchased under the ESPP in each period. July 1, 2022 to January 1, 2022 to July 1, 2021 to December 31, 2022 June 30, 2022 December 31, 2021 Purchase date December 31, 2022 June 30, 2022 December 31, 2021 After-tax contributions (in thousands) $ 549 $ 1,137 $ 1,141 Shares of common stock purchased 43,160 79,859 43,685 Expected term (in years) 0.50 0.50 0.50 Risk-free interest rate 2.5 % 0.2 % 0.1 % Expected volatility 89.6 % 66.2 % 65.1 % Expected dividend yield 0.0 % 0.0 % 0.0 %
Time-Based Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Schedule of Stock Option Activity	The following table summarizes activity for time-based stock options under the 2016 Stock Plan and the 2020 Stock Plan for the year ended December 31, 2022: Number of Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2021 6,906,367 $ 16.80 7.90 $ 111,021 Granted 3,658,461 20.58 Exercised ( 737,144 ) 4.47 Cancelled ( 551,132 ) 32.60 Outstanding at December 31, 2022 9,276,552 $ 18.33 7.85 $ 34,647 Vested at December 31, 2022 4,415,876 $ 13.49 6.94 $ 29,401 Unvested at December 31, 2022 4,860,676 $ 22.73 8.67 $ 5,246
Schedule of Estimated Fair Value of Stock Options	The following table summarizes the assumptions used in calculating the fair value of the time-based stock options granted. Year Ended December 31, 2022 2021 2020 Expected term (in years) 6.25 6.25 6.25 Risk-free interest rate 1.6 % to 4.2 % 0.6 % to 1.6 % 0.4 % to 1.8 % Expected volatility 72.7 % to 76.2 % 74.7 % to 76.6 % 73.5 % to 77.6 % Expected dividend yield 0.0 % 0.0 % 0.0 %
Performance-Based Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Schedule of Stock Option Activity	The following table summarizes activity for performance-based stock options for the year ended December 31, 2022: Number of Weighted-Average Weighted-Average Aggregate Outstanding at December 31, 2021 1,813,260 $ 5.41 8.11 $ 45,912 Exercised ( 20,729 ) 5.22 Cancelled ( 18,348 ) 5.22 Outstanding at December 31, 2022 1,774,183 $ 5.41 7.18 $ 17,128 Vested at December 31, 2022 927,394 $ 5.22 7.17 $ 9,014 Unvested at December 31, 2022 846,789 $ 5.62 7.19 $ 8,114

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share	The following table summarizes the computation of basic and diluted net loss per share of the Company: Year Ended December 31, 2022 2021 2020 (in thousands, except share and per share data) Net loss $ ( 290,509 ) $ ( 363,872 ) $ ( 52,412 ) Dividend upon extinguishment of Series C Preferred Stock — — ( 177,789 ) Net loss attributable to common stockholders $ ( 290,509 ) $ ( 363,872 ) $ ( 230,201 ) Net loss attributable to common stockholders per share, basic and diluted $ ( 2.59 ) $ ( 3.82 ) $ ( 5.40 ) Weighted average shares of common stock, basic and diluted 112,233,649 95,136,719 42,619,582
Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share	he Company excluded the following potentially dilutive securities, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share for the years ended December 31, 2022, 2021, and 2020 , as the effect would be anti-dilutive and reduce the net loss per share calculated for each period. Year Ended December 31, 2022 2021 2020 Options to purchase common stock 11,050,735 8,719,627 7,697,058 Unvested restricted stock — — 84,489 Unvested restricted stock units 1,566,760 691,205 — 12,617,495 9,410,832 7,781,547

Acquisition of ZebiAI (Tables)

Acquisition of ZebiAI (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combination, Description [Abstract]
Summary of Net Assets Acquired Based on Estimated Fair Values	The following table summarizes net assets acquired based on their estimated fair values as of the Acquisition Date: Amount (in thousands) Acquired IPR&D asset $ 123,000 Loss on initial consolidation of VIE 11,855 Assets obtained in asset acquisition 662 Liabilities assumed in asset acquisition ( 2,330 ) Intangible asset 2,300 Net acquired assets $ 135,487

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Summary of Reconciliation of Expected Income Tax (Benefit) Computed Using Federal Statutory Income Tax Rate to Effective Income Tax Rate	A reconciliation of the expected income tax (benefit) computed using the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows for the years ended December 31, 2022, 2021, and 2020: December 31, 2022 2021 2020 Income tax computed at federal statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.5 % 5.7 % 5.7 % Change in valuation allowance ( 30.2 )% ( 20.5 )% ( 27.3 )% IPR&D — ( 7.0 )% — R&D credit carryovers 4.2 % 2.2 % 7.6 % Stock-based compensation ( 2.1 )% ( 0.4 )% ( 6.7 )% Permanent differences ( 0.6 )% ( 1.0 )% ( 0.3 )% Total 0.0 % 0.0 % 0.0 %
Summary of Deferred Tax Assets and Liabilities	The Company’s deferred tax assets and liabilities at December 31, 2022 and 2021, consist of the following: December 31, 2022 2021 (in thousands) Deferred tax assets: Net operating losses $ 119,688 $ 108,800 Tax credit carryforwards 30,593 18,288 Capitalized R&D 55,303 — Lease liability 18,307 6,010 Stock-based compensation 14,510 8,374 Intangibles 1,875 1,859 Depreciation and amortization 568 477 Other 7,270 4,304 Total gross deferred tax assets 248,114 148,112 Valuation allowance ( 230,518 ) ( 142,674 ) Net deferred tax assets 17,596 5,438 Deferred tax liabilities Operating lease assets ( 17,596 ) ( 5,438 ) Total deferred tax liabilities ( 17,596 ) ( 5,438 ) $ — $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
399 Binney Street [Member]
Operating Leased Assets [Line Items]
Schedule of Operating Leases Presentation in Consolidated Balance Sheets	The following table summarizes the presentation of amounts recorded on the Company’s consolidated balance sheets for the operating lease at 399 Binney Street as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 18,828 $ 20,780 Liabilities: Operating lease liabilities $ 2,170 $ 1,844 Operating lease liabilities, net of current portion 18,886 21,056 Total operating lease liabilities $ 21,056 $ 22,900
Summary of Operating Lease Presentation in Consolidated Statements of Operations and Comprehensive Loss	The following table summarizes the effect of lease costs for the Company's operating lease at 399 Binney Street on the Company’s condensed consolidated statements of operations and comprehensive loss for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 3,350 $ 3,262 $ 3,273 General and administrative expenses 893 1,002 899 $ 4,243 $ 4,264 $ 4,172
Summary of Future Minimum Lease Payments	The minimum lease payments for the Company’s operating lease at 399 Binney Street as of December 31, 2022 for the next five years and thereafter are expected to be as follows: Year Ending December 31, Amount (in thousands) 2023 $ 4,254 2024 4,377 2025 4,503 2026 4,634 2027 4,768 Thereafter 6,557 Total lease payments 29,093 Less: interest ( 8,037 ) Present value of operating lease liabilities $ 21,056
60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Schedule of Operating Leases Presentation in Consolidated Balance Sheets	The following table summarizes the presentation of amounts recorded on the Company’s consolidated balance sheets for the operating lease at 60 Hampshire Street as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 (in thousands) Assets: Operating lease assets $ 44,926 $ — Liabilities: Current operating lease liabilities $ 2,106 $ — Operating lease liabilities, net of current portion 34,580 — Total operating lease liabilities $ 36,686 $ —
Summary of Operating Lease Presentation in Consolidated Statements of Operations and Comprehensive Loss	The following table summarizes the effect of lease costs for the Company's operating lease at 60 Hampshire Street on the Company’s condensed consolidated statements of operations and comprehensive loss for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 (in thousands) Research and development expenses $ 2,675 $ — $ — General and administrative expenses 564 — — $ 3,239 $ — $ —
Summary of Future Minimum Lease Payments	The minimum lease payments for the Company’s operating lease at 60 Hampshire Street as of December 31, 2022 for the next five years and thereafter are expected to be as follows: Year Ending December 31, Amount (in thousands) 2023 $ 4,966 2024 5,109 2025 5,257 2026 5,409 2027 5,565 Thereafter 27,084 Total lease payments 53,390 Less: interest ( 16,704 ) Present value of operating lease liabilities $ 36,686

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Detail) $ in Thousands	Dec. 31, 2022 USD ($) Program	Dec. 31, 2021 USD ($)
Nature of Business and Basis of Presentation [Line Items]
Accumulated deficit | $	$ (1,058,609)	$ (768,100)
HR+/HER2- Breast Cancer [Member]
Nature of Business and Basis of Presentation [Line Items]
Number of discovery stage programs	3
Precision Oncology and Genetic Disease Indications [Member]
Nature of Business and Basis of Presentation [Line Items]
Number of discovery stage programs	5

Significant Accounting Polici_2

Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
Maturity days for highly liquid investments	The Company considers all short-term, highly liquid investments with original maturities of 90 days or less at acquisition date to be cash equivalents.
Restricted cash	$ 2,578,000	$ 2,578,000
Operating lease option to extent	true
Operating lease option to terminate	true
Impairment loss of long lived assets	$ 0	0	$ 0
Description of Income tax benefit, likelihood of realized upon ultimate settlement	greater than 50%
Laboratory and Computer Equipment [Member]
Significant Accounting Policies [Line Items]
Property and equipment, useful life	3 years
Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Property and equipment, useful life	5 years
Letter of Credit [Member]
Significant Accounting Policies [Line Items]
Restricted cash	$ 2,600,000	$ 2,600,000

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis and Level of the Fair Value Hierarchy (Detail) - Fair value on a recurring basis [Member] - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Investments:
Total assets	$ 975,519	$ 929,845
Liabilities
Contingent Milestone Payments	27,378	45,258
Total liabilities	27,378	45,258
Investments [Member]
Investments:
Total investments	847,123	677,954
Investments [Member] | U.S. treasury bills [Member]
Investments:
Total investments	466,603	469,386
Investments [Member] | U.S. agency securities [Member]
Investments:
Total investments	380,520	208,568
Level 1 [Member]
Investments:
Total assets	118,446	251,891
Level 2 [Member]
Investments:
Total assets	857,073	677,954
Level 2 [Member] | Investments [Member]
Investments:
Total investments	847,123	677,954
Level 2 [Member] | Investments [Member] | U.S. treasury bills [Member]
Investments:
Total investments	466,603	469,386
Level 2 [Member] | Investments [Member] | U.S. agency securities [Member]
Investments:
Total investments	380,520	208,568
Level 3 [Member]
Liabilities
Contingent Milestone Payments	27,378	45,258
Total liabilities	27,378	45,258
Cash equivalents [Member]
Cash equivalents:
Assets, fair value	128,396	251,891
Cash equivalents [Member] | Money market funds [Member]
Cash equivalents:
Assets, fair value	118,446	251,891
Cash equivalents [Member] | U.S. treasury bills [Member]
Cash equivalents:
Assets, fair value	9,950
Cash equivalents [Member] | Level 1 [Member]
Cash equivalents:
Assets, fair value	118,446	251,891
Cash equivalents [Member] | Level 1 [Member] | Money market funds [Member]
Cash equivalents:
Assets, fair value	118,446	$ 251,891
Cash equivalents [Member] | Level 2 [Member]
Cash equivalents:
Assets, fair value	9,950
Cash equivalents [Member] | Level 2 [Member] | U.S. treasury bills [Member]
Cash equivalents:
Assets, fair value	$ 9,950

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - ZebiAI [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Apr. 22, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business combination contingent consideration liability, contingent earnout payments		$ 100
Number of common stock issued upon milestone achievement	301,939
Contingent consideration payment description	The outstanding Contingent Milestone Payments are payable in shares of common stock based on a fixed amount assigned to each milestone and the average closing price of the Company’s common stock for the 5-day period prior to the milestone achievement.
Number of shares that would be issued upon milestone achievement	4,954,739
Average stock price upon milestone settlement	$ 14.58
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business combination contingent consideration liability, milestones payments		85
Business combination contingent consideration liability, contingent earnout payments		$ 100

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Changes in Fair Value of Contingent Consideration Liability (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	$ 50,258
Fair value of Contingent Milestone Payments upon acquisition		$ 47,422
Change in fair value of Contingent Milestone Payments	(11,677)	2,836
Common stock issued upon milestone achievement	(6,203)
Ending balance	$ 32,378	$ 50,258

Investments - Summary of Fair V

Investments - Summary of Fair Value of Available-for-Sale Investments by Type of Security (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	$ 857,543	$ 679,042
Unrealized Gains	108
Unrealized Losses	(10,528)	(1,088)
Fair Value	847,123	677,954
Investments with a maturity of one year or less [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	593,211	298,301
Unrealized Gains	58
Unrealized Losses	(8,627)	(366)
Fair Value	584,642	297,935
Investments with a maturity of one to two years [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	264,332	380,741
Unrealized Gains	50
Unrealized Losses	(1,901)	(722)
Fair Value	262,481	380,019
U.S treasury bills [Member] | Investments with a maturity of one year or less [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	356,728	189,406
Unrealized Gains	9
Unrealized Losses	(5,523)	(228)
Fair Value	351,214	189,178
U.S treasury bills [Member] | Investments with a maturity of one to two years [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	116,290	280,743
Unrealized Gains	14
Unrealized Losses	(915)	(535)
Fair Value	115,389	280,208
U.S agency securities [Member] | Investments with a maturity of one year or less [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	236,483	108,895
Unrealized Gains	49
Unrealized Losses	(3,104)	(138)
Fair Value	233,428	108,757
U.S agency securities [Member] | Investments with a maturity of one to two years [Member]
Schedule Of Held To Maturity Securities [Line Items]
Amortized Cost	148,042	99,998
Unrealized Gains	36
Unrealized Losses	(986)	(187)
Fair Value	$ 147,092	$ 99,811

Investments - Additional Inform

Investments - Additional Information (Detail) $ in Thousands	Dec. 31, 2022 USD ($) DebtSecurity	Dec. 31, 2021 DebtSecurity
Investments [Abstract]
Debt securities unrealized loss position | DebtSecurity	126	88
Debt securities in continuous unrealized loss position for more than 12 months | $	$ 372,750

Investments - Available-for-sal

Investments - Available-for-sale Debt Securities in an Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 Months, Fair Value	$ 333,557	$ 677,954
Less than 12 Months, Unrealized Losses	(3,509)	(1,088)
12 Months or Longer, Fair Value	372,750
12 Months or Longer, Unrealized Losses	(7,019)
Total, Fair Value	706,307	677,954
Total, Unrealized Losses	(10,528)	(1,088)
U.S treasury bills [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 Months, Fair Value	143,089	469,386
Less than 12 Months, Unrealized Losses	(1,860)	(763)
12 Months or Longer, Fair Value	275,445
12 Months or Longer, Unrealized Losses	(4,578)
Total, Fair Value	418,534	469,386
Total, Unrealized Losses	(6,438)	(763)
U.S agency securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Less than 12 Months, Fair Value	190,468	208,568
Less than 12 Months, Unrealized Losses	(1,649)	(325)
12 Months or Longer, Fair Value	97,305
12 Months or Longer, Unrealized Losses	(2,441)
Total, Fair Value	287,773	208,568
Total, Unrealized Losses	$ (4,090)	$ (325)

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant and Equipment [Line Items]
Property and equipment	$ 30,023	$ 20,910
Less: accumulated depreciation	(18,389)	(14,367)
Total property and equipment, net	11,634	6,543
Laboratory Equipment [Member]
Property Plant and Equipment [Line Items]
Property and equipment	21,472	15,797
Leasehold Improvements [Member]
Property Plant and Equipment [Line Items]
Property and equipment	3,826	2,897
Computer Equipment [Member]
Property Plant and Equipment [Line Items]
Property and equipment	1,743	1,093
Furniture and Fixtures [Member]
Property Plant and Equipment [Line Items]
Property and equipment	1,762	989
Construction in Process [Member]
Property Plant and Equipment [Line Items]
Property and equipment	$ 1,220	$ 134

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 4,130	$ 3,925	$ 3,549

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
External research and development costs	$ 19,276	$ 9,353
Consulting and professional services	831	1,109
Compensation costs	1,043	593
Other	1,553	2,502
Total accrued expenses	$ 22,703	$ 13,557

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($)	1 Months Ended			12 Months Ended
	Sep. 30, 2022	Oct. 31, 2021	Aug. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Voting Rights				Each share of common stock entitles the stockholder to one vote on all matters submitted to a vote of the Company’s stockholders.
Dividends declared				$ 0
Common stock restriction period				4 years
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares sold	11,320,755	15,188,679		11,320,755	15,188,679
Additional shares issued		1,981,132
Offering price per share	$ 26.50	$ 26.50
Net proceeds	$ 284,700,000	$ 382,200,000
Underwriting discounts, commissions and other offering expenses	$ 15,300,000	$ 20,300,000
Common Stock [Member] | Sales Agreement [Member] | Cowen [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate gross proceeds from the sale of shares			$ 300,000,000
Common stock shares sold				0
Maximum [Member] | Sales Agreement [Member] | Cowen [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of commission owed to sales agent under at-the-market offering			3%

Stock Compensation - Additional

Stock Compensation - Additional Information (Detail) - USD ($)			6 Months Ended			12 Months Ended
	Jan. 01, 2022	Jan. 01, 2021	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Aug. 01, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense						$ 56,138,000	$ 48,454,000	$ 31,960,000
Time-Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value						$ 15,500,000	$ 32,400,000	$ 2,400,000
Weighted average grant date fair value of stock option granted						$ 13.67	$ 22.95	$ 14.77
Total unrecognized compensation cost related to the unvested stock-based awards, Value			$ 66,700,000			$ 66,700,000
Total unrecognized compensation cost related to the unvested stock-based awards, Weighted average period						1 year 5 months 19 days
Number of stock options granted						3,658,461
Performance-Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value						$ 400,000	$ 1,100,000
Weighted average grant date fair value of stock option granted							$ 20.28	$ 37.48
Total unrecognized compensation cost related to the unvested stock-based awards, Value			8,500,000			$ 8,500,000
Total unrecognized compensation cost related to the unvested stock-based awards, Weighted average period						9 months 14 days
Number of stock options granted						0
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares, vested						$ 8,600,000
Total unrecognized compensation cost related to the unvested stock-based awards, Value			$ 35,000,000			$ 35,000,000
Total unrecognized compensation cost related to the unvested stock-based awards, Weighted average period						1 year 6 months 18 days
2016 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Award, Number of Shares Authorized									0
2020 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Award, Number of Shares Authorized			10,783,577			10,783,577		8,376,080
Percentage of additional common stock authorized		5%
Increase in number of shares of common stock available for issuance	5,410,515
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Award, Number of Shares Authorized			2,906,999			2,906,999		1,092,532
Percentage of additional common stock authorized								1%
Increase in number of shares of common stock available for issuance	1,082,103
Percentage of fair market value of common stock								85%
Shares authorized additionally under ESPP		2,185,064
Total unrecognized compensation cost related to the unvested stock-based awards, Value			$ 0			$ 0
Shares of common stock purchased			43,160	79,859	43,685

Stock Compensation - Schedule o

Stock Compensation - Schedule of Total Stock-based Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 56,138	$ 48,454	$ 31,960
Research and development expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	30,671	24,922	14,691
General and administrative expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 25,467	$ 23,532	$ 17,269

Stock Compensation - Schedule_2

Stock Compensation - Schedule of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Time-Based Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options and Warrants Outstanding, Number of Shares Beginning Balance	6,906,367
Granted, Number of Shares	3,658,461
Exercised, Number of Shares	(737,144)
Cancelled, Number of Shares	(551,132)
Options and Warrants Outstanding, Number of Shares Ending Balance	9,276,552	6,906,367
Shares, Vested	4,415,876
Shares, Unvested	4,860,676
Weighted Average Exercise Price Per Share, Outstanding Beginning Balance	$ 16.80
Weighted Average Exercise Price Per Share, Granted	20.58
Weighted Average Exercise Price Per Share, Exercised	4.47
Weighted Average Exercise Price Per Share, Cancelled	32.60
Weighted Average Exercise Price Per Share, Outstanding Ending Balance	18.33	$ 16.80
Weighted Average Exercise Price Per Share, Vested	13.49
Weighted Average Exercise Price Per Share, Unvested	$ 22.73
Weighted Average Remaining Contractual Life, Outstanding	7 years 10 months 6 days	7 years 10 months 24 days
Weighted Average Remaining Contractual Life, Vested	6 years 11 months 8 days
Weighted Average Remaining Contractual Life, Unvested	8 years 8 months 1 day
Aggregate Intrinsic Value, Outstanding Value	$ 34,647	$ 111,021
Aggregate Intrinsic Value, Vested Value	29,401
Aggregate Intrinsic Value, Unvested Value	$ 5,246
Performance-Based Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options and Warrants Outstanding, Number of Shares Beginning Balance	1,813,260
Granted, Number of Shares	0
Exercised, Number of Shares	(20,729)
Cancelled, Number of Shares	(18,348)
Options and Warrants Outstanding, Number of Shares Ending Balance	1,774,183	1,813,260
Shares, Vested	927,394
Shares, Unvested	846,789
Weighted Average Exercise Price Per Share, Outstanding Beginning Balance	$ 5.41
Weighted Average Exercise Price Per Share, Exercised	5.22
Weighted Average Exercise Price Per Share, Cancelled	5.22
Weighted Average Exercise Price Per Share, Outstanding Ending Balance	5.41	$ 5.41
Weighted Average Exercise Price Per Share, Vested	5.22
Weighted Average Exercise Price Per Share, Unvested	$ 5.62
Weighted Average Remaining Contractual Life, Outstanding	7 years 2 months 4 days	8 years 1 month 9 days
Weighted Average Remaining Contractual Life, Vested	7 years 2 months 1 day
Weighted Average Remaining Contractual Life, Unvested	7 years 2 months 8 days
Aggregate Intrinsic Value, Outstanding Value	$ 17,128	$ 45,912
Aggregate Intrinsic Value, Vested Value	9,014
Aggregate Intrinsic Value, Unvested Value	$ 8,114

Stock Compensation - Schedule_3

Stock Compensation - Schedule of Estimated Fair Value of Stock Options (Detail) - Time-Based Stock Options [Member]	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)	6 years 3 months	6 years 3 months	6 years 3 months
Risk-free interest rate minimum	1.60%	0.60%	0.40%
Risk-free interest rate maximum	4.20%	1.60%	1.80%
Expected volatility rate minimum	72.70%	74.70%	73.50%
Expected volatility rate maximum	76.20%	76.60%	77.60%
Expected dividend yield	0%	0%	0%

Stock Compensation - Schedule_4

Stock Compensation - Schedule of Restricted Stock Units Activity (Details) - Restricted Stock Units (RSUs) [Member]	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares - Beginning | shares	691,205
Number of Shares Underlying RSUs, Granted | shares	1,389,696
Number of Shares Underlying RSUs, Vested | shares	(398,330)
Number of Shares Underlying RSUs, Cancelled | shares	(115,811)
Shares - Ending | shares	1,566,760
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 34.51
Weighted Average Grant Date Fair Value, Granted | $ / shares	20.85
Weighted Average Grant Date Fair Value, Vested | $ / shares	27.75
Weighted Average Grant Date Fair Value, Cancelled | $ / shares	27.59
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 24.62

Stock Compensation - Schedule_5

Stock Compensation - Schedule of Estimated Fair Value of Employee Stock Purchase Plan (Details) - USD ($) $ in Thousands	6 Months Ended			12 Months Ended
	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
After-tax contributions				$ 1,686	$ 1,141
Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Purchase date	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
After-tax contributions	$ 549	$ 1,137	$ 1,141
Shares of common stock purchased	43,160	79,859	43,685
Expected term (in years)	6 months	6 months	6 months
Risk-free interest rate	2.50%	0.20%	0.10%
Expected volatility	89.60%	66.20%	65.10%
Expected dividend yield	0%	0%	0%

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net loss	$ (290,509)	$ (363,872)	$ (52,412)
Dividend upon extinguishment of Series C Preferred Stock	0		(177,789)
Net loss attributable to common stockholders	$ (290,509)	$ (363,872)	$ (230,201)
Net loss attributable to common stockholders per share, basic	$ (2.59)	$ (3.82)	$ (5.40)
Net loss attributable to common stockholders per share, diluted	$ (2.59)	$ (3.82)	$ (5.40)
Weighted average shares of common stock, basic	112,233,649	95,136,719	42,619,582
Weighted average shares of common stock, diluted	112,233,649	95,136,719	42,619,582

Net Loss Per Share - Additional

Net Loss Per Share - Additional Information (Detail) - $ / shares	Jul. 08, 2020	Jul. 07, 2020
Series C Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Preferred Stock Convertible Conversion Price	$ 3.027603	$ 3.21

Net Loss Per Share - Summary _2

Net Loss Per Share - Summary of Antidilutive Securities Excluded From Computation of Earnings Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	12,617,495	9,410,832	7,781,547
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	11,050,735	8,719,627	7,697,058
Unvested restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			84,489
Unvested restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,566,760	691,205

Acquisition of ZebiAI - Additio

Acquisition of ZebiAI - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Apr. 22, 2021	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Incremental share-based compensation expense recognized in connection with acquisition			$ 4,600
Fair value of contingent milestone payments and earnout payments		$ 32,378	50,258
ZebiAI [Member]
Business Acquisition [Line Items]
Acquisition date	Apr. 22, 2021
Payment for upfront consideration	$ 20,000
Aggregate fair value consideration transferred	61,800
Milestone payments	$ 85,000
Percentage of payment related to collaboration or other agreements	10%
Business combination contingent consideration liability, contingent earnout payments	$ 100,000
Consideration transferred	135,500
Loss on initial consolidation of VIE	$ 11,855
Number of shares that would be issued upon milestone achievement		4,954,739
Contingent consideration payment description		The outstanding Contingent Milestone Payments are payable in shares of common stock based on a fixed amount assigned to each milestone and the average closing price of the Company’s common stock for the 5-day period prior to the milestone achievement.
ZebiAI [Member] | General and Administrative Expense [Member]
Business Acquisition [Line Items]
Acquisition-related costs			$ 900
ZebiAI [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Issued shares of common stock	1,914,219
ZebiAI [Member] | Milestone Payments [Member]
Business Acquisition [Line Items]
Fair value of contingent milestone payments and earnout payments	$ 42,400
ZebiAI [Member] | Earnout Payments [Member]
Business Acquisition [Line Items]
Fair value of contingent milestone payments and earnout payments	$ 5,000

Acquisition of ZebiAI - Summary

Acquisition of ZebiAI - Summary of Net Assets Acquired Based on Estimated Fair Values (Detail) - ZebiAI [Member] $ in Thousands	Apr. 22, 2021 USD ($)
Business Acquisition [Line Items]
Acquired IPR&D asset	$ 123,000
Loss on initial consolidation of VIE	11,855
Assets obtained in asset acquisition	662
Liabilities assumed in asset acquisition	(2,330)
Intangible asset	2,300
Net acquired assets	$ 135,487

Collaboration and License Agree

Collaboration and License Agreement with Genentech, Inc. - Additional Information (Detail) - USD ($)		1 Months Ended			12 Months Ended
	May 13, 2021	Oct. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Collaboration And License Arrangement [Line Items]
Collaboration revenue					$ 1,381,000	$ 3,029,000	$ 82,654,000
Contract asset			$ 4,537,000		4,913,000	4,537,000
Other liabilities			15,000,000			15,000,000
Accrued expenses			13,557,000		22,703,000	13,557,000
Other Liabilities [Member]
Collaboration And License Arrangement [Line Items]
Cash received for milestone payment			15,000,000			15,000,000
Other Current Liabilities [Member]
Collaboration And License Arrangement [Line Items]
Cash received for milestone payment					$ 25,000,000
Genentech [Member] | Genentech Agreement [Member]
Collaboration And License Arrangement [Line Items]
Collaborative arrangement, purpose					In December 2020, the Company and Genentech, Inc. ("Genentech") entered into the Collaboration and License Agreement ("Genentech Agreement"), which granted Genentech a license to develop and commercialize GDC-1971 (formerly known as RLY-1971).
Collaborative arrangement, rights and obligations					In 2022, the Company completed enrollment of a Phase 1a dose escalation study of GDC-1971 as a monotherapy in patients with advanced or metastatic solid tumors ("Phase 1a Trial for GDC-1971"). The Company is also responsible for the one-time transfer of the active pharmaceutical ingredient (“API”) and other materials related to GDC-1971 to Genentech. Genentech will be responsible for conducting any additional clinical development of GDC-1971, including in any combination trials with Genentech’s compound, GDC-6036, that directly binds to and inhibits KRAS G12C, or other compounds. Genentech initiated the cohort of GDC-1971 in combination with GDC-6036 in a Phase 1b trial in July 2021, and a Phase 1b trial of GDC-1971 in combination with atezolizumab, its PD-L1 antibody, in August 2022.
Non-refundable upfront payment				$ 75,000,000
Milestone payment receivable					$ 5,000,000
Maximum additional amount received upon milestone achievement					685,000,000
Collaboration agreement transaction price					86,800,000
Non-refundable milestone payment transfer amount	$ 5,000,000
Non-refundable milestone payment for completion amount					5,000,000
Variable consideration related to reimbursements due for research and development services					1,800,000
Development based milestone payments under agreement					0
Collaboration revenue					1,000,000	2,600,000	82,700,000
Milestone payment received		$ 10,000,000	$ 15,000,000
Genentech [Member] | Genentech Agreement [Member] | Research and Development Services [Member]
Collaboration And License Arrangement [Line Items]
Collaboration revenue					700,000	1,700,000	0
Genentech [Member] | Genentech Agreement [Member] | Transfer of Active Pharmaceutical Ingredients [Member]
Collaboration And License Arrangement [Line Items]
Collaboration revenue					0	$ 300,000	$ 0
Genentech [Member] | Genentech Agreement [Member] | Stand-alone Selling Prices ("SSP") [Member]
Collaboration And License Arrangement [Line Items]
Collaboration agreement transaction price					86,800,000
Genentech [Member] | Genentech Agreement [Member] | Stand-alone Selling Prices ("SSP") [Member] | Transfer of License [Member]
Collaboration And License Arrangement [Line Items]
Remaining performance obligations					83,600,000
Genentech [Member] | Genentech Agreement [Member] | Stand-alone Selling Prices ("SSP") [Member] | Research and Development Services [Member]
Collaboration And License Arrangement [Line Items]
Remaining performance obligations					2,900,000
Genentech [Member] | Genentech Agreement [Member] | Stand-alone Selling Prices ("SSP") [Member] | Transfer of Active Pharmaceutical Ingredients [Member]
Collaboration And License Arrangement [Line Items]
Remaining performance obligations					300,000
Genentech [Member] | Genentech Agreement [Member] | Outside US [Member]
Collaboration And License Arrangement [Line Items]
Maximum additional amount received upon milestone achievement					$ 410,000,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)		12 Months Ended
	Jun. 15, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies Disclosure [Line Items]
Prepaid balance		$ 12,110,000	$ 11,465,000
Accrued expenses		22,703,000	13,557,000
DE Shaw Research [Member]
Commitments and Contingencies Disclosure [Line Items]
Research and development expense		9,400,000	9,500,000	$ 6,400,000
Prepaid balance		4,900,000	4,400,000
Accrued expenses		$ 0	0
DE Shaw Research [Member] | License Agreement Terms [Member]
Commitments and Contingencies Disclosure [Line Items]
Research and development arrangement, annual fee	$ 9,900,000				$ 1,000,000
Research and development arrangement, term of contract					3 years
Research and development arrangement, expiration date	Aug. 16, 2025
Outstanding convertible preferred stock converted into common shares		3,281,253
Milestone payment due for first three targets		$ 7,300,000
Milestone payment due for each target after first three target		6,300,000
Other Third Parties [Member]
Commitments and Contingencies Disclosure [Line Items]
Research and development expense		2,900,000	5,400,000	$ 2,700,000
Other Third Parties [Member] | License Agreement Terms [Member]
Commitments and Contingencies Disclosure [Line Items]
Potential development milestone payments		$ 0	$ 500,000
Series A Preferred Stock [Member] | DE Shaw Research [Member] | License Agreement Terms [Member]
Commitments and Contingencies Disclosure [Line Items]
Shares held					9,999,999
Series C Preferred Stock [Member] | DE Shaw Research [Member] | License Agreement Terms [Member]
Commitments and Contingencies Disclosure [Line Items]
Shares held					1,557,875
Maximum [Member] | DE Shaw Research [Member] | License Agreement Terms [Member]
Commitments and Contingencies Disclosure [Line Items]
Agreement renewal period		1 year
Potential development milestone payments		$ 7,300,000

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Jun. 30, 2032	Apr. 30, 2029	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	May 31, 2021 ft²	Sep. 30, 2020 ft²	Jan. 31, 2018 ft²	Dec. 31, 2017 ft²
Operating Leased Assets [Line Items]
Operating lease option to terminate			true
Right of use asset			$ 63,754	$ 20,780
399 Binney Street [Member]
Operating Leased Assets [Line Items]
Land subject to ground leases | ft²							1,824	44,807	44,336
Letter of credit			900
Fixed lease payments			4,100	4,000	$ 3,800
Right of use asset			$ 18,828	$ 20,780
Weighted-average remaining lease term			6 years 3 months 29 days	7 years 3 months 29 days
Weighted-average discount rate			10.40%	10.40%
399 Binney Street [Member] | Forecast [Member]
Operating Leased Assets [Line Items]
Operating lease agreement expiration date		2029-04
Letter of credit expiration date		Apr. 30, 2029
60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Land subject to ground leases | ft²						41,474
Letter of credit			$ 1,700
Fixed lease payments			11,500	$ 0	$ 0
Right of use asset			$ 44,926
Weighted-average remaining lease term			9 years 6 months
Weighted-average discount rate			8%
60 Hampshire Street [Member] | Forecast [Member]
Operating Leased Assets [Line Items]
Operating lease agreement expiration date	2032-06
Letter of credit expiration date	Jun. 30, 2032

Leases - Schedule of Operating

Leases - Schedule of Operating Leases Presentation in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Leased Assets [Line Items]
Operating lease assets	$ 63,754	$ 20,780
Operating lease liabilities	4,276	1,844
Operating lease liabilities, net of current portion	53,466	21,056
399 Binney Street [Member]
Operating Leased Assets [Line Items]
Operating lease assets	18,828	20,780
Operating lease liabilities	2,170	1,844
Operating lease liabilities, net of current portion	18,886	21,056
Total operating lease liabilities	21,056	$ 22,900
60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Operating lease assets	44,926
Operating lease liabilities	2,106
Operating lease liabilities, net of current portion	34,580
Total operating lease liabilities	$ 36,686

Leases - Summary of Operating L

Leases - Summary of Operating Lease Presentation in Consolidated Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
399 Binney Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	$ 4,243	$ 4,264	$ 4,172
60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	3,239
Research and development expenses [Member] | 399 Binney Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	3,350	3,262	3,273
Research and development expenses [Member] | 60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	2,675
General and administrative expenses [Member] | 399 Binney Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	893	$ 1,002	$ 899
General and administrative expenses [Member] | 60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
Operating lease costs	$ 564

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
399 Binney Street [Member]
Operating Leased Assets [Line Items]
2023	$ 4,254
2024	4,377
2025	4,503
2026	4,634
2027	4,768
Thereafter	6,557
Total lease payments	29,093
Less: interest	(8,037)
Present value of operating lease liabilities	21,056	$ 22,900
60 Hampshire Street [Member]
Operating Leased Assets [Line Items]
2023	4,966
2024	5,109
2025	5,257
2026	5,409
2027	5,565
Thereafter	27,084
Total lease payments	53,390
Less: interest	(16,704)
Present value of operating lease liabilities	$ 36,686

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Line Items]
Income tax benefits	$ 0	$ 0	$ 0
Net operating loss carryforwards, federal	412,000,000	371,400,000
Net operating loss carryforwards, state	501,700,000	466,200,000
Increase in valuation allowance	87,800,000	76,900,000
Unrecognized tax benefits	$ 0	$ 0
Description of income tax examinations	There are currently no pending tax examinations.
CARES Act, description of corporate tax payers	Corporate taxpayers may carryback NOLs originating during 2018 through 2020 for up to five years, which was not previously allowed under the 2017 Tax Act. The CARES Act also eliminates the 80% of taxable income limitations by allowing corporate entities to fully utilize NOL carryforwards to offset taxable income in 2018, 2019, or 2020. Taxpayers may generally deduct interest up to the sum of 50% of adjusted taxable income plus business interest income (30% limit under the 2017 Tax Act) for tax years beginning January 1, 2019 and 2020. The CARES Act allows taxpayers with alternative minimum tax credits to claim a refund in 2020 for the entire amount of the credits instead of recovering the credits through refunds over a period of years, as originally enacted by the 2017 Tax Act.
CARES Act, percentage of eliminates of taxable income	80%
CARES Act, maximum percentage of interest deducted by tax payers	50%
CARES Act, percentage of interest deducted by tax payers	30%
CARES Act, percentage of corporate charitable deduction limit	25%
CARES Act, period of qualified improvement property for cost-recovery	15 years
CARES Act, percentage of bonus depreciation	100%
Maximum [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryback period	5 years
Federal [Member]
Income Tax Disclosure [Line Items]
Income tax benefits	$ 0
Net operating loss carryforwards, subject to expiration	43,100,000
Net operating loss carryforwards, not subject to expiration	$ 368,900,000
Net operating loss carryforwards, beginning to expiring year	2035	2035
Research and development tax credit carryforwards	$ 25,900,000	$ 14,900,000
State [Member]
Income Tax Disclosure [Line Items]
Income tax benefits		$ 0
Net operating loss carryforwards, beginning to expiring year	2035	2030
Research and development tax credit carryforwards	$ 5,600,000	$ 4,200,000

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Expected Income Tax (Benefit) Computed Using Federal Statutory Income Tax Rate to Effective Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax computed at federal statutory rate	21%	21%	21%
State taxes, net of federal benefit	6.50%	5.70%	5.70%
Change in valuation allowance	(30.20%)	(20.50%)	(27.30%)
IPR&D		(7.00%)
R&D credit carryovers	4.20%	2.20%	7.60%
Stock-based compensation	(2.10%)	(0.40%)	(6.70%)
Permanent differences	(0.60%)	(1.00%)	(0.30%)
Total	0%	0%	0%

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating losses	$ 119,688	$ 108,800
Tax credit carryforwards	30,593	18,288
Capitalized R&D	55,303
Lease liability	18,307	6,010
Stock-based compensation	14,510	8,374
Intangibles	1,875	1,859
Depreciation and amortization	568	477
Other	7,270	4,304
Total gross deferred tax assets	248,114	148,112
Valuation allowance	(230,518)	(142,674)
Net deferred tax assets	17,596	5,438
Deferred tax liabilities
Operating lease assets	(17,596)	(5,438)
Total deferred tax liabilities	$ (17,596)	$ (5,438)

Employee Benefits - Additional

Employee Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Employer matching contribution	$ 2.3	$ 1.2