Arvinas (ARVN) 10-K 27 Feb 24 2023 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Feb. 20, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38672
Entity Registrant Name	ARVINAS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2566120
Entity Address, Address Line One	5 Science Park
Entity Address, Address Line Two	395 Winchester Ave
Entity Address, City or Town	New Haven
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06511
City Area Code	203
Local Phone Number	535-1456
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	ARVN
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 1,293.4
Entity Common Stock Shares Outstanding		68,083,928
Documents Incorporated by Reference	Part III of this Annual Report incorporates by reference information from the definitive Proxy Statement for the registrant’s 2024 Annual Meeting of Stockholders, which is expected to be filed with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2023.
Entity Central Index Key	0001655759
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	Deloitte & Touche LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	34

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 311,700,000	$ 81,300,000
Restricted cash	5,500,000	5,500,000
Marketable securities	949,300,000	1,124,000,000
Accounts receivable	0	1,000,000
Other receivables	7,200,000	7,000,000
Prepaid expenses and other current assets	6,500,000	21,400,000
Total current assets	1,280,200,000	1,240,200,000
Property, equipment and leasehold improvements, net	11,500,000	13,400,000
Operating lease right of use assets	2,500,000	4,400,000
Collaboration contract asset and other assets	10,400,000	10,800,000
Total assets	1,304,600,000	1,268,800,000
Current liabilities:
Accounts payable and accrued liabilities	92,200,000	74,700,000
Deferred revenue	163,000,000	218,600,000
Current portion of operating lease liability	1,900,000	1,800,000
Total current liabilities	257,100,000	295,100,000
Deferred revenue	386,200,000	405,100,000
Long term debt	800,000	1,000,000
Operating lease liability	500,000	2,700,000
Total liabilities	644,600,000	703,900,000
Commitments and contingencies (Note 12)
Stockholders' equity:
Preferred stock, $0.001 par value, zero shares issued and outstanding as of December 31, 2023 and 2022, respectively	0	0
Common stock, $0.001 par value, 68.0 and 53.2 shares issued and outstanding as of December 31, 2023 and 2022, respectively	100,000	100,000
Accumulated deficit	(1,332,700,000)	(965,400,000)
Additional paid-in capital	1,995,700,000	1,549,400,000
Accumulated other comprehensive loss	(3,100,000)	(19,200,000)
Total stockholders' equity	660,000,000	564,900,000
Total liabilities and stockholders' equity	$ 1,304,600,000	$ 1,268,800,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Millions	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, issued (in shares)	0	0
Preferred outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, issued (in shares)	68	53.2
Common stock, outstanding (in shares)	68	53.2

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Consolidated Statements of Operations
Revenue	$ 78.5	$ 131.4	$ 53.6
Operating expenses:
Research and development	379.7	315	180.4
General and administrative	100.3	79.6	61.6
Total operating expenses	480	394.6	242
Loss from operations	(401.5)	(263.2)	(188.4)
Other income (expense)
Other (expense) income, net	(1.2)	0.2	2.5
Interest income, net	38.8	12	1.8
Total other income	37.6	12.2	4.3
Net loss before income taxes and loss from equity method investment	(363.9)	(251)	(184.1)
Income tax expense	(0.9)	(20.9)	0
Loss from equity method investment	(2.5)	(10.6)	(6.9)
Net loss	$ (367.3)	$ (282.5)	$ (191)
Net loss per common share - basic (in usd per share)	$ (6.62)	$ (5.31)	$ (3.82)
Net loss per common share - diluted (in usd per share)	$ (6.62)	$ (5.31)	$ (3.82)
Weighted-average common shares outstanding - basic (in shares)	55.5	53.2	50
Weighted-average common shares outstanding - diluted (in shares)	55.5	53.2	50
Consolidated Statements of Comprehensive Loss
Net loss	$ (367.3)	$ (282.5)	$ (191)
Other comprehensive loss:
Unrealized gain (loss) on available-for-sale securities	16.1	(14.5)	(5.2)
Comprehensive loss	$ (351.2)	$ (297)	$ (196.2)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common	Accumulated Deficit	Additional Paid-in Capital	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2020		48.5
Beginning balance at Dec. 31, 2020	$ 642.2	$ 0	$ (491.9)	$ 1,133.5	$ 0.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	57.1			57.1
Net loss	(191)		(191)
Restricted stock vesting (in shares)		0.2
Issuance of common stock under equity incentive plans (in shares)		0.8
Issuance of common stock under equity incentive plans	18.7			18.7
Common stock issued, net of issuance costs (in shares)		3.5
Common stock issued, net of issuance costs	259.9			259.9
Unrealized gain (loss) on available-for-sale securities	(5.2)				(5.2)
Ending balance (in shares) at Dec. 31, 2021		53
Ending balance at Dec. 31, 2021	781.7	$ 0	(682.9)	1,469.2	(4.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, offering costs	4.6
Stock-based compensation	75.5			75.5
Net loss	(282.5)		(282.5)
Issuance of common stock under equity incentive plans (in shares)		0.2
Issuance of common stock under equity incentive plans	4.8	$ 0.1		4.7
Unrealized gain (loss) on available-for-sale securities	(14.5)
Unrealized gain (loss) on available-for-sale securities	$ (14.6)				(14.6)
Ending balance (in shares) at Dec. 31, 2022	53.2	53.2
Ending balance at Dec. 31, 2022	$ 564.9	$ 0.1	(965.4)	1,549.4	(19.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	71.6			71.6
Net loss	(367.3)		(367.3)
Issuance of common stock under equity incentive plans (in shares)		0.4
Issuance of common stock under equity incentive plans	4.5			4.5
Common stock issued, net of issuance costs (in shares)		14.4
Common stock issued, net of issuance costs	370.2			370.2
Unrealized gain (loss) on available-for-sale securities	$ 16.1				16.1
Ending balance (in shares) at Dec. 31, 2023	68	68
Ending balance at Dec. 31, 2023	$ 660	$ 0.1	$ (1,332.7)	$ 1,995.7	$ (3.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, offering costs	$ 17

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]
Issuance of common stock, offering costs	$ 17	$ 4.6

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (367.3)	$ (282.5)	$ (191)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	4.8	6.3	4.8
Net accretion of bond discounts/premiums	(16.6)	5.7	9.4
Forgiveness of debt income	0	0	(1)
Loss on sale of marketable securities	0.9	0.4	0.2
Amortization of right-of-use assets	1.9	1.9	1.2
Amortization of collaboration contract asset	1.3	1.8	0.4
Stock-based compensation	71.6	75.5	57.1
Changes in operating assets and liabilities:
Accounts receivable	1	14	(14)
Other receivables	(0.2)	3.7	(3.3)
Prepaid expenses and other current assets	14.1	(1.8)	(13.6)
Collaboration contract asset	0	0	(12.9)
Accounts payable and accrued liabilities	17.3	20.2	27.9
Operating lease liabilities	(2)	(1.9)	(1.3)
Deferred revenue	(74.6)	(116.8)	695.5
Net cash (used in) provided by operating activities	(347.8)	(273.5)	559.4
Cash flows from investing activities:
Purchase of marketable securities	(956.3)	(886.4)	(1,744.6)
Maturities of marketable securities	1,103.9	1,076.9	428.5
Sale of marketable securities	58.8	59.1	7.2
Purchase of property, equipment and leasehold improvements	(2.9)	(6.8)	(4.7)
Net cash provided by (used in) investing activities	203.5	242.8	(1,313.6)
Cash flows from financing activities:
Proceeds from issuance of common stock and pre-funded warrants	387.2	0	264.6
Payment of common stock offering costs	(17)	0	(4.6)
Proceeds from exercise of stock options and issuance of ESPP shares	4.5	4.7	18.6
Net cash provided by financing activities	374.7	4.7	278.6
Net increase (decrease) in cash, cash equivalents and restricted cash	230.4	(26)	(475.6)
Cash, cash equivalents and restricted cash, beginning of the period	86.8	112.8	588.4
Cash, cash equivalents and restricted cash, end of the period	317.2	86.8	112.8
Supplemental disclosure of cash flow information:
Purchases of property, equipment and leasehold improvements unpaid at period end	0	0.1	0.5
Cash paid for interest	0	0	0.1
Cash paid for taxes	$ 11.1	$ 11.1	$ 0

Nature of Business and Basis of

Nature of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Nature of Business and Basis of Presentation Nature of Business Arvinas, Inc. is a clinical-stage biotechnology company dedicated to improving the lives of patients suffering from debilitating and life-threatening diseases through the discovery, development and commercialization of therapies that degrade disease-causing proteins. Arvinas, Inc. has four wholly owned subsidiaries; Arvinas Operations, Inc. formed in 2013, Arvinas Androgen Receptor, Inc. formed in 2015, Arvinas Estrogen Receptor, Inc. formed in 2016, and Arvinas Winchester, Inc. formed in 2018 (collectively, "Arvinas" or the "Company"). Basis of Presentation The Company's consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the accounts of Arvinas, Inc. and its wholly owned subsidiaries. All intercompany transactions have been eliminated upon consolidation. The accounting policies used to prepare the Company's consolidated financial statements are the same as those used to prepare the consolidated financial statements in prior years. The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts and disclosures in the consolidated financial statements and notes. While management believes that estimates and assumptions used in the preparation of the consolidated financial statements and notes are appropriate, actual results could differ from those estimates. The most significant estimates are those used in the determination of the Company’s revenue recognition, uncertain tax positions and research and development expenses. Risks and Uncertainties The Company is subject to a number of risks similar to other biotechnology companies in the early stage, including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s products and protection of proprietary technology. If the Company does not successfully obtain regulatory approval, it will be unable to generate revenue from product sales or achieve profitability. To date, the Company has not generated any revenue from product sales and expects to incur additional operating losses and negative operating cash flows for the foreseeable future. The Company has financed its operations primarily through sales of equity interests, proceeds from collaborations, grant funding and debt financing. The Company had cash, cash equivalents, restricted cash and marketable securities of approximately $1.3 billion as of December 31, 2023.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Cash and Cash Equivalents The Company classifies as cash and cash equivalents amounts on deposit in banks and cash invested temporarily in various instruments, primarily money market accounts, with original maturities of three months or less at time of purchase. The carrying amounts reported in the consolidated balance sheets represent the fair values of cash and cash equivalents and are considered Level 1 financial instruments. Restricted Cash Restricted cash represents a letter of credit collateralized by a certificate of deposit in the same amount as required under the terms of the Company's laboratory and office space. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total amounts shown in the consolidated statements of cash flows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, (dollars in millions) 2023 2022 2021 Cash and cash equivalents $ 311.7 $ 81.3 $ 108.3 Restricted cash 5.5 5.5 4.5 Cash, cash equivalents and restricted cash $ 317.2 $ 86.8 $ 112.8 Concentration of Credit Risk The Company maintains its cash in financial institution accounts that may at times exceed federally insured limits. The cash balances in the financial institutions are insured by the Federal Deposit Insurance Corporation ("FDIC") up to $250,000. Cash may also be maintained at commercial institutions that are not insured by the FDIC. For the years ended December 31, 2023, 2022 and 2021, one collaborator represented 97%, 88% and 68% of the Company's revenue, respectively. Marketable Securities The Company's marketable securities are classified as available-for-sale securities and are carried at their fair value based on the quoted market prices of the securities, with unrealized gains and losses reported as accumulated other comprehensive income (loss), a separate component of stockholders' equity. Realized gains and losses on available-for-sale securities are included in other income in the period earned or incurred. Property, Equipment, and Leasehold Improvements Property and equipment are recorded at cost. Depreciation is calculated using the straight-line method over the estimated useful lives, which range from three years for office equipment to five years for laboratory equipment. Maintenance and repairs which do not extend the lives of the assets are charged directly to expense as incurred. Upon retirement or disposal, cost and related accumulated depreciation is removed from the related accounts, and any resulting gain or loss is recognized as a component of income or loss for the period. Leasehold improvements are recorded at cost and amortized using the straight-line method over the shorter of the lease term or the useful life of the asset. Impairment of Long-Lived Assets The Company monitors its long-lived assets for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. No such impairments were recorded during 2023, 2022 or 2021. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker in assessing performance and allocating resources. The Company, through its Chief Executive Officer in his role as chief operating decision maker, views Company operations and manages the business as one operating segment. All of the Company’s tangible assets are held in the United States and all of the Company’s revenue has been generated in the United States. Revenue Recognition and Deferred Revenue Revenues from Contracts The Company recognizes revenue under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers. The Company’s revenue is generated through research collaboration and license agreements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones and royalty payments based on product sales derived from the collaboration. Under ASC 606, the Company evaluates whether the license agreement, research and development services and participation in research and development steering committees represent separate or combined performance obligations. The Company has determined that these services within its existing contracts represent combined single performance obligations. The research collaboration and license agreements typically include contingent milestone payments related to specified preclinical and clinical development milestones and regulatory milestones. These milestone payments represent variable consideration to be included within the transaction price using the most likely amount method. The Company determined that the most likely amount to be recognized was zero, against which no constraint was applied. The Company continually assesses the probability of significant reversals for any amounts that become likely to be realized prior to recognizing the variable consideration associated with these payments within the transaction price. Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. Management makes its best estimate of the period over which the Company expects to fulfill its performance obligations, which includes access to technology through the license agreement and research activities. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period. Management evaluates changes in the duration of the performance period at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate. For the years ended December 31, 2023, 2022 and 2021, the transaction price allocated to the combined performance obligation identified under the individual research collaboration and license agreements was recognized as revenue on either a straight-line basis over the estimated performance period under the arrangement or over the estimated performance period based on the Company’s best estimate of costs to be incurred. Straight-line basis was considered the best measure of progress for certain agreements in which control of the combined obligation transfers to the customers, due to the contract containing license rights to technology, research and development services, and joint committee participation, which in totality are expected to occur ratably over the performance period. For agreements accounted for under the costs to be incurred method, collaboration revenue is recognized as program costs are incurred by measuring actual costs incurred to date compared to the total expected costs to satisfy the performance obligations. Management evaluates estimates of expected costs to satisfy the performance obligations at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate. The Company’s contracts may also call for certain sales-based milestone and royalty payments upon successful commercialization of a target. The Company recognizes revenues from sales-based milestone and royalty payments at the later of a) the occurrence of the subsequent sale, or b) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied (or partially satisfied). The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated by customers from the use of the technology. To date, no revenue from these sales-based milestone and royalty payments has been recognized for any periods. Amounts received prior to satisfying the above revenue recognition criteria are recorded as contract liabilities in the Company’s accompanying consolidated balance sheets. The Company expenses direct and incremental costs to obtaining and fulfilling a contract as and when incurred if the expected amortization period of the asset that would be recognized is one year or less, or if the amount of the asset is immaterial. Otherwise, such costs are capitalized as collaboration contract assets and amortized as general and administrative expenses over the total estimated period of performance of each underlying contract. Equity Method Investments The Company accounts for investments for which it does not have a controlling interest in accordance with ASC 323, Investments – Equity Method and Joint Ventures . The Company recognizes its pro-rata share of income and losses in the investment in “Loss from equity method investment” on the consolidated statement of operations and comprehensive loss, with a corresponding change to the investment in equity method investment in the consolidated balance sheet until such investment is reduced to zero. Income Taxes Arvinas, Inc. and its wholly owned subsidiaries use the asset and liability method of accounting for income taxes, as set forth in ASC 740, Accounting for Income Taxes . Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequence of temporary differences between the carrying amounts and the tax basis of assets and liabilities and net operating loss carry forwards, all calculated using presently enacted tax rates. A valuation allowance is established to reduce deferred tax assets to their estimated realizable value. The Company provides a valuation allowance to the extent that it is more likely than not that all or a portion of the deferred tax assets will not be realized. The Company follows the authoritative guidance for recognizing and measuring uncertainty in income tax positions taken or expected to be taken in a tax return. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in tax expense. As of December 31, 2023 and 2022, management evaluated the effect of ASC 740 guidance related to uncertain income tax positions and recorded provisions of $5.9 million and $4.1 million, respectively, relating primarily to state income tax filing positions in various jurisdictions. Equity-based Compensation The Company measures employee, board of director and consultant equity-based compensation for stock option and restricted stock grants based on the grant date fair value of the equity awards. Equity-based compensation expense is recognized over the requisite service period of the awards, net of estimated forfeitures. Estimated forfeitures are updated on a periodic basis based on actual experience. For equity awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved. The Company classifies equity-based compensation expense in its consolidated statement of operations in the same manner in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified. 401(k) Savings Plan The Company has a defined-contribution savings 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 pretax basis. Under the 401(k) Plan, the Company made discretionary matching contributions on behalf of eligible employees totaling $3.1 million, $2.2 million and $1.3 million for the years ended December 31, 2023, 2022 and 2021, respectively. Research and Development Expenses Research and development expenses include (i) employee-related expenses, including salaries, benefits, travel and stock-based compensation expense; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization agreements, investigational sites and consultants; (iii) the cost of acquiring, developing and manufacturing clinical study materials; (iv) costs associated with preclinical and clinical activities and regulatory operations; and (v) costs incurred in development of intellectual property. Costs incurred in connection with research and development activities are expensed as incurred. The Company enters into consulting, research and other agreements with commercial entities, researchers, universities and others for the provision of goods and services. Such arrangements are generally cancellable upon reasonable notice and payment of costs incurred. Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data provided by the respective vendors, including the Company’s clinical sites. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved and experience with similar contracts. The Company monitors each of these factors and adjusts estimates accordingly. Fair Value Measurements The Company determines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Inputs used in the valuation techniques to determine fair values are classified based on a three-level hierarchy. The basis for fair value measurements for each level within the hierarchy is described below, with Level 1 having the highest priority and Level 3 having the lowest. The three levels of the fair value hierarchy are as follows: Level 1— Inputs are based upon observable or quoted prices (unadjusted) for identical instruments traded in active markets. The Company’s Level 1 financial instruments consist of cash equivalents. Level 2— Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities. Level 3— Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models and similar techniques. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Net Loss per Common Share Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common shares. The weighted-average number of common shares included in the computation of basic and diluted net loss per common share gives effect to pre-funded warrants. See Note 9, Equity , and Note 13, Net Loss Per Share . New Accounting Pronouncements Recently Adopted Accounting Pronouncements There have been no recently adopted accounting pronouncements with a material impact to the Company's consolidated financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Income Taxes (Topic 740) - In December 2023, the FASB also issued ASU 2023-09, " Improvements to Income Tax Disclosures ," which requires enhanced income tax disclosures, including specific categories and disaggregation of information in the effective tax rate reconciliation, disaggregated information related to income taxes paid, income or loss from continuing operations before income tax expense or benefit and income tax expense or benefit from continuing operations. The requirements of the ASU are effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently in the process of evaluating the impact of this pronouncement on our related disclosures.

Research Collaboration and Lice

Research Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2023
Research Collaboration And License Agreements [Abstract]
Research Collaboration and License Agreements	Research Collaboration and License Agreements ARV-471 Collaboration Agreement In July 2021, the Company entered into a collaboration agreement with Pfizer (the “ARV-471 Collaboration Agreement”) pursuant to which the Company granted Pfizer worldwide co-exclusive rights to develop and commercialize products containing the Company’s proprietary compound ARV-471 (the “Licensed Products”). Under the ARV-471 Collaboration Agreement, the Company received an upfront, non-refundable payment of $650.0 million. In addition, the Company will be eligible to receive up to an additional $1.4 billion in contingent payments based on specific regulatory and sales-based milestones for the Licensed Products. Of the total contingent payments, $400.0 million in regulatory milestones are related to marketing approvals and $1.0 billion are related to sales-based milestones. The Company and Pfizer share equally all development costs, including costs of conducting clinical trials, for the Licensed Products, subject to certain exceptions. Except for certain regions described below, the parties will also share equally all profits and losses in commercialization and medical affairs activities for the Licensed Products in all other countries, subject to certain exceptions. The Company will be the marketing authorization holder in the United States and, subject to marketing approval, book sales in the United States, while Pfizer will hold marketing authorizations outside the United States. The parties will determine which, if any, regions within the world will be solely commercialized by one party, and in such region the parties will adjust their share of profits and losses for the Licensed Products based on the role each party will be performing. In addition, in connection with the execution of the ARV-471 Collaboration Agreement, the Company and Pfizer entered into a Stock Purchase Agreement (the" Pfizer Stock Purchase Agreement") for the sale and issuance of 3,457,815 shares of the Company’s common stock (the “Shares”) to Pfizer at a price of $101.22 per share, for an aggregate purchase price of $350.0 million (the “Pfizer Equity Transaction”), less financial advisor fees of $4.6 million, which was consummated in September 2021. Pursuant to terms of the Pfizer Stock Purchase Agreement, Pfizer has agreed not to sell or transfer the Shares without prior written approval of the Company for a specified time period, subject to specified exceptions. The Company determined that the ARV-471 Collaboration Agreement and the Pfizer Equity Transaction entered into with Pfizer concurrently should be evaluated as a combined contract in accordance with Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers . The Company determined the fair value of the shares sold under the Pfizer Equity Transaction to be $85.4 million less than the contractual purchase price stipulated in the agreement. In accordance with the applicable accounting guidance in ASC 815-40, Contracts in Entity’s Own Equity , the Company determined that the sale of stock should be recorded at fair value and therefore allocated the excess consideration received under the Pfizer Equity Transaction to the ARV-471 Collaboration Agreement, which, along with the non-refundable payment of $650.0 million, is being recognized as revenue over the total estimated period of performance based on the Company’s best estimate of costs to be incurred. As a direct result of the Company’s entry into the ARV-471 Collaboration Agreement, the Company incurred direct and incremental costs to obtain the contract, paid to a financial advisor, totaling $12.9 million. In accordance with ASC 340, Other Assets and Deferred Costs , the Company recognized an asset of $12.9 million in collaboration contract asset and other assets in the consolidated balance sheet, which is being amortized as general and administrative expense over the total estimated period of performance under the ARV-471 Collaboration Agreement. Bayer Collaboration Agreement In June 2019, the Company and Bayer AG entered into a Collaboration and License Agreement (the "Bayer Collaboration Agreement") setting forth the Company’s collaboration with Bayer AG to identify or optimize proteolysis targeting chimeras, or PROTAC targeted protein degraders, that mediate for degradation of target proteins ("Targets"), using the Company’s proprietary platform technology, which Targets will be selected by Bayer AG, subject to certain exclusions and limitations. Under the terms of the Bayer Collaboration Agreement, the Company received an upfront, non-refundable payment of $17.5 million in exchange for the use of the Company’s technology license. In addition, the Company received an additional $12.0 million from Bayer AG from inception through 2023, including $1.5 million received during the year ended December 31, 2023 and $3.0 million received in each of the years ended December 31, 2022 and 2021. These payments are being recognized over the total estimated period of performance. The Company is also eligible to receive up to $197.5 million in development milestone payments and up to $490.0 million in sales-based milestone payments for all designated Targets. In addition, the Company is eligible to receive, on net sales of PROTAC targeted protein degrader-related products, mid-single digit to low-double digit tiered royalties, which may be subject to reductions. There were no development or sales-based milestone payments or royalties received through December 31, 2023. The Company determined that the Bayer Collaboration Agreement and a Stock Purchase Agreement entered into with Bayer AG at the same time should be evaluated as a combined contract in accordance with ASC 606, Revenue from Contracts with Customers . The Company determined the fair value of the shares sold under the Stock Purchase Agreement to be $2.9 million less than the contractual purchase price stipulated in the agreement. In accordance with the applicable accounting guidance in ASC 815-40, Contracts in Entity’s Own Equity , the Company determined that the sale of stock should be recorded at fair value. Therefore, the Company allocated the additional $2.9 million of consideration received under the Stock Purchase Agreement to the Bayer Collaboration Agreement and added such amount to the total transaction price. Pfizer Research Collaboration Agreement In December 2017, the Company entered into a Research Collaboration and License Agreement with Pfizer (the "Pfizer Research Collaboration Agreement"). Under the terms of the Pfizer Research Collaboration Agreement, the Company received an upfront, non-refundable payment and certain additional payments totaling $28.0 million in 2018 in exchange for use of the Company’s technology license and to fund Pfizer-related research as defined within the Pfizer Research Collaboration Agreement. These payments are being recognized over the total estimated period of performance. The Company is eligible to receive up to an additional $37.5 million in non-refundable option payments if Pfizer exercises its options for all targets under the Pfizer Research Collaboration Agreement. The Company is also entitled to receive up to $225.0 million in development milestone payments and up to $550.0 million in sales-based milestone payments for all designated targets under the Pfizer Research Collaboration Agreement, as well as tiered royalties based on sales. Pfizer selected additional targets and initiated additional services totaling $1.0 million and $3.5 million in December 2022 and 2021, respectively, which were included in accounts receivable as of December 31, 2022 and 2021. There were no sales-based milestone payments or royalties received through December 31, 2023. Genentech Modification In November 2017, the Company entered into an Amended and Restated Option, License, and Collaboration Agreement (the "Genentech Modification") with Genentech, Inc. and F. Hoffman-La Roche Ltd (together "Genentech"), amending a previous Genentech agreement entered into in September 2015. Under the Genentech Modification, the Company received upfront, non-refundable payments of $34.5 million (in addition to $11.0 million received under the previous agreement in 2015) to fund Genentech-related research. Upfront non-refundable payments are recognized as revenue over the total estimated period of performance. The Company is eligible to receive up to $44.0 million per target in development milestone payments, $52.5 million in regulatory milestone payments and $60.0 million in commercial milestone payments based on sales as well as tiered royalties based on sales. There were no development, regulatory or commercial milestone payments or royalties received through December 31, 2023. Changes in the Company's contract balances were as follows: December 31, (dollars in millions) 2023 2022 Accounts receivable Beginning balance $ 1.0 $ 15.0 Additions 21.7 6.4 Payments received (22.7) (20.4) Ending balance $ — $ 1.0 Accounts payable related to collaborations Beginning balance $ 5.0 $ — Additions 44.1 5.0 Payments made (36.0) — Ending balance $ 13.1 $ 5.0 Contract assets: Collaboration contract asset Beginning balance $ 10.7 $ 12.5 Additions — — Amortization (1.3) (1.8) Ending balance $ 9.4 $ 10.7 Contract liabilities: Deferred revenue Beginning balance $ 623.7 $ 740.5 Additions to collaboration agreements 1.5 4.0 Revenue recognized from balances held at the beginning of the period (76.0) (120.0) Revenue recognized from balances not held at the beginning of the period — (0.8) Ending balance $ 549.2 $ 623.7 During the fourth quarter of 2023, the Company had a change to its estimate to satisfy the performance obligations under the ARV-471 Collaboration Agreement due to the expansion of the development programs. The changes in accounting estimate resulted in a decrease in revenue and net income of $35.0 million and a decrease in net loss per share by $0.63 for the year ended December 31, 2023. The reversed revenue will be recognized in future periods as the Company continues to advance on the performance obligation under the collaboration. During the year ended December 31, 2023, the Company also changed its estimate of the duration of the performance period under the Bayer Collaboration Agreement and Pfizer Research Collaboration Agreement as a result of updated research timelines. The changes in accounting estimate resulted in a decrease in revenue and net income of $10.6 million and a decrease in net loss per share by $0.19 for the year ended December 31, 2023. The reversed revenue will be recognized in future periods as the Company continues to advance on the performance obligation under the updated collaboration timelines. During the years ended December 31, 2022 and 2021, the Company recorded cumulative catch-up adjustments from contract modifications totaling $0.7 million and $(0.8) million, respectively, relating to performance obligations which were satisfied in prior periods. The aggregate amount of the transaction price allocated to performance obligations that were unsatisfied as of December 31, 2023 totaled $549.2 million, which is expected to be recognized in the following periods: (dollars in millions) 2024 $ 163.0 2025 153.4 2026 105.0 2027 57.6 2028 59.8 Thereafter 10.4 Total $ 549.2

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	Marketable Securities and Fair Value Measurements The following is a summary of the Company’s available for sale marketable securities measured at fair value on a recurring basis. December 31, 2023 (dollars in millions) Valuation Hierarchy Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Corporate bonds Level 2 $ 934.4 $ 1.5 $ (4.6) $ 931.3 Government securities Level 2 18.0 — — 18.0 Total $ 952.4 $ 1.5 $ (4.6) $ 949.3 December 31, 2022 (dollars in millions) Valuation Hierarchy Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Corporate bonds Level 2 $ 1,008.0 $ — $ (18.5) $ 989.5 Government securities Level 2 135.2 — (0.7) 134.5 Total $ 1,143.2 $ — $ (19.2) $ 1,124.0 The Company generally does not intend to sell any investments prior to recovery of their amortized cost basis for any investment in an unrealized loss position. As such, the Company has classified these losses as temporary in nature. The carrying value of accounts receivable and accounts payable and accrued liabilities approximate their fair values due to the short-term nature of these assets and liabilities.

Property, Equipment and Leaseho

Property, Equipment and Leasehold Improvements	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Equipment and Leasehold Improvements	Property, Equipment and Leasehold Improvements Property, equipment and leasehold improvements consist of the following: December 31, (dollars in millions) 2023 2022 Laboratory equipment $ 18.5 $ 17.1 Office equipment 2.6 2.0 Leasehold improvements 11.5 10.9 Total property, equipment and leasehold improvements 32.6 30.0 Less: accumulated depreciation and amortization (21.1) (16.6) Property, equipment and leasehold improvements, net $ 11.5 $ 13.4 Depreciation expense totaled $4.8 million, $6.3 million, and $4.8 million for the years ended December 31, 2023, 2022 and 2021, respectively.

Right of Use Assets and Liabili

Right of Use Assets and Liabilities	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Right of Use Assets and Liabilities	Right-of-Use Assets and Liabilities The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (ROU) assets and operating lease liabilities in the accompanying consolidated balance sheets. ROU assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease ROU 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 do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments, which ranges from 3.0% – 7.5%. Lease expense is recognized on a straight-line basis over the lease term. The Company considers options to extend or terminate the lease in recognizing ROU assets and lease liabilities when it is reasonably certain that such options will be exercised. In May 2021, the Company entered into a lease arrangement, which was amended in August 2022, for approximately 160,000 square feet of laboratory and office space to be occupied in 2025. Once occupied, the base rent will range from $7.7 million to $8.8 million annually over a ten-year lease term. In connection with the signing of the lease, as amended, the Company issued a letter of credit totaling $5.5 million, collateralized by a certificate of deposit in the same amount, which is presented as restricted cash in the accompanying consolidated balance sheets. The Company has operating leases for its corpor ate office, laboratories and certain equipment, which expire no later than October 2025. The leases have a weighted-average remaining term of 1.4 years. The components of lease expense were as follows: Year Ended December 31, (dollars in millions) 2023 2022 2021 Operating lease cost $ 2.1 $ 2.1 $ 1.4 Supplemental cash flow information related to leases was as follows: December 31, (dollars in millions) 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2.0 $ 1.9 $ 1.2 Supplemental non-cash information: Right-of-use assets obtained in exchange for new lease obligations $ — $ 2.4 $ 3.2 Maturities of operating lease liabilities as of December 31, 2023 were as follows: (dollars in millions) 2024 $ 2.0 2025 0.5 Total lease payments 2.5 Less: imputed interest (0.1) Total $ 2.4

Accounts Payable and Accrued Li

Accounts Payable and Accrued Liabilities	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities Accounts payable and accrued liabilities consisted of the following: December 31, (dollars in millions) 2023 2022 Accounts payable $ 17.8 $ 5.7 Accrued liabilities Research and development expenses 43.1 35.9 Employee expenses 25.7 18.7 Professional fees 2.5 2.4 General and administrative and commercial expenses 2.4 1.7 Income taxes 0.7 10.3 $ 92.2 $ 74.7

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Debt obligations consisted of the following: (dollars in millions) Maturity Date Interest Rate December 31, December 31, 2018 Assistance Agreement Debt 09/28 3.25% $ 1.0 $ 1.0 Less: current installments included within Accounts Payable and Accrued Liabilities (0.2) — Total long-term debt $ 0.8 $ 1.0 In June 2018, the Company entered into an Assistance Agreement with the State of Connecticut (the "2018 Assistance Agreement") to provide funding for the expansion and renovation of laboratory and office space (the "Project"). Under the terms of the 2018 Assistance Agreement, the Company was entitled to borrow from the State of Connecticut a maximum of $2.0 million, provided that the funding did not exceed more than 50% of the total Project costs. In September 2018, the Company borrowed $2.0 million under the 2018 Assistance Agreement, bearing interest at 3.25% per annum with interest payments required for the first 60 months from the funding date. Thereafter, the loan will begin to fully amortize through month 120, maturing in September 2028 . In April 2021, borrowings totaling $1.0 million were forgiven by the State of Connecticut as the Company met certain employment conditions, as defined in the agreement. The 2018 Assistance Agreement requires that the Company be located in the State of Connecticut through September 2028 with a default penalty of repayment of the full original funding amount of $2.0 million plus liquidated damages of 7.5% of the total amount of funding received. In connection with an Assistance Agreement with the State of Connecticut (the "Assistance Agreement") entered into in 2014, under which all the borrowings by the Company were forgiven in accordance with the Assistance Agreement, the Company is required to be located in the State of Connecticut through January 2024, with a default penalty of repayment of the full original funding amount of $2.5 million plus liquidated damages of 7.5%. Minimum future principal payments on long-term debt as of December 31, 2023 are as follows: (dollars in millions) 2024 $ 0.2 2025 0.2 2026 0.2 2027 0.2 2028 0.2 Total $ 1.0 During the years ended December 31, 2023, 2022 and 2021, interest expense was immaterial.

Equity

Equity	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Equity	Equity Preferred Stock As of December 31, 2023 and 2022, the Company had authorized 5,000,000 shares of preferred stock, at a $0.001 par value per share. Preferred stock may be issued in one or more series upon authorization of the Company's board of directors. The board of directors is authorized to fix the designations, powers, preferences and the relative, participating, optional or other special rights and any qualifications, limitations and restrictions of the shares of each series of preferred stock. The authorized shares of the Company's preferred stock are available for issuance without further action by the Company's stockholders, unless such action is required by applicable law or the rules of any stock exchange on which our securities may be listed. Common Stock As of December 31, 2023 and 2022, the Company had authorized 200,000,000 shares of common stock, at a $0.001 par value per share. The holders of shares of common stock are entitled to one vote for each share of common stock held at all meetings of stockholders and written actions in lieu of meetings. The holders of shares of common stock are entitled to receive dividends, if and when declared by the Board of Directors. No dividends have been declared or paid by the Company since its inception. In November 2023, the Company completed a private placement offering with certain institutional investors in which the Company issued and sold 12,963,542 shares of common stock at a price of $21.36 per share and, to one investor, in lieu of common stock, pre-funded warrants to purchase up to 3,422,380 shares of common stock at a price of $21.359 per pre-funded warrant. Each pre-funded warrant has an exercise price of $0.001 per share, is exercisable immediately and is exercisable until exercised in full. The aggregate gross proceeds from the issuance of common stock and pre-funded warrants totaled approximately $350.0 million, before deducting placement agent fees and offering costs of approximately $15.9 million . In September 2021, in connection with the Pfizer Stock Purchase Agreement, the Company issued 3,457,815 shares of common stock to Pfizer at a price of $101.22 per share, which resulted in aggregate gross proceeds of $350 million , less financial advisor fees of $4.6 million, as further described in Note 3 to our consolidated financial statements . Pursuant to terms of the Pfizer Stock Purchase Agreement, Pfizer has agreed not to sell or transfer the Shares without prior written approval of the Company for a specified period, subject to specified exceptions. Equity Distribution Agreements In August 2021, the Company entered into an Equity Distribution Agreement with Piper Sandler & Company (“Piper Sandler”) and Cantor Fitzgerald & Co. (“Cantor”), as agents, pursuant to which the Company may offer and sell from time to time, through the agents, up to $300.0 million of the common stock registered under a universal shelf registration statement pursuant to one or more “at-the-market" offerings. Under this agreement, during the year ended December 31, 2023, the Company issued 1,449,275 shares of common stock under this agreement, resulting in gross proceeds of approximately $37.2 million, less offering costs of approximately $1.1 million. In November 2023, the Company amended and restated the Equity Distribution Agreement with Piper Sandler and Cantor, pursuant to which the Company may offer and sell from time to time, through the agents, up to approximately $262.8 million of the common stock registered under a universal shelf registration statement pursuant to one or more “at-the-market” offerings. During the year ended December 31, 2023 , under this amended and restated agreement, no shares were issued. Share-based Compensation 2018 Employee Stock Purchase Plan In September 2018, the Company adopted the 2018 Employee Stock Purchase Plan (the "2018 ESPP"), with the first offering period under the 2018 ESPP commencing on January 1, 2020, by initially providing participating employees with the opportunity to purchase an aggregate of 311,850 shares of the Company's common stock. The number of shares of the Company's common stock reserved for issuance under the 2018 ESPP increased, pursuant to the terms of the 2018 ESPP, by additional shares equal to 1% of the Company’s then-outstanding common stock, effective as of January 1 of each year. As of December 31, 2023, 2,440,434 shares remained available for purchase. During the years ended December 31, 2023, 2022 and 2021, the Company issued 78,528, 24,898 and 19,357 shares, respectively, of common stock under the 2018 ESPP. 2018 Stock Incentive Plan In September 2018, the Company’s board of directors adopted, and the Company’s stockholders approved, the 2018 Stock Incentive Plan (the "2018 Plan"), which became effective upon the effectiveness of the registration statement on Form S-1 for the Company’s initial public offering. The number of common shares initially available for issuance under the 2018 Plan equaled the sum of (1) 4,067,007 shares of common stock; plus (2) the number of shares of common stock (up to 1,277,181 shares) issued in respect of incentive units granted under the Incentive Plan that were subject to vesting immediately prior to the effectiveness of the registration statement that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase on the first day of each year beginning with the year ended December 31, 2019 and continuing to, and including, the year ending December 31, 2028, equal to the lesser of 4,989,593 shares of the Company’s common stock, 4% of the number of shares of the Company’s common stock outstanding on the first day of the year or an amount determined by the Company’s board of directors. As of December 31, 2023, 2,099,162 shares are available for issuance under the 2018 Plan. Common shares subject to outstanding equity awards that expire or are terminated, surrendered, or cancelled without having been fully exercised or are forfeited in whole or in part are available for future grants of awards. Compensation Expense For the years ended December 31, 2023, 2022 and 2021, the Company recognized compensation expense of $71.6 million, $75.5 million and $57.1 million, respectively, related to the issuance of incentive awards, including $0.8 million, $0.7 million and $0.3 million, respectively, related to the 2018 ESPP. As of December 31, 2023, there was $53.6 million of compensation expense that is expected to be recognized over a weighted-average period of approximately 1.6 years. Stock Options The fair value of the stock options granted during each of the years ended December 31, 2023, 2022 and 2021 was determined using the Black-Scholes option pricing model at the grant date with the following range of assumptions: Year ended December 31, 2023 2022 2021 Expected volatility 71% - 75% 73% - 76% 74% - 78% Expected term (years) 5.5 - 7.0 5.5 - 7.0 5.3 - 7.0 Risk free interest rate 3.4% - 4.8% 1.5% - 4.2% 0.5% - 1.3% Expected dividend yield 0 % 0 % 0 % Exercise price $16.21 - $36.27 $36.79 - $78.91 $66.82 - $100.40 Given the Company’s common stock has not been trading for a sufficient period of time, the Company calculates volatility of its common stock by utilizing a weighted-average of a collection of peer company volatilities and its own common stock volatility. The expected term is calculated utilizing the simplified method. A summary of the stock option activity under the 2018 Plan as of December 31, 2023 is presented below. These amounts include stock options granted to employees, directors and consultants. (dollars in millions, except weighted-average exercise price) Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Outstanding as of December 31, 2022 6,814,634 $ 49.06 7.7 $ 34.5 Granted 1,846,724 $ 32.48 Exercised (142,764) $ 18.97 Forfeited (580,367) $ 56.45 Expired (4,433) $ 71.30 Outstanding as of December 31, 2023 7,933,794 $ 45.22 7.2 $ 62.6 Vested and exercisable as of December 31, 2023 4,739,559 $ 43.79 6.3 $ 46.9 Vested and expected to vest as of December 31, 2023 7,678,026 $ 45.27 7.2 $ 61.0 The weighted-average grant date fair value of options granted during the years ended December 31, 2023, 2022 and 2021 was $21.99, $39.17 and $52.85, respectively. The total intrinsic value of options exercised during the years ended December 31, 2023, 2022 and 2021 was $1.4 million, $7.9 million and $46.9 million, respectively. Restricted Stock Units A summary of restricted stock unit activity under the 2018 Plan for the year ended December 31, 2023 is presented below. These amounts include restricted stock units granted to employees. Shares Weighted-Average Grant Date Fair Value Per Share Unvested restricted stock units as of December 31, 2022 489,216 $ 51.37 Granted 885,494 $ 32.27 Exercised (154,146) $ 44.79 Forfeited (68,708) $ 41.48 Unvested restricted stock units as of December 31, 2023 1,151,856 $ 38.16 The total fair value of RSUs vested during the years ended December 31, 2023, 2022 and 2021 was $6.9 million, $0.9 million and $0.9 million, respectively.

Equity Method Investments

Equity Method Investments	12 Months Ended
	Dec. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments In July 2019, the Company and Bayer CropScience LP ("Bayer LP") formed Oerth Bio, a joint venture to research, develop and commercialize PROTAC targeted protein degraders for applications in the field of agriculture. Pursuant to the terms of the joint venture agreement, the Company made an in-kind intellectual property contribution to Oerth Bio in the form of a license to certain of the Company’s proprietary technology and Bayer LP committed and subsequently made cash contributions to Oerth Bio totaling $56.0 million, as well as an in-kind intellectual property contribution. The Company and Bayer LP each held an initial ownership interest in Oerth Bio representing 50% of the ownership interests. A 15% ownership interest of Oerth Bio was reserved for the future grants of incentive units to employees and service providers and, as a result, the Company's ownership interest totaled 45.0%, 46.5% and 48.4% as of December 31, 2023, 2022 and 2021, respectively, as a result of vested incentive units. Under the joint venture agreement, the Company has no obligation to provide additional funding and the Company’s ownership interest will not be diluted from future contributions from Bayer LP. The activities of Oerth Bio are controlled by a management board under the joint control of the Company and Bayer LP. As Oerth Bio is jointly controlled by the Company and Bayer LP, the Company accounts for its interest using the equity method of accounting. The Company determined that Oerth Bio is a variable interest entity and, accordingly, the Company has evaluated the significant activities of Oerth Bio under the variable interest entity model and concluded that the significant activities consist primarily of research and development activities and, as the Company does not have the sole power to direct such activities, the Company is not the primary beneficiary. Operating expenses and net loss of Oerth Bio for the years ended December 31 2023, 2022 and 2021 totaled $8.3 million , $22.9 million and $14.3 million, respectively. The Company recognized equity method losses of $2.5 million , $10.6 million and $6.9 million for the years ended December 31, 2023 , 2022 and 2021, respectively. As of December 31, 2023 , and 2022, the Company’s carrying value of the investment was zero. The Company also provides Oerth Bio with compensated research and development and administrative services through a separate agreement. The se

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the years ended December 31, 2023, 2022 and 2021, income tax expense totaled $0.9 million, $20.9 million and zero, respectively, and consisted of the following: Year Ended December 31, 2023 2022 2021 Current: U.S.: Federal $ (1.7) $ 8.2 $ — State and local 2.6 12.7 — Total current 0.9 20.9 — Deferred: U.S.: Federal — — — State and local — — — Total deferred — — — Income tax expense $ 0.9 $ 20.9 $ — The Company generated a taxable loss for the year ended December 31, 2023 primarily due to operating losses. The Company has not recorded any income tax benefits for the net operating losses incurred in the period due to its uncertainty of realizing a benefit from those items. For the year ended December 31, 2022, the Company generated taxable income and paid income taxes primarily due to revenue recognition for tax purposes from the ARV-471 Collaboration Agreement and the mandatory capitalization of qualified research and development expenses incurred on or after January 1, 2022, which, upon recognition for tax purposes, would create additional deferred tax assets. Under the Tax Cuts and Jobs Act of 2017, qualified research expenses incurred after 2021 are no longer immediately deductible for tax purposes and instead must be capitalized and amortized over at least five years for tax purposes. For the year ended December 31, 2021, the Company had no income tax expense due to incurred operating losses. The Company had also not recorded any income tax benefits for the net operating losses incurred in that period due to its uncertainty of realizing a benefit from those items. All of the Company’s losses before income taxes were generated in the United States. A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate for the years ended December 31, 2023, 2022 and 2021 were as follows: Year ended December 31, 2023 2022 2021 Federal statutory rate 21.0 % 21.0 % 21.0 % State taxes 18.4 % (1.6) % 16.3 % Federal research tax credit 7.6 % 3.4 % 2.7 % Other — % (0.1 %) — % Return to provision (0.2) % 3.6 % 1.1 % Uncertain tax positions (0.5 %) (1.2 %) — % Stock compensation (1.2) % (1.4) % (2.7) % Change in valuation allowance (45.4) % (31.7) % (38.4) % (0.3 %) (8.0 %) 0.0 % Deferred income taxes represent the tax effect of transactions that are reported in different periods for financial and tax reporting purposes. Temporary differences and carryforwards that give rise to a significant portion of the deferred income tax benefits and liabilities were as follows as of December 31, 2023 and 2022: December 31, (dollars in millions) 2023 2022 Deferred income tax assets: Deferred revenue $ 151.2 $ 143.0 Capitalized research and development 93.6 56.3 Stock compensation 43.4 25.9 Tax credits 43.8 10.4 Loss carryforwards 65.8 3.8 Other 13.3 7.7 Total deferred income tax assets 411.1 247.1 Deferred income tax liabilities: Property, equipment and leasehold improvements (2.4) (2.6) Other (0.8) (1.0) Total deferred income tax liabilities (3.2) (3.6) Less valuation allowance (407.9) (243.5) Net deferred income tax liability $ — $ — A valuation allowance is established when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company has provided a valuation allowance against the full amount of the deferred tax assets since it is more likely than not that the benefits will not be realized. This assessment is based on the Company's historical cumulative losses, which provide strong objective evidence that cannot be overcome with projections of income, as well as the fact the Company expects continuing losses in the future. All, or a portion of, the remaining valuation allowance may be reduced in future years based on an assessment of earnings sufficient to utilize these potential tax benefits. The valuation allowance increased by $164.0 million and $104.0 million in 2023 and 2022, respectively, due to increases in net operating loss carryforwards, revenue recognition for tax purposes from the ARV-471 Collaboration Agreement and the mandatory capitalization of qualified research and development costs in 2023 and 2022. The Company had $235.9 million and zero of federal net operating loss carryforwards as of December 31, 2023 and 2022, respectively. Federal net operating losses incurred in 2018 and in future years may be carried forward indefinitely, but the deductibility of such carryforwards is limited to 80% of the Company’s taxable income in the year in which carryforwards are used. The Company had $250.0 million and $63.4 million of state and local net operating loss carryforwards as of December 31, 2023 and 2022, respectively, which expire at various dates beginning in 2035. The Company had $29.1 million and zero of federal tax credit carryforwards as of December 31, 2023 and 2022, respectively. The Company had $18.7 million and $13.1 million of state tax credit carryforwards as of December 31, 2023 and 2022, respectively, which expire at various dates beginning in 2040. During 2021, the Company performed a Section 382 analysis to determine whether an ownership change occurred for tax purposes. Based on this analysis, the Company determined that ownership changes occurred on July 31, 2018 and December 31, 2020 due to various equity offerings, vesting of restricted stock awards and stock option exercises. These ownership changes resulted in Section 382 limitations on the Company’s net operating loss and tax credit carryforwards generated before these dates. However, because the amount of the Section 382 limitations (including carryover of the unused Section 382 limitations and realized built-in gains) exceeds the amount of the Company’s carryforwards generated before these dates, the limitations will not affect the Company's ability to fully utilize these carryforwards. The Company complies with the provisions of ASC 740, Accounting for Income Taxes, in accounting for its uncertain tax positions. ASC 740 addresses the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the financial statements. Under ASC 740, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. As of December 31, 2023 and 2022, the Company recorded net uncertain tax positions of $4.9 million and $3.2 million, respectively, relating primarily to state income tax filing positions in various jurisdictions. Changes in the Company's gross unrecognized tax benefits were as follows: Year ended December 31, (dollars in millions) 2023 2022 2021 Beginning of period balance - gross $ 4.1 $ — $ — Increases for tax positions taken during the current period 1.8 4.1 — Decreases for tax positions taken during a prior period — — — End of period balance - gross $ 5.9 $ 4.1 $ — The Company recognizes interest accrued related to unrecognized tax benefits and penalties in tax expense. The Company's accrual for interest and penalties as of December 31, 2023 totaled $0.4 million. The Company's accrual for interest and penalties as of December 31, 2022 was immaterial. The Company is required to file income tax returns in the U.S. Federal and various state jurisdictions. As a result of the Company’s net operating loss carryforwards, the Company’s federal and state statutes of limitations generally remain open for all tax years until its net operating loss and tax credit carryforwards are utilized or expire prior to utilization. The Company does not currently have any federal or state income tax examinations in progress. For the year ended December 31, 2021, the Company recorded a benefit from expected cash refunds to be provided by the State of Connecticut, equal to 65% of research and development credits, of $1.6 million, which is included in Other income, net in the accompanying consolidated statements of operations and comprehensive loss, due to the Company being a state franchise taxpayer. For the years ended December 31, 2023 and 2022, the Company did not record any such benefits. The benefit results from the exchange of the state research and development tax credit carryforwards for cash refunds. As of December 31, 2023 and 2022, the Company had receivables of zero and $1.9 million, respectively, relating to research and development credits due to the Company.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company may be subject to legal proceedings, claims and disputes that arise in the ordinary course of business. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount, which could differ materially. Legal fees and other costs associated with such actions are expensed as incurred. As of December 31, 2023 and 2022, the Company has accrued $15.2 million and $7.0 million, respectively, for such matters, primarily related to a contract dispute with the potential means of resolution involving contract modification and, or payment of consideration. An estimate of the possible range of loss associated with the dispute cannot be made at this time and the Company has accrued its best estimate as of December 31, 2023. Clinical and Preclinical Development and Licensing Arrangements From time to time, the Company enters into contracts in the normal course of business with various third parties who support its clinical trials, preclinical research studies, and other services related to its development activities. The scope of the services under these agreements can generally be modified at any time, and the agreement can be terminated by either party after a period of notice and receipt of written notice. In addition, under licensing and related arrangements to which we are a party, we may be obligated to make milestone payments to third parties. The payment obligations under these arrangements are contingent upon future events, such as achievement of specified milestones or generation of product sales, and the amount, timing and likelihood of such payments are not known. Yale University License Agreement In July 2013, the Company entered into an exclusive license agreement, including the right to grant sublicenses, with Yale University to develop protein degradation technologies. Under the license agreement, the Company is required to pay a minimum license maintenance royalty totaling $0.1 million per year until the first sale to a third party of any licensed product, followed by success-based milestones for the first two licensed products for the development of the protein degradation technologies totaling approximately $3.0 million for the first licensed product and approximately $1.5 million for the second licensed product, and low single-digit royalties on aggregate worldwide net sales of certain licensed products, which may be subject to reductions, and subject to minimum royalty payments that range from $0.2 million to $0.5 million. During each of the years ended December 31, 2023, 2022 and 2021, the Company paid $0.3 million, $0.1 million and $0.1 million, respectively, under the license agreement. FMI Agreement In June 2022, the Company entered into a Master In Vitro Diagnostics Agreement with Foundation Medicine, Inc. (the "FMI Agreement") for the development and commercialization of one or more of Foundation Medicine’s companion in vitro diagnostic assays for use with one or more of the Company's therapeutic products. The FMI Agreement does not have a fixed duration, and the Company may terminate the FMI Agreement for convenience by providing adequate written notice to Foundation Medicine, Inc., subject to payment of applicable termination fees. Either party may terminate the FMI Agreement in its entirety for an uncured material breach by the other party, upon the bankruptcy or insolvency of the other party or by the mutual written agreement of both parties. Additionally, Foundation Medicine may terminate the FMI Agreement with respect to an applicable program, if (a) a reasonably necessary third party license is not secured by Foundation Medicine or if the Company does not consent to payments for such license (b) Foundation Medicine reasonably determines that further development of the applicable assay is not technically feasible or (c) following a certain number of years after the first commercial launch of the applicable assay for use with the applicable therapeutic product. Certain license and other rights and certain obligations of Foundation Medicine survive termination of the FMI Agreement. If the FMI Agreement is terminated in its entirety or with respect to any program, the Company has certain payment obligations remaining to Foundation Medicine and may also be required to pay a termination fee, if applicable. ARV-766 In exchange for the development of FoundationOne® Liquid CDx as a companion diagnostic for use with ARV-766 for AR mCRPC in the United States and European Union, pursuant to the terms of the FMI Agreement, the Company is subject to success-based milestone payments of up to low tens of millions of dollars, in addition to certain validation fees per sample and related pass-through costs.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic and diluted loss per common share was calculated as follows: Year ended December 31, (dollars and shares in millions, except per common share amounts) 2023 2022 2021 Net loss $ (367.3) $ (282.5) $ (191.0) Weighted-average common shares outstanding - basic and diluted 55.5 53.2 50.0 Net loss per common share $ (6.62) $ (5.31) $ (3.82) The weighted-average number of common shares included in the computation of basic and diluted net loss per common share gives effect to pre-funded warrants which allows holders to acquire a specified number of common shares at a nominal exercise price of $0.001 per share and are classified as equity. The shares underlying the pre-funded warrants are exercisable for little or no consideration and therefore the underlying shares are considered outstanding at the issuance of the pre-funded warrants for purposes of calculating the weighted-average number of common shares outstanding in basic and diluted net loss per share for common share. See Note 9, Equity. The Company reported net losses for each of the years ended December 31 2023, 2022 and 2021, and therefore excluded all stock options, restricted stock awards and restricted stock units from the computation of diluted net loss per common share as their inclusion would have had an anti-dilutive effect, as summarized below: Year ended December 31, (shares in millions) 2023 2022 2021 Stock options 7.9 6.8 5.3 Restricted stock units 1.2 0.5 0.1 9.1 7.3 5.4

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net loss	$ (367.3)	$ (282.5)	$ (191)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents
Restricted Cash	Restricted Cash Restricted cash represents a letter of credit collateralized by a certificate of deposit in the same amount as required under the terms of the Company's laboratory and office space.
Concentration of Credit Risk	Concentration of Credit Risk
Marketable Securities	Marketable Securities
Property, Equipment, and Leasehold Improvements	Property, Equipment, and Leasehold Improvements
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
Segment Information	Segment Information
Revenue Recognition and Deferred Revenue	Revenue Recognition and Deferred Revenue Revenues from Contracts The Company recognizes revenue under Accounting Standards Codification ("ASC") 606, Revenue from Contracts with Customers. The Company’s revenue is generated through research collaboration and license agreements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones and royalty payments based on product sales derived from the collaboration. Under ASC 606, the Company evaluates whether the license agreement, research and development services and participation in research and development steering committees represent separate or combined performance obligations. The Company has determined that these services within its existing contracts represent combined single performance obligations. The research collaboration and license agreements typically include contingent milestone payments related to specified preclinical and clinical development milestones and regulatory milestones. These milestone payments represent variable consideration to be included within the transaction price using the most likely amount method. The Company determined that the most likely amount to be recognized was zero, against which no constraint was applied. The Company continually assesses the probability of significant reversals for any amounts that become likely to be realized prior to recognizing the variable consideration associated with these payments within the transaction price. Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. Management makes its best estimate of the period over which the Company expects to fulfill its performance obligations, which includes access to technology through the license agreement and research activities. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period. Management evaluates changes in the duration of the performance period at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate. For the years ended December 31, 2023, 2022 and 2021, the transaction price allocated to the combined performance obligation identified under the individual research collaboration and license agreements was recognized as revenue on either a straight-line basis over the estimated performance period under the arrangement or over the estimated performance period based on the Company’s best estimate of costs to be incurred. Straight-line basis was considered the best measure of progress for certain agreements in which control of the combined obligation transfers to the customers, due to the contract containing license rights to technology, research and development services, and joint committee participation, which in totality are expected to occur ratably over the performance period. For agreements accounted for under the costs to be incurred method, collaboration revenue is recognized as program costs are incurred by measuring actual costs incurred to date compared to the total expected costs to satisfy the performance obligations. Management evaluates estimates of expected costs to satisfy the performance obligations at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate. The Company’s contracts may also call for certain sales-based milestone and royalty payments upon successful commercialization of a target. The Company recognizes revenues from sales-based milestone and royalty payments at the later of a) the occurrence of the subsequent sale, or b) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied (or partially satisfied). The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated by customers from the use of the technology. To date, no revenue from these sales-based milestone and royalty payments has been recognized for any periods. Amounts received prior to satisfying the above revenue recognition criteria are recorded as contract liabilities in the Company’s accompanying consolidated balance sheets. The Company expenses direct and incremental costs to obtaining and fulfilling a contract as and when incurred if the expected amortization period of the asset that would be recognized is one year or less, or if the amount of the asset is immaterial. Otherwise, such costs are capitalized as collaboration contract assets and amortized as general and administrative expenses over the total estimated period of performance of each underlying contract.
Equity Method Investments	Equity Method Investments The Company accounts for investments for which it does not have a controlling interest in accordance with ASC 323, Investments – Equity Method and Joint Ventures
Income Taxes	Income Taxes Arvinas, Inc. and its wholly owned subsidiaries use the asset and liability method of accounting for income taxes, as set forth in ASC 740, Accounting for Income Taxes . Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequence of temporary differences between the carrying amounts and the tax basis of assets and liabilities and net operating loss carry forwards, all calculated using presently enacted tax rates. A valuation allowance is established to reduce deferred tax assets to their estimated realizable value. The Company provides a valuation allowance to the extent that it is more likely than not that all or a portion of the deferred tax assets will not be realized.
Equity-based Compensation	Equity-based Compensation The Company measures employee, board of director and consultant equity-based compensation for stock option and restricted stock grants based on the grant date fair value of the equity awards. Equity-based compensation expense is recognized over the requisite service period of the awards, net of estimated forfeitures. Estimated forfeitures are updated on a periodic basis based on actual experience. For equity awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved. The Company classifies equity-based compensation expense in its consolidated statement of operations in the same manner in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified.
401(k) Savings plan	401(k) Savings Plan
Research and Development Expenses	Research and Development Expenses Research and development expenses include (i) employee-related expenses, including salaries, benefits, travel and stock-based compensation expense; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization agreements, investigational sites and consultants; (iii) the cost of acquiring, developing and manufacturing clinical study materials; (iv) costs associated with preclinical and clinical activities and regulatory operations; and (v) costs incurred in development of intellectual property. Costs incurred in connection with research and development activities are expensed as incurred. The Company enters into consulting, research and other agreements with commercial entities, researchers, universities and others for the provision of goods and services. Such arrangements are generally cancellable upon reasonable notice and payment of costs incurred. Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data provided by the respective vendors, including the Company’s clinical sites. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved and experience with similar contracts. The Company monitors each of these factors and adjusts estimates accordingly.
Fair Value Measurements	Fair Value Measurements The Company determines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Inputs used in the valuation techniques to determine fair values are classified based on a three-level hierarchy. The basis for fair value measurements for each level within the hierarchy is described below, with Level 1 having the highest priority and Level 3 having the lowest. The three levels of the fair value hierarchy are as follows: Level 1— Inputs are based upon observable or quoted prices (unadjusted) for identical instruments traded in active markets. The Company’s Level 1 financial instruments consist of cash equivalents. Level 2— Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities. Level 3— Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models and similar techniques.
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common shares. The weighted-average number of common shares included in the computation of basic and diluted net loss per common share gives effect to pre-funded warrants. See Note 9, Equity , and Note 13, Net Loss Per Share
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements There have been no recently adopted accounting pronouncements with a material impact to the Company's consolidated financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Income Taxes (Topic 740) - In December 2023, the FASB also issued ASU 2023-09, " Improvements to Income Tax Disclosures ," which requires enhanced income tax disclosures, including specific categories and disaggregation of information in the effective tax rate reconciliation, disaggregated information related to income taxes paid, income or loss from continuing operations before income tax expense or benefit and income tax expense or benefit from continuing operations. The requirements of the ASU are effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently in the process of evaluating the impact of this pronouncement on our related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of cash and cash equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total amounts shown in the consolidated statements of cash flows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, (dollars in millions) 2023 2022 2021 Cash and cash equivalents $ 311.7 $ 81.3 $ 108.3 Restricted cash 5.5 5.5 4.5 Cash, cash equivalents and restricted cash $ 317.2 $ 86.8 $ 112.8
Schedule of restrictions on cash and cash equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total amounts shown in the consolidated statements of cash flows for the years ended December 31, 2023, 2022 and 2021: Year Ended December 31, (dollars in millions) 2023 2022 2021 Cash and cash equivalents $ 311.7 $ 81.3 $ 108.3 Restricted cash 5.5 5.5 4.5 Cash, cash equivalents and restricted cash $ 317.2 $ 86.8 $ 112.8

Research Collaboration and Li_2

Research Collaboration and License Agreements (Tables)	12 Months Ended
	Dec. 31, 2023
Research Collaboration And License Agreements [Abstract]
Summary of contract balances	Changes in the Company's contract balances were as follows: December 31, (dollars in millions) 2023 2022 Accounts receivable Beginning balance $ 1.0 $ 15.0 Additions 21.7 6.4 Payments received (22.7) (20.4) Ending balance $ — $ 1.0 Accounts payable related to collaborations Beginning balance $ 5.0 $ — Additions 44.1 5.0 Payments made (36.0) — Ending balance $ 13.1 $ 5.0 Contract assets: Collaboration contract asset Beginning balance $ 10.7 $ 12.5 Additions — — Amortization (1.3) (1.8) Ending balance $ 9.4 $ 10.7 Contract liabilities: Deferred revenue Beginning balance $ 623.7 $ 740.5 Additions to collaboration agreements 1.5 4.0 Revenue recognized from balances held at the beginning of the period (76.0) (120.0) Revenue recognized from balances not held at the beginning of the period — (0.8) Ending balance $ 549.2 $ 623.7
Schedule of transaction price allocated to performance obligations	The aggregate amount of the transaction price allocated to performance obligations that were unsatisfied as of December 31, 2023 totaled $549.2 million, which is expected to be recognized in the following periods: (dollars in millions) 2024 $ 163.0 2025 153.4 2026 105.0 2027 57.6 2028 59.8 Thereafter 10.4 Total $ 549.2

Marketable Securities and Fai_2

Marketable Securities and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Summary of assets measured at fair value on a recurring basis	The following is a summary of the Company’s available for sale marketable securities measured at fair value on a recurring basis. December 31, 2023 (dollars in millions) Valuation Hierarchy Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Corporate bonds Level 2 $ 934.4 $ 1.5 $ (4.6) $ 931.3 Government securities Level 2 18.0 — — 18.0 Total $ 952.4 $ 1.5 $ (4.6) $ 949.3 December 31, 2022 (dollars in millions) Valuation Hierarchy Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Corporate bonds Level 2 $ 1,008.0 $ — $ (18.5) $ 989.5 Government securities Level 2 135.2 — (0.7) 134.5 Total $ 1,143.2 $ — $ (19.2) $ 1,124.0

Property, Equipment and Lease_2

Property, Equipment and Leasehold Improvements (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of property, equipment and leasehold improvements	Property, equipment and leasehold improvements consist of the following: December 31, (dollars in millions) 2023 2022 Laboratory equipment $ 18.5 $ 17.1 Office equipment 2.6 2.0 Leasehold improvements 11.5 10.9 Total property, equipment and leasehold improvements 32.6 30.0 Less: accumulated depreciation and amortization (21.1) (16.6) Property, equipment and leasehold improvements, net $ 11.5 $ 13.4

Right of Use Assets and Liabi_2

Right of Use Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Schedule of components of lease expense	The components of lease expense were as follows: Year Ended December 31, (dollars in millions) 2023 2022 2021 Operating lease cost $ 2.1 $ 2.1 $ 1.4
Schedule of supplemental cash flow information related to leases	Supplemental cash flow information related to leases was as follows: December 31, (dollars in millions) 2023 2022 2021 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2.0 $ 1.9 $ 1.2 Supplemental non-cash information: Right-of-use assets obtained in exchange for new lease obligations $ — $ 2.4 $ 3.2
Schedule of maturities of operating lease liabilities	Maturities of operating lease liabilities as of December 31, 2023 were as follows: (dollars in millions) 2024 $ 2.0 2025 0.5 Total lease payments 2.5 Less: imputed interest (0.1) Total $ 2.4

Accounts Payable and Accrued _2

Accounts Payable and Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of components of accounts payable and accrued liabilities	Accounts payable and accrued liabilities consisted of the following: December 31, (dollars in millions) 2023 2022 Accounts payable $ 17.8 $ 5.7 Accrued liabilities Research and development expenses 43.1 35.9 Employee expenses 25.7 18.7 Professional fees 2.5 2.4 General and administrative and commercial expenses 2.4 1.7 Income taxes 0.7 10.3 $ 92.2 $ 74.7

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Debt obligations consisted of the following: (dollars in millions) Maturity Date Interest Rate December 31, December 31, 2018 Assistance Agreement Debt 09/28 3.25% $ 1.0 $ 1.0 Less: current installments included within Accounts Payable and Accrued Liabilities (0.2) — Total long-term debt $ 0.8 $ 1.0
Schedule of minimum future principal payments on long-term debt	Minimum future principal payments on long-term debt as of December 31, 2023 are as follows: (dollars in millions) 2024 $ 0.2 2025 0.2 2026 0.2 2027 0.2 2028 0.2 Total $ 1.0

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2023
Schedule of assumptions used to determine fair value of stock options granted	The fair value of the stock options granted during each of the years ended December 31, 2023, 2022 and 2021 was determined using the Black-Scholes option pricing model at the grant date with the following range of assumptions: Year ended December 31, 2023 2022 2021 Expected volatility 71% - 75% 73% - 76% 74% - 78% Expected term (years) 5.5 - 7.0 5.5 - 7.0 5.3 - 7.0 Risk free interest rate 3.4% - 4.8% 1.5% - 4.2% 0.5% - 1.3% Expected dividend yield 0 % 0 % 0 % Exercise price $16.21 - $36.27 $36.79 - $78.91 $66.82 - $100.40
Summary of stock option activity	A summary of the stock option activity under the 2018 Plan as of December 31, 2023 is presented below. These amounts include stock options granted to employees, directors and consultants. (dollars in millions, except weighted-average exercise price) Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Outstanding as of December 31, 2022 6,814,634 $ 49.06 7.7 $ 34.5 Granted 1,846,724 $ 32.48 Exercised (142,764) $ 18.97 Forfeited (580,367) $ 56.45 Expired (4,433) $ 71.30 Outstanding as of December 31, 2023 7,933,794 $ 45.22 7.2 $ 62.6 Vested and exercisable as of December 31, 2023 4,739,559 $ 43.79 6.3 $ 46.9 Vested and expected to vest as of December 31, 2023 7,678,026 $ 45.27 7.2 $ 61.0
Restricted stock units
Summary of restricted stock activity	A summary of restricted stock unit activity under the 2018 Plan for the year ended December 31, 2023 is presented below. These amounts include restricted stock units granted to employees. Shares Weighted-Average Grant Date Fair Value Per Share Unvested restricted stock units as of December 31, 2022 489,216 $ 51.37 Granted 885,494 $ 32.27 Exercised (154,146) $ 44.79 Forfeited (68,708) $ 41.48 Unvested restricted stock units as of December 31, 2023 1,151,856 $ 38.16

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of income tax expense	For the years ended December 31, 2023, 2022 and 2021, income tax expense totaled $0.9 million, $20.9 million and zero, respectively, and consisted of the following: Year Ended December 31, 2023 2022 2021 Current: U.S.: Federal $ (1.7) $ 8.2 $ — State and local 2.6 12.7 — Total current 0.9 20.9 — Deferred: U.S.: Federal — — — State and local — — — Total deferred — — — Income tax expense $ 0.9 $ 20.9 $ —
Reconciliation of the U.S. federal statutory income tax rate to effective income tax rate	A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate for the years ended December 31, 2023, 2022 and 2021 were as follows: Year ended December 31, 2023 2022 2021 Federal statutory rate 21.0 % 21.0 % 21.0 % State taxes 18.4 % (1.6) % 16.3 % Federal research tax credit 7.6 % 3.4 % 2.7 % Other — % (0.1 %) — % Return to provision (0.2) % 3.6 % 1.1 % Uncertain tax positions (0.5 %) (1.2 %) — % Stock compensation (1.2) % (1.4) % (2.7) % Change in valuation allowance (45.4) % (31.7) % (38.4) % (0.3 %) (8.0 %) 0.0 %
Summary of deferred income tax benefits and liabilities	Temporary differences and carryforwards that give rise to a significant portion of the deferred income tax benefits and liabilities were as follows as of December 31, 2023 and 2022: December 31, (dollars in millions) 2023 2022 Deferred income tax assets: Deferred revenue $ 151.2 $ 143.0 Capitalized research and development 93.6 56.3 Stock compensation 43.4 25.9 Tax credits 43.8 10.4 Loss carryforwards 65.8 3.8 Other 13.3 7.7 Total deferred income tax assets 411.1 247.1 Deferred income tax liabilities: Property, equipment and leasehold improvements (2.4) (2.6) Other (0.8) (1.0) Total deferred income tax liabilities (3.2) (3.6) Less valuation allowance (407.9) (243.5) Net deferred income tax liability $ — $ —
Summary of unrecognized tax benefits	Changes in the Company's gross unrecognized tax benefits were as follows: Year ended December 31, (dollars in millions) 2023 2022 2021 Beginning of period balance - gross $ 4.1 $ — $ — Increases for tax positions taken during the current period 1.8 4.1 — Decreases for tax positions taken during a prior period — — — End of period balance - gross $ 5.9 $ 4.1 $ —

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Basic and diluted loss per common share	Basic and diluted loss per common share was calculated as follows: Year ended December 31, (dollars and shares in millions, except per common share amounts) 2023 2022 2021 Net loss $ (367.3) $ (282.5) $ (191.0) Weighted-average common shares outstanding - basic and diluted 55.5 53.2 50.0 Net loss per common share $ (6.62) $ (5.31) $ (3.82)
Securities excluded from the computation of diluted net loss per share	The Company reported net losses for each of the years ended December 31 2023, 2022 and 2021, and therefore excluded all stock options, restricted stock awards and restricted stock units from the computation of diluted net loss per common share as their inclusion would have had an anti-dilutive effect, as summarized below: Year ended December 31, (shares in millions) 2023 2022 2021 Stock options 7.9 6.8 5.3 Restricted stock units 1.2 0.5 0.1 9.1 7.3 5.4

Nature of Business and Basis _2

Nature of Business and Basis of Presentation (Details) $ in Billions	12 Months Ended
	Dec. 31, 2023 USD ($) Subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of wholly owned subsidiaries | Subsidiary	4
Cash, cash equivalents, restricted cash and marketable securities | $	$ 1.3

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Cash Reconciliation (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 311.7	$ 81.3	$ 108.3
Restricted cash	5.5	5.5	4.5
Cash, cash equivalents and restricted cash	$ 317.2	$ 86.8	$ 112.8	$ 588.4

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) operating_segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Impairment of long lived assets	$ 0	$ 0	$ 0
Number of operating segments | operating_segment	1
Equity method investments	$ 0
Discretionary matching contributions	$ 3,100,000	$ 2,200,000	$ 1,300,000
Office equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	3 years
Laboratory equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	5 years
Customer Concentration Risk | Revenue | Collaborator One
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	97%	88%	68%
Maximum
Summary Of Significant Accounting Policies [Line Items]
Federal deposit insurance corporation premium expense	$ 250,000

Research Collaboration and Li_3

Research Collaboration and License Agreements - Additional Information (Details) - USD ($)	1 Months Ended			4 Months Ended	12 Months Ended				55 Months Ended	73 Months Ended	74 Months Ended
	Sep. 30, 2021	Jul. 31, 2021	Nov. 30, 2017	Dec. 31, 2015	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Jun. 30, 2019	Dec. 31, 2017
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved					$ 9,400,000	$ 10,700,000	$ 12,500,000		$ 9,400,000	$ 9,400,000	$ 9,400,000
Gross proceeds					370,200,000		259,900,000
Collaboration contract asset and other assets					10,400,000	10,800,000			10,400,000	10,400,000	10,400,000
Accounts receivable					0	1,000,000	15,000,000		0	0	0
Revenue					78,500,000	131,400,000	53,600,000
Net income (loss)					$ (367,300,000)	$ (282,500,000)	$ (191,000,000)
Net loss per common share - basic (in usd per share)					$ (6.62)	$ (5.31)	$ (3.82)
Net loss per common share - diluted (in usd per share)					$ (6.62)	$ (5.31)	$ (3.82)
Revenue adjustments arising from contract modifications						$ 700,000	$ (800,000)
Expansion of Development Programs
Research Collaboration And License Agreements [Line Items]
Revenue					$ (35,000,000)
Net income (loss)					$ (35,000,000)
Net loss per common share - basic (in usd per share)					$ (0.63)
Net loss per common share - diluted (in usd per share)					$ (0.63)
Updated Research Timelines
Research Collaboration And License Agreements [Line Items]
Revenue					$ (10,600,000)
Net income (loss)					$ (10,600,000)
Net loss per common share - basic (in usd per share)					$ (0.19)
Net loss per common share - diluted (in usd per share)					$ (0.19)
Common Shares
Research Collaboration And License Agreements [Line Items]
Common stock issued, net of issuance costs (in shares)					14,400,000		3,500,000
Pfizer, Inc.
Research Collaboration And License Agreements [Line Items]
Payments received								$ 28,000,000
Pfizer, Inc. | Collaboration Agreement
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved		$ 650,000,000
Collaboration agreement direct and incremental costs incurred					$ 12,900,000
Collaboration contract asset and other assets					12,900,000				12,900,000	12,900,000	12,900,000
Pfizer, Inc. | Stock Purchase Agreement
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved		650,000,000
Fair value of the shares sold		$ 85,400,000
Pfizer, Inc. | Stock Purchase Agreement | Common Shares
Research Collaboration And License Agreements [Line Items]
Common stock issued, net of issuance costs (in shares)	3,457,815
Share price, issued and sold (in usd per share)	$ 101.22
Gross proceeds	$ 350,000,000
Financial advisor fees	$ 4,600,000
Pfizer, Inc. | Development Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved													$ 225,000,000
Pfizer, Inc. | Sales-based Milestone Payments
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved					1,000,000,000				1,000,000,000	1,000,000,000	1,000,000,000
Payments received										0
Pfizer, Inc. | Sales-based Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved													550,000,000
Pfizer, Inc. | Option Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved													$ 37,500,000
Pfizer, Inc. | Additional Target and Services
Research Collaboration And License Agreements [Line Items]
Accounts receivable						1,000,000	$ 3,500,000
Pfizer, Inc. | Regulatory Milestone Payments
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved					400,000,000				400,000,000	400,000,000	400,000,000
Pfizer, Inc. | Regulatory Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved					1,400,000,000				1,400,000,000	1,400,000,000	1,400,000,000
Bayer A G
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved												$ 17,500,000
Bayer A G | Stock Purchase Agreement
Research Collaboration And License Agreements [Line Items]
Fair value of the shares sold					2,900,000
Additional consideration received					2,900,000
Bayer A G | Research Funding Payments
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved					12,000,000				12,000,000	$ 12,000,000	12,000,000
Payments received					$ 1,500,000	$ 3,000,000	$ 3,000,000
Bayer A G | Development Milestone Payments
Research Collaboration And License Agreements [Line Items]
Payments received									0
Bayer A G | Development Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved												197,500,000
Bayer A G | Sales-based Milestone Payments
Research Collaboration And License Agreements [Line Items]
Payments received									$ 0
Bayer A G | Sales-based Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved												$ 490,000,000
Genentech, Inc. and F. Hoffman-La Roche Ltd.
Research Collaboration And License Agreements [Line Items]
Payments received			$ 34,500,000	$ 11,000,000
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Development Milestone Payments
Research Collaboration And License Agreements [Line Items]
Payments received											0
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Development Milestone Payments | Maximum
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved			44,000,000
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Regulatory Milestone Payments
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved			52,500,000
Payments received											0
Genentech, Inc. and F. Hoffman-La Roche Ltd. | Commercial Milestones
Research Collaboration And License Agreements [Line Items]
Contract revenue receivable if milestones achieved			$ 60,000,000
Payments received											$ 0

Research Collaboration and Li_4

Research Collaboration and License Agreements - Summary of Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts receivable
Beginning balance	$ 1	$ 15
Additions	21.7	6.4
Payments received	(22.7)	(20.4)
Ending balance	0	1	$ 15
Accounts payable related to collaborations
Beginning balance	5	0
Additions	44.1	5
Payments made	(36)	0
Ending balance	13.1	5	0
Contract assets: Collaboration contract asset
Beginning balance	10.7	12.5
Additions	0	0
Amortization	(1.3)	(1.8)	(0.4)
Ending balance	9.4	10.7	12.5
Contract liabilities: Deferred revenue
Beginning balance	623.7	740.5
Additions to collaboration agreements	1.5	4
Revenue recognized from balances held at the beginning of the period	(76)	(120)
Revenue recognized from balances not held at the beginning of the period	0	(0.8)
Ending balance	$ 549.2	$ 623.7	$ 740.5

Research Collaboration and Li_5

Research Collaboration and License Agreements - Transaction Price Allocated to Performance Obligations (Details) $ in Millions	Dec. 31, 2023 USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 549.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 163
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 153.4
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 105
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 57.6
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 59.8
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 10.4
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Marketable Securities and Fai_3

Marketable Securities and Fair Value Measurements (Details) - Level 2 - Fair Value, Recurring - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 952.4	$ 1,143.2
Gross Unrealized Gains	1.5	0
Gross Unrealized Losses	(4.6)	(19.2)
Fair Value	949.3	1,124
Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	934.4	1,008
Gross Unrealized Gains	1.5	0
Gross Unrealized Losses	(4.6)	(18.5)
Fair Value	931.3	989.5
Government securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	18	135.2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(0.7)
Fair Value	$ 18	$ 134.5

Property, Equipment and Lease_3

Property, Equipment and Leasehold Improvements - Schedule of Property, Equipment and Leasehold Improvements (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 32.6	$ 30
Less: accumulated depreciation and amortization	(21.1)	(16.6)
Property, equipment and leasehold improvements, net	11.5	13.4
Laboratory equipment
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	18.5	17.1
Office equipment
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	2.6	2
Leasehold improvements
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements, gross	$ 11.5	$ 10.9

Property, Equipment and Lease_4

Property, Equipment and Leasehold Improvements - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 4.8	$ 6.3	$ 4.8

Right of Use Assets and Liabi_3

Right of Use Assets and Liabilities - Additional Information (Details) ft² in Thousands, $ in Millions	1 Months Ended
	May 31, 2021 USD ($) ft²	Dec. 31, 2023
Lessee Lease Description [Line Items]
Lease for laboratory and office space (in square feet) | ft²	160
Base rent period	10 years
Operating lease, weighted average remaining lease term (in years)		1 year 4 months 24 days
Asset Pledged as Collateral | Letter of Credit
Lessee Lease Description [Line Items]
Debt securities	$ 5.5
Minimum
Lessee Lease Description [Line Items]
Percentage of incremental borrowing for lease payments		3%
Base rent	7.7
Maximum
Lessee Lease Description [Line Items]
Percentage of incremental borrowing for lease payments		7.50%
Base rent	$ 8.8

Right of Use Assets and Liabi_4

Right of Use Assets and Liabilities - Components of Lease Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease cost	$ 2.1	$ 2.1	$ 1.4

Right of Use Assets and Liabi_5

Right of Use Assets and Liabilities - Schedule of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 2	$ 1.9	$ 1.2
Supplemental non-cash information:
Right-of-use assets obtained in exchange for new lease obligations	$ 0	$ 2.4	$ 3.2

Right of Use Assets and Liabi_6

Right of Use Assets and Liabilities - Schedule of Maturities of Lease Liabilities (Details) $ in Millions	Dec. 31, 2023 USD ($)
Leases [Abstract]
2024	$ 2
2025	0.5
Total lease payments	2.5
Less: imputed interest	(0.1)
Total	$ 2.4

Accounts Payable and Accrued _3

Accounts Payable and Accrued Liabilities - Components of Accrued Expenses (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accounts payable	$ 17.8	$ 5.7
Accrued liabilities
Research and development expenses	43.1	35.9
Employee expenses	25.7	18.7
Professional fees	2.5	2.4
General and administrative and commercial expenses	2.4	1.7
Income taxes	0.7	10.3
Accounts payable and accrued liabilities	$ 92.2	$ 74.7

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt	$ 1
Less: current installments included within Accounts Payable and Accrued Liabilities	(0.2)	$ 0
Long term debt	$ 0.8	1
2018 Assistance Agreement
Debt Instrument [Line Items]
Interest Rate	3.25%
Long-term debt	$ 1	$ 1

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended			12 Months Ended
	Apr. 30, 2021	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2014
Debt Instrument [Line Items]
Percentage of maximum funding on total project costs			50%
Loan forgiveness				$ 0	$ 0	$ 1
Interest expense				$ 0	$ 0	$ 0
2018 Assistance Agreement
Debt Instrument [Line Items]
Debt instrument, interest rate per annum				3.25%
2018 Assistance Agreement | State of Connecticut
Debt Instrument [Line Items]
Debt instrument face amount		$ 2
Debt instrument, interest rate per annum		3.25%
Debt instrument interest payments term		60 months
Debt instrument amortization period (month)		120 months
Loan forgiveness	$ 1
Percentage of liquidated damages		7.50%
2018 Assistance Agreement | State of Connecticut | Maximum
Debt Instrument [Line Items]
Debt instrument face amount			$ 2
2014 Assistance Agreement | State of Connecticut
Debt Instrument [Line Items]
Debt instrument face amount							$ 2.5
Percentage of liquidated damages							7.50%

Long-Term Debt - Schedule of An

Long-Term Debt - Schedule of Anticipated Future Minimum Payments on Long-Term Debt Excluding Discount on Debt (Details) $ in Millions	Dec. 31, 2023 USD ($)
Debt Disclosure [Abstract]
2024	$ 0.2
2025	0.2
2026	0.2
2027	0.2
2028	0.2
Long-term debt	$ 1

Equity - Additional Information

Equity - Additional Information (Details) $ / shares in Units, $ in Millions		1 Months Ended			12 Months Ended
	Jan. 01, 2020	Nov. 30, 2023 USD ($) $ / shares shares	Aug. 31, 2023 USD ($) shares	Sep. 30, 2021 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) vote $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2019 shares	Aug. 31, 2021 USD ($)	Sep. 30, 2018 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Preferred stock, shares authorized (in shares) | shares					5,000,000	5,000,000
Preferred stock par value (in usd per share) | $ / shares					$ 0.001	$ 0.001
Common stock, shares authorized (in shares) | shares					200,000,000	200,000,000
Common stock, par value (in usd per share) | $ / shares					$ 0.001	$ 0.001
Number of votes per common stock share held | vote					1
Fees and expenses					$ 17	$ 0	$ 4.6
Common stock issued, net of issuance costs					370.2		259.9
Proceeds from issuance of common stock and pre-funded warrants					387.2	0	264.6
Compensation expense, total					71.6	$ 75.5	$ 57.1
Compensation expense not yet recognized					$ 53.6
Weighted average grant date fair value of options granted (in usd per share) | $ / shares					$ 21.99	$ 39.17	$ 52.85
Intrinsic value of options exercised					$ 1.4	$ 7.9	$ 46.9
Pre-Funded Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Warrant exercise price (in usd per share) | $ / shares		$ 0.001
Weighted Average
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense not yet recognized, period of recognition (in years)					1 year 7 months 6 days
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance (in shares) | shares										4,067,007
Common stock, shares remained available for purchase and issuance (in shares) | shares					2,099,162
Annual increase in reserved shares of outstanding common stock (percentage)								4%
2018 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance (in shares) | shares										1,277,181
2018 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual increase in reserved shares of common stock (in shares) | shares								4,989,593
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance (in shares) | shares										311,850
Common stock reserved for issuance on outstanding common stock (percentage)	1%
Common stock, shares remained available for purchase and issuance (in shares) | shares					2,440,434
Common stock, shares issued (in shares) | shares					78,528	24,898	19,357
ESPP | 2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense, total					$ 0.8	$ 0.7	$ 0.3
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested in period, fair value					$ 6.9	$ 0.9	$ 0.9
Private Placement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fees and expenses		$ 15.9
Proceeds from issuance of common stock and pre-funded warrants		$ 350
Common Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock issued, net of issuance costs (in shares) | shares					14,400,000		3,500,000
Common Shares | Private Placement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued in transaction (in shares) | shares		12,963,542
Sale of stock, price (in usd per share) | $ / shares		$ 21.36
Common Shares | Private Placement | Pre-Funded Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock, price (in usd per share) | $ / shares		$ 21.359
Warrants to be purchased (in shares) | shares		3,422,380
Common Shares | Pfizer, Inc. | Stock Purchase Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock issued, net of issuance costs (in shares) | shares				3,457,815
Share price, issued and sold (in usd per share) | $ / shares				$ 101.22
Common stock issued, net of issuance costs				$ 350
Financial advisor fees				$ 4.6
Common Shares | Piper Sandler and Cantor | Equity Distribution Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fees and expenses			$ 1.1
Common stock issued, net of issuance costs (in shares) | shares			1,449,275		0
Common stock issued, net of issuance costs			$ 37.2
Common stock aggregate offering price		$ 262.8							$ 300

Equity - Schedule of Assumption

Equity - Schedule of Assumptions Used to Determine Fair Value of and Stock Options Granted (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, minimum (percentage)	71%	73%	74%
Expected volatility, maximum (percentage)	75%	76%	78%
Risk free interest rate, minimum (percentage)	3.40%	1.50%	0.50%
Risk free interest rate, maximum (percentage)	4.80%	4.20%	1.30%
Expected dividend yield (percentage)	0%	0%	0%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 6 months	5 years 6 months	5 years 3 months 18 days
Exercise price (in usd per share)	$ 16.21	$ 36.79	$ 66.82
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	7 years	7 years	7 years
Exercise price (in usd per share)	$ 36.27	$ 78.91	$ 100.40

Equity - Summary of Stock Optio

Equity - Summary of Stock Option Activity (Details) - 2018 Plan - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Options
Beginning balance (in shares)	6,814,634
Granted (in shares)		1,846,724
Exercised (in shares)		(142,764)
Forfeited (in shares)		(580,367)
Expired (in shares)		(4,433)
Ending balance (in shares)	7,933,794	6,814,634
Vested and exercisable, ending balance (in shares)	4,739,559
Vested and expected to vest (in shares)	7,678,026
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 49.06
Granted (in dollars per share)		$ 32.48
Exercised (in dollars per share)		18.97
Forfeited (in dollars per share)		56.45
Expired (in dollars per share)		71.30
Ending balance (in dollars per share)	45.22	$ 49.06
Vested and exercisable (in dollars per share)	43.79
Vested and expected to vest (in dollars per share)	$ 45.27
Weighted Average Remaining Contractual Term (Years)
Outstanding	7 years 2 months 12 days	7 years 8 months 12 days
Vested and exercisable	6 years 3 months 18 days
Vested and expected to vest	7 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding	$ 62.6	$ 34.5
Vested and exercisable	46.9
Vested and expected to vest	$ 61

Equity - Summary of Restricted

Equity - Summary of Restricted Stock Grant Activity (Details) - 2018 Plan - Restricted stock units - Employees	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Shares
Beginning balance (in shares) | shares	489,216
Granted (in shares) | shares	885,494
Exercised (in shares) | shares	(154,146)
Forfeited (in shares) | shares	(68,708)
Ending balance (in shares) | shares	1,151,856
Weighted-Average Grant Date Fair Value Per Share
Beginning balance (in usd per share) | $ / shares	$ 51.37
Granted (in dollars per share) | $ / shares	32.27
Exercised (in usd per share) | $ / shares	44.79
Forfeited (in usd per share) | $ / shares	41.48
Ending balance (in usd per share) | $ / shares	$ 38.16

Equity Method Investments (Deta

Equity Method Investments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jul. 31, 2019
Schedule Of Equity Method Investments [Line Items]
Operating expenses	$ 480,000,000	$ 394,600,000	$ 242,000,000
Net loss	(367,300,000)	(282,500,000)	(191,000,000)
Loss from equity method investment	(2,500,000)	(10,600,000)	(6,900,000)
Equity method investments	0
Oerth
Schedule Of Equity Method Investments [Line Items]
Operating expenses	8,300,000	22,900,000	14,300,000
Net loss	$ (8,300,000)	$ (22,900,000)	$ (14,300,000)
Oerth
Schedule Of Equity Method Investments [Line Items]
Ownership interest, percentage	45%	46.50%	48.40%
Future grant of incentive units to service providers, percentage				15%
Loss from equity method investment	$ (2,500,000)	$ (10,600,000)	$ (6,900,000)
Equity method investments	$ 0	$ 0
Bayer LP | Oerth
Schedule Of Equity Method Investments [Line Items]
Equity interest				$ 56,000,000
Ownership interest, percentage				50%

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current:
Federal	$ (1.7)	$ 8.2	$ 0
State and local	2.6	12.7	0
Total current	0.9	20.9	0
Deferred:
Federal	0	0	0
State and local	0	0	0
Total deferred	0	0	0
Income tax expense	$ 0.9	$ 20.9	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Line Items]
Income tax expense	$ 0.9	$ 20.9	$ 0
Net uncertain tax positions	4.9	3.2
Unrecognized tax benefits, income tax penalties and interest accrued	$ 0.4	$ 0
Effective income tax rate reconciliation, tax credit, research and development, percentage	(7.60%)	(3.40%)	(2.70%)
Effective income tax rate reconciliation, tax credit, research and development	$ 0		$ 1.6
Federal
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 235.9	$ 0
Operating losses carry forward, maximum deductibility percentage	80%
Federal tax credit carryforwards	$ 29.1	0
State
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	250	63.4
Federal tax credit carryforwards	18.7	13.1
Research and Development Tax Credits
Income Tax Disclosure [Line Items]
(Decrease) Increase in valuation allowance	$ 164	$ 104
Effective income tax rate reconciliation, tax credit, research and development, percentage	65%	65%	65%
Receivables relating to research and development credits	$ 0	$ 1.9

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the U.S. Federal Statutory Income Tax Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Federal statutory rate	21%	21%	21%
State taxes	18.40%	(1.60%)	16.30%
Federal research tax credit	7.60%	3.40%	2.70%
Other	0%	(0.10%)	0%
Return to provision	(0.20%)	3.60%	1.10%
Uncertain tax positions	(0.50%)	(1.20%)	0%
Stock compensation	(1.20%)	(1.40%)	(2.70%)
Change in valuation allowance	(45.40%)	(31.70%)	(38.40%)
Reconciliation of effective income tax rate	(0.30%)	(8.00%)	0%

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred income tax assets:
Deferred revenue	$ 151.2	$ 143
Capitalized research and development	93.6	56.3
Stock compensation	43.4	25.9
Tax credits	43.8	10.4
Loss carryforwards	65.8	3.8
Other	13.3	7.7
Total deferred income tax assets	411.1	247.1
Deferred income tax liabilities:
Property, equipment and leasehold improvements	(2.4)	(2.6)
Other	(0.8)	(1)
Total deferred income tax liabilities	(3.2)	(3.6)
Less valuation allowance	(407.9)	(243.5)
Net deferred income tax liability	$ 0	$ 0

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning of period balance - gross	$ 4.1	$ 0	$ 0
Increases for tax positions taken during the current period	1.8	4.1	0
Decreases for tax positions taken during a prior period	0	0	0
End of period balance - gross	$ 5.9	$ 4.1	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions		1 Months Ended	12 Months Ended
	Jun. 04, 2022 USD ($)	Jul. 31, 2013 USD ($) product	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Commitments And Contingencies [Line Items]
Loss contingency			$ 15.2	$ 7
Yale University
Commitments And Contingencies [Line Items]
Royalty payment			$ 0.3	$ 0.1	$ 0.1
Yale University | License, First Licensed Product | Success-Based Milestone Payments
Commitments And Contingencies [Line Items]
Required milestone payments		$ 3
Yale University | License, Second Licensed Product | Success-Based Milestone Payments
Commitments And Contingencies [Line Items]
Required milestone payments		1.5
Minimum | Yale University
Commitments And Contingencies [Line Items]
Annual payment for license		$ 0.1
Number of licensed products | product		2
Royalty payment		$ 0.2
Maximum | Yale University
Commitments And Contingencies [Line Items]
Royalty payment		$ 0.5
Maximum | Foundation Medicine, Inc. | Success-Based Milestone Payments
Commitments And Contingencies [Line Items]
Milestone payments (up to)	$ 10

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Loss per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Nov. 30, 2023
Earnings Per Share [Abstract]
Net loss	$ (367.3)	$ (282.5)	$ (191)
Weighted average common shares outstanding - basic (in shares)	55.5	53.2	50
Weighted-average common shares outstanding - diluted (in shares)	55.5	53.2	50
Net loss per common share - basic (in usd per share)	$ (6.62)	$ (5.31)	$ (3.82)
Net loss per common share - diluted (in usd per share)	$ (6.62)	$ (5.31)	$ (3.82)
Pre-Funded Warrant
Class of Warrant or Right [Line Items]
Warrant exercise price (in usd per share)				$ 0.001

Net Loss Per Share - Securities

Net Loss Per Share - Securities Excluded from the Computations of Diluted Net Loss Per Share (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computations of diluted net loss per share (in shares)	9.1	7.3	5.4
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computations of diluted net loss per share (in shares)	7.9	6.8	5.3
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from the computations of diluted net loss per share (in shares)	1.2	0.5	0.1