Avidity Biosciences (RNA) 10-K 27 Feb 25 2024 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2024	Feb. 14, 2025	Jun. 30, 2024
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39321
Entity Registrant Name	AVIDITY BIOSCIENCES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1336960
Entity Address, Address Line One	10578 Science Center Drive
Entity Address, Address Line Two	Suite 125
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	401-7900
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	RNA
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 [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 4.4
Entity Common Stock, Shares Outstanding		120,212,301
Documents Incorporated by Reference	Certain sections of the registrant’s definitive proxy statement for the 2025 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Entity Central Index Key	0001599901
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2024
Audit Information [Abstract]
Auditor Firm ID	243
Auditor Name	BDO USA, P.C.
Auditor Location	San Diego, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 219,868	$ 185,082
Marketable securities	1,281,629	410,269
Prepaid and other assets	40,793	15,956
Total current assets	1,542,290	611,307
Property and equipment, net	12,670	8,381
Restricted cash	2,795	295
Right-of-use assets	5,619	8,271
Other assets	521	301
Total assets	1,563,895	628,555
Current liabilities:
Accounts payable and accrued liabilities	69,524	34,341
Accrued compensation	3,663	14,335
Lease liabilities, current portion	3,844	3,639
Deferred revenue, current portion	20,987	28,365
Total current liabilities	98,018	80,680
Lease liabilities, net of current portion	2,957	6,213
Deferred revenue, net of current portion	37,961	40,898
Total liabilities	138,936	127,791
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock, $0.0001 par value; authorized shares – 400,000; issued and outstanding shares – 119,893 and 79,275 at December 31, 2024 and 2023, respectively	12	8
Additional paid-in capital	2,315,111	1,071,395
Accumulated other comprehensive income	2,902	125
Accumulated deficit	(893,066)	(570,764)
Total stockholders’ equity	1,424,959	500,764
Total liabilities and stockholders’ equity	$ 1,563,895	$ 628,555

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	119,893,000	79,275,000
Common stock, shares outstanding (in shares)	119,893,000	79,275,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Collaboration revenue	$ 10,897	$ 9,560	$ 9,224
Operating expenses:
Research and development	303,593	190,968	150,404
General and administrative	86,240	54,190	37,733
Total operating expenses	389,833	245,158	188,137
Loss from operations	(378,936)	(235,598)	(178,913)
Other income (expense):
Interest income	56,882	23,972	4,975
Other expense	(248)	(594)	(57)
Total other income	56,634	23,378	4,918
Net loss	$ (322,302)	$ (212,220)	$ (173,995)
Net loss per share, basic (in dollars per share)	$ (2.89)	$ (2.91)	$ (3.34)
Net loss per share, diluted (in dollars per share)	$ (2.89)	$ (2.91)	$ (3.34)
Weighted-average shares outstanding, basic (in shares)	111,582	73,012	52,162
Weighted-average shares outstanding, diluted (in shares)	111,582	73,012	52,162
Other comprehensive income (loss):
Net unrealized gains (losses) on marketable securities	$ 2,777	$ 2,823	$ (2,511)
Comprehensive loss	$ (319,525)	$ (209,397)	$ (176,506)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders’ Equity - USD ($) shares in Thousands, $ in Thousands	Total	Public Stock Offering	Private Placement	Pre Funded Warrants Private Placement	Common Stock	Common Stock Public Stock Offering	Common Stock Private Placement	Additional Paid-in Capital	Additional Paid-in Capital Public Stock Offering	Additional Paid-in Capital Private Placement	Additional Paid-in Capital Pre Funded Warrants Private Placement	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021					47,754
Beginning balance at Dec. 31, 2021	$ 381,430				$ 5			$ 566,161				$ (187)	$ (184,549)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)						21,572
Issuance of common stock, net of issuance costs		$ 344,616				$ 2			$ 344,614
Issuance of common stock upon exercise of stock options (in shares)					351
Issuance of common stock upon exercise of stock options	470							470
Issuance of common stock under employee stock purchase plan (in shares)					91
Issuance of common stock under employee stock purchase plan	922							922
Vesting of early exercise options	4							4
Stock-based compensation	27,139							27,139
Net loss	(173,995)												(173,995)
Other comprehensive loss (income)	(2,511)											(2,511)
Ending balance (in shares) at Dec. 31, 2022					69,768
Ending balance at Dec. 31, 2022	578,075				$ 7			939,310				(2,698)	(358,544)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)						4,107	5,075
Issuance of common stock, net of issuance costs		60,547	$ 31,190				$ 1		60,547	$ 31,189
Issuance of common stock upon exercise of stock options (in shares)					149
Issuance of common stock upon exercise of stock options	573							573
Issuance of common stock under employee stock purchase plan (in shares)					176
Issuance of common stock under employee stock purchase plan	1,554							1,554
Stock-based compensation	38,222							38,222
Net loss	(212,220)												(212,220)
Other comprehensive loss (income)	$ 2,823											2,823
Ending balance (in shares) at Dec. 31, 2023	79,275				79,275
Ending balance at Dec. 31, 2023	$ 500,764				$ 8			1,071,395				125	(570,764)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)						20,969	15,225
Issuance of common stock, net of issuance costs		$ 762,161	$ 238,388	$ 141,395		$ 2	$ 2		$ 762,159	$ 238,386	$ 141,395
Issuance of common stock upon exercise of stock options (in shares)	3,498				3,498
Issuance of common stock upon exercise of stock options	$ 48,204							48,204
Issuance of common stock under employee stock purchase plan (in shares)					179
Issuance of common stock under employee stock purchase plan	2,209							2,209
Issuance of common stock in connection with vesting of restricted stock units (in shares)					747
Stock-based compensation	51,363							51,363
Net loss	(322,302)												(322,302)
Other comprehensive loss (income)	$ 2,777											2,777
Ending balance (in shares) at Dec. 31, 2024	119,893				119,893
Ending balance at Dec. 31, 2024	$ 1,424,959				$ 12			$ 2,315,111				$ 2,902	$ (893,066)

Consolidated Statements of St_2

Consolidated Statements of Stockholders’ Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Public Stock Offering
Public offering issuance costs	$ 49,749
Private Placement
Public offering issuance costs	12,821
Pre Funded Warrants Private Placement
Public offering issuance costs	$ 7,605

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net loss	$ (322,302)	$ (212,220)	$ (173,995)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,776	2,101	1,387
Stock-based compensation expense	51,363	38,222	27,139
Amortization of premiums and discounts on marketable securities, net	(21,447)	(11,274)	(615)
Noncash operating lease costs	3,297	2,978	2,749
Changes in operating assets and liabilities:
Prepaid and other assets	(25,057)	(3,444)	(6,616)
Accounts payable and accrued liabilities	35,183	1,769	18,315
Accrued compensation	(10,672)	3,145	2,250
Operating lease liabilities	(3,696)	(3,328)	(1,762)
Deferred revenue	(10,315)	62,987	(5,120)
Net cash used in operating activities	(300,870)	(119,064)	(136,268)
Cash flows from investing activities
Purchases of marketable securities	(1,433,535)	(461,002)	(355,837)
Maturities of marketable securities	586,400	335,160	168,705
Purchases of property and equipment	(7,066)	(4,228)	(2,823)
Net cash used in investing activities	(854,201)	(130,070)	(189,955)
Cash flows from financing activities
Proceeds from issuance of common stock in public offerings, net of issuance costs	762,161	60,547	344,779
Proceeds from issuance of common stock in private placements, net of issuance costs and allocation to deferred revenues (Note 5)	238,388	31,190	0
Proceeds from issuance of pre-funded warrants in a private placement, net of issuance costs	141,395	0	0
Proceeds from the issuance of common stock under employee incentive equity plans	50,413	2,127	1,392
Net cash provided by financing activities	1,192,357	93,864	346,171
Net increase (decrease) in cash, cash equivalents and restricted cash	37,286	(155,270)	19,948
Cash, cash equivalents and restricted cash at beginning of period	185,377	340,647	320,699
Cash, cash equivalents and restricted cash at end of period	222,663	185,377	340,647
Supplemental schedule of noncash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	0	1,741	0
Costs incurred, but not paid, in connection with purchases of property and equipment included in accounts payable and accrued liabilities	$ 3,424	$ 0	$ 233

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Description of Business Avidity Biosciences, Inc. (the Company or Avidity) is a biopharmaceutical company committed to delivering a new class of RNA therapeutics called Antibody Oligonucleotide Conjugates (AOCs). The Company’s proprietary AOC platform is designed to combine the specificity of monoclonal antibodies with the precision of RNA therapeutics to target the root cause of diseases previously untreatable with such therapeutics. Liquidity Since inception, the Company has relied on various means of raising capital, including public offerings, various sales agreements, the sale and issuance of convertible preferred stock, funding under collaboration agreements, and a private placement of common stock. The Company has devoted substantially all of its resources to organizing and staffing the Company, business planning, raising capital, developing its proprietary AOC platform, identifying potential product candidates, establishing its intellectual property portfolio, conducting research, preclinical studies, advancing its clinical programs and providing other general and administrative support for these operations. In addition, the Company has a limited operating history, has incurred operating losses since inception and expects that it will continue to incur net losses into the foreseeable future as it continues the development of its product candidates and development programs. As of December 31, 2024, the Company had an accumulated deficit of $893.1 million and cash, cash equivalents, and marketable securities of $1.5 billion. The Company believes that existing cash, cash equivalents and marketable securities will be sufficient to fund the Company’s operations for at least 12 months from the date of the filing of this Form 10-K. The Company plans to finance its future cash needs through equity offerings, debt financings or other capital sources, including potential collaborations, licenses and other similar arrangements. If the Company is not able to secure adequate additional funding, it may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, and/or delay or reduce the scope of its planned development programs. Any of these actions could materially harm the Company’s business, results of operations, and future prospects. Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the Securities and Exchange Commission (SEC). The consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair presentation of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these consolidated financial statements are not necessarily indicative of the results that may be expected for any future periods. Certain prior year amounts have been reclassified to conform to the current year presentation. In December 2023, the Company formed Avidity Biosciences Ireland Limited, a wholly-owned subsidiary (the Subsidiary). The accompanying consolidated financial statements reflect the operations of Avidity Biosciences, Inc. and the Subsidiary. Intercompany balances and transactions have been eliminated in consolidation. The activity and balances attributable to the Subsidiary for the year ended December 31, 2024 were immaterial.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires the Company to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the consolidated financial statements and accompanying notes. Although estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking and money market accounts. Restricted cash represents cash held as collateral for the letters of credit required under the Company’s facility lease and is reported as a long-term asset in the accompanying consolidated balance sheets. Cash and cash equivalents are considered Level 1 investments. Marketable Securities The Company’s marketable securities primarily consist of U.S. Government debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the consolidated statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses recognized during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets See Note 4 (Marketable Securities) for further information. Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has established guidelines regarding approved investments, credit quality, diversification, liquidity and maturities of investments, which are designed to maintain safety and liquidity. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institutions in which those deposits are held. Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs, such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. None of the Company’s non-financial assets are recorded at fair value on a non-recurring basis. The carrying amounts reflected in the Company’s consolidated balance sheets for prepaid and other assets and accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The Company recognizes transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. There have been no transfers into or out of Level 3 assets during any of the periods presented. See Note 3 (Fair Value Measurements) for information on assets measured at fair value. Property and Equipment, net Property and equipment, including leasehold improvements, are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the related assets, which ranges from three Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset or an asset group may not be recoverable. If such triggering event is determined to have occurred, the asset’s or asset group’s carrying value is compared to the future undiscounted cash flows expected to be generated. The Company has not recognized any impairment losses in any of the periods presented in these consolidated financial statements. Segment Information Our operations constitute a single operating and reportable segment, headquartered in the United States. Operating segments are defined as components of an enterprise for which discrete financial information is available and is evaluated regularly by the chief operating decision maker (“CODM”), in deciding how to allocate resources and assess performance. Our CODM is our Chief Executive Officer, who reviews consolidated financial information for the purposes of allocating resources and assessing performance. All of our property and equipment is located within the United States and all of our revenues were derived within the United States. See Note 10 (Segment Information) for further information. Revenue Recognition To date, all the Company’s revenue has been derived from collaboration and research agreements. The terms of these arrangements include the following types of payments to the Company: non-refundable, upfront license fees; development, regulatory and commercial milestone payments; payments for research and development services provided by the Company or for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. At the inception of a collaboration arrangement, the Company first assesses whether the contractual arrangement is within the scope of Accounting Standards Codification (ASC) Topic 808, Collaborative Arrangements (ASC 808) to determine whether the arrangement involves a joint operating activity and involves two (or more) parties that are both active participants in the activity and exposed to significant risks and rewards dependent on the commercial success of such activity. Then the Company determines whether the collaboration arrangement in its entirety represents a contract with a customer as defined by ASC Topic 606 (ASC 606). If only a portion of the collaboration arrangement is potentially with a customer, the Company applies the distinct good or service unit-of-account guidance in ASC 606 to determine whether there is a unit of account that should be accounted for under ASC 606. The Company performs the following steps in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of these agreements: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when, or as, the Company satisfies each performance obligation. The Company applies significant judgment when making estimates and assumptions under these agreements, including (i) evaluating whether contractual obligations represent distinct performance obligations, ii) the assessment of whether options represent material rights, (iii) determining whether there are observable standalone prices and allocating transaction price to performance obligations within a contract, (iv) assessing whether any licenses are functional or symbolic, (v) determining when performance obligations have been met, and (vi) assessing the recognition of variable consideration. The Company evaluates each performance obligation to determine if it can be satisfied and recognized as revenue at a point in time or over time. The Company receives payments from its collaborators based on billing schedules established in each contract. Upfront and other payments may require deferral of revenue recognition to a future period until the Company performs its obligations under its research and collaboration arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. License fees, non-refundable upfront fees, and funding of research activities are considered fixed, while milestone payments are identified as variable consideration and excluded from the transaction price. The Company will recognize revenue for sales-based royalty if and when a subsequent sale occurs. See Note 5 (Collaboration, License and Research Agreements) for further information. Research and Development Costs and Accruals Research and development costs are expensed as incurred and include salaries, benefits and stock-based compensation associated with research and development personnel, third-party research and development expenses, license fees, laboratory supplies, facilities, overhead costs, and consultants. Nonrefundable advance payments for goods and services that will be used in future research and development activities are capitalized and recorded as expense in the period that the Company receives the goods or when services are performed. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying consolidated balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of these accrued liabilities, the Company analyzes progress of the services, including the phase or completion of events, invoices received, and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Upfront and milestone payments to acquire contractual rights to licensed technology are expensed when incurred if there is uncertainty in the Company receiving future economic benefit from the acquired contractual rights. Certain of these contractual rights may require the Company to make additional milestone payments upon initiation of a pivotal trial and the U.S. Food and Drug Administration approval. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. Income Taxes Income taxes are accounted for using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company is subject to taxation in the United States and various state jurisdictions. As of December 31, 2024, the Company’s tax years since conversion to a corporation in 2019 are subject to examination by taxing authorities. Leases The Company determines if an arrangement is a lease at inception. Lease right-of-use assets represent Company's right to use an underlying asset for the lease term and lease liabilities represent Company's obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The interest rate used to determine the present value of the future lease payments is our incremental borrowing rate, because the interest rate implicit in most of our leases is not readily determinable. The incremental borrowing rate is estimated to approximate the interest rate on a collateralized basis with similar terms and payments, and in similar economic environments. The operating lease right-of-use asset also includes any lease payments made and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Variable lease payments that do not depend on a rate or index, payments associated with non-lease components, and costs related to leases with terms of less than 12 months are expensed as incurred. Warrants The Company accounts for warrants as equity-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in ASC 480, Distinguishing Liabilities from Equity (ASC 480) and ASC 815, Derivatives and Hedging (ASC 815). The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, meet the definition of a liability pursuant to ASC 480, and whether the warrants meet all of the requirements for equity classification under ASC 815, including whether the warrants are indexed to the Company’s own common stock and whether the warrant holders could potentially require “net cash settlement” in a circumstance outside of the Company’s control, among other conditions for equity classification. This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent quarterly period end date while the warrants are outstanding. For warrants that meet all criteria for equity classification, the warrants are required to be recorded as additional paid-in capital in the consolidated balance sheets at the time of issuance. Equity-classified warrants are measured at their estimated fair value on the issuance date. Stock-Based Compensation Stock-based compensation expense is incurred related to stock option and restricted stock grants, and to shares sold under the Employee Stock Purchase Plan (ESPP). Stock-based compensation expense for stock option grants is determined using the Black-Scholes-Merton (BSM) option pricing model and is recorded at the estimated fair value of the award as of the grant date and recognized as expense on a straight-line basis over the requisite service period (usually the vesting period) of the stock-based award. Stock-based compensation expense for Restricted Stock Units (RSUs) is recorded at the market price of a share of the Company's stock on the date of grant and is recognized as expense on a straight-line basis over the service period. Stock-based compensation expense for Performance Stock Units (PSUs) is recorded at the market price of a share of the Company's stock on the date of grant and recognized on a straight-line basis over the requisite service periods beginning when the achievement of the performance condition is determined to be probable. Stock-based compensation expense for employee stock purchases under the Company’s ESPP is determined using the BSM option pricing model and is recorded at the estimated fair value of the purchase as of the plan enrollment date and is recognized as expense on a straight-line basis over the applicable six-month ESPP offering period. The estimation of fair value for stock-based compensation requires management to make estimates and judgments about, among other things, the estimated life of options and volatility of the Company’s common stock. These judgments directly affect the amount of compensation expense that will be recognized. Forfeitures are accounted for as incurred. Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including cumulative translation adjustments and unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the consolidated statements of operation and comprehensive loss for all periods presented. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, adjusted for the weighted-average number of common shares outstanding that are subject to repurchase or forfeiture. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the common stock equivalent securities would be anti-dilutive. The pre-funded common stock warrants are included in the calculation of basic and diluted net loss per share as the exercise price of $0.001 per share is not substantive and the shares are issuable for little or no consideration. Common stock equivalent securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares; in thousands): December 31, 2024 2023 2022 Common stock options issued and outstanding 12,635 12,495 9,352 Restricted stock units 2,111 758 — Performance stock units 925 750 — ESPP shares pending issuance 12 12 5 Total 15,683 14,015 9,357 Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances income tax disclosures, primarily through standardization and disaggregation of the income tax rate reconciliation and disaggregation of income taxes paid. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. ASU 2023-09 can be applied either prospectively or retrospectively and early adoption is permitted. The Company is currently evaluating the impact that this guidance will have on the presentation of its consolidated financial statements and accompanying notes. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which requires that public business entities disclose additional information about specific expense captions in the notes to financial statements at interim and annual reporting periods. The amendment in the update does not change or remove current expense disclosures, rather, it requires enhanced disaggregated disclosures of specific expense captions and affects where that information is presented within the notes to the financial statements. ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. ASU 2024-03 can be applied either prospectively or retrospectively and early adoption is permitted. The Company is currently evaluating the impact that this guidance will have on the presentation of its consolidated financial statements and accompanying notes. Recently Adopted Accounting Pronouncements

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables summarize the Company’s cash equivalents and marketable securities measured at fair value (in thousands): Fair Value Measurements Using As of December 31, 2024 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 7,439 $ 7,439 $ — $ — Marketable securities: U.S. Treasury securities 1,281,139 1,281,139 — — Negotiable certificates of deposit 490 — 490 — Total $ 1,289,068 $ 1,288,578 $ 490 $ — Fair Value Measurements Using As of December 31, 2023 Total Quoted Prices in Significant Significant Marketable securities: U.S. Treasury securities $ 399,890 $ 399,890 $ — $ — U.S. Government agency securities 4,998 — 4,998 — Negotiable certificates of deposit 5,381 — 5,381 — Total $ 410,269 $ 399,890 $ 10,379 $ —

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The Company’s marketable securities, which consist of highly liquid marketable debt securities, are classified as available-for-sale and are stated at fair value. The following tables summarize the Company’s marketable securities (in thousands): As of December 31, 2024 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 947,916 $ 2,154 $ (80) $ 949,990 Negotiable certificates of deposit 1 or less 490 — — 490 U.S. Treasury securities 1 - 2 330,321 1,218 (390) 331,149 Total $ 1,278,727 $ 3,372 $ (470) $ 1,281,629 As of December 31, 2023 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 301,053 $ 102 $ (530) $ 300,625 U.S. Government agency securities 1 or less 5,000 — (2) 4,998 Negotiable certificates of deposit 1 or less 4,410 1 (4) 4,407 U.S. Treasury securities 1 - 2 98,701 600 (36) 99,265 Negotiable certificates of deposit 1 - 2 980 — (6) 974 Total $ 410,144 $ 703 $ (578) $ 410,269 The unrealized losses on the Company’s marketable securities were caused by interest rate increases and resulted in the decrease in market value of these securities. There were no allowances for credit losses at December 31, 2024 and 2023 because (i) the decline in fair value is attributable to changes in interest rates and not credit quality, (ii) the Company does not intend to sell the investments before maturity, and (iii) it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases. The following table summarizes marketable securities in a continuous unrealized loss position for which an allowance for credit losses was not recorded (in thousands): Less Than 12 Months 12 Months or Greater Total As of December 31, 2024 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 247,404 $ (470) $ — $ — $ 247,404 $ (470) Total $ 247,404 $ (470) $ — $ — $ 247,404 $ (470) Less Than 12 Months 12 Months or Greater Total As of December 31, 2023 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 214,291 $ (566) $ — $ — $ 214,291 $ (566) U.S. Government agency securities 4,998 (2) — — 4,998 (2) Negotiable certificates of deposit 3,665 (10) — — 3,665 (10) Total $ 222,954 $ (578) $ — $ — $ 222,954 $ (578) Accrued interest receivable on available-for-sale securities was $8.7 million and $2.6 million at December 31, 2024 and 2023, respectively. We have not written off any accrued interest receivable in any of the periods presented in these consolidated financial statements.

Collaboration, License and Rese

Collaboration, License and Research Agreements	12 Months Ended
	Dec. 31, 2024
Collaboration License And Research Agreements [Abstract]
Collaboration, License and Research Agreements	Collaboration, License and Research Agreements Research Collaboration and License Agreement and Securities Purchase Agreement with Bristol Myers Squibb Company In November 2023, the Company entered into (i) a Research Collaboration and License Agreement (the BMS Collaboration Agreement) with Bristol Myers Squibb Company (BMS) to expand on the research with MyoKardia Inc. (MyoKardia) and (ii) a Securities Purchase Agreement (the BMS Purchase Agreement) with BMS for the sale of 5,075,304 shares of the Company's common stock in a private placement transaction. The BMS Collaboration Agreement and the BMS Purchase Agreement are referred to herein as the "BMS Agreements." Under the terms of the BMS Collaboration Agreement, BMS will have the right to select up to five cardiovascular targets (each a “Target”) for collaborative research programs under which the Company will utilize its proprietary AOC platform to conduct research and development activities in order to identify, generate, and optimize AOC compounds directed to such Targets with the goal of generating an applicable development candidate. On a Target-by-Target basis, after the Company completes specified research activities in accordance with a research plan, BMS will have the right to develop, manufacture and commercialize such compounds generated during the research term, and products containing such compounds, worldwide. The research and activities conducted under the BMS Collaboration Agreement is governed by a joint steering committee comprised of representatives from the Company and BMS. Avidity received approximately $100 million upfront, including a $60 million nonrefundable cash payment and approximately $40 million from the sale of Avidity common stock at $7.8813 per share, which included an $8.7 million premium for the per share amount in excess of the fair value at the time of the transaction. Avidity is also eligible to receive up to approximately $1.35 billion in research and development milestone payments, up to approximately $825 million in commercial milestone payments, and tiered royalties from high single digits up to low double-digits on net sales. Avidity is responsible for its own research costs incurred under the agreement, subject to a cumulative spending cap of $40 million. BMS will fund all future clinical development, regulatory and commercialization activities coming from this collaboration. We have determined that the BMS Agreements should be accounted for separately from the research collaboration with MyoKardia (the MyoKardia Agreement). We identified two distinct units of accounting under the BMS Agreements. The first distinct unit of accounting includes (i) a license to technology and patents; (ii) collaboration services, including research services and technical and regulatory support; and (iii) participation on research oversight committees. The Company has determined that these elements individually are either not capable of being distinct or are not distinct within the context of the contract and, therefore, will account for them as a single distinct performance obligation for purposes of revenue recognition. The second distinct unit of accounting is related to the sale of common stock, which will be accounted for as an issuance of equity at fair value in accordance with the applicable accounting standards. Consideration received related to the premium on sale of the Company's common stock was allocated to the transaction price for purposes of revenue recognition. At the time the BMS Agreements were entered into, the fixed and determinable amount related to the first unit of accounting was $68.7 million, which includes the upfront cash payment and premium on sale of the Company's common stock. The Company will recognize revenue using the input method in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the seven-year period in which it expects to deliver its performance obligation as this method provides the most faithful depiction of the Company's transfer of services under the BMS Agreements. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which adjusts the percentage of revenue that is recognized for the period. The remaining $31.3 million was allocated to the second unit of accounting related to the sale of common stock (Note 8). The initial consideration related to the $60 million cash payment and approximate $40 million sale of common stock was received prior to December 31, 2023. $9.8 million in revenues were recognized related to the BMS Agreements in 2024. No revenues were recognized related to the BMS Agreements in 2023. Research Collaboration and License Agreement with Eli Lilly and Company In April 2019, the Company entered into a Research Collaboration and License Agreement (the Lilly Agreement) with Eli Lilly and Company (Lilly) for the discovery, development and commercialization of AOC products directed against certain targets in immunology and other select indications on a worldwide basis. Under the Lilly Agreement, the Company granted Lilly an exclusive, worldwide, royalty-bearing license, with the right to sublicense (subject to certain conditions), under the Company’s technology to research, develop, manufacture and sell products containing AOCs that are directed to up to six mRNA targets. The Company retains the right to use its technology to perform its obligations under the Lilly Agreement and for all purposes not granted to Lilly. The Company agreed that it will not, itself or with a third party, research, develop, manufacture or commercialize or otherwise exploit any compound or product directed against targets subject to the Lilly Agreement. In consideration of the rights granted to Lilly under the Lilly Agreement, the Company received a one-time upfront fee of $20.0 million and is eligible to receive up to $60.0 million in development milestone payments, up to $140.0 million in regulatory milestone payments and up to $205.0 million in commercialization milestone payments per target. In addition, Lilly is obligated to reimburse the Company for research expenses, as defined in and incurred under the Lilly Agreement. Lilly is obligated to pay the Company a tiered royalty ranging from the mid-single to low-double digits on worldwide annual net sales of licensed products, subject to specified and capped reductions for the market entry of biosimilar products, loss of patent coverage of licensed products, and for payments owed to third parties for additional rights necessary to commercialize licensed products in the territory. Lilly’s royalty obligations and the Lilly Agreement will expire on a licensed product-by-licensed product and country-by-country basis on the later of ten years from the date of the first commercial sale or when there is no longer a valid patent claim covering such licensed product in such country. The Company has identified multiple promises to deliver goods and services, which include at inception of the agreement: (i) a license to technology and patents, information and know-how; and (ii) collaboration, including research services and technical and regulatory support provided by the Company. At inception, the Company has identified one performance obligation for the promises under the Lilly Agreement since the elements are either not capable of being distinct or are not distinct within the context of the contract. Accordingly, the Company recognizes revenue for the fixed or determinable collaboration in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the 5-year period in which it expects to deliver its performance obligation. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which adjusts the percentage of revenue that is recognized for the period. In connection with the Lilly Agreement, the Company recognized revenue of $1.1 million, $9.5 million, and $9.0 million for the years ended December 31, 2024, 2023, and 2022, respectively. There were no collaboration receivables related to the Lilly Agreement as of December 31, 2024. Collaboration receivables were $0.8 million related to the Lilly Agreement as of December 31, 2023, which are included in prepaid and other assets on the consolidated balance sheets. Research Agreement with MyoKardia, Inc. In December 2020, the Company entered into a Research Collaboration (the MyoKardia Agreement) with MyoKardia, a wholly-owned subsidiary of BMS, to demonstrate the potential utility of AOCs in cardiac tissue by leveraging MyoKardia’s genetic cardiomyopathy platform including, among other aspects, its novel target discovery engine and proprietary cardiac disease models. In connection with the MyoKardia Agreement, the Company recognized an immaterial amount of revenue in each of the periods presented. Under the terms of the MyoKardia Agreement, in July 2023, BMS as the successor in interest to MyoKardia, exercised its option to negotiate and enter into a License Agreement covering AOCs that modulate the function of cardiovascular targets. The Research Collaboration with MyoKardia was terminated in November 2023 upon execution of the Research Collaboration and License Agreement with BMS. The amounts received that have not yet been recognized as revenue are deferred on the Company’s consolidated balance sheet and will be recognized over the remaining research and development period until the performance obligation is satisfied. A reconciliation of the closing balance of deferred revenue related to all collaboration agreements for the years ended December 31, 2024 and 2023 is as follows (in thousands): Revenue recognized that was included in the balance at the beginning of the period $ (4,933) Balance at December 31, 2022 6,175 Unearned revenue from cash received during the period 68,736 Revenue recognized that was included in the balance at the beginning of the period (5,648) Balance at December 31, 2023 69,263 Revenue recognized that was included in the balance at the beginning of the period (10,315) Balance at December 31, 2024 $ 58,948

Composition of Certain Consolid

Composition of Certain Consolidated Financial Statement Items	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
Composition of Certain Consolidated Financial Statement Items	Composition of Certain Consolidated Financial Statement Items Prepaid and other assets (in thousands) December 31, 2024 2023 Accounts receivable $ — $ 1,105 Prepaid assets 12,571 7,333 Interest receivable and other assets 28,222 7,518 Total prepaid and other assets $ 40,793 $ 15,956 Property and equipment, net (in thousands) December 31, 2024 2023 Laboratory equipment $ 14,180 $ 11,208 Computers and software 261 127 Office furniture and equipment 1,979 1,979 Leasehold improvements 288 288 Construction in process 3,959 — Property and equipment, gross 20,667 13,602 Less accumulated depreciation and amortization (7,997) (5,221) Total property and equipment, net $ 12,670 $ 8,381 Depreciation and amortization expense related to property and equipment was $2.8 million, $2.1 million, and $1.4 million for the years ended December 31, 2024, 2023, and 2022, respectively. Accounts payable and accrued liabilities (in thousands) December 31, 2024 2023 Accounts payable $ 8,461 $ 8,809 Accrued non-clinical liabilities 17,226 4,054 Accrued manufacturing and technical development 35,680 15,481 Accrued clinical liabilities 8,157 5,997 Total accounts payable and accrued liabilities $ 69,524 $ 34,341

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Agreements The Company determines if an arrangement is a finance lease, operating lease or short-term lease at inception. During the periods presented, the Company was party to various non-cancellable office and laboratory space operating leases and short-term leases. Short-term leases are not subject to recognition of a right-of-use (ROU) asset or liability or straight-line lease expense requirements. As of December 31, 2024, the Company’s ROU assets and liabilities related to the operating lease for the Company headquarters are as follows (in thousands): ROU assets $ 5,619 Lease liabilities, current portion $ 3,844 Lease liabilities, net of current portion 2,957 Total lease liabilities $ 6,801 As of December 31, 2024, maturities of the lease liabilities due under the operating lease are as follows (in thousands): Year ending December 31, 2025 $ 3,854 2026 3,639 Total lease payments 7,493 Less imputed interest (692) Total operating lease liabilities 6,801 Less lease liabilities, current portion (3,844) Lease liabilities, net of current portion $ 2,957 Other information related to leases was as follows (in thousands): Year Ended December 31, 2024 2023 2022 Cash paid included in operating cash flows $ 3,696 $ 3,328 $ 1,762 Weighted-average remaining lease term (in years) 1.9 2.9 3.9 Weighted-average discount rate 5.9 % 5.9 % 5.5 % Lease cost was $3.3 million, $3.0 million and $2.7 million for the years ended December 31, 2024, 2023, and 2022, respectively. Short-term and variable lease costs were immaterial for all periods presented. In April 2024, the Company entered into a sublease agreement with Turning Point Therapeutics, Inc. to rent 105,000 square feet for office and laboratory space for the Company’s future corporate headquarters. The term of the sublease is approximately 9 years, 9 months with payments expected to begin in August 2025. Pursuant to the terms of the sublease agreement, the sublandlord will provide the Company with a tenant improvement allowance of up to $33.6 million. An additional tenant improvement allowance of up to $5.0 million is also available to be repaid in equal installments through monthly rent payments, subject to 8% interest per annum and annual increases of 3% per annum. The Company also has an option and a right of first refusal for an additional 80,000 square feet in an adjacent available building, which has not been exercised. Total aggregate future lease commitments under the sublease agreement are approximately $72.6 million, excluding the option and refusal for the adjacent available building, and inclusive of a 3% annual rent increases and various agreed upon rent abatement amounts. The sublease will be measured and recognized upon commencement of the sublease. As of December 31, 2024, the sublease had not commenced because construction of improvements to bring the facility to its intended use was not substantially complete. In connection with the sublease agreement, the Company is required to maintain a letter of credit for the benefit of the sublandlord in the amount of $2.5 million, which was delivered in April 2024 and is included in restricted cash in the Company’s consolidated balance sheets. Litigation Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. There are no such matters currently outstanding for which any liabilities have been accrued. Contractual Obligations The Company enters into contracts in the normal course of business for contract research services, contract manufacturing services, professional services, and other services and products for operating purposes. These contracts may include certain provisions that could require payments for early termination. The amount of any such termination payments will vary depending on the timing of the termination and the specific terms of the contract. Further, the Company has entered into various contracts to acquire contractual rights to licensed technology, some of which may require the Company to make additional milestone payments upon initiation of a pivotal trial and U.S. Food and Drug Administration approval.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Amended and Restated Certificate of Incorporation On June 16, 2020, the Company’s certificate of incorporation was amended and restated to authorize 400,000,000 shares of common stock and 40,000,000 shares of undesignated preferred stock, each with a par value of $0.0001 per share. There was no preferred stock outstanding as of December 31, 2024, 2023, or 2022. Common Stock On November 8, 2022, we entered into a sales agreement (the 2022 Sales Agreement) with the Cowen and Company, LLC (the Sales Agent), under which we could, from time to time, sell shares of our common stock having an aggregate offering price of up to $200.0 million through the Sales Agent. Sales of the shares of common stock were made at prevailing market prices at the time of sale, or as otherwise agreed with the Sales Agent. During the years ended December 31, 2024 and 2023, we sold 418,408 and 4,107,810 shares of its common stock, respectively, pursuant to the Sales Agreement and received net proceeds of $5.6 million and $60.5 million, respectively, after deducting offering-related transaction costs and commissions of $0.1 million and $1.4 million, respectively. On November 27, 2023, we sold 5,075,304 unregistered shares of our common stock to BMS in a private placement under the terms of the BMS Purchase Agreement. The approximate proceeds related to the sale were $40.0 million of which $31.2 million was recorded as common stock and additional paid in capital, net of issuance costs of $0.1 million, and $8.7 million was recorded as deferred revenue (Note 5). On March 4, 2024, we sold 15,224,773 unregistered shares of our common stock and pre-funded warrants in lieu of common stock to purchase up to an aggregate of 9,030,851 shares of our common stock to investors in a private placement at an offering price of $16.50 per share and $16.499 per pre-funded warrant, which represents the offering price per share of common stock less an exercise price of $0.001 per share. We valued the common stock at the offering price, concluding that the offering price approximated fair value. The net proceeds from the private placement were $379.8 million after deducting placement fees and offering costs of $20.4 million. The resale of the shares, including the shares issuable upon exercise of the pre-funded warrants, were subsequently registered on a Registration Statement on Form S-3 filed with the SEC on April 2, 2024, which became automatically effective upon its filing. The pre-funded warrants are a freestanding instrument that do not meet the definition of a liability pursuant to ASC 480 and do not meet the definition of a derivative pursuant to ASC 815. We valued the pre-funded warrants at the offering price, concluding that the offering price approximated fair value. The pre-funded warrants meet the equity classification criteria and were accounted for as a component of additional paid-in capital. The pre-funded warrants are immediately exercisable and do not expire. One of the investors who participated in the private placement met the criteria of a related party as such investor was a principal owner of more than 10% of the voting interest in the Company (the Principal Owner). The Principal Owner purchased 2,121,213 shares of the Company's common stock for $35.0 million. The purchase of common stock under the private placement by the Principal Owner was carried out at arm's length as substantiated by the fact that the per share purchase price equaled the price paid by other participants. No amounts were due from the Principal Owner as of December 31, 2024. On June 17, 2024, we completed a public offering of 12,132,500 shares of our common stock at a public offering price of $38.00 per share. Net proceeds from the offering were approximately $432.8 million, after deducting underwriting discounts and offering expenses of $28.3 million. The shares sold in the offering were registered pursuant to the Company's shelf registration statement on Form S-3, which became automatically effective upon its filing on May 9, 2024. On August 9, 2024, we entered into a sales agreement (the 2024 Sales Agreement) with TD Securities (USA) LLC (the 2024 Sales Agent) which contained substantially similar terms as the 2022 Sales Agreement. The 2022 Sales Agreement was terminated upon effectiveness of the 2024 Sales Agreement. Under the 2024 Sales Agreement, we may, from time to time, sell shares of our common stock having an aggregate offering price of up to $400.0 million through the 2024 Sales Agent. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the 2024 Sales Agent. We are not obligated to sell, and the 2024 Sales Agent is not obligated to buy or sell, any shares of common stock under the 2024 Sales Agreement. As of December 31, 2024, we had sold no shares of our common stock under the 2024 Sales Agreement. On August 16, 2024, we completed a public offering of 8,418,000 shares of our common stock at a public offering price of $41.00 per share. Net proceeds from the offering were approximately $323.7 million, after deducting underwriting discounts and offering expenses of $21.4 million. The shares sold in the offering were registered pursuant to the Company's shelf registration statement on Form S-3, which became automatically effective upon its filing on May 9, 2024. Equity Incentive Plans The Company's board of directors adopted, and the company's shareholders approved, the 2013 Equity Incentive Plan (the 2013 Plan) and the 2020 Incentive Award Plan (the 2020 Plan). Under the plans, the Company may grant stock options, restricted stock, dividend equivalents, restricted stock units, stock appreciation rights, and other stock or cash-based awards to individuals who are then employees, officers, non-employee directors or consultants of the Company. The Company ceased granting awards under the 2013 Plan in June 2020 upon adopting the 2020 Plan. A total of 3,900,000 shares of common stock were initially reserved for issuance under the 2020 Plan. The number of shares of common stock available for issuance under the 2020 Plan will be increased annually on the first day of each fiscal year during the term of the 2020 Plan, beginning with the 2021 fiscal year, by an amount equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year or (b) such smaller number of shares as determined by the Company’s board of directors. At December 31, 2024, 1,591,462 shares were available for grant under the 2020 Plan, inclusive of 3,963,742 additional shares which were reserved for issuance during the year ended December 31, 2024. In December 2022, the Company’s board of directors adopted the 2022 Employment Inducement Incentive Award Plan, which it amended in June 2024 (the Inducement Plan). Under the Inducement Plan, the Company may grant non-qualified stock options, restricted stock, restricted stock units, stock appreciation rights, and other stock or cash-based awards to an employee in connection with his or her commencement of employment with the Company or an affiliate. A total of 4,500,000 shares of common stock were reserved for issuance under the Inducement Plan. At December 31, 2024, 697,350 shares were available for grant under the Inducement Plan, inclusive of 3,000,000 additional shares which were reserved for issuance during the year ended December 31, 2024. Stock Options Options granted from the 2013 Plan, 2020 Plan, and the Inducement Plan are exercisable at various dates and will expire no more than ten years from their date of grant. Options generally vest over a four-year period. Prior to the IPO, the exercise price of options was determined by the Company’s board of directors. Following the IPO, the Company grants options with an exercise price equal to the fair market value of the Company’s stock on the date of the option grant. Stock option activity in 2024 for employee and non-employee awards and related information is as follows (in thousands, except per share and contractual term data): Number of Outstanding Options Weighted- Weighted- Aggregate Balance at December 31, 2023 12,495 $ 14.91 Granted 4,162 27.06 Exercised (3,498) 13.78 Forfeited/expired (524) 15.70 Balance at December 31, 2024 12,635 $ 19.19 7.88 $ 149,957 Vested and expected to vest at December 31, 2024 12,635 $ 19.19 7.88 $ 149,957 Exercisable at December 31, 2024 5,772 $ 15.32 6.89 $ 79,900 The aggregate intrinsic values presented in the table above were calculated as the difference between the closing price of the Company’s common stock at December 31, 2024 and the exercise price of stock options that had strike prices below the closing price. The following summarizes additional information regarding stock options (in thousands, except per share data): Year Ended December 31, 2024 2023 2022 Cash received from options exercised $ 48,207 $ 573 $ 470 Intrinsic value of options exercised $ 83,422 $ 2,421 $ 6,724 Weighted-average grant date fair value per share $ 19.26 $ 10.33 $ 11.11 The total intrinsic values of options exercised was calculated as the difference between the fair value of the Company’s common stock at the time of the option exercise and the exercise price of that stock option. Restricted Stock Units and Performance Stock Units During the year ended December 31, 2024, under the 2020 Incentive Award Plan and the 2022 Employment Inducement Incentive Award Plan, the Company granted Restricted Stock Units (RSUs) and Performance Stock Units (PSUs) to employees of the Company. PSUs were granted to the Company's officers. RSUs and PSUs are valued at the market price of a share of the Company’s stock on the date of grant. RSUs vest ratably on an annual basis over a service period and are payable in shares of common stock on the vesting date. Compensation expense for RSUs is recognized on a straight-line basis over the service period. Compensation expense for PSUs is recognized on a straight-line basis over the requisite service periods when the achievement of the performance condition is determined to be probable, using management's best estimate. If a performance condition is not determined to be probable or is not met, no stock-based compensation expense is recognized, and any previously recognized expense is reversed. Forfeitures are recorded in the period in which they occur. The following table summarizes the RSU activity for the year ended December 31, 2024 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Balance at December 31, 2023 758 $ 18.73 Granted 1,711 25.51 Vested (184) 18.79 Forfeited (174) 14.82 Balance at December 31, 2024 2,111 $ 24.54 During the years ended December 31, 2024 and 2023, stock-based compensation expense of $7.0 million and $0.9 million was recognized, respectively. There was no stock-based compensation expense recognized for the year ended December 31, 2022. During the year ended December 31, 2024, 184,293 RSUs vested with a total fair value of $3.5 million. During the years ended December 31, 2023 and 2022, no RSUs vested. The following table summarizes the PSU activity for the year ended December 31, 2024 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Balance at December 31, 2023 750 $ 6.57 Granted 738 43.22 Vested (563) 6.57 Forfeited — — Balance at December 31, 2024 925 $ 35.80 During the year ended December 31, 2024, the performance conditions related to 750,000 units of outstanding PSUs were met or deemed probable resulting in (1) the vesting of 562,500 shares, (2) the expected vesting of 187,500 shares in March 2025, and (3) the recognition of $4.8 million in stock-based compensation expense. No stock-based compensation expense has been recognized for the remaining 738,000 outstanding PSUs as the performance conditions were not deemed probable. The total fair value of PSU shares vested during the year ended December 31, 2024 was $22.1 million. During the years ended December 31, 2023 and 2022, no PSUs vested and no stock-based compensation expense was recognized. Employee Stock Purchase Plan In June 2020, the Company adopted the ESPP, which permits participants to contribute up to 15% of their eligible compensation during defined rolling six-month offering periods to purchase the Company’s common stock. The purchase price of the shares will be 85% of the lower of the fair market value of the Company’s common stock on the first day of trading of the offering period or on the applicable purchase date. The Company issued 179,150, 175,511, and 90,535 shares of common stock under the ESPP during the years ended December 31, 2024, 2023, and 2022, respectively. The Company had an outstanding liability of $0.3 million at December 31, 2024, which is included in accounts payable and accrued liabilities on the consolidated balance sheet, for employee contributions to the ESPP for shares pending issuance at the end of the current offering period. As of December 31, 2024, 193,367 shares of common stock were available for issuance under the ESPP. Stock-Based Compensation Expense The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and shares purchasable under the ESPP were as follows: Options ESPP Year Ended December 31, Year Ended December 31, 2024 2023 2022 2024 2023 2022 Risk-free interest rate 3.5% - 4.7% 3.5% - 4.9% 1.5% - 4.2% 4.3% - 5.4% 5.4% 2.2% - 4.7% Expected volatility 79% - 82% 78% - 82% 85% 64% - 82% 68% - 76% 78% - 79% Expected term (in years) 5.3 - 6.1 5.5 - 6.1 5.5 - 6.1 0.5 0.5 0.5 Expected dividend yield —% —% —% —% —% —% Risk-Free Interest Rate. The Company bases the risk-free interest rate assumption for equity awards on the rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. Expected Volatility. The expected volatility of stock options is estimated based on the average historical volatilities of common stock of comparable publicly traded companies and the Company's own volatility. The comparable companies are chosen based on their size and stage in the life cycle. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Prior to 2023, the Company exclusively used peer group companies to determine expected volatility. The expected volatility for employee stock purchases under the ESPP is based on the Company's own historical volatility for the prior six months to conform with the six-month ESPP offering period. Expected Term. The Company's limited option exercise history does not provide a reasonable basis for estimating expected term, therefore the Company has estimated the expected life of its stock options using the simplified method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The expected life assumption for employee stock purchases under the ESPP is six months to conform with the six-month ESPP offering period. Expected Dividend Yield. The Company’s expected dividend yield assumption is zero as it has never paid dividends and has no present intention to do so in the future. The allocation of stock-based compensation expense was as follows (in thousands): Year Ended December 31, 2024 2023 2022 Research and development expense $ 26,120 $ 22,007 $ 15,222 General and administrative expense 25,243 16,215 11,917 Total stock-based compensation expense $ 51,363 $ 38,222 $ 27,139 As of December 31, 2024, the unrecognized compensation cost related to outstanding time-based options and RSUs was $102.5 million and $45.2 million, respectively, which is expected to be recognized over a weighted-average period of 2.7 years and 3.2 years, respectively. Unrecognized compensation cost related to PSUs was $32.1 million as of December 31, 2024 for which $0.2 million is deemed probable and is expected to be recognized over a weighted-average period of 0.2 years. As of December 31, 2024, the unrecognized compensation cost related to stock purchase rights under the ESPP was $0.9 million, which is expected to be recognized over a weighted-average period of 0.5 years.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company operated as a nontaxable partnership until its conversion on March 31, 2019. The Company had deferred tax assets in existence on March 31, 2019 when the Company became a taxable entity. Deferred tax assets were not recognized due to the uncertainty that such assets will be realized. The Company retained the valuation allowance on the deferred tax assets at December 31, 2019. No provision for income taxes was recorded for the years ended December 31, 2024, 2023, and 2022. A reconciliation of the federal statutory income tax rate and the Company’s effective income tax rate is as follows (in thousands): Year Ended December 31, 2024 2023 2022 Income tax expense (benefit) at statutory rates $ (67,683) $ (44,566) $ (36,539) State income tax, net of federal benefit (8,170) (5,882) (11,821) Permanent items 66 51 1 Reserve for uncertain tax positions 10,572 5,993 2,583 Research and development tax credits (42,279) (24,054) (9,983) Valuation allowance 98,813 61,332 54,093 Stock-based compensation (15,264) 3,331 492 Section 162(m) disallowance 20,604 291 1,077 Rate adjustment 2,766 2,526 (5) Other 575 978 102 Income tax expense (benefit) $ — $ — $ — Significant components of the Company’s deferred tax assets as of December 31, 2024, and 2023 are shown below (in thousands): December 31, 2024 2023 Deferred tax assets: Net operating loss carryforwards $ 83,371 $ 72,658 Section 174 R&E capitalization 103,288 52,085 Research and development tax credits 62,793 31,053 Deferred revenue 12,529 125 Accrued expenses 287 2,809 Intangibles and fixed assets 698 1,265 Lease liabilities 1,446 2,342 Stock-based compensation 8,418 12,451 Total deferred tax assets 272,830 174,788 Less valuation allowance (271,636) (172,822) Net deferred tax assets 1,194 1,966 Deferred tax liabilities: Right-of-use assets (1,194) (1,966) Total deferred tax liabilities (1,194) (1,966) Net deferred tax assets $ — $ — The Company has established a valuation allowance against its net deferred tax assets due to the uncertainty that such assets will be realized. The Company periodically evaluates the recoverability of the deferred tax assets. At such time as it is determined that it is more likely than not that the deferred tax assets will be realizable, the valuation allowance will be released. The change in the valuation allowance was an increase of $98.8 million and $61.3 million for the years ended December 31, 2024 and 2023, respectively. At December 31, 2024, the Company had federal and state net operating loss (NOL) carryforwards of $249.4 million and $439.3 million, respectively. The federal NOL carryforwards will carryforward indefinitely and can offset 80% of future taxable income each year, and the state NOLs begin to expire in 2039 unless previously utilized. At December 31, 2024, the Company had federal and state research and development tax credits of approximately $13.3 million and $15.8 million, respectively. The federal research and development tax credits begin to expire in 2039 unless previously utilized, and the California state credits carry forward indefinitely. At December 31, 2024, the Company had federal orphan drug tax credits of $58.0 million, which begin to expire in 2041. Pursuant to Section 382 and Section 383 of the Internal Revenue Code of 1986, as amended (the "Code"), the Company’s ability to use NOL and R&D tax credit carryforwards (“tax attribute carryforwards”) to offset future taxable income may be limited if the Company experienced a cumulative change in ownership by certain stockholders or groups of stockholders of more than 50 percentage points within a three-year testing period. The Company determined there was one ownership change through December 31, 2023. Limitations as a result of these ownership changes did not impact the Company’s deferred tax assets. Due to the existence of a valuation allowance, impacts to the Company’s deferred tax assets would not impact the Company’s effective tax rate. The following table summarizes the activity related to the Company’s gross unrecognized tax benefits for the years ended December 31, 2024, 2023 and 2022 (in thousands): Year Ended December 31, 2024 2023 2022 Gross unrecognized tax benefits at the beginning of the year $ 11,049 $ 4,771 $ 1,996 Increases related to current year positions 11,110 6,156 2,614 Increases related to prior year positions — 122 161 Gross unrecognized tax benefits at the end of the year $ 22,159 $ 11,049 $ 4,771 The unrecognized tax benefit amounts are reflected in the determination of the Company’s deferred tax assets. If recognized, none of these amounts would affect the Company’s effective tax rate, since it would be offset by a corresponding adjustment to the deferred tax asset valuation allowance. The Company does not foresee material changes to its liability for uncertain tax benefits within the next twelve months. The Company’s policy is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had no accrual for interest or penalties as of December 31, 2024 or 2023. As of December 31, 2024, the Company’s tax years since conversion to a corporation in 2019 are subject to examination by U.S. federal and various state taxing authorities.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
Segment Information	Segment Information Our operations constitute a single operating and reportable segment. Factors considered in determining operating and reportable segments include the organization of our business, the nature of our technology and the information reviewed by our CODM. Operating segments are defined as components of an enterprise for which discrete financial information is available and is evaluated regularly by the CODM, in deciding how to allocate resources and assess performance. Our CODM is our Chief Executive Officer. Our revenues are derived from our research collaboration and license agreements, which are further described in “Note 5 – Collaboration, License and Research Agreements”. The CODM utilizes consolidated net loss in assessing performance and allocating resources by comparing net loss against prior periods and the Company’s forecast. The measure of segment assets is reported on the consolidated balance sheets as total consolidated assets. The following table presents financial information, including significant segment expenses, which are regularly provided to the CODM and included within consolidated net loss (in thousands): Year Ended December 31, 2024 2023 2022 Collaboration revenue $ 10,897 $ 9,560 $ 9,224 Operating expenses, excluding stock-based compensation and depreciation Research and development (275,176) (167,299) (134,184) General and administrative (60,518) (37,536) (25,427) Total operating expenses, excluding stock-based compensation and depreciation (335,694) (204,835) (159,611) Stock-based compensation (51,363) (38,222) (27,139) Depreciation (2,776) (2,101) (1,387) Total operating expenses (389,833) (245,158) (188,137) Other income 56,634 23,378 4,918 Net loss $ (322,302) $ (212,220) $ (173,995) The following table presents the measure of segment assets regularly provided to the CODM (in thousands): December 31, 2024 2023 Cash, cash equivalents and marketable securities $ 1,501,497 $ 595,351

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net loss	$ (322,302)	$ (212,220)	$ (173,995)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	12 Months Ended
	Dec. 31, 2024 shares	Dec. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		From time to time, our officers (as defined in Rule 16a–1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the three months ended December 31, 2024, our officers or directors took the following actions with respect to such trading arrangements: Action Date Trading Arrangement Total Shares to be Sold Expiration Date Rule 10b5-1* Non-Rule 10b5-1** Troy Wilson (Ph.D., J.D.) (1) Adopt 12/4/2024 X 190,106 (2) 3/31/2026 Arthur A. Levin (Ph.D.) Adopt 10/17/2024 X 309,096 12/31/2025 ____________________ * Intended to satisfy the affirmative defense of Rule 10b5-1(c) * * Not intended to satisfy the affirmative defense of Rule 10b5-1(c) (1) This plan was adopted by Mr. Wilson and certain irrevocable trusts for the benefit of Mr. Wilson's family members, none of which Mr. Wilson controls. (2) Represents the aggregate maximum number of shares to be sold under this plan by Mr. Wilson and all signatories to this plan. The maximum number of shares to be sold under this plan by Mr. Wilson is 59,000.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Troy Wilson [Member]
Trading Arrangements, by Individual
Name	Troy Wilson
Title	Ph.D., J.D.
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	12/4/2024
Expiration Date	3/31/2026
Arrangement Duration	482 days
Aggregate Available	190,106	190,106
Arthur A. Levin [Member]
Trading Arrangements, by Individual
Name	Arthur A. Levin
Title	Ph.D.
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	10/17/2024
Expiration Date	12/31/2025
Arrangement Duration	440 days
Aggregate Available	309,096	309,096

Insider Trading Policies and Pr

Insider Trading Policies and Procedures	12 Months Ended
	Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	We have developed and implemented a cybersecurity risk management program intended to protect the confidentiality, integrity, and availability of our critical systems and information. We design and assess our program based on the National Institute of Standards and Technology Cybersecurity Framework, or NIST CSF. This means that we use the NIST CSF as a guide to help us identify, assess and manage cybersecurity risks relevant to our business. It does not, however, mean that we meet any technical standards, specifications or requirements. Our cybersecurity risk management program is integrated into our overall enterprise risk management program, and shares reporting channels and governance processes that apply across the risk management program to other legal, compliance, operational and financial risk areas. However, there can be no assurance that our cybersecurity risk management program and processes, including our policies, controls or procedures, will be fully implemented, complied with or effective in protecting our systems and information. Key elements of our cybersecurity risk management program include but are not limited to the following: • risk assessments to help identify material risks from cybersecurity threats to our critical systems and information; • a security team that includes internal IT and data privacy personnel and external managed services partners, principally responsible for managing (i) our cybersecurity risk assessment processes, (ii) our security controls and (iii) our response to cybersecurity incidents; • use of external service providers, where appropriate, to assess, test or otherwise assist with aspects of our security controls, including: • annual external and internal penetration tests; • 24-hour monitoring of our networks and cloud resources to help detect, respond to and recover from cyber-attacks; • IT managed services that includes help desk support and managed infrastructure (networks and servers support); and • a ransomware defense plan. • cybersecurity awareness training for our employees, including incident response personnel and senior management; • a cybersecurity incident response plan that includes procedures for responding to cybersecurity incidents; and • third-party risk management and reporting process for key service providers based on our assessment of their criticality to our operations and respective risk profile, suppliers and vendors with access to our information systems or data. We have not identified risks from known cybersecurity threats, including as a result of any prior cybersecurity incidents, that have materially affected us, including our operations, business strategy, results of operations or financial condition. We face risks from cybersecurity threats that, if realized, are reasonably likely to materially affect us, including our business strategy, results of operations or financial condition. In the event we experience a cybersecurity incident we consider to be material, we will disclose such incident consistent with the requirements of Item 1.05 of Form 8-K.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Our cybersecurity risk management program is integrated into our overall enterprise risk management program, and shares reporting channels and governance processes that apply across the risk management program to other legal, compliance, operational and financial risk areas.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Our board of directors considers cybersecurity risk as part of its risk oversight function and has delegated to the audit committee of the board of directors, or the audit committee, oversight of cybersecurity and other information technology risks. The audit committee oversees management’s implementation of our cybersecurity risk management program.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our board of directors considers cybersecurity risk as part of its risk oversight function and has delegated to the audit committee of the board of directors, or the audit committee, oversight of cybersecurity and other information technology risks. The audit committee oversees management’s implementation of our cybersecurity risk management program.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	The audit committee receives periodic reports from management on our cybersecurity risks. In addition, management alerts the audit committee of any material cybersecurity incidents. The audit committee reports to the full board of directors regarding its activities, including those related to cybersecurity. Board members receive presentations on cybersecurity topics from management and have available to them external resources related to cybersecurity as part of the board of directors' continuing education on topics that impact companies similar to ours.
Cybersecurity Risk Role of Management [Text Block]	Our cybersecurity function is overseen by our Senior Vice President of Information Technology, who leads a team that is responsible for assessing and managing our risks from cybersecurity threats. The team has primary responsibility for our overall cybersecurity risk management program and supervises both our internal cybersecurity personnel and our retained external cybersecurity consultants. Our management team takes steps to stay informed about and monitor efforts to prevent, detect, mitigate and remediate cybersecurity risks and incidents through various means, which may include briefings from internal security personnel; threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us; and alerts and reports produced by security tools deployed in the IT environment.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Our cybersecurity function is overseen by our Senior Vice President of Information Technology, who leads a team that is responsible for assessing and managing our risks from cybersecurity threats. The team has primary responsibility for our overall cybersecurity risk management program and supervises both our internal cybersecurity personnel and our retained external cybersecurity consultants.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our cybersecurity function is overseen by our Senior Vice President of Information Technology, who leads a team that is responsible for assessing and managing our risks from cybersecurity threats. The team has primary responsibility for our overall cybersecurity risk management program and supervises both our internal cybersecurity personnel and our retained external cybersecurity consultants. Our management team takes steps to stay informed about and monitor efforts to prevent, detect, mitigate and remediate cybersecurity risks and incidents through various means, which may include briefings from internal security personnel; threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us; and alerts and reports produced by security tools deployed in the IT environment.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Our management team takes steps to stay informed about and monitor efforts to prevent, detect, mitigate and remediate cybersecurity risks and incidents through various means, which may include briefings from internal security personnel; threat intelligence and other information obtained from governmental, public or private sources, including external consultants engaged by us; and alerts and reports produced by security tools deployed in the IT environment.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the Securities and Exchange Commission (SEC). The consolidated financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair presentation of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these consolidated financial statements are not necessarily indicative of the results that may be expected for any future periods. Certain prior year amounts have been reclassified to conform to the current year presentation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires the Company to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the consolidated financial statements and accompanying notes. Although estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with original maturities of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents include cash in readily available checking and money market accounts. Restricted cash represents cash held as collateral for the letters of credit required under the Company’s facility lease and is reported as a long-term asset in the accompanying consolidated balance sheets. Cash and cash equivalents are considered Level 1 investments.
Marketable Securities	Marketable Securities The Company’s marketable securities primarily consist of U.S. Government debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the consolidated balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the consolidated statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses recognized during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets
Concentration of Credit Risk	Concentration of Credit Risk
Fair Value of Financial Instruments	Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs, such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. None of the Company’s non-financial assets are recorded at fair value on a non-recurring basis. The carrying amounts reflected in the Company’s consolidated balance sheets for prepaid and other assets and accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The Company recognizes transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. There have been no transfers into or out of Level 3 assets during any of the periods presented.
Property and Equipment, net	Property and Equipment, net Property and equipment, including leasehold improvements, are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recorded using the straight-line method over the estimated useful lives of the related assets, which ranges from three
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
Segment Information	Segment Information Our operations constitute a single operating and reportable segment, headquartered in the United States. Operating segments are defined as components of an enterprise for which discrete financial information is available and is evaluated regularly by the chief operating decision maker (“CODM”), in deciding how to allocate resources and assess performance. Our CODM is our Chief Executive Officer, who reviews consolidated financial information for the purposes of allocating resources and assessing performance. All of our property and equipment is located within the United States and all of our revenues were derived within the United States.
Revenue Recognition	Revenue Recognition To date, all the Company’s revenue has been derived from collaboration and research agreements. The terms of these arrangements include the following types of payments to the Company: non-refundable, upfront license fees; development, regulatory and commercial milestone payments; payments for research and development services provided by the Company or for manufacturing supply services the Company provides through its contract manufacturers; and royalties on net sales of licensed products. At the inception of a collaboration arrangement, the Company first assesses whether the contractual arrangement is within the scope of Accounting Standards Codification (ASC) Topic 808, Collaborative Arrangements (ASC 808) to determine whether the arrangement involves a joint operating activity and involves two (or more) parties that are both active participants in the activity and exposed to significant risks and rewards dependent on the commercial success of such activity. Then the Company determines whether the collaboration arrangement in its entirety represents a contract with a customer as defined by ASC Topic 606 (ASC 606). If only a portion of the collaboration arrangement is potentially with a customer, the Company applies the distinct good or service unit-of-account guidance in ASC 606 to determine whether there is a unit of account that should be accounted for under ASC 606. The Company performs the following steps in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of these agreements: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when, or as, the Company satisfies each performance obligation. The Company applies significant judgment when making estimates and assumptions under these agreements, including (i) evaluating whether contractual obligations represent distinct performance obligations, ii) the assessment of whether options represent material rights, (iii) determining whether there are observable standalone prices and allocating transaction price to performance obligations within a contract, (iv) assessing whether any licenses are functional or symbolic, (v) determining when performance obligations have been met, and (vi) assessing the recognition of variable consideration. The Company evaluates each performance obligation to determine if it can be satisfied and recognized as revenue at a point in time or over time. The Company receives payments from its collaborators based on billing schedules established in each contract. Upfront and other payments may require deferral of revenue recognition to a future period until the Company performs its obligations under its research and collaboration arrangements. Amounts are recorded as accounts receivable when the Company’s right to consideration is unconditional. License fees, non-refundable upfront fees, and funding of research activities are considered fixed, while milestone payments are identified as variable consideration and excluded from the transaction price. The Company will recognize revenue for sales-based royalty if and when a subsequent sale occurs.
Research and Development Costs and Accruals	Research and Development Costs and Accruals Research and development costs are expensed as incurred and include salaries, benefits and stock-based compensation associated with research and development personnel, third-party research and development expenses, license fees, laboratory supplies, facilities, overhead costs, and consultants. Nonrefundable advance payments for goods and services that will be used in future research and development activities are capitalized and recorded as expense in the period that the Company receives the goods or when services are performed. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying consolidated balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of these accrued liabilities, the Company analyzes progress of the services, including the phase or completion of events, invoices received, and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Upfront and milestone payments to acquire contractual rights to licensed technology are expensed when incurred if there is uncertainty in the Company receiving future economic benefit from the acquired contractual rights. Certain of these contractual rights may require the Company to make additional milestone payments upon initiation of a pivotal trial and the U.S. Food and Drug Administration approval.
Patent Costs	Patent Costs
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Deferred tax assets and liabilities are determined based on the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit would more likely than not be realized assuming examination by the taxing authority. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company is subject to taxation in the United States and various state jurisdictions. As of December 31, 2024, the Company’s tax years since conversion to a corporation in 2019 are subject to examination by taxing authorities.
Leases	Leases The Company determines if an arrangement is a lease at inception. Lease right-of-use assets represent Company's right to use an underlying asset for the lease term and lease liabilities represent Company's obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. The interest rate used to determine the present value of the future lease payments is our incremental borrowing rate, because the interest rate implicit in most of our leases is not readily determinable. The incremental borrowing rate is estimated to approximate the interest rate on a collateralized basis with similar terms and payments, and in similar economic environments. The operating lease right-of-use asset also includes any lease payments made and excludes lease incentives. The lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Variable lease payments that do not depend on a rate or index, payments associated with non-lease components, and costs related to leases with terms of less than 12 months are expensed as incurred.
Warrants	Warrants The Company accounts for warrants as equity-classified instruments based on an assessment of the warrant’s specific terms and applicable authoritative guidance in ASC 480, Distinguishing Liabilities from Equity (ASC 480) and ASC 815, Derivatives and Hedging (ASC 815). The assessment considers whether the warrants are freestanding financial instruments pursuant to ASC 480, meet the definition of a liability pursuant to ASC 480, and whether the warrants meet all of the requirements for equity classification under ASC 815, including whether the warrants are indexed to the Company’s own common stock and whether the warrant holders could potentially require “net cash settlement” in a circumstance outside of the Company’s control, among other conditions for equity classification. This assessment, which requires the use of professional judgment, is conducted at the time of warrant issuance and as of each subsequent quarterly period end date while the warrants are outstanding. For warrants that meet all criteria for equity classification, the warrants are required to be recorded as additional paid-in capital in the consolidated balance sheets at the time of issuance. Equity-classified warrants are measured at their estimated fair value on the issuance date.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense is incurred related to stock option and restricted stock grants, and to shares sold under the Employee Stock Purchase Plan (ESPP). Stock-based compensation expense for stock option grants is determined using the Black-Scholes-Merton (BSM) option pricing model and is recorded at the estimated fair value of the award as of the grant date and recognized as expense on a straight-line basis over the requisite service period (usually the vesting period) of the stock-based award. Stock-based compensation expense for Restricted Stock Units (RSUs) is recorded at the market price of a share of the Company's stock on the date of grant and is recognized as expense on a straight-line basis over the service period. Stock-based compensation expense for Performance Stock Units (PSUs) is recorded at the market price of a share of the Company's stock on the date of grant and recognized on a straight-line basis over the requisite service periods beginning when the achievement of the performance condition is determined to be probable. Stock-based compensation expense for employee stock purchases under the Company’s ESPP is determined using the BSM option pricing model and is recorded at the estimated fair value of the purchase as of the plan enrollment date and is recognized as expense on a straight-line basis over the applicable six-month ESPP offering period. The estimation of fair value for stock-based compensation requires management to make estimates and judgments about, among other things, the estimated life of options and volatility of the Company’s common stock. These judgments directly affect the amount of compensation expense that will be recognized. Forfeitures are accounted for as incurred.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including cumulative translation adjustments and unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the consolidated statements of operation and comprehensive loss for all periods presented.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, adjusted for the weighted-average number of common shares outstanding that are subject to repurchase or forfeiture. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the common stock equivalent securities would be anti-dilutive. The pre-funded common stock warrants are included in the calculation of basic and diluted net loss per share as the exercise price of $0.001 per share is not substantive and the shares are issuable for little or no consideration.
Recently Issued Accounting Pronouncements and Recently Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In December 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which enhances income tax disclosures, primarily through standardization and disaggregation of the income tax rate reconciliation and disaggregation of income taxes paid. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. ASU 2023-09 can be applied either prospectively or retrospectively and early adoption is permitted. The Company is currently evaluating the impact that this guidance will have on the presentation of its consolidated financial statements and accompanying notes. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40), which requires that public business entities disclose additional information about specific expense captions in the notes to financial statements at interim and annual reporting periods. The amendment in the update does not change or remove current expense disclosures, rather, it requires enhanced disaggregated disclosures of specific expense captions and affects where that information is presented within the notes to the financial statements. ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. ASU 2024-03 can be applied either prospectively or retrospectively and early adoption is permitted. The Company is currently evaluating the impact that this guidance will have on the presentation of its consolidated financial statements and accompanying notes. Recently Adopted Accounting Pronouncements

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2024
Accounting Policies [Abstract]
Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share/Unit	Common stock equivalent securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares; in thousands): December 31, 2024 2023 2022 Common stock options issued and outstanding 12,635 12,495 9,352 Restricted stock units 2,111 758 — Performance stock units 925 750 — ESPP shares pending issuance 12 12 5 Total 15,683 14,015 9,357

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Cash Equivalents and Marketable Securities Measured at Fair Value	The following tables summarize the Company’s cash equivalents and marketable securities measured at fair value (in thousands): Fair Value Measurements Using As of December 31, 2024 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 7,439 $ 7,439 $ — $ — Marketable securities: U.S. Treasury securities 1,281,139 1,281,139 — — Negotiable certificates of deposit 490 — 490 — Total $ 1,289,068 $ 1,288,578 $ 490 $ — Fair Value Measurements Using As of December 31, 2023 Total Quoted Prices in Significant Significant Marketable securities: U.S. Treasury securities $ 399,890 $ 399,890 $ — $ — U.S. Government agency securities 4,998 — 4,998 — Negotiable certificates of deposit 5,381 — 5,381 — Total $ 410,269 $ 399,890 $ 10,379 $ —

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Marketable Securities	The Company’s marketable securities, which consist of highly liquid marketable debt securities, are classified as available-for-sale and are stated at fair value. The following tables summarize the Company’s marketable securities (in thousands): As of December 31, 2024 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 947,916 $ 2,154 $ (80) $ 949,990 Negotiable certificates of deposit 1 or less 490 — — 490 U.S. Treasury securities 1 - 2 330,321 1,218 (390) 331,149 Total $ 1,278,727 $ 3,372 $ (470) $ 1,281,629 As of December 31, 2023 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 301,053 $ 102 $ (530) $ 300,625 U.S. Government agency securities 1 or less 5,000 — (2) 4,998 Negotiable certificates of deposit 1 or less 4,410 1 (4) 4,407 U.S. Treasury securities 1 - 2 98,701 600 (36) 99,265 Negotiable certificates of deposit 1 - 2 980 — (6) 974 Total $ 410,144 $ 703 $ (578) $ 410,269
Schedule of Available-for-sale Securities in an Unrealized Loss Position	The following table summarizes marketable securities in a continuous unrealized loss position for which an allowance for credit losses was not recorded (in thousands): Less Than 12 Months 12 Months or Greater Total As of December 31, 2024 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 247,404 $ (470) $ — $ — $ 247,404 $ (470) Total $ 247,404 $ (470) $ — $ — $ 247,404 $ (470) Less Than 12 Months 12 Months or Greater Total As of December 31, 2023 Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. Treasury securities $ 214,291 $ (566) $ — $ — $ 214,291 $ (566) U.S. Government agency securities 4,998 (2) — — 4,998 (2) Negotiable certificates of deposit 3,665 (10) — — 3,665 (10) Total $ 222,954 $ (578) $ — $ — $ 222,954 $ (578)

Collaboration, License and Re_2

Collaboration, License and Research Agreements (Tables)	12 Months Ended
	Dec. 31, 2024
Collaboration License And Research Agreements [Abstract]
Schedule of Reconciliation of Deferred Revenue	A reconciliation of the closing balance of deferred revenue related to all collaboration agreements for the years ended December 31, 2024 and 2023 is as follows (in thousands): Revenue recognized that was included in the balance at the beginning of the period $ (4,933) Balance at December 31, 2022 6,175 Unearned revenue from cash received during the period 68,736 Revenue recognized that was included in the balance at the beginning of the period (5,648) Balance at December 31, 2023 69,263 Revenue recognized that was included in the balance at the beginning of the period (10,315) Balance at December 31, 2024 $ 58,948

Composition of Certain Consol_2

Composition of Certain Consolidated Financial Statement Items (Tables)	12 Months Ended
	Dec. 31, 2024
Property, Plant and Equipment [Abstract]
Schedule of Other Current Assets	Prepaid and other assets (in thousands) December 31, 2024 2023 Accounts receivable $ — $ 1,105 Prepaid assets 12,571 7,333 Interest receivable and other assets 28,222 7,518 Total prepaid and other assets $ 40,793 $ 15,956
Schedule of Property and Equipment	Property and equipment, net (in thousands) December 31, 2024 2023 Laboratory equipment $ 14,180 $ 11,208 Computers and software 261 127 Office furniture and equipment 1,979 1,979 Leasehold improvements 288 288 Construction in process 3,959 — Property and equipment, gross 20,667 13,602 Less accumulated depreciation and amortization (7,997) (5,221) Total property and equipment, net $ 12,670 $ 8,381
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable and accrued liabilities (in thousands) December 31, 2024 2023 Accounts payable $ 8,461 $ 8,809 Accrued non-clinical liabilities 17,226 4,054 Accrued manufacturing and technical development 35,680 15,481 Accrued clinical liabilities 8,157 5,997 Total accounts payable and accrued liabilities $ 69,524 $ 34,341

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule Of Leases Recorded On Balance Sheet	As of December 31, 2024, the Company’s ROU assets and liabilities related to the operating lease for the Company headquarters are as follows (in thousands): ROU assets $ 5,619 Lease liabilities, current portion $ 3,844 Lease liabilities, net of current portion 2,957 Total lease liabilities $ 6,801
Schedule of Lessee, Operating Lease, Liability, Maturity	As of December 31, 2024, maturities of the lease liabilities due under the operating lease are as follows (in thousands): Year ending December 31, 2025 $ 3,854 2026 3,639 Total lease payments 7,493 Less imputed interest (692) Total operating lease liabilities 6,801 Less lease liabilities, current portion (3,844) Lease liabilities, net of current portion $ 2,957
Schedule of Lease, Cost	Other information related to leases was as follows (in thousands): Year Ended December 31, 2024 2023 2022 Cash paid included in operating cash flows $ 3,696 $ 3,328 $ 1,762 Weighted-average remaining lease term (in years) 1.9 2.9 3.9 Weighted-average discount rate 5.9 % 5.9 % 5.5 %

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2024
Equity [Abstract]
Schedule of Stock Option Activity	Stock option activity in 2024 for employee and non-employee awards and related information is as follows (in thousands, except per share and contractual term data): Number of Outstanding Options Weighted- Weighted- Aggregate Balance at December 31, 2023 12,495 $ 14.91 Granted 4,162 27.06 Exercised (3,498) 13.78 Forfeited/expired (524) 15.70 Balance at December 31, 2024 12,635 $ 19.19 7.88 $ 149,957 Vested and expected to vest at December 31, 2024 12,635 $ 19.19 7.88 $ 149,957 Exercisable at December 31, 2024 5,772 $ 15.32 6.89 $ 79,900 The following summarizes additional information regarding stock options (in thousands, except per share data): Year Ended December 31, 2024 2023 2022 Cash received from options exercised $ 48,207 $ 573 $ 470 Intrinsic value of options exercised $ 83,422 $ 2,421 $ 6,724 Weighted-average grant date fair value per share $ 19.26 $ 10.33 $ 11.11
Schedule of Unvested Restricted Stock Units Roll Forward	The following table summarizes the RSU activity for the year ended December 31, 2024 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Balance at December 31, 2023 758 $ 18.73 Granted 1,711 25.51 Vested (184) 18.79 Forfeited (174) 14.82 Balance at December 31, 2024 2,111 $ 24.54 The following table summarizes the PSU activity for the year ended December 31, 2024 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Balance at December 31, 2023 750 $ 6.57 Granted 738 43.22 Vested (563) 6.57 Forfeited — — Balance at December 31, 2024 925 $ 35.80
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and shares purchasable under the ESPP were as follows: Options ESPP Year Ended December 31, Year Ended December 31, 2024 2023 2022 2024 2023 2022 Risk-free interest rate 3.5% - 4.7% 3.5% - 4.9% 1.5% - 4.2% 4.3% - 5.4% 5.4% 2.2% - 4.7% Expected volatility 79% - 82% 78% - 82% 85% 64% - 82% 68% - 76% 78% - 79% Expected term (in years) 5.3 - 6.1 5.5 - 6.1 5.5 - 6.1 0.5 0.5 0.5 Expected dividend yield —% —% —% —% —% —%
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and shares purchasable under the ESPP were as follows: Options ESPP Year Ended December 31, Year Ended December 31, 2024 2023 2022 2024 2023 2022 Risk-free interest rate 3.5% - 4.7% 3.5% - 4.9% 1.5% - 4.2% 4.3% - 5.4% 5.4% 2.2% - 4.7% Expected volatility 79% - 82% 78% - 82% 85% 64% - 82% 68% - 76% 78% - 79% Expected term (in years) 5.3 - 6.1 5.5 - 6.1 5.5 - 6.1 0.5 0.5 0.5 Expected dividend yield —% —% —% —% —% —%
Schedule of Allocated Stock-based Compensation Expense	The allocation of stock-based compensation expense was as follows (in thousands): Year Ended December 31, 2024 2023 2022 Research and development expense $ 26,120 $ 22,007 $ 15,222 General and administrative expense 25,243 16,215 11,917 Total stock-based compensation expense $ 51,363 $ 38,222 $ 27,139

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2024
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Income Taxes Computed by Applying Statutory Federal Income Tax Rate	A reconciliation of the federal statutory income tax rate and the Company’s effective income tax rate is as follows (in thousands): Year Ended December 31, 2024 2023 2022 Income tax expense (benefit) at statutory rates $ (67,683) $ (44,566) $ (36,539) State income tax, net of federal benefit (8,170) (5,882) (11,821) Permanent items 66 51 1 Reserve for uncertain tax positions 10,572 5,993 2,583 Research and development tax credits (42,279) (24,054) (9,983) Valuation allowance 98,813 61,332 54,093 Stock-based compensation (15,264) 3,331 492 Section 162(m) disallowance 20,604 291 1,077 Rate adjustment 2,766 2,526 (5) Other 575 978 102 Income tax expense (benefit) $ — $ — $ —
Schedule of Components of Deferred Tax Assets	Significant components of the Company’s deferred tax assets as of December 31, 2024, and 2023 are shown below (in thousands): December 31, 2024 2023 Deferred tax assets: Net operating loss carryforwards $ 83,371 $ 72,658 Section 174 R&E capitalization 103,288 52,085 Research and development tax credits 62,793 31,053 Deferred revenue 12,529 125 Accrued expenses 287 2,809 Intangibles and fixed assets 698 1,265 Lease liabilities 1,446 2,342 Stock-based compensation 8,418 12,451 Total deferred tax assets 272,830 174,788 Less valuation allowance (271,636) (172,822) Net deferred tax assets 1,194 1,966 Deferred tax liabilities: Right-of-use assets (1,194) (1,966) Total deferred tax liabilities (1,194) (1,966) Net deferred tax assets $ — $ —
Schedule of Activity Related to Gross Unrecognized Tax Benefits	The following table summarizes the activity related to the Company’s gross unrecognized tax benefits for the years ended December 31, 2024, 2023 and 2022 (in thousands): Year Ended December 31, 2024 2023 2022 Gross unrecognized tax benefits at the beginning of the year $ 11,049 $ 4,771 $ 1,996 Increases related to current year positions 11,110 6,156 2,614 Increases related to prior year positions — 122 161 Gross unrecognized tax benefits at the end of the year $ 22,159 $ 11,049 $ 4,771

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2024
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table presents financial information, including significant segment expenses, which are regularly provided to the CODM and included within consolidated net loss (in thousands): Year Ended December 31, 2024 2023 2022 Collaboration revenue $ 10,897 $ 9,560 $ 9,224 Operating expenses, excluding stock-based compensation and depreciation Research and development (275,176) (167,299) (134,184) General and administrative (60,518) (37,536) (25,427) Total operating expenses, excluding stock-based compensation and depreciation (335,694) (204,835) (159,611) Stock-based compensation (51,363) (38,222) (27,139) Depreciation (2,776) (2,101) (1,387) Total operating expenses (389,833) (245,158) (188,137) Other income 56,634 23,378 4,918 Net loss $ (322,302) $ (212,220) $ (173,995)
Schedule of Reconciliation of Assets from Segment to Consolidated	The following table presents the measure of segment assets regularly provided to the CODM (in thousands): December 31, 2024 2023 Cash, cash equivalents and marketable securities $ 1,501,497 $ 595,351

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Accumulated deficit	$ 893,066	$ 570,764
Cash, cash equivalents and marketable securities	$ 1,500,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2024 USD ($) Segment $ / shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Realized gains and losses on marketable securities		$ 0	$ 0	$ 0
Unrealized gains and losses on marketable securities		$ 0	0	0
Prepaid and other assets [Extensible Enumeration]		Prepaid and other assets
Transfers of financial instrument classified as asset into level 3		$ 0	0	0
Transfers of financial instrument classified as asset out of level 3		0	0	0
Impairments of long-lived assets		$ 0	$ 0	$ 0
Number of operating segments | Segment		1
Number of reportable segments | Segment		1
Pre-Funded Common Stock Warrant
Summary Of Significant Accounting Policies [Line Items]
Class of warrant or right, exercise price (in dollar per share) | $ / shares		$ 0.001
Employee Stock
Summary Of Significant Accounting Policies [Line Items]
Award offering period	6 months	6 months
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets		3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets		5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share/Unit (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total (in shares)	15,683	14,015	9,357
Common stock options issued and outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total (in shares)	12,635	12,495	9,352
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total (in shares)	2,111	758	0
Performance stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total (in shares)	925	750	0
ESPP shares pending issuance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total (in shares)	12	12	5

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	$ 1,281,629	$ 410,269
Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	1,289,068	410,269
Recurring | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	7,439
Recurring | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	1,281,139	399,890
Recurring | U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:		4,998
Recurring | Negotiable certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	490	5,381
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	1,288,578	399,890
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	7,439
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	1,281,139	399,890
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:		0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Negotiable certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	490	10,379
Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	0
Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Significant Other Observable Inputs (Level 2) | U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:		4,998
Recurring | Significant Other Observable Inputs (Level 2) | Negotiable certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	490	5,381
Recurring | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	0	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:		0
Recurring | Significant Unobservable Inputs (Level 3) | Negotiable certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	$ 0	$ 0

Marketable Securities - Schedul

Marketable Securities - Schedule of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 1,278,727	$ 410,144
Unrealized Gains	3,372	703
Unrealized Losses	(470)	(578)
Estimated Fair Value, current	1,281,629	410,269
Estimated Fair Value	1,281,629	410,269
U.S. Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	947,916	301,053
Amortized Cost, noncurrent	330,321	98,701
Estimated Fair Value, current	949,990	300,625
Estimate Fair Value, noncurrent	331,149	99,265
U.S. Treasury securities | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	2,154	102
Unrealized Losses	(80)	(530)
U.S. Treasury securities | 1 - 2
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	1,218	600
Unrealized Losses	(390)	(36)
U.S. Government agency securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current		5,000
Estimated Fair Value, current		4,998
U.S. Government agency securities | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains		0
Unrealized Losses		(2)
Negotiable certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	490	4,410
Amortized Cost, noncurrent		980
Estimated Fair Value, current	490	4,407
Estimate Fair Value, noncurrent		974
Negotiable certificates of deposit | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	1
Unrealized Losses	$ 0	(4)
Negotiable certificates of deposit | 1 - 2
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains		0
Unrealized Losses		$ (6)

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Allowances for credit losses	$ 0	$ 0
Accrued interest receivable on available-for-sale securities	8.7	2.6
Debt securities, available-for-sale, accrued interest writeoff	$ 0	$ 0	$ 0

Marketable Securities - Sched_2

Marketable Securities - Schedule of Available-for-sale Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value
Less Than 12 months, Fair Value	$ 247,404	$ 222,954
12 months or Greater, Fair Value	0	0
Total Fair Value	247,404	222,954
Unrealized Losses
Less Than 12 months, Gross Unrealized Losses	(470)	(578)
12 months or Greater, Gross Unrealized Losses	0	0
Total Gross Unrealized Losses	(470)	(578)
U.S. Treasury securities
Fair Value
Less Than 12 months, Fair Value	247,404	214,291
12 months or Greater, Fair Value	0	0
Total Fair Value	247,404	214,291
Unrealized Losses
Less Than 12 months, Gross Unrealized Losses	(470)	(566)
12 months or Greater, Gross Unrealized Losses	0	0
Total Gross Unrealized Losses	$ (470)	(566)
U.S. Government agency securities
Fair Value
Less Than 12 months, Fair Value		4,998
12 months or Greater, Fair Value		0
Total Fair Value		4,998
Unrealized Losses
Less Than 12 months, Gross Unrealized Losses		(2)
12 months or Greater, Gross Unrealized Losses		0
Total Gross Unrealized Losses		(2)
Negotiable certificates of deposit
Fair Value
Less Than 12 months, Fair Value		3,665
12 months or Greater, Fair Value		0
Total Fair Value		3,665
Unrealized Losses
Less Than 12 months, Gross Unrealized Losses		(10)
12 months or Greater, Gross Unrealized Losses		0
Total Gross Unrealized Losses		$ (10)

Collaboration, License and Re_3

Collaboration, License and Research Agreements - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Nov. 27, 2023 USD ($) shares	Nov. 30, 2023 USD ($) $ / shares shares	Apr. 30, 2019 USD ($) Product Obligation	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration revenue				$ 10,897	$ 9,560	$ 9,224
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees received		$ 100,000
Collaborative arrangement, nonrefundable cash payment received		60,000
Sale of stock, consideration received on transaction		40,000
Cumulative spending cap		40,000
Collaboration revenue				$ 9,800	0
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, period				7 years
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS | First Unit Of Accounting
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, amount		68,700
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS | Second Unit Of Accounting
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, amount		$ 31,300
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS | Private Placement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Sale of stock number of shares issued in transaction (in shares) | shares	5,075,304	5,075,304
Sale of stock, consideration received on transaction	$ 40,000	$ 40,000
Sale of stock, price per share (in dollars per share) | $ / shares		$ 7.8813
Premium In excess of fair value	$ 8,700	$ 8,700
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development milestone payment eligible to receive		1,350,000
Commercialization milestone payment eligible to receive		$ 825,000
Research Collaboration and License Agreement with Eli Lilly
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees received			$ 20,000
Collaboration revenue				$ 1,100	9,500	$ 9,000
License agreement expiry period			10 years
Number of performance obligation | Obligation			1
Period for expected performance obligation				5 years
Collaboration receivables				$ 0	$ 800
Research Collaboration and License Agreement with Eli Lilly | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Development milestone payment eligible to receive			$ 60,000
Commercialization milestone payment eligible to receive			$ 205,000
Rights to antibody oligonucleotide conjugates for messengers RNA targets. | Product			6
Regulatory milestone payment eligible to receive			$ 140,000

Collaboration, License and Re_4

Collaboration, License and Research Agreements - Schedule of Reconciliation of Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Contract With Customer, Liability [Roll Forward]
Revenue recognized that was included in the balance at the beginning of the period	$ (10,315)	$ (5,648)	$ (4,933)
Beginning balance	69,263	6,175
Unearned revenue from cash received during the period		68,736
Ending balance	$ 58,948	$ 69,263	$ 6,175

Composition of Certain Consol_3

Composition of Certain Consolidated Financial Statement Items - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Accounts receivable	$ 0	$ 1,105
Prepaid assets	12,571	7,333
Interest receivable and other assets	28,222	7,518
Total prepaid and other assets	$ 40,793	$ 15,956

Composition of Certain Consol_4

Composition of Certain Consolidated Financial Statement Items - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 20,667	$ 13,602
Less accumulated depreciation and amortization	(7,997)	(5,221)
Total property and equipment, net	12,670	8,381
Laboratory equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	14,180	11,208
Computers and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	261	127
Office furniture and equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,979	1,979
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	288	288
Construction in process
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,959	$ 0

Composition of Certain Consol_5

Composition of Certain Consolidated Financial Statement Items - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation expenses related to property and equipment	$ 2,776	$ 2,101	$ 1,387

Composition of Certain Consol_6

Composition of Certain Consolidated Financial Statement Items - Schedule of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Accounts payable	$ 8,461	$ 8,809
Accrued non-clinical liabilities	17,226	4,054
Accrued manufacturing and technical development	35,680	15,481
Accrued clinical liabilities	8,157	5,997
Total accounts payable and accrued liabilities	$ 69,524	$ 34,341

Commitments and Contingencies -

Commitments and Contingencies - Schedule Of Leases Recorded On Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
ROU assets	$ 5,619	$ 8,271
Lease liabilities, current portion	3,844	3,639
Lease liabilities, net of current portion	2,957	$ 6,213
Total operating lease liabilities	$ 6,801

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Lessee, Operating Lease, Liability, Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
2025	$ 3,854
2026	3,639
Total lease payments	7,493
Less imputed interest	(692)
Total operating lease liabilities	6,801
Less lease liabilities, current portion	(3,844)	$ (3,639)
Lease liabilities, net of current portion	$ 2,957	$ 6,213

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Lessee Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Cash paid included in operating cash flows	$ 3,696	$ 3,328	$ 1,762
Weighted-average remaining lease term (in years)	1 year 10 months 24 days	2 years 10 months 24 days	3 years 10 months 24 days
Weighted-average discount rate	5.90%	5.90%	5.50%

Commitments and Contingencies_4

Commitments and Contingencies - Additional Information (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2024 USD ($) ft²	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Long-Term Purchase Commitment [Line Items]
Lease cost		$ 3,300	$ 3,000	$ 2,700
Aggregate future lease payments		7,493
Loss contingencies accrued		$ 0
Turning Point Therapeutics, Inc.
Long-Term Purchase Commitment [Line Items]
Area of land | ft²	105,000
Term of contract	9 years 9 months
Tenant improvement allowance	$ 33,600
Additional tenant improvement allowance	$ 5,000
Additional tenant improvement allowance interest rate	0.08
Additional tenant improvement allowance interest rate, annual increase	0.03
Operating lease not yet commenced, area of additional rentable space | ft²	80,000
Aggregate future lease payments	$ 72,600
Restricted cash	$ 2,500

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands							1 Months Ended		3 Months Ended	12 Months Ended
	Aug. 16, 2024	Aug. 09, 2024	Jun. 17, 2024	Mar. 04, 2024	Nov. 27, 2023	Nov. 08, 2022	Nov. 30, 2023	Jun. 30, 2020	Mar. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Jun. 16, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized (in shares)										400,000,000	400,000,000		400,000,000
Preferred stock, shares authorized (in shares)													40,000,000
Common stock, par value (in dollars per share)										$ 0.0001	$ 0.0001		$ 0.0001
Preferred stock, par value (in dollars per share)													$ 0.0001
Preferred stock, shares outstanding (in shares)										0	0	0
Proceeds from issuance of common stock in public offerings, net of issuance costs										$ 762,161	$ 60,547	$ 344,779
Award vesting period										4 years
Total stock-based compensation expense										$ 51,363	38,222	27,139
Expected dividend yield										0%
Unrecognized compensation cost, options										$ 102,500
Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
PSUs vested (in shares)									187,500
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense										$ 7,000	$ 900	$ 0
PSUs vested (in shares)										184,293	0	0
Fair value of shares vested during the period										$ 3,500
Granted (in shares)										1,711,000
Unrecognized compensation cost, excluding options										$ 45,200
Performance Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense										$ 4,800	$ 0	$ 0
PSUs vested (in shares)										562,500	0	0
Fair value of shares vested during the period										$ 22,100
Outstanding PSUs (in shares)										750,000
Granted (in shares)										738,000
Unrecognized compensation cost, excluding options										$ 32,100
Unrecognized compensation cost, probable amount										$ 200
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant (in shares)										193,367
Participant maximum contribution as percentage of eligible compensation								15%
Award offering period								6 months		6 months
Percentage of purchase price of shares of lower of fair market value								85%
Issuance of common stock under employee stock purchase plan (in shares)										179,150	175,511	90,535
Outstanding liability										$ 300
Expected dividend yield										0%	0%	0%
Unrecognized compensation cost, excluding options										$ 900
Weighted-average period of unrecognized compensation cost										6 months
Common stock options issued and outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield										0%	0%	0%
Weighted-average period of unrecognized compensation cost										2 years 8 months 12 days
Weighted Average | Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period of unrecognized compensation cost										3 years 2 months 12 days
Weighted Average | Performance Stock Units (PSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average period of unrecognized compensation cost										2 months 12 days
2020 Incentive Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance (in shares)								3,900,000
Percentage of shares of common stock outstanding on final day of immediately preceding calendar year								5%
Shares available for grant (in shares)										1,591,462
Additional shares reserved for future issuance (in shares)										3,963,742
2020 Incentive Award Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period										10 years
2022 Employment Inducement Incentive Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock reserved for future issuance (in shares)												4,500,000
Shares available for grant (in shares)										697,350
Additional shares reserved for future issuance (in shares)										3,000,000
2022 Employment Inducement Incentive Award Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period										10 years
2013 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period										10 years
Pre-Funded Common Stock Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Class of warrant or right, exercise price (in dollar per share)										$ 0.001
Research Collaboration, License Agreement and Securities Purchase Agreement with BMS
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock, consideration received on transaction							$ 40,000
Private Placement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Public offering issuance costs										$ 12,821	$ 74
Issuance of common stock, net of issuance costs										238,388	31,190
Private Placement | Research Collaboration, License Agreement and Securities Purchase Agreement with BMS
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)					5,075,304		5,075,304
Public offering issuance costs					$ 100
Sale of stock, consideration received on transaction					40,000		$ 40,000
Issuance of common stock, net of issuance costs					31,200
Premium In excess of fair value					$ 8,700		$ 8,700
Sale of stock, price per share (in dollars per share)							$ 7.8813
Private Placement Offering 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)				15,224,773
Sale of stock, consideration received on transaction				$ 379,800
Sale of stock, price per share (in dollars per share)				$ 16.50
Payments of stock issuance costs				$ 20,400
Private Placement Offering 2024 | Principal Owner
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)				2,121,213
Sale of stock, consideration received on transaction				$ 35,000
Private Placement Offering 2024 | Pre-Funded Common Stock Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Class of warrant or right, number of securities called by warrants or rights (in shares)				9,030,851
Sale of stock, price per share (in dollars per share)				$ 16.499
Class of warrant or right, exercise price (in dollar per share)				$ 0.001
Public Stock Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)	8,418,000		12,132,500
Public offering issuance costs										49,749	1,385	$ 18,230
Sale of stock, consideration received on transaction	$ 323,700		$ 432,800
Issuance of common stock, net of issuance costs										$ 762,161	$ 60,547	$ 344,616
Sale of stock, price per share (in dollars per share)	$ 41		$ 38
Payments of stock issuance costs	$ 21,400		$ 28,300
Sales Agent | Private Placement, 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of common stock maximum aggregate offering price						$ 200,000
Sales Agent | Private Placement, 2021 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)										418,408	4,107,810
Proceeds from issuance of common stock in public offerings, net of issuance costs										$ 5,600	$ 60,500
Public offering issuance costs										$ 100	$ 1,400
TD Securities (USA), LLC | Private Placement 2024 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)										0
Sale of common stock maximum aggregate offering price		$ 400,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Additional Information Regarding Stock Options (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) $ / shares shares
Number of Outstanding Options
Beginning balance (in shares) | shares	12,495
Granted (in shares) | shares	4,162
Exercised (in shares) | shares	(3,498)
Forfeited/expired (in shares) | shares	(524)
Ending balance (in shares) | shares	12,635
Vested and expected to vest (in shares) | shares	12,635
Exercisable (in shares) | shares	5,772
Weighted- Average Exercise Price Per Share
Beginning balance (in dollars per share) | $ / shares	$ 14.91
Granted (in dollars per share) | $ / shares	27.06
Exercised (in dollars per share) | $ / shares	13.78
Forfeited/expired (in dollars per share) | $ / shares	15.70
Ending balance (in dollars per share) | $ / shares	19.19
Vested and expected to vest (in dollars per share) | $ / shares	19.19
Exercisable (in dollars per share) | $ / shares	$ 15.32
Weighted- Average Remaining Contractual Term (in years)
Outstanding	7 years 10 months 17 days
Vested and expected to vest	7 years 10 months 17 days
Exercisable	6 years 10 months 20 days
Aggregate Intrinsic Value
Outstanding | $	$ 149,957
Vested and expected to vest | $	149,957
Exercisable | $	$ 79,900

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Additional Information Regarding Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Equity [Abstract]
Cash received from options exercised	$ 48,207	$ 573	$ 470
Intrinsic value of options exercised	$ 83,422	$ 2,421	$ 6,724
Weighted-average grant date fair value per share (in dollars per share)	$ 19.26	$ 10.33	$ 11.11

Stockholders' Equity - Schedu_3

Stockholders' Equity - Schedule of Unvested Restricted Stock Units Roll Forward (Details) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Restricted stock units
Number of Shares
Beginning balance (in shares)	758,000
Granted (in shares)	1,711,000
Vested (in shares)	(184,293)	0	0
Forfeited (in shares)	(174,000)
Ending balance (in shares)	2,111,000	758,000
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 18.73
Granted (in dollars per share)	25.51
Vested (in dollars per share)	18.79
Forfeited (in dollars per share)	14.82
Ending balance (in dollars per share)	$ 24.54	$ 18.73
Performance Stock Units (PSUs)
Number of Shares
Beginning balance (in shares)	750,000
Granted (in shares)	738,000
Vested (in shares)	(562,500)	0	0
Forfeited (in shares)	0
Ending balance (in shares)	925,000	750,000
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 6.57
Granted (in dollars per share)	43.22
Vested (in dollars per share)	6.57
Forfeited (in dollars per share)	0
Ending balance (in dollars per share)	$ 35.80	$ 6.57

Stockholders' Equity - Schedu_4

Stockholders' Equity - Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0%
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	3.50%	3.50%	1.50%
Risk-free interest rate, Maximum	4.70%	4.90%	4.20%
Expected volatility, Minimum	79%	78%
Expected volatility, Maximum	82%	82%
Expected volatility			85%
Expected dividend yield	0%	0%	0%
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	4.30%		2.20%
Risk-free interest rate, Maximum	5.40%		4.70%
Risk-free interest rate		5.40%
Expected volatility, Minimum	64%	68%	78%
Expected volatility, Maximum	82%	76%	79%
Expected term (in years)	6 months	6 months	6 months
Expected dividend yield	0%	0%	0%
Minimum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 18 days	5 years 6 months	5 years 6 months
Maximum | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days

Stockholders' Equity - Schedu_5

Stockholders' Equity - Schedule of Allocated Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 51,363	$ 38,222	$ 27,139
Research and development expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	26,120	22,007	15,222
General and administrative expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 25,243	$ 16,215	$ 11,917

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes Disclosure [Line Items]
Provision for income taxes	$ 0	$ 0	$ 0
Increase in the valuation allowance	98,800	61,300
Unrecognized tax benefits that would impact effective tax rate	0
Accruals for interest or penalties	0	$ 0
Federal
Income Taxes Disclosure [Line Items]
Net operating loss (NOL) carryforwards	249,400
Federal and state tax credit carryforwards	13,300
Federal | Orphan Drug Tax Credits
Income Taxes Disclosure [Line Items]
Federal and state tax credit carryforwards	58,000
State
Income Taxes Disclosure [Line Items]
Net operating loss (NOL) carryforwards	439,300
Federal and state tax credit carryforwards	$ 15,800

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Taxes Computed by Applying Statutory Federal Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income tax expense (benefit) at statutory rates	$ (67,683)	$ (44,566)	$ (36,539)
State income tax, net of federal benefit	(8,170)	(5,882)	(11,821)
Permanent items	66	51	1
Reserve for uncertain tax positions	10,572	5,993	2,583
Research and development tax credits	(42,279)	(24,054)	(9,983)
Valuation allowance	98,813	61,332	54,093
Stock-based compensation	(15,264)	3,331	492
Section 162(m) disallowance	20,604	291	1,077
Rate adjustment	2,766	2,526	(5)
Other	575	978	102
Income tax expense (benefit)	$ 0	$ 0	$ 0

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Net operating loss carryforwards	$ 83,371	$ 72,658
Section 174 R&E capitalization	103,288	52,085
Research and development tax credits	62,793	31,053
Deferred revenue	12,529	125
Accrued expenses	287	2,809
Intangibles and fixed assets	698	1,265
Lease liabilities	1,446	2,342
Stock-based compensation	8,418	12,451
Total deferred tax assets	272,830	174,788
Less valuation allowance	(271,636)	(172,822)
Net deferred tax assets	1,194	1,966
Deferred tax liabilities:
Right-of-use assets	(1,194)	(1,966)
Total deferred tax liabilities	(1,194)	(1,966)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Acti

Income Taxes - Schedule of Activity Related to Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Unrecognized Tax Benefits [Roll Forward]
Gross unrecognized tax benefits at the beginning of the year	$ 11,049	$ 4,771	$ 1,996
Increases related to current year positions	11,110	6,156	2,614
Increases related to prior year positions	0	122	161
Gross unrecognized tax benefits at the end of the year	$ 22,159	$ 11,049	$ 4,771

Segment Information (Details)

Segment Information (Details)	12 Months Ended
	Dec. 31, 2024 Segment
Segment Reporting [Abstract]
Number of reportable segments	1
Number of operating segments	1

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Collaboration revenue	$ 10,897	$ 9,560	$ 9,224
Operating expenses:
Total stock-based compensation expense	(51,363)	(38,222)	(27,139)
Depreciation	(2,776)	(2,101)	(1,387)
Total operating expenses	(389,833)	(245,158)	(188,137)
Other income	56,634	23,378	4,918
Net loss	(322,302)	(212,220)	(173,995)
Reportable Segment
Segment Reporting Information [Line Items]
Collaboration revenue	10,897	9,560	9,224
Operating expenses:
Research and development	(275,176)	(167,299)	(134,184)
General and administrative	(60,518)	(37,536)	(25,427)
Total operating expenses, excluding stock-based compensation and depreciation	(335,694)	(204,835)	(159,611)
Total stock-based compensation expense	(51,363)	(38,222)	(27,139)
Depreciation	(2,776)	(2,101)	(1,387)
Total operating expenses	(389,833)	(245,158)	(188,137)
Other income	56,634	23,378	4,918
Net loss	$ (322,302)	$ (212,220)	$ (173,995)

Segment Information - Schedul_2

Segment Information - Schedule of Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting [Abstract]
Cash, cash equivalents and marketable securities	$ 1,501,497	$ 595,351