Dyne Therapeutics (DYN) 10-Q 12 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 08, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	Dyne Therapeutics, Inc.
Entity Central Index Key	0001818794
Entity File Number	001-39509
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-4883909
Entity Address, Address Line One	1560 Trapelo Road
Entity Address, City or Town	Waltham
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02451
City Area Code	781
Local Phone Number	786-8230
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	DYN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		101,765,958

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 532,163	$ 121,626
Marketable securities	191,511	1,474
Prepaid expenses and other current assets	12,716	6,275
Total current assets	736,390	129,375
Property and equipment, net	4,896	4,780
Right-of-use assets	25,621	28,612
Restricted cash	1,937	2,315
Total assets	768,844	165,082
Current liabilities:
Accounts payable	6,157	22,936
Accrued expenses and other current liabilities	32,289	23,439
Lease liabilities	4,814	4,720
Total current liabilities	43,260	51,095
Lease liabilities, net of current portion	20,044	22,695
Total liabilities	63,304	73,790
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at September 30, 2024 and December 31, 2023	0	0
Common stock, $0.0001 par value; 200,000,000 shares authorized at September 30, 2024 and December 31, 2023; 100,753,378 and 61,468,743 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively	10	6
Additional paid-in capital	1,565,438	723,796
Accumulated other comprehensive loss	478	0
Accumulated deficit	(860,386)	(632,510)
Total stockholders’ equity	705,540	91,292
Total liabilities and stockholders’ equity	$ 768,844	$ 165,082

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	101,753,378	61,468,743
Common stock, shares outstanding	101,753,378	61,468,743

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses:
Research and development	$ 92,800	$ 55,251	$ 199,601	$ 151,918
General and administrative	12,859	7,022	47,177	22,556
Total operating expenses	105,659	62,273	246,778	174,474
Loss from operations	(105,659)	(62,273)	(246,778)	(174,474)
Other income (expense):
Interest income	9,276	2,189	19,330	5,890
Other income (expense), net	(742)	(126)	(428)	(715)
Total other income (expense), net	8,534	2,063	18,902	5,175
Net loss	$ (97,125)	$ (60,210)	$ (227,876)	$ (169,299)
Net loss per share - basic	$ (0.96)	$ (0.99)	$ (2.49)	$ (2.86)
Net loss per share - diluted	$ (0.96)	$ (0.99)	$ (2.49)	$ (2.86)
Weighted average common shares outstanding, basic	100,882,042	61,109,917	91,511,621	59,107,795
Weighted average common shares outstanding, diluted	100,882,042	61,109,917	91,511,621	59,107,795
Comprehensive loss:
Net Income (Loss)	$ (97,125)	$ (60,210)	$ (227,876)	$ (169,299)
Other comprehensive loss:
Unrealized (losses) gains on marketable securities, net	718	43	478	558
Comprehensive loss	$ (96,407)	$ (60,167)	$ (227,398)	$ (168,741)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Public Offering [Member]	Market Offering [Member]	Common Stock	Common Stock Public Offering [Member]	Common Stock Market Offering [Member]	Additional Paid-In Capital	Additional Paid-In Capital Public Offering [Member]	Additional Paid-In Capital Market Offering [Member]	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance at Dec. 31, 2022	$ 252,364			$ 6			$ 649,502			$ (571)	$ (396,573)
Beginning Balance, Shares at Dec. 31, 2022				55,636,505
Issuance of stock, net of issuance costs		$ 28,186						$ 28,186
Issuance of stock, net of issuance costs, Shares					2,335,150
Exercise of stock options	587						587
Exercise of stock options, Shares				232,292
Stock-based compensation	4,617						4,617
Vesting of restricted shares				101,533
Unrealized gains on marketable securities	368									368
Net Income (Loss)	(44,187)										(44,187)
Ending Balance at Mar. 31, 2023	241,935			$ 6			682,892			(203)	(440,760)
Ending Balance, Shares at Mar. 31, 2023				58,305,480
Beginning Balance at Dec. 31, 2022	252,364			$ 6			649,502			(571)	(396,573)
Beginning Balance, Shares at Dec. 31, 2022				55,636,505
Unrealized gains on marketable securities	558
Net Income (Loss)	(169,299)
Ending Balance at Sep. 30, 2023	152,038			$ 6			717,917			(13)	(565,872)
Ending Balance, Shares at Sep. 30, 2023				61,322,283
Beginning Balance at Mar. 31, 2023	241,935			$ 6			682,892			(203)	(440,760)
Beginning Balance, Shares at Mar. 31, 2023				58,305,480
Issuance of stock, net of issuance costs		24,184						24,184
Issuance of stock, net of issuance costs, Shares					2,173,913
Exercise of stock options	764						764
Exercise of stock options, Shares				432,626
Stock-based compensation	4,749						4,749
Vesting of restricted stock units				101,967
Unrealized gains on marketable securities	147									147
Net Income (Loss)	(64,902)										(64,902)
Ending Balance at Jun. 30, 2023	206,877			$ 6			712,589			(56)	(505,662)
Ending Balance, Shares at Jun. 30, 2023				61,013,986
Exercise of stock options	453						453
Exercise of stock options, Shares				125,461
Stock-based compensation	4,875						4,875
Vesting of restricted stock units				182,836
Unrealized gains on marketable securities	43									43
Net Income (Loss)	(60,210)										(60,210)
Ending Balance at Sep. 30, 2023	152,038			$ 6			717,917			(13)	(565,872)
Ending Balance, Shares at Sep. 30, 2023				61,322,283
Beginning Balance at Dec. 31, 2023	91,292			$ 6			723,796				(632,510)
Beginning Balance, Shares at Dec. 31, 2023				61,468,743
Issuance of stock, net of issuance costs		323,851	$ 97,871		$ 2	$ 1		323,849	$ 97,870
Issuance of stock, net of issuance costs, Shares					19,722,500	3,800,465
Exercise of stock options	10,916						10,916
Exercise of stock options, Shares				1,858,791
Stock-based compensation	19,906						19,906
Vesting of restricted stock units				239,150
Unrealized gains on marketable securities	(132)									(132)
Net Income (Loss)	(65,649)										(65,649)
Ending Balance at Mar. 31, 2024	478,055			$ 9			1,176,337			(132)	(698,159)
Ending Balance, Shares at Mar. 31, 2024				87,089,649
Beginning Balance at Dec. 31, 2023	$ 91,292			$ 6			723,796				(632,510)
Beginning Balance, Shares at Dec. 31, 2023				61,468,743
Exercise of stock options, Shares	3,812,308
Unrealized gains on marketable securities	$ 478
Net Income (Loss)	(227,876)
Ending Balance at Sep. 30, 2024	705,540			$ 10			1,565,438			478	(860,386)
Ending Balance, Shares at Sep. 30, 2024				101,753,378
Beginning Balance at Mar. 31, 2024	478,055			$ 9			1,176,337			(132)	(698,159)
Beginning Balance, Shares at Mar. 31, 2024				87,089,649
Issuance of stock, net of issuance costs		$ 351,329			$ 1			$ 351,328
Issuance of stock, net of issuance costs, Shares					12,075,000
Exercise of stock options	4,283						4,283
Exercise of stock options, Shares				564,904
Stock-based compensation	6,736						6,736
Vesting of restricted stock units				389,965
Unrealized gains on marketable securities	(108)									(108)
Net Income (Loss)	(65,102)										(65,102)
Ending Balance at Jun. 30, 2024	775,193			$ 10			1,538,684			(240)	(763,261)
Ending Balance, Shares at Jun. 30, 2024				100,119,518
Exercise of stock options	18,009						18,009
Exercise of stock options, Shares				1,388,613
Stock-based compensation	8,745						8,745
Vesting of restricted stock units				245,247
Unrealized gains on marketable securities	718									718
Net Income (Loss)	(97,125)										(97,125)
Ending Balance at Sep. 30, 2024	$ 705,540			$ 10			$ 1,565,438			$ 478	$ (860,386)
Ending Balance, Shares at Sep. 30, 2024				101,753,378

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - Common Stock - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023
Public Offering [Member]
Stock issuance costs	$ 23	$ 21.3
Market Offering [Member]
Stock issuance costs		$ 3.3	$ 0.8	$ 1

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net loss	$ (227,876)	$ (169,299)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	35,387	14,242
Depreciation and amortization expense	1,223	1,274
Non-cash lease expense	434	620
Accretion of premium on marketable securities	(2,768)	(908)
Loss (gain) on sale of marketable securities	(26)	23
Loss (gain) on disposal of property and equipment	(2)	118
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(6,442)	(781)
Accounts payable and other liabilities	(7,964)	1,559
Net cash used in operating activities	(208,034)	(153,152)
Cash flows from investing activities:
Purchases of property and equipment	(1,301)	(647)
Purchases of marketable securities	(264,729)	(44,262)
Maturities of marketable securities	76,215	100,195
Sales of marketable securities	1,749	1,829
Net cash (used in) provided by investing activities	(188,066)	57,115
Cash flows from financing activities:
Proceeds from issuance of common stock in public offering, net of issuance costs	675,180	0
Proceeds from issuance of common stock in at-the-market offering, net of issuance costs	97,871	52,370
Proceeds from exercise of stock options	33,208	1,805
Net cash provided by financing activities	806,259	54,175
Net increase (decrease) in cash, cash equivalents and restricted cash	410,159	(41,862)
Cash, cash equivalents and restricted cash, beginning of period	123,941	174,466
Cash, cash equivalents and restricted cash, end of period	534,100	132,604
Supplemental disclosures of cash flow information:
Purchase of property and equipment in accounts payable	$ 48	$ 27

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (97,125)	$ (65,102)	$ (65,649)	$ (60,210)	$ (64,902)	$ (44,187)	$ (227,876)	$ (169,299)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Item 5. Other Information. Director and Officer Trading Arrangements A portion of the compensation of our directors and officers (as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934, as amended, or the Exchange Act, is in the form of equity awards and, from time to time, directors and officers engage in open-market transactions with respect to the securities acquired pursuant to such equity awards or other securities of ours, including to satisfy tax withholding obligations when equity awards vest or are exercised, and for diversification or other personal reasons. Transactions in our securities by directors and officers are required to be made in accordance with our insider trading policy, which requires that the transactions be in accordance with applicable U.S. federal securities laws that prohibit trading while in possession of material nonpublic information. Rule 10b5-1 under the Exchange Act provides an affirmative defense that enables directors and officers to prearrange transactions in our securities in a manner that avoids concerns about initiating transactions while in possession of material nonpublic information. The following table describes, for the quarterly period covered by this report, each trading arrangement for the sale or purchase of our securities adopted or terminated by our directors and officers that is either (1) a contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c), which we refer to as a “Rule 10b5-1 trading arrangement” or (2) a “non-Rule 10b5-1 trading arrangement” (as defined in Item 408(c) of Regulation S-K): Name (Title) Action Taken (Date of Action) Type of Trading Arrangement Nature of Trading Arrangement Duration of Trading Arrangement Aggregate Number of Securities Susanna High ( Chief Operating Officer ) Termination ( October 1, 2024 ) Rule 10b5-1 trading arrangement Sale (1) (1) Doug Kerr ( Chief Medical Officer ) Adoption ( September 5, 2024 ) Durable Rule 10b5-1 trading arrangement for sell-to-cover transactions related to restricted stock units Sale Until final settlement of any covered RSU Indeterminable(2) Johanna Friedl-Naderer ( Chief Commercial Officer ) Adoption ( September 5, 2024 ) Durable Rule 10b5-1 trading arrangement for sell-to-cover transactions related to restricted stock units Sale Until final settlement of any covered RSU Indeterminable(2) (1) This trading plan had a scheduled expiration date of June 30, 2025 . The number of shares of the Company's common stock to be sold under the plan was up to 195,323 shares. (2) The number of shares subject to covered RSUs that will be sold to satisfy applicable tax withholding obligations upon vesting is unknown as the number will vary based on the extent to which vesting conditions are satisfied, the market price of the Company’s common stock at the time of settlement and the potential future grant of additional RSUs subject to this arrangement. This trading arrangement, which applies to RSUs whether vesting is based on the passage of time and/or the achievement of performance goals, provides for the automatic sale of shares that would otherwise be issuable on each settlement date of a covered RSU in an amount sufficient to satisfy the applicable withholding obligation, with the proceeds of the sale delivered to the Company in satisfaction of the applicable withholding obligation.
Susanna High [Member]
Trading Arrangements, by Individual
Name	Susanna High	[1]
Title	Chief Operating Officer	[1]
Rule 10b5-1 Arrangement Terminated	true	[1]
Termination Date	October 1, 2024	[1]
Expiration Date	June 30, 2025
Aggregate Available	195,323
Doug Kerr [Member]
Trading Arrangements, by Individual
Name	Doug Kerr	[2]
Title	Chief Medical Officer	[2]
Rule 10b5-1 Arrangement Adopted	true	[2]
Adoption Date	September 5, 2024	[2]
Johanna Friedl-Naderer [Member]
Trading Arrangements, by Individual
Name	Johanna Friedl-Naderer	[2]
Title	Chief Commercial Officer	[2]
Rule 10b5-1 Arrangement Adopted	true	[2]
Adoption Date	September 5, 2024	[2]
[1] This trading plan had a scheduled expiration date of June 30, 2025 . The number of shares of the Company's common stock to be sold under the plan was up to 195,323 shares. The number of shares subject to covered RSUs that will be sold to satisfy applicable tax withholding obligations upon vesting is unknown as the number will vary based on the extent to which vesting conditions are satisfied, the market price of the Company’s common stock at the time of settlement and the potential future grant of additional RSUs subject to this arrangement. This trading arrangement, which applies to RSUs whether vesting is based on the passage of time and/or the achievement of performance goals, provides for the automatic sale of shares that would otherwise be issuable on each settlement date of a covered RSU in an amount sufficient to satisfy the applicable withholding obligation, with the proceeds of the sale delivered to the Company in satisfaction of the applicable withholding obligation.

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Dyne Therapeutics, Inc. (the “Company”) is a clinical-stage muscle disease company focused on advancing innovative life-transforming therapeutics for people living with genetically driven diseases. The Company was incorporated in Delaware on December 1, 2017 and has a principal place of business in Waltham, Massachusetts. The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, risks of failure of preclinical studies and clinical trials, the need to obtain marketing approval for its product candidates, fluctuations in operating results, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes and the ability to secure additional capital to fund operations. Product candidates and programs currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization of a product. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The accompanying condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations with proceeds from the sales of equity securities. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the issuance of these condensed consolidated financial statements. To continue its development efforts, the Company will need to obtain substantial additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements in order to fund its research and development and ongoing operating expenses. The Company may not be able to obtain financing on acceptable terms, when needed or at all, and the Company may not be able to enter into collaborations, strategic alliances or licensing arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Any collaborations, strategic alliances or licensing arrangements may require the Company to relinquish rights to certain of its technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to the Company. If the Company is unable to obtain funding, the Company could be forced to delay, limit, reduce or eliminate some or all of its research and development programs, pipeline expansion or future commercialization efforts or grant rights to develop and market product candidates, which could adversely affect its business prospects. Although management will continue to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations when needed or at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accompanying financial statements have been prepared in conformity with generally accepted accounting principles (“GAAP”) in the United States of America. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The financial statements of the Company included herein have been prepared, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). The unaudited interim financial statements have been prepared on the same basis as audited annual financial statements, except certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. In the opinion of management, the interim financial information reflects all adjustments, all of which are of a normal and recurring nature, necessary for a fair representation of the results for the reported periods. Accordingly, these financial statements should be read in conjunction with the financial statements and notes thereto included in the Company’s annual report on Form 10-K filed with the SEC on March 5, 2024. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024, any other interim periods, or any future year or period. Fair value measurements Certain assets and liabilities are carried at fair value. 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—Unadjusted quoted prices in active markets that are accessible to the reporting entity at the measurement date for identical assets and liabilities. • Level 2—Inputs other than quoted prices in active markets for identical assets and liabilities that are observable either directly or indirectly for substantially the full term of the asset or liability. Level 2 inputs include the following: • quoted prices for similar assets and liabilities in active markets; • quoted prices for identical or similar assets or liabilities in markets that are not active; • observable inputs other than quoted prices that are used in the valuation of the asset or liabilities (e.g., interest rate and yield curve quotes at commonly quoted intervals); and • inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3—Unobservable inputs for the assets or liability (i.e., supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). Net loss per share Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: September 30, 2024 2023 Options to purchase common stock 7,743,732 9,085,392 Unvested restricted stock units 2,718,092 1,381,259 Total 10,461,824 10,466,651 Recently Issued Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued ASU 2023-07 , Segment Reporting (Topic 280). The amendments in this update expand segment disclosure requirements, including new segment disclosure requirements for entities with a single reportable segment among other disclosure requirements. This update is effective for the Company in the consolidated financial statements for the year ending December 31, 2024 , and interim periods beginning on January 1, 2025. The adoption of this standard only impacts disclosures and is not expected to have a material impact on the Company’s consolidated financial statements.

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	9 Months Ended
	Sep. 30, 2024
Restricted Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	3. Cash, Cash Equivalents and Restricted Cash Cash includes cash in readily available checking accounts and cash equivalents include money market funds that invest in U.S. treasury securities and all highly liquid investments maturing within 90 days from the date of purchase. Amounts included in restricted cash represent amounts pledged as collateral for letters of credit required for security deposits on the Company’s leased facilities. Cash, cash equivalents and restricted cash consisted of the following: September 30, December 31, (in thousands) 2024 2023 Cash and cash equivalents $ 532,163 $ 121,626 Restricted cash 1,937 2,315 Total $ 534,100 $ 123,941

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements The following tables set forth marketable securities for the periods presented: As of September 30, 2024 (in thousands) Amortized Unrealized Unrealized Total Commercial paper 31,269 38 — 31,307 Corporate debt securities 150,579 429 ( 5 ) 151,003 Certificates of deposit 9,185 16 — 9,201 Total $ 191,033 $ 483 $ ( 5 ) $ 191,511 As of December 31, 2023 (in thousands) Amortized Unrealized Unrealized Total Corporate debt securities 1,474 — — 1,474 Total $ 1,474 $ — $ — $ 1,474 The following tables set forth by level, within the fair value hierarchy (see Note 2), the assets carried at fair value on a recurring basis for the periods presented: Fair value measurements as of September 30, 2024 (in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 190,076 $ — $ — $ 190,076 Marketable securities Commercial paper — 31,307 — 31,307 Corporate debt securities — 151,003 — 151,003 Certificates of deposit — 9,201 — 9,201 Total $ 190,076 $ 191,511 $ — $ 381,587 Fair Value Measurements as of December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 66,179 $ — $ — $ 66,179 U.S. treasury notes 18,689 — — 18,689 Marketable securities Corporate debt securities — 1,474 — 1,474 Total $ 84,868 $ 1,474 $ — $ 86,342 The fair value of U.S. government treasury notes and money market funds were determined by the Company based on quoted market prices, which represent a Level 1 measurement within the fair value hierarchy. Certificates of deposit, commercial paper and corporate debt securities were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 2 measurement within the fair value hierarchy. There were no transfers between Level 1, Level 2, or Level 3 during the periods presented. The following table summarizes the scheduled maturity for the Company's marketable securities for the periods presented: (in thousands) September 30, 2024 Maturing in one year or less $ 155,951 Maturing after one year through two years 35,560 Maturing after two years — Total $ 191,511 Financial instruments not recorded at fair value The carrying values of cash, cash equivalents, accounts payable and accrued expenses that are reported on the balance sheets approximate their fair value due to the short-term nature of these assets and liabilities.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment consisted of the following: September 30, December 31, (in thousands) 2024 2023 Laboratory equipment $ 8,710 $ 7,546 Office and computer equipment 2,246 2,091 Construction in process 450 431 Property and equipment—at cost 11,406 10,068 Less accumulated depreciation and amortization ( 6,510 ) ( 5,288 ) Property and equipment—net $ 4,896 $ 4,780 Depreciation and amortization expense for the three and nine months ended September 30, 2024 was $ 0.4 million and $ 1.2 million, respectively. Depreciation and amortization expense for the three and nine months ended September 30, 2023 was $ 0.4 million and $ 1.3 million, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: September 30, December 31, (in thousands) 2024 2023 Payroll and benefits $ 11,310 $ 10,498 Consulting services 1,048 423 Legal services 551 397 Research and development 19,380 12,121 Total $ 32,289 $ 23,439

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stockholders' Equity	7. Stockholders' Equity Common Stock In November 2021, the Company entered into an Open Market Sale Agreement (the "Sales Agreement") with Jefferies LLC ("Jefferies") as the Company's sales agent, and filed a universal shelf registration statement on Form S-3 (the "2021 Shelf Registration Statement") that included a prospectus relating to the Sales Agreement and pursuant to which, from time to time, the Company could offer and sell shares of its common stock having an aggregate offering price of up to $ 150.0 million in an "at-the-market" offering. On January 4, 2024, the Company notified Jefferies that it was suspending and terminating the prospectus filed under the 2021 Shelf Registration Statement relating to the Sales Agreement for the Company's "at-the-market" offering program. On March 5, 2024, the Company filed a universal shelf registration statement on Form S-3 with the SEC, (the “2024 Shelf Registration Statement”) that included a prospectus relating to the Sales Agreement (the “2024 ATM Prospectus”). Under the 2024 Shelf Registration Statement, the Company may offer and sell debt securities, common stock, preferred stock, units and/or warrants from time to time at an indeterminate aggregate offering price in one or more offerings. Under the 2024 ATM Prospectus, in accordance with the Sales Agreement, the Company may offer and sell shares of its common stock having an aggregate offering price of up to $ 200.0 million in an “at-the-market” offering. During the nine months ended September 30, 2024 , the Company issued and sold an aggregate of 3,800,465 shares of common stock pursuant to the Sales Agreement for aggregate net proceeds of $ 97.9 million, after deducting fees and offering expenses payable by the Company. The Company sold such shares at a weighted average price of $ 26.86 per share. In January 2024, the Company completed a follow-on public offering, pursuant to which the Company issued and sold 19,722,500 shares of the Company’s common stock. The Company received net proceeds of $ 323.9 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. Forbion Capital Fund IV Cooperatief U.A. and related affiliated entities (collectively, “Forbion”) were a beneficial owner of more than 5.0 % of the Company's outstanding common stock as of the closing of the January 2024 offering. Two members of the Company's board of directors are partners at Forbion. In the January 2024 offering, the Company issued and sold 1,714,285 shares of common stock that Forbion and related affiliated entities purchased at the public offering price of $ 17.50 per share for aggregate gross proceeds of $ 30.0 million. The shares were purchased on the same terms as the other shares that were offered and sold in the offering. In May 2024, the Company completed a follow-on public offering, pursuant to which the Company issued and sold 12,075,000 shares of the Company's common stock. The Company received net proceeds of $ 351.3 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. 2020 Stock Incentive Plan In August 2020 the Company’s board of directors adopted and the Company’s stockholders approved the 2020 Stock Incentive Plan, (the "2020 Plan"), which became effective on September 16, 2020. The 2020 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards to employees, directors, consultants and advisors of the Company. The 2020 Plan is administered by the Company’s board of directors or by a committee appointed by the board of directors. Upon the effectiveness of the 2020 Plan, the Company ceased granting awards under the 2018 Stock Incentive Plan. As of September 30, 2024 , 4,213,838 shares remained available for future issuance under the 2020 Plan. 2024 Inducement Stock Incentive Plan In March 2024, the Company's board of directors adopted the 2024 Inducement Stock Incentive Plan (the "2024 Inducement Plan"). The 2024 Inducement Plan provides for the grant of nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards with respect to an aggregate of 900,000 shares of Common Stock (subject to adjustment as provided in the 2024 Inducement Plan). Awards under the 2024 Inducement Plan may only be granted to new employees who were not previously an employee or director of the Company or are commencing employment with the Company following a bona fide period of non-employment, in either case, as an inducement material to the individual’s entering into employment with the Company and in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). As of September 30, 2024 , 220,147 shares remained available for future issuance under the 2024 Inducement Plan. Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The fair value is determined based upon the quoted price of the Company’s common stock. The Company lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The assumptions that the Company used to determine the grant-date fair value of options granted were as follows: Nine Months Ended September 30, 2024 2023 Expected volatility 66 % 67 % Risk-free interest rate 3.46 % — 4.65 % 3.42 % — 4.47 % Expected term (in years) 6 6 Expected dividend yield — — Stock option activity A summary of the Company’s stock option activity and related information for the nine months ended September 30, 2024 is as follows: (in thousands, except share and per share data) Options Weighted Weighted Aggregate Outstanding as of January 1, 2024 9,914,719 $ 10.48 7.7 $ 38,732 Granted 2,129,193 31.25 Exercised ( 3,812,308 ) 8.71 Canceled ( 487,872 ) 12.31 Outstanding as of September 30, 2024 7,743,732 $ 16.95 7.2 $ 149,870 Options exercisable as of September 30, 2024 3,515,127 $ 11.61 6.1 $ 85,447 Options vested or expected to vest as of September 30, 2024 7,743,732 $ 16.95 7.2 $ 149,870 The intrinsic value of options exercised for the nine months ended September 30, 2024 and 2023 totaled $ 83.3 million and $ 8.0 million, respectively. The weighted-average grant date fair value of the options granted during the nine months ended September 30, 2024 and 2023 was $ 19.65 and $ 7.79 per share, respectively. As of September 30, 2024 there was $ 52.4 million of unrecognized compensation expense, which the Company expects to recognize over a weighted-average period of 2.8 years. In March 2024, the Company entered into separation and consulting agreements with its former chief executive officer resulting in the acceleration of vesting and modification of previously issued stock option awards. The acceleration of vesting and modification resulted in the recognition of $ 3.2 million of stock-based compensation expense for the nine months ended September 30, 2024, all of which was recorded in the first quarter of 2024. The expense was recorded within general and administrative expenses on the condensed consolidated statement of operations and comprehensive loss. Based upon the terms of the separation and consulting agreements, options to purchase 223,533 shares of common stock were forfeited in March 2024. In September 2024, the Company entered into a consulting agreement with its former chief business officer resulting in the modification of previously issued stock option awards. The modification resulted in the recognition of $ 0.6 million of stock-based compensation expense for the nine months ended September 30, 2024, all of which was recorded in the third quarter of 2024. The expense was recorded within general and administrative expenses on the condensed consolidated statement of operations and comprehensive loss. Based on the terms of the consulting agreement, options to purchase 95,587 shares of common stock were forfeited in September 2024. Restricted stock units A restricted stock unit (“RSU”) represents the right to receive one share of common stock upon vesting of the RSU. The Company grants RSUs with service conditions that vest in four equal annual installments provided that the employee remains employed with the Company, RSUs with service conditions that vest in sixteen equal quarterly installments provided that the employee remains employed with the Company and RSUs with performance-based vesting conditions. As of September 30, 2024 , there are no RSUs with performance-based vesting conditions outstanding. The fair value of each RSU is based on the closing price of the Company’s common stock on the date of grant. A summary of the Company’s RSU activity and related information for the nine months ended September 30, 2024 is as follows: Number of Shares Underlying RSUs Weighted Issued and unvested as of January 1, 2024 3,422,212 $ 11.50 Granted 394,554 34.32 Vested ( 874,362 ) 12.50 Forfeited ( 224,312 ) 11.78 Issued and unvested as of September 30, 2024 2,718,092 $ 14.47 As of September 30, 2024 , there was $ 33.4 million of unrecognized compensation costs ​​​​​​​related to unvested RSUs, which are expected to be recognized over a weighted-average period of 2.9 years. In March 2024, the Company entered into separation and consulting agreements with its former chief executive officer resulting in the acceleration of vesting and modification of previously issued restricted stock unit awards. The acceleration of vesting and modification resulted in the recognition of $ 10.5 million of stock-based compensation expense for the nine months ended September 30, 2024, all of which was recorded in the first quarter of 2024. The expense was recorded within general and administrative expenses on the condensed consolidated statement of operations and comprehensive loss. In September 2024, the Company entered into a consulting agreement with its former chief business officer resulting in the modification of previously issued restricted stock unit awards. The modification resulted in the recognition of $ 0.5 million of stock-based compensation expense for the nine months ended September 30, 2024, all of which was recorded in the third quarter of 2024. The expense was recorded within general and administrative expenses on the condensed consolidated statement of operations and comprehensive loss. Based upon the terms of the consulting agreement, 99,448 restricted stock units were forfeited in September, 2024. The Company recorded stock-based compensation expense in the following expense categories of its condensed consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2024 2023 2024 2023 Research and development $ 4,450 $ 2,868 $ 12,252 $ 8,202 General and administrative 4,295 2,007 23,135 6,040 Total $ 8,745 $ 4,875 $ 35,387 $ 14,242

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Fair Value Measurements	Fair value measurements Certain assets and liabilities are carried at fair value. 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—Unadjusted quoted prices in active markets that are accessible to the reporting entity at the measurement date for identical assets and liabilities. • Level 2—Inputs other than quoted prices in active markets for identical assets and liabilities that are observable either directly or indirectly for substantially the full term of the asset or liability. Level 2 inputs include the following: • quoted prices for similar assets and liabilities in active markets; • quoted prices for identical or similar assets or liabilities in markets that are not active; • observable inputs other than quoted prices that are used in the valuation of the asset or liabilities (e.g., interest rate and yield curve quotes at commonly quoted intervals); and • inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3—Unobservable inputs for the assets or liability (i.e., supported by little or no market activity). Level 3 inputs include management’s own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk).
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 shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: September 30, 2024 2023 Options to purchase common stock 7,743,732 9,085,392 Unvested restricted stock units 2,718,092 1,381,259 Total 10,461,824 10,466,651
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued ASU 2023-07 , Segment Reporting (Topic 280). The amendments in this update expand segment disclosure requirements, including new segment disclosure requirements for entities with a single reportable segment among other disclosure requirements. This update is effective for the Company in the consolidated financial statements for the year ending December 31, 2024 , and interim periods beginning on January 1, 2025. The adoption of this standard only impacts disclosures and is not expected to have a material impact on the Company’s consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Potential Dilutive Securities Excluded From Calculation Of Net Loss Per Share	The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: September 30, 2024 2023 Options to purchase common stock 7,743,732 9,085,392 Unvested restricted stock units 2,718,092 1,381,259 Total 10,461,824 10,466,651

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2024
Restricted Cash and Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents and restricted cash consisted of the following: September 30, December 31, (in thousands) 2024 2023 Cash and cash equivalents $ 532,163 $ 121,626 Restricted cash 1,937 2,315 Total $ 534,100 $ 123,941

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Summary of Marketable Securities by Security Type	The following tables set forth marketable securities for the periods presented: As of September 30, 2024 (in thousands) Amortized Unrealized Unrealized Total Commercial paper 31,269 38 — 31,307 Corporate debt securities 150,579 429 ( 5 ) 151,003 Certificates of deposit 9,185 16 — 9,201 Total $ 191,033 $ 483 $ ( 5 ) $ 191,511 As of December 31, 2023 (in thousands) Amortized Unrealized Unrealized Total Corporate debt securities 1,474 — — 1,474 Total $ 1,474 $ — $ — $ 1,474
Summary of Assets Carried at Fair Value on Recurring Basis	The following tables set forth by level, within the fair value hierarchy (see Note 2), the assets carried at fair value on a recurring basis for the periods presented: Fair value measurements as of September 30, 2024 (in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 190,076 $ — $ — $ 190,076 Marketable securities Commercial paper — 31,307 — 31,307 Corporate debt securities — 151,003 — 151,003 Certificates of deposit — 9,201 — 9,201 Total $ 190,076 $ 191,511 $ — $ 381,587 Fair Value Measurements as of December 31, 2023 (in thousands) Level 1 Level 2 Level 3 Total Assets: Cash equivalents Money market funds $ 66,179 $ — $ — $ 66,179 U.S. treasury notes 18,689 — — 18,689 Marketable securities Corporate debt securities — 1,474 — 1,474 Total $ 84,868 $ 1,474 $ — $ 86,342
Summary of Scheduled Maturity for Marketable Securities	The following table summarizes the scheduled maturity for the Company's marketable securities for the periods presented: (in thousands) September 30, 2024 Maturing in one year or less $ 155,951 Maturing after one year through two years 35,560 Maturing after two years — Total $ 191,511

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consisted of the following: September 30, December 31, (in thousands) 2024 2023 Laboratory equipment $ 8,710 $ 7,546 Office and computer equipment 2,246 2,091 Construction in process 450 431 Property and equipment—at cost 11,406 10,068 Less accumulated depreciation and amortization ( 6,510 ) ( 5,288 ) Property and equipment—net $ 4,896 $ 4,780

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following: September 30, December 31, (in thousands) 2024 2023 Payroll and benefits $ 11,310 $ 10,498 Consulting services 1,048 423 Legal services 551 397 Research and development 19,380 12,121 Total $ 32,289 $ 23,439

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted	The assumptions that the Company used to determine the grant-date fair value of options granted were as follows: Nine Months Ended September 30, 2024 2023 Expected volatility 66 % 67 % Risk-free interest rate 3.46 % — 4.65 % 3.42 % — 4.47 % Expected term (in years) 6 6 Expected dividend yield — —
Summary of Stock Option Activity and Related Information	A summary of the Company’s stock option activity and related information for the nine months ended September 30, 2024 is as follows: (in thousands, except share and per share data) Options Weighted Weighted Aggregate Outstanding as of January 1, 2024 9,914,719 $ 10.48 7.7 $ 38,732 Granted 2,129,193 31.25 Exercised ( 3,812,308 ) 8.71 Canceled ( 487,872 ) 12.31 Outstanding as of September 30, 2024 7,743,732 $ 16.95 7.2 $ 149,870 Options exercisable as of September 30, 2024 3,515,127 $ 11.61 6.1 $ 85,447 Options vested or expected to vest as of September 30, 2024 7,743,732 $ 16.95 7.2 $ 149,870
Summary of RSU Activity	A summary of the Company’s RSU activity and related information for the nine months ended September 30, 2024 is as follows: Number of Shares Underlying RSUs Weighted Issued and unvested as of January 1, 2024 3,422,212 $ 11.50 Granted 394,554 34.32 Vested ( 874,362 ) 12.50 Forfeited ( 224,312 ) 11.78 Issued and unvested as of September 30, 2024 2,718,092 $ 14.47
Summary of Stock-based Compensation Expense	The Company recorded stock-based compensation expense in the following expense categories of its condensed consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2024 2023 2024 2023 Research and development $ 4,450 $ 2,868 $ 12,252 $ 8,202 General and administrative 4,295 2,007 23,135 6,040 Total $ 8,745 $ 4,875 $ 35,387 $ 14,242

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024
Nature Of Business And Basis Of Presentation [Line Items]
Entity incorporation date	Dec. 01, 2017

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Net loss per share (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Total	$ 10,461,824	$ 10,466,651
Options to purchase common stock
Total	7,743,732	9,085,392
Unvested restricted common stock
Total	$ 2,718,092	$ 1,381,259

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Additional Information) (Details)	Nov. 30, 2023
Accounting Policies [Abstract]
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Dec. 31, 2024
Change in Accounting Principle, Accounting Standards Update, Adopted	true

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalent maturity period	90 days

Cash, Cash Equivalents and Re_4

Cash, Cash Equivalents and Restricted Cash - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Restricted Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 532,163	$ 121,626
Restricted cash	1,937	2,315
Total	$ 534,100	$ 123,941

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Marketable Securities by Security Type (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 191,033	$ 1,474
Unrealized Gains	483	0
Unrealized Losses	(5)	0
Total	191,511	1,474
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	31,269
Unrealized Gains	38
Unrealized Losses	0
Total	31,307
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	150,579	1,474
Unrealized Gains	429	0
Unrealized Losses	(5)	0
Total	151,003	$ 1,474
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	9,185
Unrealized Gains	16
Unrealized Losses	0
Total	$ 9,201

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Assets Carried at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Total	$ 381,587	$ 86,342
Level 1
Assets:
Total	190,076	84,868
Level 2
Assets:
Total	191,511	1,474
Cash Equivalents | Money Market Funds
Assets:
Total	190,076	66,179
Cash Equivalents | U.S. treasury notes
Assets:
Total		18,689
Cash Equivalents | Level 1 | Money Market Funds
Assets:
Total	190,076	66,179
Cash Equivalents | Level 1 | U.S. treasury notes
Assets:
Total		18,689
Marketable Securities | Commercial Paper
Assets:
Total	31,307
Marketable Securities | Corporate Debt Securities
Assets:
Total	151,003	1,474
Marketable Securities | Certificates of Deposit
Assets:
Total	9,201
Marketable Securities | Level 1 | Commercial Paper
Assets:
Total	0
Marketable Securities | Level 2
Assets:
Total	31,307
Marketable Securities | Level 2 | Corporate Debt Securities
Assets:
Total	151,003	$ 1,474
Marketable Securities | Level 2 | Certificates of Deposit
Assets:
Total	$ 9,201

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair value assets, transfers among level 1, level 2 or level 3	$ 0	$ 0

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Scheduled Maturity for Marketable Securities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Fair Value Disclosures [Abstract]
Maturing in one year or less	$ 155,951
Maturing after one year through two years	35,560
Maturing after two years	0
Total	$ 191,511

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment—at cost	$ 11,406	$ 10,068
Less accumulated depreciation and amortization	(6,510)	(5,288)
Property and equipment—net	4,896	4,780
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment—at cost	8,710	7,546
Office and Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment—at cost	2,246	2,091
Construction in Process
Property Plant And Equipment [Line Items]
Property and equipment—at cost	$ 450	$ 431

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 400	$ 400	$ 1,223	$ 1,274

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Payroll and benefits	$ 11,310	$ 10,498
Consulting services	1,048	423
Legal services	551	397
Research and development	19,380	12,121
Total	$ 32,289	$ 23,439

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended			9 Months Ended
	Mar. 05, 2024 USD ($)	May 31, 2024 USD ($) shares	Jan. 31, 2024 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Director Installment $ / shares shares	Sep. 30, 2023 USD ($) $ / shares	Dec. 31, 2023 shares	Nov. 30, 2021 USD ($)
Stock based compensation expense reversal
Members of the Company's board of directors | Director							2
Common stock, shares issued | shares				101,753,378			101,753,378		61,468,743
Net proceeds from issuance of common stock							$ 97,871	$ 52,370
Weighted-average grant date fair value of options granted | $ / shares							$ 19.65	$ 7.79
Stock-based compensation expense				$ 8,745		$ 4,875	$ 35,387	$ 14,242
Intrinsic value of options exercised							$ 83,300	$ 8,000
Common Stock [Member]
Stock based compensation expense reversal
Common stock, shares issued | shares		12,075,000	19,722,500	3,800,465			3,800,465
Net proceeds from issuance of common stock		$ 351,300	$ 323,900				$ 97,900
Sale price per share | $ / shares				$ 26.86			$ 26.86
Common Stock [Member] | Forbion and related affiliated entities
Stock based compensation expense reversal
Common stock, shares issued | shares			1,714,285
Sale price per share | $ / shares			$ 17.5
Aggregate gross proceeds			$ 30,000
Forbion [Member]
Stock based compensation expense reversal
Subsidiary, Ownership Percentage, Noncontrolling Owner				5%			5%
Stock Option
Stock based compensation expense reversal
Unrecognized compensation expense				$ 52,400			$ 52,400
Unrecognized share based compensation expense, recognition period							2 years 9 months 18 days
Stock-based compensation expense					$ 3,200		$ 600
Stock Option | Separation and Consulting Agreements [Member]
Stock based compensation expense reversal
Stock option awards, forfeited | shares					223,533		95,587
Restricted Stock Units ("RSUs")
Stock based compensation expense reversal
Unrecognized compensation expense				$ 33,400			$ 33,400
Unrecognized share based compensation expense, recognition period							2 years 10 months 24 days
Stock-based compensation expense					$ 10,500		$ 500
Number of share of common stock receivable upon vesting | shares							1
Restricted Stock Units ("RSUs") | Separation and Consulting Agreements [Member]
Stock based compensation expense reversal
Stock option awards, forfeited | shares							99,448
2024 ATM Prospectus | Common Stock [Member]
Stock based compensation expense reversal
Sale of Stock, Consideration Received Per Transaction	$ 200,000
Market Offering [Member] | Common Stock [Member]
Stock based compensation expense reversal
Common stock aggregate offer price										$ 150,000
2020 Plan
Stock based compensation expense reversal
Number of shares available for future issuance | shares				4,213,838			4,213,838
2020 Plan | Restricted Stock Units ("RSUs")
Stock based compensation expense reversal
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights							The Company grants RSUs with service conditions that vest in four equal annual installments provided that the employee remains employed with the Company, RSUs with service conditions that vest in sixteen equal quarterly installments provided that the employee remains employed with the Company and RSUs with performance-based vesting conditions. As of September 30, 2024, there are no RSUs with performance-based vesting conditions outstanding.
Share-based Compensation Arrangement By Share-based Payment Award Grant Service Conditions to Vest Number of Annual Installments | Installment							4
2024Plan
Stock based compensation expense reversal
Number of shares available for future issuance | shares				220,147			220,147
2024Plan | Common Stock [Member]
Stock based compensation expense reversal
Number of shares granted | shares							900,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Assumptions Used to Determine Grant-Date Fair Value of Options Granted (Details)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Expected volatility	66%	67%
Risk-free interest rate, minimum	3.46%	3.42%
Risk-free interest rate, maximum	4.65%	4.47%
Expected term (in years)	6 years	6 years

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Activity and Related Information (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Options
Outstanding, beginning of period | shares	9,914,719
Granted | shares	2,129,193
Exercised | shares	(3,812,308)
Canceled | shares	(487,872)
Outstanding, end of period | shares	7,743,732	9,914,719
Options exercisable as of September 30, 2024 | shares	3,515,127
Options vested or expected to vest as of September 30, 2024 | shares	7,743,732
Weighted Average Exercise Price
Outstanding, beginning of period | $ / shares	$ 10.48
Granted | $ / shares	31.25
Exercised | $ / shares	8.71
Canceled | $ / shares	12.31
Outstanding, end of period | $ / shares	16.95	$ 10.48
Options exercisable as of September 30, 2024 | $ / shares	11.61
Options vested or expected to vest as of September 30, 2024 | $ / shares	$ 16.95
Weighted Average Remaining Life (in years)
Outstanding	7 years 2 months 12 days	7 years 8 months 12 days
Options exercisable as of September 30, 2024	6 years 1 month 6 days
Options vested or expected to vest as of September 30, 2024	7 years 2 months 12 days
Aggregate Intrinsic Value
Outstanding | $	$ 149,870	$ 38,732
Options exercisable as of September 30, 2024 | $	85,447
Options vested or expected to vest as of September 30, 2024 | $	$ 149,870

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of RSU Activity (Details) - Restricted Stock Units ("RSUs") - 2020 Plan	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Number of Shares Underlying RSUs
Issued and unvested as of January 1, 2024 | shares	3,422,212
Granted | shares	394,554
Vested | shares	(874,362)
Forfeited | shares	(224,312)
Issued and unvested as of September 30, 2024 | shares	2,718,092
Weighted Average Grant Date Fair Value
Issued and unvested as of January 1, 2024 | $ / shares	$ 11.5
Granted | $ / shares	34.32
Vested | $ / shares	12.5
Forfeited | $ / shares	11.78
Issued and unvested as of September 30, 2024 | $ / shares	$ 14.47

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,745	$ 4,875	$ 35,387	$ 14,242
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,450	2,868	12,252	8,202
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 4,295	$ 2,007	$ 23,135	$ 6,040