Neurogene (NGNE) 10-K 18 Mar 24 2023 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2023	Mar. 13, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36327
Entity Registrant Name	Neurogene Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-0542593
Entity Address, Address Line One	535 W 24th St.
Entity Address, Address Line Two	5th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10011
City Area Code	855
Local Phone Number	508-3568
Title of 12(b) Security	Common stock, par value $0.000001 per share
Trading Symbol	NGNE
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 33,350,835
Entity Common Stock, Shares Outstanding		12,852,985
Documents Incorporated by Reference	The information required by Part III of this Report, to the extent not set forth herein, is incorporated by reference from the registrant’s definitive proxy statement relating to the Annual Meeting of Stockholders to be held in 2024, which shall be filed with the Securities and Exchange Commission within 120 days after the end of the fiscal year to which this Report relates (the “2024 Proxy Statement”).
Entity Central Index Key	0001404644
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	Deloitte & Touche LLP	Ernst & Young LLP
Auditor Location	Seattle, WA	Stamford, Connecticut
Auditor Firm ID	34	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 148,210	$ 82,021
Short-term investments	48,947	0
Prepaid expenses and other current assets	3,191	2,698
Total current assets	200,348	84,719
Property and equipment, net	17,174	20,115
Operating lease right-of-use assets	3,681	4,344
Finance lease right-of-use assets	98	87
Restricted cash	508	0
Other non-current assets	764	0
Total assets	222,573	109,265
Current liabilities:
Accounts payable	2,596	625
Accrued expenses and other current liabilities	17,495	5,324
Operating lease liabilities, current	2,559	678
Finance lease liabilities, current	42	24
Lease contingent value rights liability, current	281	0
Total current liabilities	22,973	6,651
Operating lease liabilities, non-current	12,302	3,921
Finance lease liabilities, non-current	65	66
Lease contingent value rights liability, non-current	1,006	0
Other liabilities	203	0
Total liabilities	36,549	10,638
Commitments and contingencies (Note 10)
Convertible preferred stock:
Total convertible preferred stock	0	244,366
Stockholders' equity (deficit)
Preferred stock, $0.000001 par value; 50,000,000 and 0 shares authorized as of December 31, 2023 and 2022, respectively; 0 shares issued and outstanding as of December 31, 2023 and 2022, respectively	0	0
Common stock, value, issued	0	0
Additional paid-in capital	373,178	5,098
Accumulated deficit	(187,154)	(150,837)
Total stockholders' equity (deficit)	186,024	(145,739)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	222,573	109,265
Series A-1 Convertible Preferred Stock
Convertible preferred stock:
Total convertible preferred stock	0	34,414
Series A-2 Convertible Preferred Stock
Convertible preferred stock:
Total convertible preferred stock	0	28,675
Series B Convertible Preferred Stock
Convertible preferred stock:
Total convertible preferred stock	0	181,277
Class A Common Stock
Stockholders' equity (deficit)
Common stock, value, issued	0	0
Class B Common Stock
Stockholders' equity (deficit)
Common stock, value, issued	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Preferred stock, par or stated value per share (in dollars per share)	$ 0.000001	$ 0.000001
Preferred stock, shares authorized (in shares)	50,000,000	0
Preferred Stock, shares, issued (in shares)	0	0
Preferred Stock, shares, outstanding (in shares)	0	0
Common stock, par or stated value per share (in dollars per share)	$ 0.000001	$ 0.000001
Common stock, shares authorized (in shares)	450,000,000	0
Common stock, shares, issued (in shares)	12,823,665	0
Common stock, shares, outstanding (in shares)	12,823,665	0
Series A-1 Convertible Preferred Stock
Temporary equity, par or stated value per share (in dollars per share)	$ 0.0001	$ 0.0001
Temporary equity, shares authorized (in shares)	0	18,604,653
Temporary equity, shares issued (in shares)	0	18,604,653
Temporary equity, shares outstanding (in shares)	0	18,604,653
Temporary equity, liquidation preference		$ 40,000
Series A-2 Convertible Preferred Stock
Temporary equity, par or stated value per share (in dollars per share)	$ 0.0001	$ 0.0001
Temporary equity, shares authorized (in shares)	0	13,291,208
Temporary equity, shares issued (in shares)	0	13,291,208
Temporary equity, shares outstanding (in shares)	0	13,291,208
Temporary equity, liquidation preference		$ 28,675
Series B Convertible Preferred Stock
Temporary equity, par or stated value per share (in dollars per share)	$ 0.0001	$ 0.0001
Temporary equity, shares authorized (in shares)	0	88,114,739
Temporary equity, shares issued (in shares)	0	74,405,719
Temporary equity, shares outstanding (in shares)	0	74,405,719
Temporary equity, liquidation preference		$ 181,550
Class A Common Stock
Common stock, par or stated value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	0	126,000,000
Common stock, shares, issued (in shares)	0	428,334
Common stock, shares, outstanding (in shares)	0	428,334
Class B Common Stock
Common stock, par or stated value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	0	120,010,600
Common stock, shares, issued (in shares)	0	0
Common stock, shares, outstanding (in shares)	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Operating expenses:
Research and development		$ 44,394	$ 47,505
General and administrative		11,189	9,012
Total operating expenses		55,583	56,517
Loss from operations		(55,583)	(56,517)
Other income (expense):
Interest income		2,951	1,337
Interest expense		(12)	(2)
Fair value allocated to bargain purchase gain		16,355	0
Other expense		(28)	(7)
Net loss		$ (36,317)	(55,189)
Class A Common Stock
Other income (expense):
Net loss			$ (55,189)
Earnings Per Share [Abstract]
Net income (loss) per share, basic (in dollars per share)	[1]		$ (139.88)
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]		394,533
Net income (loss) per share, diluted (in dollars per share)	[1]		$ (139.88)
Weighted-average shares outstanding used in computing net income (loss) per share, diluted (in shares)	[1]		394,533
Class B Common Stock
Other income (expense):
Net loss			$ 0
Earnings Per Share [Abstract]
Net income (loss) per share, basic (in dollars per share)	[1]		$ 0
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]		0
Net income (loss) per share, diluted (in dollars per share)	[1]		$ 0
Weighted-average shares outstanding used in computing net income (loss) per share, diluted (in shares)	[1]		0
[1] On December 18, 2023, the Company completed its reverse merger, which among other things, resulted in Neurogene OpCo merging with and into a wholly owned subsidiary of Neoleukin Therapeutics, Inc. As the earnings per share information for the pre-merger period is not comparable to the earnings per share information for the post-merger period, the earnings per share information is being presented separately for these periods. See Note 3, Net Income (Loss) Per share , for additional information. (a) Presents information for the pre-merger period for Class A common stock. The pre-merger period is January 1, 2023 through December 17, 2023 for the year ended December 31, 2023 and the full fiscal year ended December 31, 2022. (b) Presents information for the pre-merger period for Class B common stock. The pre-merger period is January 1, 2023 through December 17, 2023 for the year ended December 31, 2023 and the full fiscal year ended December 31, 2022. (c) Presents information for the post-merger period for common stock. The post-merger period is December 18, 2023 through December 31, 2023.

Consolidated Statements of Chan

Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders’ Deficit - USD ($) $ in Thousands	Total	Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger	Series A-1 Convertible Preferred Stock	Series A-2 Convertible Preferred Stock	Series B Convertible Preferred Stock	Class A Common Stock	Class B Common Stock	Preferred Stock	Common Stock	Common Stock Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger	Common Stock Conversion of Class A common stock into common stock and related change in par value	Common Stock Class A Common Stock	Common Stock Class A Common Stock Conversion of Class A common stock into common stock and related change in par value	Common Stock Class B Common Stock	Additional Paid- In Capital	Additional Paid- In Capital Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021			18,604,653	13,291,208	47,131,133
Beginning balance at Dec. 31, 2021			$ 34,414	$ 28,675	$ 114,818
Increase (Decrease) in Temporary Equity [Roll Forward]
Series B convertible preferred stock, net of offering costs (in shares)					27,274,586
Series B convertible preferred stock, net of $91 offering costs					$ 66,459
Ending balance at Dec. 31, 2022	$ 244,366		$ 34,414	$ 28,675	$ 181,277
Ending balance (in shares) at Dec. 31, 2022			18,604,653	13,291,208	74,405,719
Beginning balance (in shares) at Dec. 31, 2021								0
Beginning balance (in shares) at Dec. 31, 2021									0			419,783		0
Beginning balance at Dec. 31, 2021	(91,875)							$ 0	$ 0			$ 0		$ 0	$ 3,773		$ (95,648)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	1,252
Class A common stock issued upon exercise of stock options (in shares)												8,551
Class A common stock issued upon exercise of stock options	73
Net loss	(55,189)					$ (55,189)	$ 0
Ending balance at Dec. 31, 2022	$ (145,739)							$ 0	$ 0			$ 0		$ 0	5,098		(150,837)
Ending balance (in shares) at Dec. 31, 2022	0					428,334	0		0			428,334		0
Ending balance (in shares) at Dec. 31, 2022	0							0
Increase (Decrease) in Temporary Equity [Roll Forward]
Additional convertible preferred stock issued in conjunction with anti-dilution adjustment (in shares)			1,890,302	1,350,436	10,264,533
Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger (in shares)			(20,494,955)	(14,641,644)	(84,670,252)
Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger			$ (34,414)	$ (28,675)	$ (181,277)
Ending balance at Dec. 31, 2023	$ 0		$ 0	$ 0	$ 0
Ending balance (in shares) at Dec. 31, 2023			0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 1,418														1,418
Class A common stock issued upon exercise of stock options (in shares)	20,348											20,348
Class A common stock issued upon exercise of stock options	$ 168														168
Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger (in shares)										7,231,747	(3,240,888)		3,240,888
Conversion of convertible preferred stock into common stock and pre-funded warrants in connection with the reverse merger		$ 244,366														$ 244,366
Issuance of Class A common stock and pre-funded warrants in the pre-closing financing, net of $6,946 offering costs (in shares)												2,792,206
Issuance of Class A common stock and pre-funded warrants in the pre-closing financing, net of $6,946 offering costs	88,056														88,056
Transactions costs associated with the reverse merger	(4,140)														(4,140)
Issuance of common stock and pre-funded warrants to former stockholders of Neoleukin Therapeutics, Inc. in connection with the reverse merger (in shares)									2,351,030
Issuance of common stock and pre-funded warrants to former stockholders of Neoleukin Therapeutics, Inc. in connection with the reverse merger	38,212														38,212
Net loss	(36,317)																(36,317)
Ending balance at Dec. 31, 2023	$ 186,024							$ 0	$ 0			$ 0		$ 0	373,178		(187,154)
Ending balance (in shares) at Dec. 31, 2023	12,823,665					0	0		12,823,665			0		0
Ending balance (in shares) at Dec. 31, 2023	0							0
Beginning balance (in shares) at Dec. 31, 2022			18,604,653	13,291,208	74,405,719
Beginning balance at Dec. 31, 2022	$ 244,366		$ 34,414	$ 28,675	$ 181,277
Beginning balance (in shares) at Dec. 31, 2022	0							0
Beginning balance (in shares) at Dec. 31, 2022	0					428,334	0		0			428,334		0
Beginning balance at Dec. 31, 2022	$ (145,739)							$ 0	$ 0			$ 0		$ 0	5,098		(150,837)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss						$ (49,971)	$ 0
Ending balance (in shares) at Dec. 18, 2023						12,823,665
Ending balance at Dec. 31, 2023	0		$ 0	$ 0	$ 0
Ending balance (in shares) at Dec. 31, 2023			0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	13,654
Ending balance at Dec. 31, 2023	$ 186,024							$ 0	$ 0			$ 0		$ 0	$ 373,178		$ (187,154)
Ending balance (in shares) at Dec. 31, 2023	12,823,665					0	0		12,823,665			0		0
Ending balance (in shares) at Dec. 31, 2023	0							0

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders’ Deficit (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Offering costs	$ 6,946	$ 91

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows used in operating activities:
Net income (loss)	$ (36,317)	$ (55,189)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	1,418	1,252
Fair value allocated to bargain purchase gain	(16,355)	0
Depreciation and amortization of property and equipment	3,262	3,196
Non-cash operating lease expense	663	608
Amortization of finance lease right-of-use assets	35	4
Amortization and accretion of premiums/discounts on held-to-maturity investments	(105)	0
Changes in assets and liabilities:
Prepaid expenses and other current assets	326	716
Other assets	(764)	0
Accounts payable	667	(3,607)
Accrued expenses and other current liabilities	(3,574)	806
Operating lease liabilities	(678)	(610)
Net cash used in operating activities	(51,422)	(52,824)
Cash flows used in investing activities:
Purchases of property and equipment	(321)	(2,230)
Cash and restricted cash acquired from reverse merger transaction	22,243	0
Reverse merger transaction costs paid	(1,285)	0
Proceeds from maturities of held-to-maturity investments	5,000	0
Net cash used in investing activities	25,637	(2,230)
Cash flows provided by financing activities:
Proceeds from pre-closing financing, net of offering costs paid	92,343	0
Proceeds from issuance of Series B convertible preferred stock, net of offering costs paid	0	66,459
Proceeds from the issuance of common stock upon exercise of options	168	73
Principal payments on finance leases	(29)	(1)
Net cash provided by financing activities	92,482	66,531
Net increase in cash, cash equivalents and restricted cash	66,697	11,477
Cash, cash equivalents and restricted cash at beginning of year	82,021	70,544
Cash, cash equivalents and restricted cash at end of year	148,718	82,021
Supplemental disclosure of non-cash investing and financing activities:
Additions to finance lease right of use assets from new finance lease liabilities	46	91
Operating lease liabilities assumed in connection with the reverse merger	10,940	0
Contingent consideration liability assumed in the reverse merger	1,287	0
Other liabilities assumed in the reverse merger	10,110	0
Assets acquired in the reverse merger including $53.9 million in short-term investments and $0.8 million in other monetary assets	54,661	0
Issuance of common stock and pre-funded warrants to former stockholders of Neoleukin Therapeutics, Inc. in connection with the reverse merger	38,212	0
Offering costs in connection with pre-closing financing included in accounts payable and accrued expenses	4,287	0
Transaction costs related to reverse merger included in accounts payable and accrued expenses	2,855	0
Conversion of preferred stock into common stock in connection with reverse merger	244,366	0
Supplemental cash flow information:
Cash paid for interest	$ 12	$ 2

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Statement of Cash Flows [Abstract]
Short term investments	$ 53.9
Other assets	$ 0.8

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Neurogene Inc. (formerly known as Neoleukin Therapeutics, Inc.) (the “Company” or “Neurogene”) is a clinical stage biotechnology company that is a result of the reverse merger discussed below. Pre-merger Neurogene Inc. was incorporated as a limited liability company in Delaware on January 26, 2018 and converted into a corporation on July 3, 2018, and has a principal place of business in New York, NY. The Company was formed to harness the power of gene therapy, combined with its EXACT gene regulation technology, to turn today’s complex devastating neurological diseases into treatable conditions. The Company’s first clinical-stage program to utilize the EXACT technology is NGN-401, which is under development for the treatment of Rett syndrome. In addition to NGN-401, Neurogene is also pursuing a conventional gene therapy program in an ongoing Phase 1/2 clinical trial of NGN-101 for the treatment of CLN5 Batten disease. Since beginning operations, the Company has devoted substantially all its efforts to research and development, recruiting management and technical staff, administration, and raising capital. Reverse Merger and Pre-Closing Financing On July 18, 2023, Neoleukin Therapeutics, Inc. entered into an Agreement and Plan of Merger (the “Merger Agreement”) with one of its wholly owned subsidiaries (“Merger Sub”) and Neurogene Inc. (“Neurogene OpCo”). Pursuant to the terms of the Merger Agreement, upon closing on December 18, 2023 (the “Closing”), Merger Sub merged with and into Neurogene OpCo, with Neurogene OpCo continuing as a wholly owned subsidiary of the Company and the surviving corporation of the merger (referred to herein as the “reverse merger”). At the time of Closing (or immediately prior to, where indicated), the following also occurred: • The Company changed its name from “Neoleukin Therapeutics, Inc.” to “Neurogene Inc.” and is referred to herein as the “Company.” Unless the context otherwise requires, references to “Neoleukin Therapeutics, Inc.” or “Neoleukin” refer to the Company prior to Closing. • Immediately prior to Closing, Neoleukin effected a 1-for-4 reverse stock split (the “Reverse Stock Split”). Unless noted otherwise, all references herein to share and per share amounts reflect the Reverse Stock Split. • All of the then outstanding shares of Neurogene OpCo Class A common stock were converted into 3,240,888 shares of the Company’s common stock, based on an exchange ratio of approximately 0.0756 (the “Exchange Ratio”). • All of the then outstanding shares of Neurogene OpCo preferred stock were converted into 7,231,747 shares of the Company’s common stock, based on the Exchange Ratio. Refer to Note 12, Preferred Stock , for further detail on the conversion of Neurogene OpCo preferred stock. • Each then outstanding Neurogene OpCo stock option was exchanged for an equivalent stock option of the Company, adjusted to reflect the Exchange Ratio as necessary. • Each then outstanding Neurogene OpCo pre-funded warrant to purchase shares of Neurogene OpCo common stock was converted into a pre-funded warrant to purchase shares of the Company’s common stock, adjusted to reflect the Exchange Ratio as necessary. Refer to the discussion below for further detail on Neurogene OpCo pre-funded warrants. Concurrently with the execution and delivery of the Merger Agreement, and in order to provide Neurogene OpCo with additional capital for its development programs, Neurogene OpCo entered into a subscription agreement (the “Subscription Agreement”) with certain investors. Pursuant to the terms of the Subscription Agreement, immediately prior to the Closing, Neurogene OpCo issued and sold to the investors: (i) 2,792,206 shares of Neurogene OpCo common stock and (ii) 1,811,739 pre-funded warrants, exercisable for 1,811,739 shares of Neurogene OpCo common stock, at a purchase price of approximately $20.63 per share or $20.63 per warrant, for an aggregate purchase price of approximately $95.0 million (the “Pre-Closing Financing”). On December 18, 2023, immediately prior to Closing, Neoleukin entered into a contingent value rights agreement (the “CVR Agreement”) with a rights agent and the lease representative, pursuant to which holders of Neoleukin common stock or pre-funded warrants prior to Closing received one non-transferable contingent value right (each, a “CVR”) for each outstanding share of Neoleukin common stock held by such stockholder or warrant holder immediately prior to Closing. Holders of options to purchase Neoleukin common stock outstanding immediately prior to the effective time of the reverse merger who elect to exercise those options following the reverse merger will also receive one CVR for each share of Neoleukin common stock issued upon exercise of such option, subject to certain conditions set forth in the CVR Agreement. Each CVR represents the contractual right to receive (i) certain net savings, if any, realized by the Company by June 30, 2029 in connection with Neoleukin’s legacy lease obligations (the “Lease CVR”), including those related to Neoleukin’s sublease, entered into in October 2023, (ii) 100% of net proceeds, if any, derived from any consideration paid as a result of the sale of Neoleukin’s pre-merger legacy assets pursuant any agreements entered into before Closing, and 80% of net proceeds, if any, derived from any consideration paid as a result of the sale of Neoleukin’s pre-merger legacy assets pursuant any agreements entered into within one year after Closing (the “Intellectual Property CVR”), and (iii) certain net proceeds, if any, derived from Neoleukin’s anticipated sales tax refund from Washington State relating to tax returns filed by Neoleukin prior to Closing (the “Sales Tax CVR”). As of December 31, 2023, the Company has recorded approximately $0.3 million and $1.0 million to lease contingent value rights liability, current and lease contingent value rights liability, non-current, respectively, related to amounts that are probable and estimable under the Lease CVR as of December 31, 2023. As no other amounts related to the CVR Agreement were probable as of December 31, 2023, no contingencies for the Intellectual Property CVR or Sales Tax CVR have been recorded. Refer to Note 10, Commitments and Contingencies , for further discussion on the CVR components. Based on the following factors, the Company determined under the Accounting Standards Codification (“ASC”) 805, Business Combinations , that the merger should be accounted for as a reverse asset acquisition: • Neurogene OpCo stockholders owned approximately 84% of the voting rights in the Company, and thus had sufficient voting rights to exert influence over the Company. • Neurogene OpCo designated a majority of the Company’s board of directors and maintained a majority of the composition of management. • At the time of Closing, Neoleukin did not meet the definition of a business but it did represent a group of assets. For further discussion on the reverse merger and the related accounting, refer to Note 4, Reverse Merger .

Risks and Uncertainties

Risks and Uncertainties	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Risks and Uncertainties	Risks and Uncertainties The Company is subject to risks common to companies in the biotechnology industry, including, but not limited to, successful development of technology, obtaining additional funding, protection of proprietary technology, compliance with government regulations, risks of failure of pre-clinical studies, clinical studies and clinical trials, the need to obtain marketing approval for its drug candidates and its consumer products, fluctuations in operating results, economic pressure impacting therapeutic pricing, dependence on key personnel, risks associated with changes in technologies, development by competitors of technological innovations and the ability to transition from pilot scale manufacturing to large scale production. Liquidity and Financial Condition Since its inception, the Company has funded its operations primarily with proceeds from the sales of equity securities and has incurred significant recurring losses, including net losses of $36.3 million and $55.2 million for the years ended December 31, 2023 and 2022, respectively. In addition, the Company used cash in operations of $51.4 million and $52.8 million for the years ended December 31, 2023 and 2022, respectively, and had an accumulated deficit of $187.2 million as of December 31, 2023. Management expects to incur substantial and increasing losses in future periods as the Company advances its products through its clinical and regulatory process and will rely on outside capital to fund its operations for the foreseeable future. The Company has not generated positive cash flows from operations, and there are no assurances that the Company will be successful in obtaining an adequate level of financing for the development and commercialization of its product candidates. As of December 31, 2023, the Company had cash and cash equivalents of approximately $148.2 million. On December 18, 2023, the Company closed on the merger with Neoleukin Therapeutics, Inc. (see Note 4, Reverse Merger ) and a Pre-Closing Financing (see Note 1, Organization and Description of Business ). The Company expects its available cash and cash equivalents on hand as of the issuance date of these financial statements will be sufficient to fund its obligations as they become due for at least one year beyond the issuance date of these financial statements. As a result of the reverse merger with Neoleukin Therapeutics, the Company assumed an ATM or “at-the-market” Equity Offering Sales Agreement (the “Sales Agreement”) with BofA Securities, Inc., as agent (“BofA”), pursuant to which the Company may offer and sell, from time to time through BofA, shares of the Company’s common stock, having an aggregate offering price of up to $40.0 million. In March 2024, the Company terminated the ATM. In the event the Company is unable to secure additional outside capital, management will be required to seek other alternatives which may include, among others, a delay or termination of clinical trials or the development of its product candidates, temporary or permanent curtailment of the Company’s operations, a sale of assets, or other alternatives with strategic or financial partners. The accompanying financial statements do not include any adjustments that might result from the outcome of these uncertainties. Accordingly, the financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements are presented in United States (“U.S.”) dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Use of Estimates The preparation of the financial statements in accordance with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. In preparing these financial statements, management used significant estimates in the following areas, among others: recoverability of the Company’s net deferred tax assets and related valuation allowance, useful lives and recoverability of property and equipment, determining the Incremental Borrowing Rate (“IBR”) for calculating lease liabilities and related right-of-use (“ROU”) assets and finance lease assets, clinical trial accruals, accrual estimates for all CVRs, the value attributed to employee stock options and other stock-based awards and valuation of common stock. On an ongoing basis, the Company reviews its estimates to ensure that they appropriately reflect changes in the business or as new information becomes available. Actual results may differ from these estimates. Segment Information Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company operates as a single operating segment and has one reportable segment. The Company’s operations and its assets are held in the United States. Cash and Cash Equivalents The Company considers all highly-liquid investments purchased with original maturities of 90 days or less at time of purchase to be cash equivalents. Cash and cash equivalents include cash held in banks and are stated at fair value. The following table provides a reconciliation of cash, cash equivalents, and restricted cash in the balance sheets that sum to the total of the same such amounts shown in the statements of cash flows (in thousands): December 31, 2023 2022 Cash and cash equivalents $ 148,210 $ 82,021 Restricted cash 508 — Total cash, cash equivalents and restricted cash $ 148,718 $ 82,021 Cash equivalents consist of money market funds in which the carrying value equals the fair value (see Note 6, Fair Value of Financial Instruments ). Restricted cash includes $0.5 million in cash deposits the Company maintains with its bank as collateral for the irrevocable letters of credits related to its lease obligations. Concentrations of Credit Risk Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. As of December 31, 2023, the Company had $147.7 million in excess of the federally insured limits. The Company places its cash in financial institutions that management believes to be of high credit quality. Investments Investment securities at December 31, 2023 consist of U.S. treasury notes. The Company classifies these securities as held-to-maturity. Held-to-maturity securities are those securities in which the Company has the ability and intent to hold the security until maturity. Held-to-maturity securities are recorded at amortized cost, adjusted for the amortization or accretion of premiums or discounts. Premiums and discounts are amortized or accreted over the life of the related held-to-maturity security as an adjustment to yield using the effective interest method. The Company reassesses the classification of held-to-maturity at each reporting period. The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account determined in accordance with ASC 326, which is deducted from the securities' amortized cost basis at the balance sheet date as a result of management's assessment of the net amount expected to be collected. Securities that are determined to be uncollectible are written off against the allowance. The Company did not recognize an allowance for credit losses as of December 31, 2023. Interest income is recognized when earned. Additional information regarding held-to-maturity investments is included in Note 5, Investments . Fair Value of Financial Instruments Management believes that the carrying amounts of the Company’s financial instruments, including cash, prepaid and other current assets, accounts payable and accrued expenses, approximate fair value due to the short-term nature of these instruments. 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). ◦ 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). Property and Equipment Property and equipment costs are stated at cost, net of accumulated depreciation and amortization. The cost of property and equipment costs are depreciated on the straight-line method over the following estimated useful lives: Type Estimated useful Lab equipment 5 years Manufacturing equipment 10 years Leasehold improvements Lesser of the remaining economic life of the Furniture and fixtures 5 years Software 3 years Leasehold improvements are amortized over the shorter of the estimated useful life of the assets or the remaining lease term. Major additions and betterments are capitalized; maintenance and repairs, which do not improve or extend the life of the respective assets, are charged to operating expenses as incurred. Depreciation has been calculated using the straight-line method over their estimated useful lives once the asset is placed in service. Costs of software obtained for internal use are capitalized in accordance with ASC 350 and are recognized on a straight-line basis over the useful life. Software costs that do not meet the capitalization criteria, including costs incurred in the maintenance and minor upgrade and enhancement of software without additional functionality, are expensed as incurred. No depreciation has been calculated on work in progress assets. Capitalized Software Development Costs Implementation costs incurred in a cloud computing arrangement that is a service contract are capitalized and recorded in prepaid expenses and other current assets and other non-current assets on the consolidated balance sheets. Capitalized implementation costs include external professional service costs related to technical development. Post-implementation training and maintenance costs are expensed as incurred. Capitalized eligible implementation costs related to cloud computing service contracts are included in prepaid expenses and other current assets and other non-current assets were $0.3 million and $0.4 million as of December 31, 2023, and 2022, respectively. Capitalized cloud computing implementation costs are amortized on a straight-line basis over the expected term of the arrangement. Expense recognized related to the implementation costs capitalized was $0.2 million and $0.2 million for the years ended December 31, 2023 and 2022, respectively. Cloud computing arrangements are tested for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. No impairment of cloud computing arrangements occurred in 2023 or 2022. Impairment of Long-Lived Assets Management assesses the carrying value of property and equipment and software whenever events or changes in circumstances indicate that the carrying value may not be recoverable. If there is indication of impairment, management prepares an estimate of future undiscounted cash flows expected to result from the use of the asset and its eventual disposition. If these cash flows are less than the carrying amount of the asset, an impairment loss is recognized to write down the asset to its estimated fair value. For the years ended December 31, 2023 and 2022, the Company did not recognize any impairments for its long-lived assets. Leases Operating and finance leases are accounted for in accordance with ASU 2016-02, Leases as amended. They are presented in the Company’s consolidated balance sheet as right-of-use assets from leases, current lease liabilities, and long-term lease liabilities. At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding ROU asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. As the Company’s leases do not provide an implicit rate, the Company utilizes the appropriate IBR, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Both operating and finance lease assets represent a right to use an underlying asset for the lease term, and operating and finance lease liabilities represent an obligation to make lease payments arising from the lease. Lease liabilities with a term greater than one year and their corresponding ROU assets are recognized on the balance sheet at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain of the Company’s lease agreements at the adoption date contain renewal options. The Company does not recognize right-of-use assets or lease liabilities for renewal periods upon lease inception date unless it is determined that the Company is reasonably certain of renewing the lease at inception or when a triggering event occurs. The Company also made an accounting policy election to utilize the short-term lease exemption, whereby leases with a term of 12 months or less will not follow the recognition and measurement requirements of the standard. The Company’s leases do not contain any residual value guarantees. Since the Company elected to account for each lease component and its associated non-lease components as a single combined lease component, all contract consideration is allocated to the combined lease component. Some of the Company’s lease agreements contain rent escalation clauses. For operating leases, the Company recognizes the minimum rental expense on a straight-line basis based on the fixed components of a lease arrangement. The Company will amortize this expense over the term of the lease beginning with the lease commencement date. Certain lease agreements contain variable payments, which are expensed as incurred and not included in the lease right-of-use assets and liabilities. These amounts include payments for maintenance and utilities. Variable lease components represent amounts that are not fixed in nature and are not tied to an index or rate and are recognized as incurred. Additional information and disclosures are included in Note 10, Commitments and Contingencies . Contingent Value Right s As discussed within the Reverse Merger and Pre-Closing Financing section in Note 1, Organization and Description of Business , the Company entered into a CVR Agreement on December 18, 2023 prior to Closing. Included in the CVR Agreement are three different types of CVRs: (i) the Lease CVR, (ii) the Intellectual Property CVR, and (iii) the Sales Tax CVR (together, the “CVRs”). The Company evaluated each of the CVRs to determine if they qualified as derivatives under ASC 815, Derivatives and Hedging , and concluded that since certain scope exceptions were met, the CVRs did not qualify as derivatives. Instead, the Company records a contingent consideration liability associated with the CVRs when payments are probable and estimable under ASC 450. In assessing whether payments are probable and estimable, the Company considers the existence of or ability to enter agreements with third parties or government agencies and timing of potential payments. As of December 31, 2023, the Company recorded $0.3 million and $1.0 million to lease contingent value rights liability, current and lease contingent value rights liability, non-current, respectively, related to amounts that are probable and estimable under the Lease CVR. As no other amounts related to the CVR Agreement were probable as of December 31, 2023, no contingencies for the Intellectual Property CVR or Sales Tax CVR have been recorded. Refer to Note 1, Organization and Description of Business , and Note 10, Commitments and Contingencies , for further discussion on the CVR components. Exit and Disposal Costs In connection with the reverse merger and through fiscal 2024, the Company has incurred and expects to incur costs to wind-down Neoleukin’s Phase 1 NL-201 study. This study has ceased further development, and the Company has no plans to continue developing Neoleukin’s de novo protein technology. As a result, the study’s activities do not provide the Company any future economic benefit. In accordance with ASC 420 Exit or Disposal Costs, the Company accrued the remaining costs to be incurred in the contract of approximately $0.9 million, which was included in the liabilities assumed in the reverse merger. As of December 31, 2023, no payments were made and the liability of $0.8 million was classified as accrued expenses and other current liabilities in the consolidated balance sheet. Research and Development Research and development costs are expensed as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel of the Company’s research and development personnel, facilities, supplies, rent, insurance, stock-based compensation, depreciation and external expenses incurred under agreements with contract research organizations and investigative sites that conduct preclinical studies and manufacture the drug product for the preclinical activities and other costs associated with preclinical activities. Before a compound receives regulatory approval, the Company records upfront and milestone payments to third parties under licensing arrangements as expense provided that there is no alternative future use of the rights in other research and developments projects. Non-refundable prepayments for research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Costs for certain development activities, such as outside research programs funded by the Company, are recognized based on an evaluation of the progress to completion of specific tasks with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense as applicable. There can be judgment involved in measuring the research and development expenses to be recognized in a particular period. In some cases, expense is recorded using an underlying assumption of the progress to completion of specific activities. For example, costs may be recognized based on the passage of time for activities that span reporting periods. If the provision of services is not linear then this assumption could impact the amount of expense recognized. The level of judgment varies based on the nature of the services being performed and the underlying support obtained. For some activities, such as for certain clinical trials, expense is recorded based on information obtained from vendors as an intermediary to those performing the underlying services, such as contract research organizations. These estimates are inherently more judgmental since the quality and availability of the underlying data may vary. The Company does not need to make significant estimates where costs incurred are supported by invoices or reports of costs incurred are obtained from a vendor that is directly performing the underlying services, such as a consultant or contract manufacturing organization. In-process research and development (“IPR&D”) that is acquired through licensing arrangements and accounted for as asset acquisitions are expensed immediately and within research and development expenses if the IPR&D has no alternative future use. General and Administrative General and administrative expenses consist primarily of personnel expenses, including salaries, benefits and stock-based compensation expense, for employees and consultants in executive, finance and accounting, legal, operations support, information technology and human resource functions. General and administrative expenses also include corporate facility costs not otherwise included in research and development expense, including rent, utilities, depreciation and maintenance, as well as legal fees related to intellectual property and corporate matters and fees for accounting and consulting services. Stock-Based Compensation The Company accounts for stock-based compensation awards in accordance with ASC Topic 718, Compensation – Stock Compensation (“ASC 718”). ASC 718 requires all stock-based payments, including grants of stock options and restricted stock, to be recognized in the consolidated statements of operations based on their fair values. All of the stock-based awards are subject only to service-based vesting conditions. Management estimates the fair value of the stock option awards using the Black-Scholes option pricing model, which requires the input of assumptions, including (a) the fair value of the Company’s common stock, (b) the expected stock price volatility, (c) the calculation of expected term of the award, (d) the risk-free interest rate and (e) expected dividends. Management estimates the fair value of the restricted stock awards using the fair value of the Company’s common stock. Forfeitures are recognized as they are incurred. Prior to the reverse merger, the Company periodically estimated the fair value of the Company’s common stock considering, among other things, valuations of its common stock prepared by management with the assistance of a third party valuation firm in accordance with the guidance provided by the American Institute of Certified Public Accountants 2013 Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation . Following the reverse merger, the fair value of the Company’s common stock is based on the closing stock price on the date of grant as reported on the Nasdaq Global Market. The expected life of the stock options in years is estimated using the “simplified method,” as prescribed in SEC’s Staff Accounting Bulletin (SAB) No. 107, as the Company has no historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses comparable public companies as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option. The expected dividend yield is zero as the Company has no history of paying dividends and no plans to do so in the near term. The Company classified stock-based compensation expense in its consolidated statement of operations in the same manner of the award recipient’s payroll costs. Income Taxes The Company accounts for income taxes in accordance with ASC 740 , Income Taxes , which prescribes the use of the liability method whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. A valuation allowance is provided to reduce the net deferred tax assets to a level which, more likely than not, will be realized. The Company assesses its income tax positions and records tax benefits based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company records the amount of tax benefit with a greater than 50 percent likelihood of being realized upon ultimate settlement with a taxing authority having full knowledge of all relevant information. For those income tax positions for which it is not more likely than not that a tax benefit will be sustained, no tax benefit is recognized in the financial statements. Potential interest and penalties associated with such uncertain tax positions is recorded as a component of income tax expense. Net Income (Loss) Per Share For the prior year and pre-merger periods in which the Company had multiple classes of stock participating in earnings, the Company uses the two-class method in calculating earnings per share. Basic earnings per share of Class A and Class B common stock is computed by dividing net income attributable to Neurogene OpCo by the weighted-average number of shares of Class A and Class B common stock outstanding during the period. For the post-merger period, the only period in which the Company had income, diluted earnings per share of the single class of common stock is computed by dividing net income attributable to the Company, adjusted for the assumed exchange of all potentially dilutive instruments for common stock, by the weighted-average number of shares of common stock outstanding, adjusted to give effect to potentially dilutive elements. As of December 18, 2023, the Company consummated the reverse merger, leaving only one class of common stock remaining, and as such, the two-class method is not presented for the post-merger period from December 18, 2023 to December 31, 2023. The single class of common stock remaining post-merger is referred to throughout as “common stock.” The following table sets forth the computation of basic and diluted net income (loss) per share (in thousands, except share and per share amounts): Year Ended December 31, 2023 Year Ended December 31, 2022 Pre-Merger (1) Post-Merger (2) Pre-Merger (1) Class A Class B Common stock Class A Class B Net income (loss) per share, basic: Numerator: Net income (loss) $ (49,971) $ — $ 13,654 $ (55,189) $ — Denominator: Weighted-average shares outstanding used in computing net income (loss) per share, basic 426,097 — 491,867 394,533 — Net income (loss) per share, basic $ (117.28) $ — $ 27.76 $ (139.88) $ — Net income (loss) per share, diluted: Numerator: Net income (loss) $ (49,971) $ — $ 13,654 $ (55,189) $ — Denominator: Weighted-average shares outstanding used in computing net income (loss) per share, basic 426,097 — 491,867 394,533 — Weighted-average effect of dilutive securities: Warrants to purchase common stock — — 4,063,361 — — Options to purchase common stock — — 101,719 — — Weighted-average shares outstanding used in computing net income (loss) per share, diluted 426,097 — 4,656,947 394,533 — Net income (loss) per share, diluted $ (117.28) $ — $ 2.93 $ (139.88) $ — (1) Represents the period starting January 1, 2023 through Closing for the year ended December 31, 2023 and for the year ended December 31, 2022. (2) Represents the period subsequent to Closing (December 18, 2023) through December 31, 2023. Potentially dilutive securities that were not included in the diluted per share calculations because they would be antidilutive were as follows: Year Ended December 31, 2023 Year Ended December 31, 2022 Pre-Merger (1) Post-Merger (2) Pre-Merger (1) Class A Class B Common stock Class A Class B Options to purchase common stock 614,729 — 541,180 468,632 — Restricted stock awards — — — 6,691 — Series A-1 convertible preferred stock (3) — — — 18,604,653 — Series A-2 convertible preferred stock (3) — — — 13,291,208 — Series B convertible preferred stock (3) — — — 74,405,719 — Total awards excluded 614,729 — 541,180 106,776,903 — (3) The convertible preferred stock does not reflect the application of the 0.0756 Exchange Ratio. Recently Issued Accounting Standards From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed below, the Company does not believe that the adoption of recently issued standards have or may have a material impact on our financial statements or disclosures. 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 after January 1, 2025. The Company is analyzing the impact of this standard on its disclosures in the consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures which requires consistent categories and greater disaggregation of information in the rate reconciliation and income taxes paid disaggregated by jurisdiction. This standard will be effective for annual periods beginning after December 15, 2024. The Company is currently evaluating the impact of this standard on the Company’s consolidated financial statements and related disclosures but does not expect the adoption of ASU 2020-09 to be material. Recently Adopted Accounting Pronouncements The Company adopted ASU 2016-13, Financial Instruments - Credit Losses , as amended, on January 1, 2023. This ASU sets forth a current expected credit loss model which requires the Company to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost and applies to some off-balance sheet credit exposures. The impact of ASU 2016-13 on the Company’s consolidated financial statements was not material.

Reverse Merger

Reverse Merger	12 Months Ended
	Dec. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Reverse Merger	Reverse Merger As discussed within the Reverse Merger and Pre-Closing Financing section in Note 1, Organization and Description of Business , on December 18, 2023 the reverse merger between Neoleukin, Merger Sub, and Neurogene OpCo was consummated. Pursuant to the Merger Agreement, upon Closing, Merger Sub merged with and into Neurogene OpCo, with Neurogene OpCo surviving as a wholly owned subsidiary and surviving corporation of the merger. In connection with the completion of the reverse merger, the Company changed its name from “Neoleukin Therapeutics, Inc.” to “Neurogene Inc.,” and the business conducted by the Company became primarily the business conducted by Neurogene OpCo. The reverse merger was contemplated and consummated, along with the Pre-Closing Financing, to generate capital resources to support the advancement of the Company’s pipeline and future operations. As further discussed in Note 1, Organization and Description of Business, the reverse merger was accounted for as a reverse asset acquisition pursuant to ASC 805, Business Combination s as Neoleukin did not meet the definition of a business under ASC 805 but it did represent a group of assets. Therefore, the transaction was treated as the equivalent of Neurogene issuing stock to acquire the net assets of Neoleukin. In accordance with the relative fair value allocation guidance in ASC 805, to account for the reverse merger, the Company allocated the difference between the total consideration transferred and the fair value of the net assets acquired to Neoleukin’s non-monetary assets on a pro rata basis. As the fair value of Neoleukin’s net assets acquired at Closing exceeded the total consideration transferred after the fair value allocation, (i) $1.3 million of the difference was recorded as a contingent consideration liability on the Company’s consolidated balance sheet for payments that are probable and estimable under the CVR Agreement and (ii) the remaining $16.4 million was recognized as a bargain purchase gain in the Company’s consolidated statement of operations. The following table summarizes the final purchase price paid in the reverse merger along with the fair value allocation (in thousands, except share and per share amounts): Calculation of total purchase price: Number of common shares and pre-funded warrants of the combined company owned by Neoleukin stockholders (1) 2,777,017 Multiplied by the fair value per share of Neoleukin common stock (2) $ 13.76 Fair value of Neoleukin common stock issued (2) $ 38,212 Transaction costs (6) 4,140 Contingent consideration liability (3) 1,287 Total purchase price $ 43,639 Fair value of Neoleukin net assets acquired at Closing and fair value allocation: Monetary assets acquired (4) $ 76,906 Liabilities assumed (5) (21,052) Fair value of net assets acquired $ 55,854 Less: total consideration transferred (38,212) Excess of fair value of monetary assets acquired over total consideration transferred $ 17,642 Fair value allocated to contingent consideration liability (3) 1,287 Fair value allocated to bargain purchase gain 16,355 Total fair value allocated $ 17,642 Reconciliation of allocation to purchase price: Fair value of monetary assets acquired (4) $ 76,906 Transaction costs (6) 4,140 Neoleukin liabilities assumed (5) (21,052) Fair value allocated to bargain purchase gain (16,355) Total purchase price $ 43,639 (1) The number of shares is based on a total 2,351,030 shares of Neoleukin common stock and 425,987 pre-funded warrants outstanding as of December 18, 2023. (2) The fair value of Neoleukin common stock (also referred to in discussions herein as “total consideration transferred”) was determined using the closing price of Neoleukin’s common stock on December 15, 2023, after giving effect to the Reverse Stock Split. As discussed in Note 3, Summary of Significant Accounting Policies , Neoleukin’s stock price is measured using Level 1 fair value measurements. (3) Refer to Note 10, Commitments and Contingencies , for further discussion on the contingent consideration liability. (4) In accordance with the guidance in ASC 805, Business Combinations , the fair value of the net assets acquired was allocated to any non-monetary assets on a pro rata basis. As such, the assets acquired only include cash, cash equivalents and restricted cash of $22.2 million, short-term investments of $53.9 million, and other immaterial monetary assets of $0.8 million. (5) Included in Neoleukin liabilities assumed is (i) $10.9 million in lease liabilities, (ii) $3.8 million in accrued payroll and $6.3 million in other accrued costs and accounts payable. For the lease liabilities, the Company utilized judgment in estimating the IBR used in determining the fair value of the leases upon Closing. (6) As indicated in ASC 805 regarding asset purchases, the accounting acquirer’s transaction costs incurred directly related to the asset purchase should be included in the consideration to acquire the assets. These costs were initially recorded as deferred financing costs and then reclassified to offset to equity upon Closing.

Investments

Investments	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The following table summarizes the Company’s investment securities as of December 31, 2023 (in thousands): December 31, 2023 Amortized cost, as adjusted Gross Gross Estimated fair Short-term investments: U.S. treasury notes $ 48,947 $ 16 $ — $ 48,963 December 31, 2022 Amortized cost, as adjusted Gross Gross Estimated fair Short-term investments: U.S. treasury notes $ — $ — $ — $ — All of the Company’s investments mature within the next 12 months.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments As of December 31, 2023 and December 31, 2022, financial assets measured at fair value on a recurring basis are categorized in the table below based upon the lowest level of significant input to the valuations (in thousands): December 31, 2023 Level 1 Level 2 Level 3 Assets: Money market funds $ 144,358 $ — $ — U.S. treasury notes 48,947 — — Total $ 193,305 $ — $ — December 31, 2022 Level 1 Level 2 Level 3 Assets: Money market funds $ 78,749 $ — $ — Money market funds are cash equivalents and are included in cash and cash equivalents in the consolidated balance sheet as of December 31, 2023 and 2022.

Prepaid expenses and other curr

Prepaid expenses and other current assets	12 Months Ended
	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses and other current assets	Prepaid expenses and other current assets Prepaid expenses and other assets consist of the following (in thousands): December 31, 2023 2022 Refunds and other receivables $ 600 $ 990 Prepaid expenses 1,496 1,078 Other current assets 1,095 630 Total prepaid and other current assets $ 3,191 $ 2,698

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment consist of the following (in thousands): December 31, 2023 2022 Lab equipment $ 3,144 $ 3,088 Manufacturing equipment 6,142 5,955 Leasehold improvements 15,376 15,298 Office equipment 19 — Software 268 289 Construction in progress 234 252 Total property and equipment, cost 25,183 24,882 Less accumulated depreciation and amortization (8,009) (4,767) Property and equipment, net $ 17,174 $ 20,115 Depreciation and amortization expense for the years ended December 31, 2023 and December 31, 2022 was approximately $3.3 million and $3.2 million, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): December 31, 2023 2022 Compensation and related benefits $ 3,496 $ 3,357 Research and development 4,895 1,800 Accrued severance, bonus, and retention (1) 2,476 — Accrued offering costs in connection with pre-closing financing 3,334 — Accrued transaction costs related to reverse merger 2,557 — Other 737 167 Total accrued expenses and other current liabilities $ 17,495 $ 5,324 (1) Includes accrued severance, bonus, and retention payments for current and former Neoleukin employees. Refer to Note 10, Commitments and Contingencies , for further detail.

Commitment and Contingencies

Commitment and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Finance Leases During the years ended December 31, 2023 and 2022, the Company leased information technology (“IT”) equipment and copiers for periods ranging from 36 months to 63 months. The IT equipment were classified as finance leases due to the existence of bargain purchase options in the lease agreements, and the copiers were classified as finance leases as the lease periods represented a major portion of the economic life of those assets. In connections with these leases, the Company recorded finance lease right-of-use assets and finance lease liabilities of approximately $0.1 million. Operating Leases New York Headquarters Lease In September 2019, the Company commenced a sub-lease of approximately 6,000 square feet of office space for the corporate headquarters in New York, New York with a term expiring in June 2023. In connection with the lease, the Company established an irrevocable letter of credit for approximately $0.4 million. Monthly lease payments were approximately $0.04 million. In July 2021, the sublessor was released from the original lease by the landlord, and the Company attorned to the landlord the executory terms and provisions of the sub-lease. In February 2022, the Company entered into an extension of the New York office lease (retroactive to December 2021) through June 2026, with new monthly lease payments ranging from approximately $0.03 million to $0.04 million. The Company accounted for the amendment as a contract modification, and accordingly, recorded an additional operating right-of-use asset of approximately $1.0 million and an additional operating lease liability of approximately $1.0 million. Houston Lease In August 2019, the Company entered into an agreement to lease approximately 26,905 square feet in Houston, Texas to build a manufacturing facility and office with a term expiring in August 2029. The Company has the option to renew the lease term for two additional five-year terms. The renewal periods were not included in the lease term for purposes of determining the lease liability or right-of-use asset. Monthly rent payments were approximately $0.03 million. In connection with the lease, the Company paid a security deposit of approximately $0.04 million and prepaid rent of approximately $0.04 million. In September 2020, the Company amended the lease agreement to further increase the rentable space to 42,342 square feet. The commencement date of the expansion space lease was January 1, 2021 and the monthly rent payments increased to a range of approximately $0.05 million to $0.06 million. Blaine Lease in Seattle As a result of the reverse merger, the Company assumed an operating lease for approximately 33,300 square feet of office space in Seattle, Washington for offices, a laboratory for research and development, and related uses. The lease expires on February 1, 2029, with the option to extend the lease for two five-year terms. The renewal periods were not included in the lease term for purposes of determining the lease liability or right-of-use asset. Eastlake Lease in Seattle As a result of the reverse merger, the Company assumed an operating lease for approximately 6,272 square feet of office space in Seattle, Washington, for additional office and laboratory space for research and development and related uses (the “Eastlake Lease”). The Company also assumed the existing agreement to sublease the Eastlake Lease to an unrelated third party (“Eastlake Sublease”). Pursuant to the terms of the EastLake Sublease, Neurogene is entitled to receive approximately $1.6 million in lease payments. The term of the sublease is through September 30, 2026. Supplemental lease expense related to leases for the years ended December 31, 2023 and 2022 was as follows (in thousands): Years Ended 2023 2022 Operating lease cost $ 1,037 $ 1,037 Finance lease cost Amortization of finance leases 35 4 Interest on finance lease liabilities 12 2 Variable lease cost 178 196 Short-term lease cost 80 74 Total lease cost $ 1,342 $ 1,313 The calculation of the present value of the lease payments for operating leases did not include any options to extend the leases as the Company is not reasonably certain to exercise such options. The following table summarizes the maturity of the Company’s operating and finance lease liabilities on an undiscounted cash flow basis and a reconciliation to the operating and finance lease liabilities recognized on the Company’s consolidated balance sheet as of December 31, 2023 (in thousands): Maturity of operating lease liabilities 2024 $ 3,862 2025 3,964 2026 3,672 2027 3,235 2028 3,294 2029 616 Total lease payments $ 18,643 Less: interest (3,782) Total operating lease liabilities $ 14,861 Maturity of finance lease liabilities 2024 $ 51 2025 50 2026 15 2027 6 2028 1 Total lease payments $ 123 Less: interest (16) Total finance lease liabilities $ 107 Supplemental balance sheet information related to leases as of December 31, 2023 and 2022 was as follows (in thousands): Leases December 31, 2023 2022 Operating right-of-use assets $ 3,681 $ 4,344 Operating current lease liabilities 2,559 678 Operating noncurrent lease liabilities 12,302 3,921 Total operating lease liabilities $ 14,861 $ 4,599 Finance right-of-use assets $ 98 $ 87 Finance current lease liabilities 42 24 Finance noncurrent lease liabilities 65 66 Total finance lease liabilities $ 107 $ 90 Other information December 31, 2023 2022 Cash paid for amounts included in measurement of operating lease liabilities (in thousands) $ 1,051 $ 1039 Cash paid for amounts included in measurement of finance lease liabilities (in thousands) $ 42 $ 3 Weighted-average remaining lease term - operating leases (in years) 4.88 5.72 Weighted-average remaining lease term - finance lease (in years) 2.53 3.47 Weighted-average discount rate - operating leases 9.72 % 8.86 % Weighted-average discount rate - finance lease 11.49 % 11.45 % Lease CVR In accordance with the terms of the Lease CVR within the CVR Agreement, the Company accrued for approximately $1.3 million as a contingent consideration liability on its consolidated balance sheet. As of the Closing, the expected range for the Lease CVR was approximately $1.3 million to $19.5 million based on the potential rights to CVR holders as described in the terms of the CVR Agreement. As of December 31, 2023, $1.3 million was recorded on the Company’s consolidated balance sheet as a lease contingent value rights liability consisting of lease commitments that were probable and estimable as the Closing. The commitments relate to Neoleukin’s sublease agreement, effective October 31, 2023, for one of its properties with an unrelated third party for the remainder of the lease term. All other payments under the CVR Agreement were not considered probable and estimable as of December 31, 2023 and therefore no additional contingent consideration liability has been recorded. The Company will evaluate the probable and estimable range of outcomes under the CVR Agreement at each reporting period until the end of the CVR term and adjust the amounts accrued for as necessary. The following table summarizes the maturity of the Company’s lease CVR as of December 31, 2023 (in thousands): Maturity of Lease CVR 2024 $ 281 2025 598 2026 408 Total lease CVR payments $ 1,287 Intellectual Property CVR Prior to the Closing, Neoleukin entered into a licensing agreement on December 13, 2023 with Accipiter Biosciences (“Accipiter”) to develop and commercialize Neoleukin’s de novo protein technology (the “Accipiter Licensing Agreement”). As discussed and defined within the Reverse Merger and Pre-Closing Financing section of Note 1, Organization and Description of Business , the terms of the CVR Agreement include that CVR holders are eligible to receive the Intellectual Property CVR. In addition, as discussed in Note 3, Summary of Significant Accounting Policies , contingent consideration liabilities related to the CVR Agreement will only be recorded if they are probable and estimable as of the balance sheet date. Under the Accipiter Licensing Agreement, Accipiter will make a non-refundable up-front payment of approximately $0.2 million upon the earlier of six Since the upfront payment, milestones and royalties were not considered probable as of December 31, 2023, the Company did not record a contingent consideration liability related to the Intellectual Property CVR. Employment Agreements Neoleukin entered into employment agreements with key personnel providing for severance payments, benefits, and other employee related costs in certain circumstances, as defined in the respective employment agreements. As of December 31, 2023, $2.5 million of accrued severance, bonus, and retention costs were recorded to accrued expenses and other current liabilities on the Company’s consolidated balance sheet as noted in Note 9, Accrued Expenses and Other Current Liabilities . Other Research and Development Arrangements The Company enters into agreements with contract research organizations (“CROs”) to assist in the performance of research and development activities. Expenditures to CROs will represent a significant cost in clinical development for the Company. Litigation and Legal Proceedings The Company is subject to litigation and other claims that arise in the ordinary course of business. While the ultimate result of outstanding legal matters cannot presently be determined, the Company does not expect that the ultimate disposition will have a material effect on its results of financial condition, results of operations or cash flows. However, legal matters are inherently unpredictable and subject to significant uncertainties, some of which are beyond the Company’s control. As such, there can be no assurance that the final outcome of any particular legal matter will not have a material adverse effect on the Company’s financial condition, results of operations or cash flows.

License Agreements

License Agreements	12 Months Ended
	Dec. 31, 2023
License Agreements [Abstract]
License Agreements	License Agreements License Agreement with The University of North Carolina In May 2019, Neurogene entered into an Exclusive License Agreement with the University of North Carolina at Chapel Hill (“UNC”) to obtain an exclusive, worldwide, royalty bearing license, with the right to grant sublicenses under certain patents to make, use, or sell products covered by such patents for prevention or treatment of disease or medical or genetic conditions, including CLN5 Batten disease or other diseases from dysfunction of the CLN5 gene. The Company is obligated to pay UNC up to $1.7 million in sales-related milestones for licensed products based on annual sales of the licensed product in excess of defined thresholds and low single-digit percentage royalties on net sales of licensed product for as long as there is a valid patent claim under the patent rights. Neurogene is also required to reimburse any patent expenses, as well as pay a nonrefundable annual maintenance fee which, when royalties become due and payable, will be creditable against such royalties. The annual license fee was $4,000 for each of the years ended December 31, 2023 and 2022. License Agreement with The University of Edinburgh In January 2020, Neurogene entered into an Option Agreement (the “Edinburgh Option Agreement”) with the University Court of the University of Edinburgh (“University of Edinburgh”) for an option to license certain patents covering the EXACT technology (the “Licensed Technology”). To secure the option, Neurogene was solely required to pay the costs associated with the filing, preparing, prosecution and maintenance of the patents covering the Licensed Technology during the option period. No other payments were payable under the Edinburgh Option Agreement. Neurogene subsequently exercised the option under the Edinburgh Option Agreement and then entered into the Master Collaboration Agreement (“MCA”) discussed below, and which superseded the Edinburgh Option Agreement. In December 2020, University of Edinburgh and Neurogene entered into the MCA. Under the MCA, Neurogene and University of Edinburgh agreed to collaborate on certain research and development projects (“Projects”) and Neurogene agreed to provide funding for such Projects for a 40-month initial term, which term may be extended by mutual agreement. In exchange for such funding, University of Edinburgh granted Neurogene the option to exclusively license any intellectual property arising from such Projects. If Neurogene exercises an exclusive option for a particular Project, Neurogene will enter into a separate exclusive license agreement on its own terms with University of Edinburgh. Under the MCA, Neurogene is obligated to pay semi-annual installment payments relating to funding of costs for personnel and lab consumables for the 40-month period. Either party may terminate the MCA for convenience upon 90 days’ notice. If Neurogene terminates the MCA, it would be responsible for all non-cancellable costs and commitments related to any particular Project and any and all funding costs for any person working on such Project. The expense recorded for the years ended December 31, 2023 and 2022 was $1.6 million and $1.1 million, respectively. In March 2022, Neurogene exercised its option through the collaboration under the MCA, and entered into a License Agreement (the “March 2022 Edinburgh License Agreement”) with University of Edinburgh, pursuant to which Neurogene licensed certain patents and know-how related to the EXACT technology and optimized MECP2 cassettes on an exclusive basis. Under the March 2022 Edinburgh License Agreement, Neurogene obtained an exclusive, worldwide license to the licensed patents to develop, manufacture, supply, sell, and commercialize any products that utilize the licensed patents (the “Licensed Products”) in exchange for low single-digit percentage royalties on future commercial net sales of the Licensed Products. Royalties are payable on a Licensed Product-by-Licensed Product and country-by-country basis until the latter of the expiration of the last licensed patent covering such Licensed Product in the country where the Licensed Product is sold, or, if no licensed patent exists or has expired in such country, then ten years from first commercial sale of such Licensed Product in such country. In connection with the license, Neurogene is also obligated to pay the University of Edinburgh up to $5.25 million in regulatory-related milestones and up to $25 million in sales-related milestones based on annual net sales of Licensed Products in excess of defined thresholds. During the year ended December 31, 2023, the Company expensed $0.3 million for a milestone related to the first patient dosing in the Phase 1/2 Rett study. In November 2023, Neurogene and University of Edinburgh amended the MCA. Under the amended MCA, Neurogene and University of Edinburgh agreed to continue collaborating on certain Projects and Neurogene agreed to provide funding for such Projects through December 2026 or an additional 33 months. Neurogene is obligated to pay semi-annual installment payments relating to funding of costs for personnel and lab consumables for the entire period. License Agreement with the University of North Carolina and University of Pennsylvania In July 2020, the Company entered into an exclusive license agreement with the University of North Carolina and University of Pennsylvania, or the Universities, to further develop and commercialize the licensed technology for the Optimized GALC Genes and Expression Cassettes. The Company also has the right to sublicense the technology. The Company made an upfront payment to the Universities of $0.5 million that was immediately expensed within research and development expenses as the license has no alternative future use. On an on-going basis, the Company is obligated to pay for future patent costs incurred, and such costs were immaterial for the years ended December 31, 2023 and December 31, 2022. During the year ended December 31, 2022, the Company paid the University of North Carolina a $0.5 million milestone payment after receipt of the Rare Pediatric Disease Designation of NGN-201 from the FDA for Krabbe disease. An annual license maintenance fee is also payable commencing on the first anniversary of the effective date. The amount of the license fee was approximately $0 and $0.02 million for the years ended December 31, 2023 and 2022, respectively. In October 2023, the Company terminated the license agreement. License Agreement with Virovek In September 2020, Neurogene entered into a Non-Exclusive License Agreement with Virovek, Inc., pursuant to which Neurogene has a license to use certain patents and know-how on a non-exclusive basis related to Neurogene’s baculovirus (“baculo”) process in exchange for low single-digit percentage royalties on future commercial net sales of each product using the baculo process, development milestone payments of up to $0.2 million in the aggregate, and a nonrefundable annual license fee. During the year ended December 31, 2023, the Company recorded a milestone expense of $0.1 million for first filing of the IND filed in connection with the Company’s Rett syndrome program. The license fee expense for each of the years ended December 31, 2023 and 2022 was $0.05 million. License Agreement with Sigma-Aldrich Co In January 2023, Neurogene entered into a Non-Exclusive License Agreement with Sigma-Aldrich Co. LLC, pursuant to which Neurogene has a license to certain patents and know-how on a non-exclusive basis related to certain cell lines used in Neurogene’s baculo process in exchange for a small annual fee on a product-by-product basis, payable once the first product candidate enters the clinic. In addition, on a product-by-product basis, Neurogene is obligated to pay up to $2.5 million in the aggregate for development-related milestones. During the year end ended December 31, 2023, the Company recorded the expense for the initial annual license fee of approximately $0.06 million. No expenses were recorded related to other in-process license agreements during the years ended December 31, 2023 and 2022, respectively. None will be due under these agreements unless and until certain development milestones are reached.

Preferred Stock

Preferred Stock	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Preferred Stock	Preferred Stock Preferred Stock The Company is authorized to issue 50,000,000 shares of preferred stock with a par value of $0.000001 per share as of December 31, 2023. No shares are outstanding as of December 31, 2023. Convertible Preferred Stock On March 2, 2022, the Company entered into the Series B preferred stock purchase agreement, which provided for the purchase of 27,274,586 shares of Series B preferred stock, at $2.44 per share for net proceeds of approximately $66.5 million, of which the Company received such funds from March 2022 through June 2022 . On December 18, 2023, Neurogene OpCo completed the reverse merger with Neoleukin. Neurogene OpCo’s Series A-1, Series A-2 and Series B preferred stock (collectively, “convertible preferred stock”) was subject to certain pre-existing anti-dilution provisions that were triggered upon the closing of the Pre-Closing Financing. The private placement in Neurogene OpCo closed immediately before the Closing. As a result of the pre-existing anti-dilution feature, Neurogene OpCo preferred shareholders received an additional 13,505,271 shares of preferred stock. At the effective time of the reverse merger, each issued and outstanding share of Neurogene OpCo convertible preferred stock converted automatically into 0.0756 shares of the Company’s common stock or pre-funded warrants, at the option of the preferred shareholder. At the Closing, the Company issued an aggregate of 7,231,747 shares of its common stock and 1,825,635 pre-funded warrants to Neurogene OpCo preferred shareholders. Prior to the effective time of the reverse merger, the convertible preferred stock had the followings rights and privileges: Dividends The holders of convertible preferred stock were entitled to receive non-cumulative dividends that would accrue at the rate of $0.18 per share per year, payable only when and if declared by the Board of Directors. The Company would not declare, pay or set aside any dividends on shares of any class of common stock (as defined below) unless the holders of the convertible preferred stock would first receive dividends on each outstanding share of preferred stock in the amount of the accrued dividends unpaid as of such date. No dividends were issued for the convertible preferred stock from inception through the Closing. Liquidation In the event of any liquidation, dissolution, or winding-up of the Company, which would include the sale of the Company, the convertible preferred stock was senior to common stock. The preferred shareholders would be entitled to preferential payment in the amount per share equal to the greater of (i) the original issue price and accrued dividends declared and unpaid or (ii) the amount that would be due had all convertible preferred stock been converted to common stock immediately prior to a deemed liquidation event. Upon payment of the preferred liquidation preference payments, the holders of Series A-1 and common stock participate on a pro-rata basis until the A-1 stockholders have received a liquidation preference amount of $5.38 per share of Series A-1. Any remaining distribution thereafter would be distributed to holders of common stock. Voting The preferred stockholders were entitled to the number of votes equal to the number of Class A common stock into which the shares of convertible preferred stock Series A and B held by each holder are then convertible. Conversion The preferred stockholders had the option to convert each share of convertible preferred stock into Class A or Class B common stock, as applicable, at any time, and without additional payment. The number of Class A or Class B common stock into which the convertible preferred stock converts was equal to the original issuance price (defined as $2.15 per share for the Series A and $2.44 per share for the Series B) divided by the conversion price. The conversion price would initially be $2.15 per share for the Series A and $2.44 per share for the Series B and could be adjusted for certain dilutive events such as a down-round provision, stock splits and combinations, certain dividends and distributions or any merger or reorganization. Conversion to Class A common stock would have been mandatory upon the closing of an initial public offering resulting in net proceeds of at least $75.0 million for Series A and $50.0 million for Series B and at an offering price per share greater than or equal to $4.30 per share for Series A and $3.66 per share for Series B or upon the decision of the holders of at least a majority of the outstanding preferred stock shares. Prior to the Mandatory Conversion Time (as defined in the preferred stock purchase agreement), a preferred stockholder would have had the right to elect, upon written notice to the Company, to have all or a portion of its shares of convertible preferred stock automatically convert into shares of Class B common stock at the then effective conversion rate. Redemption The convertible preferred stock was subject to redemption under certain deemed liquidation events not solely within the control of the Company, as defined, and as such was considered contingently redeemable for accounting purposes and was classified as temporary equity in the Company’s consolidated balance sheets.

Stockholders_ Equity (Deficit)

Stockholders’ Equity (Deficit)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Stockholders’ Equity (Deficit)	Stockholders’ Equity (Deficit) Common stock and pre-funded warrants The Company is authorized to issue 450,000,000 shares of common stock with a par value of $0.000001 per share as of December 31, 2023. At the effective time of the Reverse Merger on December 18, 2023, the Company issued an aggregate number of 10,472,635 shares of Company common stock to the Neurogene OpCo stockholders based on the Exchange Ratio, including those shares of Neurogene OpCo common stock issued upon the conversion of Neurogene OpCo preferred stock and those shares of the Neurogene OpCo Class A common stock issued in the Pre-Closing Financing, resulting in 12,823,665 shares of Company common stock being issued and outstanding immediately following the effective time of the Reverse Merger. The Company has pre-funded warrants outstanding to purchase an aggregate of 4,063,361 shares of common stock as of December 31, 2023. The pre-funded warrants are exercisable at any time for an exercise price of $0.000001, except that the pre-funded warrants cannot be exercised by the holders if, after giving effect thereto, the holders would beneficially own more than 9.99% of the outstanding common stock, subject to certain exceptions. However, any holder may increase or decrease such percentage to any other percentage (not in excess of 19.99%) upon at least 61 days’ prior notice from the holder to the Company. The holders of the pre-funded warrants will not have the right to vote the shares underlying the pre-funded warrants on any matter except to the extent required by Delaware law. These warrants were classified as equity. Class A and Class B Common stock Prior to the effective time of the reverse merger, Class A and Class B common stock had the followings rights and privileges: The holders of Neurogene OpCo Class A common stock were entitled to one vote for each share of Class A common stock held at all meetings of stockholders. Unless required by law, there was no cumulative voting. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, after the payment of all preferential amounts required to be paid to the holders of shares of preferred stock, the remaining funds and assets available for distribution to the stockholders of the Company would have been distributed among the holders of shares of Class A and Class B common stock, pro rata basis based on the number of shares of Class A and Class B common stock held by each such holder. Holders of shares of Class B common stock had rights to convert each share of Class B common stock held into one share of Class A common stock at their election, provided that, following the closing of any initial public offering (as defined above), the shares of the Class B common stock would have been converted into shares of Class A common stock unless such conversion would have resulted in a holder owning in excess of 4.99% of any class of securities. Neurogene OpCo had reserved shares of common stock for future issuance as follows: December 31, 2023 2022 Conversion of Series A-1 (1) — 18,604,653 Conversion of Series A-2 (1) — 13,291,208 Conversion of Series B (1) — 74,405,719 Total conversion of preferred stock — 106,301,580 Options outstanding 823,833 468,632 Shares available for future grant under the 2018 Equity Incentive Plan — 315,548 Shares available for future grant under the 2023 Equity Incentive Plan 2,237,722 — Total common stock reserved 3,061,555 107,085,760 (1) The convertible preferred stock does not reflect the application of the 0.0756 Exchange Ratio.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation In connection with the reverse merger, the Company stockholders approved the 2023 Equity Incentive Plan (the “2023 EIP”) on December 13, 2023 and Board of Directors ratified the 2023 EIP on December 18, 2023. The 2023 EIP provides for the grant of stock options, restricted stock, restricted stock units (“RSUs”) and other stock-based awards, any of which may be performance-based, and for incentive bonuses, which may be paid in cash, Company common stock or a combination thereof. The number of shares reserved for issuance under the 2023 EIP is equal to 2,237,722 shares of the Company’s common stock. The 2023 EIP provides that the number of shares reserved and available for issuance under the 2023 EIP will automatically increase on January 1 of each year beginning in 2024 and ending with a final increase on January 1, 2033 in an amount equal to 4% of the total number of shares of common stock outstanding on such date or to a lesser amount determined by the Compensation Committee of the Board of Directors. As of December 31, 2023, no shares of the Company’s common stock were issued under the 2023 EIP. In connection with the reverse merger, the Company assumed all of the options outstanding under the Neurogene OpCo 2018 Equity Incentive Plan. All of the stock options outstanding under the 2018 Stock Incentive Plan at the time of the Closing of the reverse merger were adjusted to the number of shares and exercise price to reflect the Exchange Ratio. As of December 31, 2023, 609,124 shares of the Company’s common stock were outstanding under the Neurogene OpCo 2018 Equity Incentive Plan and no further grants will be made under the Neurogene OpCo 2018 Equity Incentive Plan. In connection with the reverse merger, the Company assumed all of the options outstanding under the Neoleukin 2014 Equity Incentive Plan. As of December 31, 2023, 214,709 shares of the Company’s common stock were outstanding under the Neoleukin 2014 Equity Incentive Plan and no further grants will be made under the Neoleukin 2014 Equity Incentive Plan. The Company measures stock-based awards at their grant-date fair value and records compensation expense on a straight-line basis over the vesting period of the awards. The Company recorded stock-based compensation expense in the following expense categories in its accompanying consolidated statements of operations (in thousands): Year Ended 2023 2022 Research and development $ 897 $ 732 General and administrative 521 520 Total expense $ 1,418 $ 1,252 The following table summarizes the option activity under the stock option plans: Number Weighted Weighted Outstanding at December 31, 2022 468,632 $ 13.23 7.37 Assumption of options in connection with the reverse merger 215,207 $ 77.20 2.50 Granted 183,391 $ 18.91 Exercised (20,348) $ 8.24 Expired/Forfeited (23,049) $ 20.34 Outstanding at December 31, 2023 823,833 $ 31.43 5.89 Exercisable at December 31, 2023 527,053 $ 38.42 4.73 At December 31, 2023, the aggregate intrinsic value of outstanding options and exercisable options was approximately $2.6 million and $2.3 million, respectively. The aggregate intrinsic value of options exercised was approximately $0.3 million for the year ended December 31, 2023. The weighted-average grant date fair value of options granted was $12.99 and $15.37 per share for the years ended December 31, 2023 and 2022, respectively. The Company recorded stock-based compensation related to stock options of approximately $1.4 million and $1.0 million for the years ended December 31, 2023 and 2022, respectively. As of December 31, 2023, the total unrecognized compensation expense related to unvested stock option awards was approximately $3.2 million, which the Company expects to recognize over a weighted-average period of 2.59 years. The following table summarizes information about the outstanding and exercisable options at December 31, 2023 (in thousands, except share and per share amounts): Options Outstanding Options Exercisable Exercise Price Range Number Outstanding Weighted Average Remaining Contractual Weighted Average Exercise Price Intrinsic Value Number Exercisable Weighted Average Remaining Contractual Weighted average Exercise Price Intrinsic Value $5.19 - $9.99 108,600 5.12 $ 5.86 $ 1,469 108,315 5.12 $ 5.86 $ 1,465 $10.00 - $19.99 365,112 6.95 $ 15.06 $ 1,596 184,871 5.37 $ 13.42 $ 1,120 $20.00 - $29.99 196,723 7.14 $ 22.43 $ — 80,817 7.41 $ 22.88 $ — $30.00 - $274.80 153,398 2.27 $ 100.05 $ — 153,050 2.26 $ 99.86 $ — The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below: Year Ended 2023 2022 Expected volatility 82.96%-83.70% 71.71%-74.01% Risk-free interest rate 3.45%-4.46% 1.47%-4.22% Expected life (in years) 3.58-6.08 5.87-6.09 Expected dividend yield - - Fair value of common stock $ 18.39 $ 20.24 Restricted Stock Awards The Company granted shares of its restricted Class A common stock to certain of its employees in accordance with the terms of their restricted stock award agreements (“RSA”). The following table summarizes restricted Class A common stock activity: Number of Weighted- Unvested balance at December 31, 2022 6,691 $ 5.82 Vested (6,691) $ 5.82 Unvested balance at December 31, 2023 — $ — The Company recorded stock-based compensation expense related to RSAs of approximately $0.02 million and $0.2 million for the years ended December 31, 2023, and 2022, respectively. Employee Stock Purchase Plan In connection with the reverse merger, the Company stockholders approved the 2023 Employee Stock Purchase Plan (the “2023 ESPP”) on December 13, 2018 and Board of Directors ratified the 2023 ESPP on December 18, 2018. A total of 173,223 shares of common stock have been reserved for issuance under the 2023 ESPP. Subject to share and dollar limits as described in the plan, the 2023 ESPP allows eligible employees to contribute, through payroll deductions, up to 15% of their earnings for the purchase of the Company’s shares of common stock at the lower of 85% of the closing price of the Company’s common stock on the first trading day of the offering period or 85% of the closing price of the Company’s common stock on the last trading day of the offering period. As of December 31, 2023, no shares have been issued under the 2023 ESPP.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income (loss) before provision for income taxes consisted of the following (in thousands): Year Ended December 31, 2023 2022 United States $ (36,317) $ (55,189) Loss before provision for income taxes $ (36,317) $ (55,189) No provision for federal or state income taxes was recorded during the years ended December 31, 2023 and 2022, as the Company incurred operating losses and maintains a full valuation allowance against its net deferred tax assets. The reported amount of income tax benefit for the years ended December 31, 2023 and 2022 differs from the amount that would result from applying domestic federal statutory rates to pretax losses primarily because of changes in the valuation allowance, state taxes, and the generation of research and development credits. The reconciliation of the Federal statutory income tax provision to the Company’s effective income tax provision is as follows: Year Ended 2023 2022 Federal statutory income tax 21.0 % 21.0 % State income taxes, net of federal tax benefit (0.8) % (0.1 %) Other permanent items (0.5) % (0.4) % Research and development credit 5.8 % 3.0 % Bargain purchase gain 9.5 % — % Valuation allowance (35.0) % (23.5) % Effective income tax rate — — Significant components of the Company’s net deferred tax assets are as follows (in thousands): Year Ended 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 60,287 $ 25,253 Research and development credits 9,765 3,681 Accruals & reserves 802 727 Stock compensation 2,952 107 Amortization 778 298 Lease liability 3,157 995 Capitalized research and development expenses 22,134 8,271 Total deferred tax assets 99,875 39,332 Valuation allowance (98,926) (38,168) Net deferred tax assets 949 1,164 Deferred tax liabilities: Depreciation (152) (224) Right of use asset (797) (940) Total deferred tax liabilities (949) (1,164) Net deferred taxes $ — $ — As of December 31, 2023 and 2022, the Company had a federal net operating loss carryforward of $277.9 million and $110.5 million, respectively, which may be available to offset future income tax liabilities. Of this amount, approximately $2.3 million will begin to expire in 2038 and approximately $275.6 million are carried forward indefinitely. As of December 31, 2023 and 2022, the Company has state NOL carryforwards of $35.1 million and $36.0 million, respectively. Of this amount, approximately $33.4 million will begin to expire in 2038 and approximately $1.7 million are carried forward indefinitely. As of December 31, 2023 and 2022, the Company has federal research and development tax credit carryforwards of $7.5 million and $2.9 million, respectively, which begin to expire in 2039. As of December 31, 2023, the Company has federal orphan drug tax credit carryforwards of $2.2 million, which begin to expire in 2042. As of December 31, 2023, the Company has state research and development tax credit carryforwards of $0.1 million which begin to expire in 2036. Future realization of the tax benefits of existing temporary differences and net operating loss carryforwards ultimately depends on the existence of sufficient taxable income within the carryforward period. As of December 31, 2023 and 2022, the Company performed an evaluation to determine whether a valuation allowance was needed. The Company considered all available evidence, both positive and negative, which included the results of operations for the current and preceding years. The Company determined that it was not possible to reasonably quantify future taxable income and determined that it is more likely than not that all of the deferred tax assets will not be realized. Accordingly, the Company maintained a full valuation allowance as of December 31, 2023 and 2022. The Tax Cuts and Jobs Act (TCJA) resulted in significant changes to the treatment of research and developmental (R&D) expenditures under Section 174 of the IRC. For tax years beginning after December 31, 2021, taxpayers are required to capitalize and amortize all R&D expenditures that are paid or incurred in connection with their trade or business. Specifically, costs for U.S.-based R&D activities must be amortized over five years and costs for foreign R&D activities must be amortized over 15 years—both using a midyear convention. As of December 31, 2023, the Company capitalized a substantial amount of R&D expenditures primarily related to research and development activities performed in the US. The Company’s valuation allowance increased by $60.7 million and $13.0 million for the years ended December 31, 2023 and 2022, respectively, due primarily to the generation of NOLs. The Company’s valuation allowance for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year Ended 2023 2022 Valuation allowance beginning of year $ 38,168 $ 25,195 Increases recorded to income tax provision 12,701 12,973 Increase recorded to equity 48,057 — Valuation allowance at end of year $ 98,926 $ 38,168 Utilization of the net operating loss and research and development credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating loss and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. The Company has not completed a study to assess whether a change of ownership has occurred, or whether there have been multiple ownership changes since its formation, due to the significant cost and complexity associated with a study. There could also be additional ownership changes in the future which may result in additional limitations on the utilization of net operating loss carryforwards and tax credits. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending tax examinations. The Company’s tax returns are open under statute from 2018 to the present. As of December 31, 2023 and 2022, the Company had liabilities for uncertain tax positions of $2.6 million and $1.1 million, respectively, which, if recognized, would impact the Company’s effective income tax rate. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax provision. As of December 31, 2023 and 2022, the Company had not accrued interest or penalties related to uncertain tax positions. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year Ended 2023 2022 Beginning balance $ 1,108 $ 632 Additions based on tax positions related to current year 574 476 Additions for tax positions of prior years 929 — Ending Balance $ 2,611 $ 1,108

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company sponsors a 401(k) Plan. Employees become eligible for participation upon the start of employment. Participants may elect to have a portion of their salary deferred and contributed to the 401(k) Plan up to the limit allowed under the Internal Revenue Code. The Company makes a matching contribution to the plan for each participant who has elected to make tax-deferred contributions for the plan year. The Company made matching contributions which amounted to approximately $0.5 million and $0.5 million for each of the years ended December 31, 2023 and 2022, respectively. These amounts were charged to the consolidated statement of operations. The employer contributions vest over a five-year period.

Employee Retention Credit

Employee Retention Credit	12 Months Ended
	Dec. 31, 2023
Postemployment Benefits [Abstract]
Employee Retention Credit	Employee Retention Credit Pursuant to the Coronavirus Aid, Relief, and Economic Security Act, the Company is eligible for an employee retention credit subject to certain criteria. Since there are no generally accepted accounting principles for for-profit business entities that receive government assistance that is not in the form of a loan, an income tax credit or revenue from a contract with a customer, the Company determined the appropriate accounting treatment by analogy to other guidance. The Company accounted for the employee retention credit by recognizing the employee retention credit on a systematic basis over the periods in which the entity recognizes the payroll expenses for which the grant (i.e., tax credit) is intended to compensate when there is reasonable assurance (i.e., it is probable) that the entity will comply with any conditions attached to the grant and the grant (i.e., tax credit) will be received. The Company accounted for and received approximately $0.9 million of employee retention credits during the years ended December 31, 2023, which was recorded as a reduction of research and development expenses and general and administrative expenses on the consolidated statement of operations.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events From January 1, 2024 until the financial statements were issued, the Company granted 740,752 options and 482,384 RSUs to employees and consultants, and 29,320 options were exercised.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net income (loss)	$ 13,654	$ (36,317)	$ (55,189)

Insider Trading Arrangements

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

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements are presented in United States (“U.S.”) dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Use of Estimates	Use of Estimates The preparation of the financial statements in accordance with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. In preparing these financial statements, management used significant estimates in the following areas, among others: recoverability of the Company’s net deferred tax assets and related valuation allowance, useful lives and recoverability of property and equipment, determining the Incremental Borrowing Rate (“IBR”) for calculating lease liabilities and related right-of-use (“ROU”) assets and finance lease assets, clinical trial accruals, accrual estimates for all CVRs, the value attributed to employee stock options and other stock-based awards and valuation of common stock. On an ongoing basis, the Company reviews its estimates to ensure that they appropriately reflect changes in the business or as new information becomes available. Actual results may differ from these estimates.
Segment Information	Segment Information Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company operates as a single operating segment and has one reportable segment. The Company’s operations and its assets are held in the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. As of December 31, 2023, the Company had $147.7 million in excess of the federally insured limits. The Company places its cash in financial institutions that management believes to be of high credit quality.
Investments	Investments Investment securities at December 31, 2023 consist of U.S. treasury notes. The Company classifies these securities as held-to-maturity. Held-to-maturity securities are those securities in which the Company has the ability and intent to hold the security until maturity. Held-to-maturity securities are recorded at amortized cost, adjusted for the amortization or accretion of premiums or discounts. Premiums and discounts are amortized or accreted over the life of the related held-to-maturity security as an adjustment to yield using the effective interest method. The Company reassesses the classification of held-to-maturity at each reporting period.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Management believes that the carrying amounts of the Company’s financial instruments, including cash, prepaid and other current assets, accounts payable and accrued expenses, approximate fair value due to the short-term nature of these instruments. 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). ◦ 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).
Property and Equipment	Property and Equipment Property and equipment costs are stated at cost, net of accumulated depreciation and amortization. The cost of property and equipment costs are depreciated on the straight-line method over the following estimated useful lives: Type Estimated useful Lab equipment 5 years Manufacturing equipment 10 years Leasehold improvements Lesser of the remaining economic life of the Furniture and fixtures 5 years Software 3 years Leasehold improvements are amortized over the shorter of the estimated useful life of the assets or the remaining lease term. Major additions and betterments are capitalized; maintenance and repairs, which do not improve or extend the life of the respective assets, are charged to operating expenses as incurred. Depreciation has been calculated using the straight-line method over their estimated useful lives once the asset is placed in service. Costs of software obtained for internal use are capitalized in accordance with ASC 350 and are recognized on a straight-line basis over the useful life. Software costs that do not meet the capitalization criteria, including costs incurred in the maintenance and minor upgrade and enhancement of software without additional functionality, are expensed as incurred. No depreciation has been calculated on work in progress assets.
Capitalized Software Development Costs	Capitalized Software Development Costs
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
Leases	Leases Operating and finance leases are accounted for in accordance with ASU 2016-02, Leases as amended. They are presented in the Company’s consolidated balance sheet as right-of-use assets from leases, current lease liabilities, and long-term lease liabilities. At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding ROU asset upon commencement of the lease using the implicit rate or a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. As the Company’s leases do not provide an implicit rate, the Company utilizes the appropriate IBR, determined as the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and in a similar economic environment. Both operating and finance lease assets represent a right to use an underlying asset for the lease term, and operating and finance lease liabilities represent an obligation to make lease payments arising from the lease. Lease liabilities with a term greater than one year and their corresponding ROU assets are recognized on the balance sheet at the commencement date of the lease based on the present value of lease payments over the expected lease term. Certain of the Company’s lease agreements at the adoption date contain renewal options. The Company does not recognize right-of-use assets or lease liabilities for renewal periods upon lease inception date unless it is determined that the Company is reasonably certain of renewing the lease at inception or when a triggering event occurs. The Company also made an accounting policy election to utilize the short-term lease exemption, whereby leases with a term of 12 months or less will not follow the recognition and measurement requirements of the standard.
Contingent Value Rights	Contingent Value Right s As discussed within the Reverse Merger and Pre-Closing Financing section in Note 1, Organization and Description of Business , the Company entered into a CVR Agreement on December 18, 2023 prior to Closing. Included in the CVR Agreement are three different types of CVRs: (i) the Lease CVR, (ii) the Intellectual Property CVR, and (iii) the Sales Tax CVR (together, the “CVRs”). The Company evaluated each of the CVRs to determine if they qualified as derivatives under ASC 815, Derivatives and Hedging , and concluded that since certain scope exceptions were met, the CVRs did not qualify as derivatives. Instead, the Company records a contingent consideration liability associated with the CVRs when payments are probable and estimable under ASC 450. In assessing whether payments are probable and estimable, the Company considers the existence of or ability to enter agreements with third parties or government agencies and timing of potential payments. As of December 31, 2023, the Company recorded $0.3 million and $1.0 million to lease contingent value rights liability, current and lease contingent value rights liability, non-current, respectively, related to amounts that are probable and estimable under the Lease CVR. As no other amounts related to the CVR Agreement were probable as of December 31, 2023, no contingencies for the Intellectual Property CVR or Sales Tax CVR have been recorded. Refer to Note 1, Organization and Description of Business , and Note 10, Commitments and Contingencies , for further discussion on the CVR components.
Exit and Disposals Costs	Exit and Disposal Costs In connection with the reverse merger and through fiscal 2024, the Company has incurred and expects to incur costs to wind-down Neoleukin’s Phase 1 NL-201 study. This study has ceased further development, and the Company has no plans to continue developing Neoleukin’s de novo
Research and Development	Research and Development Research and development costs are expensed as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel of the Company’s research and development personnel, facilities, supplies, rent, insurance, stock-based compensation, depreciation and external expenses incurred under agreements with contract research organizations and investigative sites that conduct preclinical studies and manufacture the drug product for the preclinical activities and other costs associated with preclinical activities. Before a compound receives regulatory approval, the Company records upfront and milestone payments to third parties under licensing arrangements as expense provided that there is no alternative future use of the rights in other research and developments projects. Non-refundable prepayments for research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Costs for certain development activities, such as outside research programs funded by the Company, are recognized based on an evaluation of the progress to completion of specific tasks with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense as applicable. There can be judgment involved in measuring the research and development expenses to be recognized in a particular period. In some cases, expense is recorded using an underlying assumption of the progress to completion of specific activities. For example, costs may be recognized based on the passage of time for activities that span reporting periods. If the provision of services is not linear then this assumption could impact the amount of expense recognized. The level of judgment varies based on the nature of the services being performed and the underlying support obtained. For some activities, such as for certain clinical trials, expense is recorded based on information obtained from vendors as an intermediary to those performing the underlying services, such as contract research organizations. These estimates are inherently more judgmental since the quality and availability of the underlying data may vary. The Company does not need to make significant estimates where costs incurred are supported by invoices or reports of costs incurred are obtained from a vendor that is directly performing the underlying services, such as a consultant or contract manufacturing organization.
General and Administrative	General and Administrative
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation awards in accordance with ASC Topic 718, Compensation – Stock Compensation (“ASC 718”). ASC 718 requires all stock-based payments, including grants of stock options and restricted stock, to be recognized in the consolidated statements of operations based on their fair values. All of the stock-based awards are subject only to service-based vesting conditions. Management estimates the fair value of the stock option awards using the Black-Scholes option pricing model, which requires the input of assumptions, including (a) the fair value of the Company’s common stock, (b) the expected stock price volatility, (c) the calculation of expected term of the award, (d) the risk-free interest rate and (e) expected dividends. Management estimates the fair value of the restricted stock awards using the fair value of the Company’s common stock. Forfeitures are recognized as they are incurred. Prior to the reverse merger, the Company periodically estimated the fair value of the Company’s common stock considering, among other things, valuations of its common stock prepared by management with the assistance of a third party valuation firm in accordance with the guidance provided by the American Institute of Certified Public Accountants 2013 Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation . Following the reverse merger, the fair value of the Company’s common stock is based on the closing stock price on the date of grant as reported on the Nasdaq Global Market. The expected life of the stock options in years is estimated using the “simplified method,” as prescribed in SEC’s Staff Accounting Bulletin (SAB) No. 107, as the Company has no historical information from which to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for its stock option grants. The simplified method is the midpoint between the vesting period and the contractual term of the option. For stock price volatility, the Company uses comparable public companies as a basis for its expected volatility to calculate the fair value of option grants. The risk-free rate is based on the U.S. Treasury yield curve commensurate with the expected life of the option. The expected dividend yield is zero as the Company has no history of paying dividends and no plans to do so in the near term. The Company classified stock-based compensation expense in its consolidated statement of operations in the same manner of the award recipient’s payroll costs.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC 740 , Income Taxes , which prescribes the use of the liability method whereby deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. A valuation allowance is provided to reduce the net deferred tax assets to a level which, more likely than not, will be realized. The Company assesses its income tax positions and records tax benefits based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, the Company records the amount of tax benefit with a greater than 50 percent likelihood of being realized upon ultimate settlement with a taxing authority having full knowledge of all relevant information. For those income tax positions for which it is not more likely than not that a tax benefit will be sustained, no tax benefit is recognized in the financial statements. Potential interest and penalties associated with such uncertain tax positions is recorded as a component of income tax expense.
Net Income (Loss) Per Share	Net Income (Loss) Per Share For the prior year and pre-merger periods in which the Company had multiple classes of stock participating in earnings, the Company uses the two-class method in calculating earnings per share. Basic earnings per share of Class A and Class B common stock is computed by dividing net income attributable to Neurogene OpCo by the weighted-average number of shares of Class A and Class B common stock outstanding during the period. For the post-merger period, the only period in which the Company had income, diluted earnings per share of the single class of common stock is computed by dividing net income attributable to the Company, adjusted for the assumed exchange of all potentially dilutive instruments for common stock, by the weighted-average number of shares of common stock outstanding, adjusted to give effect to potentially dilutive elements. As of December 18, 2023, the Company consummated the reverse merger, leaving only one class of common stock remaining, and as such, the two-class method is not presented for the post-merger period from December 18, 2023 to December 31, 2023. The single class of common stock remaining post-merger is referred to throughout as “common stock.”
Recently Issued Accounting Standards	Recently Issued Accounting Standards From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed below, the Company does not believe that the adoption of recently issued standards have or may have a material impact on our financial statements or disclosures. 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 after January 1, 2025. The Company is analyzing the impact of this standard on its disclosures in the consolidated financial statements. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures which requires consistent categories and greater disaggregation of information in the rate reconciliation and income taxes paid disaggregated by jurisdiction. This standard will be effective for annual periods beginning after December 15, 2024. The Company is currently evaluating the impact of this standard on the Company’s consolidated financial statements and related disclosures but does not expect the adoption of ASU 2020-09 to be material. Recently Adopted Accounting Pronouncements The Company adopted ASU 2016-13, Financial Instruments - Credit Losses , as amended, on January 1, 2023. This ASU sets forth a current expected credit loss model which requires the Company to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost and applies to some off-balance sheet credit exposures. The impact of ASU 2016-13 on the Company’s consolidated financial statements was not material.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash in the balance sheets that sum to the total of the same such amounts shown in the statements of cash flows (in thousands): December 31, 2023 2022 Cash and cash equivalents $ 148,210 $ 82,021 Restricted cash 508 — Total cash, cash equivalents and restricted cash $ 148,718 $ 82,021
Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash in the balance sheets that sum to the total of the same such amounts shown in the statements of cash flows (in thousands): December 31, 2023 2022 Cash and cash equivalents $ 148,210 $ 82,021 Restricted cash 508 — Total cash, cash equivalents and restricted cash $ 148,718 $ 82,021
Property, Plant and Equipment	The cost of property and equipment costs are depreciated on the straight-line method over the following estimated useful lives: Type Estimated useful Lab equipment 5 years Manufacturing equipment 10 years Leasehold improvements Lesser of the remaining economic life of the Furniture and fixtures 5 years Software 3 years Property and equipment consist of the following (in thousands): December 31, 2023 2022 Lab equipment $ 3,144 $ 3,088 Manufacturing equipment 6,142 5,955 Leasehold improvements 15,376 15,298 Office equipment 19 — Software 268 289 Construction in progress 234 252 Total property and equipment, cost 25,183 24,882 Less accumulated depreciation and amortization (8,009) (4,767) Property and equipment, net $ 17,174 $ 20,115
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted net income (loss) per share (in thousands, except share and per share amounts): Year Ended December 31, 2023 Year Ended December 31, 2022 Pre-Merger (1) Post-Merger (2) Pre-Merger (1) Class A Class B Common stock Class A Class B Net income (loss) per share, basic: Numerator: Net income (loss) $ (49,971) $ — $ 13,654 $ (55,189) $ — Denominator: Weighted-average shares outstanding used in computing net income (loss) per share, basic 426,097 — 491,867 394,533 — Net income (loss) per share, basic $ (117.28) $ — $ 27.76 $ (139.88) $ — Net income (loss) per share, diluted: Numerator: Net income (loss) $ (49,971) $ — $ 13,654 $ (55,189) $ — Denominator: Weighted-average shares outstanding used in computing net income (loss) per share, basic 426,097 — 491,867 394,533 — Weighted-average effect of dilutive securities: Warrants to purchase common stock — — 4,063,361 — — Options to purchase common stock — — 101,719 — — Weighted-average shares outstanding used in computing net income (loss) per share, diluted 426,097 — 4,656,947 394,533 — Net income (loss) per share, diluted $ (117.28) $ — $ 2.93 $ (139.88) $ — (1) Represents the period starting January 1, 2023 through Closing for the year ended December 31, 2023 and for the year ended December 31, 2022. (2) Represents the period subsequent to Closing (December 18, 2023) through December 31, 2023.
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be antidilutive were as follows: Year Ended December 31, 2023 Year Ended December 31, 2022 Pre-Merger (1) Post-Merger (2) Pre-Merger (1) Class A Class B Common stock Class A Class B Options to purchase common stock 614,729 — 541,180 468,632 — Restricted stock awards — — — 6,691 — Series A-1 convertible preferred stock (3) — — — 18,604,653 — Series A-2 convertible preferred stock (3) — — — 13,291,208 — Series B convertible preferred stock (3) — — — 74,405,719 — Total awards excluded 614,729 — 541,180 106,776,903 — (3) The convertible preferred stock does not reflect the application of the 0.0756 Exchange Ratio.

Reverse Merger (Tables)

Reverse Merger (Tables)	12 Months Ended
	Dec. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Asset Acquisition	The following table summarizes the final purchase price paid in the reverse merger along with the fair value allocation (in thousands, except share and per share amounts): Calculation of total purchase price: Number of common shares and pre-funded warrants of the combined company owned by Neoleukin stockholders (1) 2,777,017 Multiplied by the fair value per share of Neoleukin common stock (2) $ 13.76 Fair value of Neoleukin common stock issued (2) $ 38,212 Transaction costs (6) 4,140 Contingent consideration liability (3) 1,287 Total purchase price $ 43,639 Fair value of Neoleukin net assets acquired at Closing and fair value allocation: Monetary assets acquired (4) $ 76,906 Liabilities assumed (5) (21,052) Fair value of net assets acquired $ 55,854 Less: total consideration transferred (38,212) Excess of fair value of monetary assets acquired over total consideration transferred $ 17,642 Fair value allocated to contingent consideration liability (3) 1,287 Fair value allocated to bargain purchase gain 16,355 Total fair value allocated $ 17,642 Reconciliation of allocation to purchase price: Fair value of monetary assets acquired (4) $ 76,906 Transaction costs (6) 4,140 Neoleukin liabilities assumed (5) (21,052) Fair value allocated to bargain purchase gain (16,355) Total purchase price $ 43,639 (1) The number of shares is based on a total 2,351,030 shares of Neoleukin common stock and 425,987 pre-funded warrants outstanding as of December 18, 2023. (2) The fair value of Neoleukin common stock (also referred to in discussions herein as “total consideration transferred”) was determined using the closing price of Neoleukin’s common stock on December 15, 2023, after giving effect to the Reverse Stock Split. As discussed in Note 3, Summary of Significant Accounting Policies , Neoleukin’s stock price is measured using Level 1 fair value measurements. (3) Refer to Note 10, Commitments and Contingencies , for further discussion on the contingent consideration liability. (4) In accordance with the guidance in ASC 805, Business Combinations , the fair value of the net assets acquired was allocated to any non-monetary assets on a pro rata basis. As such, the assets acquired only include cash, cash equivalents and restricted cash of $22.2 million, short-term investments of $53.9 million, and other immaterial monetary assets of $0.8 million. (5) Included in Neoleukin liabilities assumed is (i) $10.9 million in lease liabilities, (ii) $3.8 million in accrued payroll and $6.3 million in other accrued costs and accounts payable. For the lease liabilities, the Company utilized judgment in estimating the IBR used in determining the fair value of the leases upon Closing. (6) As indicated in ASC 805 regarding asset purchases, the accounting acquirer’s transaction costs incurred directly related to the asset purchase should be included in the consideration to acquire the assets. These costs were initially recorded as deferred financing costs and then reclassified to offset to equity upon Closing.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-Maturity	The following table summarizes the Company’s investment securities as of December 31, 2023 (in thousands): December 31, 2023 Amortized cost, as adjusted Gross Gross Estimated fair Short-term investments: U.S. treasury notes $ 48,947 $ 16 $ — $ 48,963 December 31, 2022 Amortized cost, as adjusted Gross Gross Estimated fair Short-term investments: U.S. treasury notes $ — $ — $ — $ — All of the Company’s investments mature within the next 12 months.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis	As of December 31, 2023 and December 31, 2022, financial assets measured at fair value on a recurring basis are categorized in the table below based upon the lowest level of significant input to the valuations (in thousands): December 31, 2023 Level 1 Level 2 Level 3 Assets: Money market funds $ 144,358 $ — $ — U.S. treasury notes 48,947 — — Total $ 193,305 $ — $ — December 31, 2022 Level 1 Level 2 Level 3 Assets: Money market funds $ 78,749 $ — $ —

Prepaid expenses and other cu_2

Prepaid expenses and other current assets (Tables)	12 Months Ended
	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure	Prepaid expenses and other assets consist of the following (in thousands): December 31, 2023 2022 Refunds and other receivables $ 600 $ 990 Prepaid expenses 1,496 1,078 Other current assets 1,095 630 Total prepaid and other current assets $ 3,191 $ 2,698

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The cost of property and equipment costs are depreciated on the straight-line method over the following estimated useful lives: Type Estimated useful Lab equipment 5 years Manufacturing equipment 10 years Leasehold improvements Lesser of the remaining economic life of the Furniture and fixtures 5 years Software 3 years Property and equipment consist of the following (in thousands): December 31, 2023 2022 Lab equipment $ 3,144 $ 3,088 Manufacturing equipment 6,142 5,955 Leasehold improvements 15,376 15,298 Office equipment 19 — Software 268 289 Construction in progress 234 252 Total property and equipment, cost 25,183 24,882 Less accumulated depreciation and amortization (8,009) (4,767) Property and equipment, net $ 17,174 $ 20,115

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): December 31, 2023 2022 Compensation and related benefits $ 3,496 $ 3,357 Research and development 4,895 1,800 Accrued severance, bonus, and retention (1) 2,476 — Accrued offering costs in connection with pre-closing financing 3,334 — Accrued transaction costs related to reverse merger 2,557 — Other 737 167 Total accrued expenses and other current liabilities $ 17,495 $ 5,324 (1) Includes accrued severance, bonus, and retention payments for current and former Neoleukin employees. Refer to Note 10, Commitments and Contingencies , for further detail.

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Lease, Cost	Supplemental lease expense related to leases for the years ended December 31, 2023 and 2022 was as follows (in thousands): Years Ended 2023 2022 Operating lease cost $ 1,037 $ 1,037 Finance lease cost Amortization of finance leases 35 4 Interest on finance lease liabilities 12 2 Variable lease cost 178 196 Short-term lease cost 80 74 Total lease cost $ 1,342 $ 1,313
Lessee, Operating Lease, Liability, to be Paid, Maturity	The following table summarizes the maturity of the Company’s operating and finance lease liabilities on an undiscounted cash flow basis and a reconciliation to the operating and finance lease liabilities recognized on the Company’s consolidated balance sheet as of December 31, 2023 (in thousands): Maturity of operating lease liabilities 2024 $ 3,862 2025 3,964 2026 3,672 2027 3,235 2028 3,294 2029 616 Total lease payments $ 18,643 Less: interest (3,782) Total operating lease liabilities $ 14,861
Finance Lease, Liability, to be Paid, Maturity	Maturity of finance lease liabilities 2024 $ 51 2025 50 2026 15 2027 6 2028 1 Total lease payments $ 123 Less: interest (16) Total finance lease liabilities $ 107
Assets And Liabilities, Lessee	Supplemental balance sheet information related to leases as of December 31, 2023 and 2022 was as follows (in thousands): Leases December 31, 2023 2022 Operating right-of-use assets $ 3,681 $ 4,344 Operating current lease liabilities 2,559 678 Operating noncurrent lease liabilities 12,302 3,921 Total operating lease liabilities $ 14,861 $ 4,599 Finance right-of-use assets $ 98 $ 87 Finance current lease liabilities 42 24 Finance noncurrent lease liabilities 65 66 Total finance lease liabilities $ 107 $ 90 Other information December 31, 2023 2022 Cash paid for amounts included in measurement of operating lease liabilities (in thousands) $ 1,051 $ 1039 Cash paid for amounts included in measurement of finance lease liabilities (in thousands) $ 42 $ 3 Weighted-average remaining lease term - operating leases (in years) 4.88 5.72 Weighted-average remaining lease term - finance lease (in years) 2.53 3.47 Weighted-average discount rate - operating leases 9.72 % 8.86 % Weighted-average discount rate - finance lease 11.49 % 11.45 %
Contractual Obligation, Fiscal Year Maturity	The following table summarizes the maturity of the Company’s lease CVR as of December 31, 2023 (in thousands): Maturity of Lease CVR 2024 $ 281 2025 598 2026 408 Total lease CVR payments $ 1,287

Stockholders_ Equity (Deficit)

Stockholders’ Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Neurogene OpCo had reserved shares of common stock for future issuance as follows: December 31, 2023 2022 Conversion of Series A-1 (1) — 18,604,653 Conversion of Series A-2 (1) — 13,291,208 Conversion of Series B (1) — 74,405,719 Total conversion of preferred stock — 106,301,580 Options outstanding 823,833 468,632 Shares available for future grant under the 2018 Equity Incentive Plan — 315,548 Shares available for future grant under the 2023 Equity Incentive Plan 2,237,722 — Total common stock reserved 3,061,555 107,085,760 (1) The convertible preferred stock does not reflect the application of the 0.0756 Exchange Ratio.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount	The Company recorded stock-based compensation expense in the following expense categories in its accompanying consolidated statements of operations (in thousands): Year Ended 2023 2022 Research and development $ 897 $ 732 General and administrative 521 520 Total expense $ 1,418 $ 1,252
Share-Based Payment Arrangement, Option, Activity	The following table summarizes the option activity under the stock option plans: Number Weighted Weighted Outstanding at December 31, 2022 468,632 $ 13.23 7.37 Assumption of options in connection with the reverse merger 215,207 $ 77.20 2.50 Granted 183,391 $ 18.91 Exercised (20,348) $ 8.24 Expired/Forfeited (23,049) $ 20.34 Outstanding at December 31, 2023 823,833 $ 31.43 5.89 Exercisable at December 31, 2023 527,053 $ 38.42 4.73
Share-Based Payment Arrangement, Option, Exercise Price Range	The following table summarizes information about the outstanding and exercisable options at December 31, 2023 (in thousands, except share and per share amounts): Options Outstanding Options Exercisable Exercise Price Range Number Outstanding Weighted Average Remaining Contractual Weighted Average Exercise Price Intrinsic Value Number Exercisable Weighted Average Remaining Contractual Weighted average Exercise Price Intrinsic Value $5.19 - $9.99 108,600 5.12 $ 5.86 $ 1,469 108,315 5.12 $ 5.86 $ 1,465 $10.00 - $19.99 365,112 6.95 $ 15.06 $ 1,596 184,871 5.37 $ 13.42 $ 1,120 $20.00 - $29.99 196,723 7.14 $ 22.43 $ — 80,817 7.41 $ 22.88 $ — $30.00 - $274.80 153,398 2.27 $ 100.05 $ — 153,050 2.26 $ 99.86 $ —
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The fair value of each option was estimated on the date of grant using the weighted average assumptions in the table below: Year Ended 2023 2022 Expected volatility 82.96%-83.70% 71.71%-74.01% Risk-free interest rate 3.45%-4.46% 1.47%-4.22% Expected life (in years) 3.58-6.08 5.87-6.09 Expected dividend yield - - Fair value of common stock $ 18.39 $ 20.24
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	The following table summarizes restricted Class A common stock activity: Number of Weighted- Unvested balance at December 31, 2022 6,691 $ 5.82 Vested (6,691) $ 5.82 Unvested balance at December 31, 2023 — $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	Income (loss) before provision for income taxes consisted of the following (in thousands): Year Ended December 31, 2023 2022 United States $ (36,317) $ (55,189) Loss before provision for income taxes $ (36,317) $ (55,189)
Schedule of Effective Income Tax Rate Reconciliation	The reconciliation of the Federal statutory income tax provision to the Company’s effective income tax provision is as follows: Year Ended 2023 2022 Federal statutory income tax 21.0 % 21.0 % State income taxes, net of federal tax benefit (0.8) % (0.1 %) Other permanent items (0.5) % (0.4) % Research and development credit 5.8 % 3.0 % Bargain purchase gain 9.5 % — % Valuation allowance (35.0) % (23.5) % Effective income tax rate — —
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s net deferred tax assets are as follows (in thousands): Year Ended 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 60,287 $ 25,253 Research and development credits 9,765 3,681 Accruals & reserves 802 727 Stock compensation 2,952 107 Amortization 778 298 Lease liability 3,157 995 Capitalized research and development expenses 22,134 8,271 Total deferred tax assets 99,875 39,332 Valuation allowance (98,926) (38,168) Net deferred tax assets 949 1,164 Deferred tax liabilities: Depreciation (152) (224) Right of use asset (797) (940) Total deferred tax liabilities (949) (1,164) Net deferred taxes $ — $ —
Summary of Valuation Allowance	The Company’s valuation allowance for the years ended December 31, 2023 and 2022 is as follows (in thousands): Year Ended 2023 2022 Valuation allowance beginning of year $ 38,168 $ 25,195 Increases recorded to income tax provision 12,701 12,973 Increase recorded to equity 48,057 — Valuation allowance at end of year $ 98,926 $ 38,168
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year Ended 2023 2022 Beginning balance $ 1,108 $ 632 Additions based on tax positions related to current year 574 476 Additions for tax positions of prior years 929 — Ending Balance $ 2,611 $ 1,108

Organization and Description _2

Organization and Description of Business (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 18, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Conversion of stock, shares converted (in shares)	10,472,635
Reverse merger, conversion ratio (in shares)	0.0756
Convertible preferred stock, shares issued upon conversion	7,231,747
Asset acquisition, percentage of net proceeds before closing		100%
Asset acquisition, percentage of net proceeds post closing		80%
Lease contingent value rights liability, current | $		$ 281	$ 0
Lease contingent value rights liability, non-current | $		$ 1,006	$ 0
Stockholders' Equity Note, Stock Split, Conversion Ratio	0.25
Neoleukin
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Conversion of stock, shares converted (in shares)	3,240,888
Asset Acquisition, Percentage of Shares Acquired		84%
Pre-closing Financing
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Class of warrant or right, number of securities called by warrants or rights (in shares)	1,811,739
Sale of stock, number of shares issued in transaction (in shares)	2,792,206
Sale of stock, price per share (in dollars per share) | $ / shares	$ 20.63
Sale of stock, consideration received on transaction | $	$ 95,000
Class of warrant or right, exercise price of warrants or rights (in dollars per share) | $ / shares	$ 20.63

Risks and Uncertainties (Detail

Risks and Uncertainties (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net income (loss)	$ 13,654	$ (36,317)	$ (55,189)
Cash used in operations		51,422	52,824
Accumulated deficit	187,154	187,154	150,837
Cash and cash equivalents	148,210	148,210	$ 82,021
Sales Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Sale of stock, maximum aggregate offering price	$ 40,000	$ 40,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 18, 2023 USD ($)
Cash and Cash Equivalents [Line Items]
Number of operating segments | segment	1
Number of reportable segments | segment	1
Restricted cash	$ 508,000	$ 0
Cash and cash equivalents, at or above FDIC insurance limits	147,700,000
Debt securities, held-to-maturity, allowance for credit loss	0
Capitalized computer software, net	300,000	400,000
Capitalized computer software, amortization	200,000	200,000
Capitalized computer software, impairments	0	0
Tangible asset impairment charges	0	0
Lease contingent value rights liability, current	281,000	0
Lease contingent value rights liability, non-current	1,006,000	$ 0
Restructuring reserve			$ 900,000
Expected dividend yield	0
Accrued Liabilities And Other Liabilities, Current
Cash and Cash Equivalents [Line Items]
Restructuring reserve	$ 800,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 148,210	$ 82,021
Restricted cash	508	0
Total cash, cash equivalents and restricted cash	$ 148,718	$ 82,021	$ 70,544

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Estimated Useful Lives (Details)	Dec. 31, 2023
Lab equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
		Dec. 31, 2023	Dec. 31, 2023	Dec. 18, 2023	Dec. 31, 2022
Numerator:
Net income (loss)		$ 13,654	$ (36,317)		$ (55,189)
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]	491,867
Net income (loss) per share, basic (in dollars per share)	[1]	$ 27.76
Numerator:
Net income (loss)		$ 13,654	$ (36,317)		(55,189)
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]	491,867
Weighted-average effect of dilutive securities:
Warrants to purchase common stock (in shares)		4,063,361
Options to purchase common stock (in shares)		101,719
Weighted-average shares outstanding used in computing net income (loss) per share, diluted (in shares)	[1]	4,656,947
Net income (loss) per share, diluted (in dollars per share)	[1]	$ 2.93
Class A Common Stock
Numerator:
Net income (loss)				$ (49,971)	$ (55,189)
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]			426,097	394,533
Net income (loss) per share, basic (in dollars per share)	[1]			$ (117.28)	$ (139.88)
Numerator:
Net income (loss)				$ (49,971)	$ (55,189)
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]			426,097	394,533
Weighted-average effect of dilutive securities:
Warrants to purchase common stock (in shares)				0	0
Options to purchase common stock (in shares)				0	0
Weighted-average shares outstanding used in computing net income (loss) per share, diluted (in shares)	[1]			426,097	394,533
Net income (loss) per share, diluted (in dollars per share)	[1]			$ (117.28)	$ (139.88)
Class B Common Stock
Numerator:
Net income (loss)				$ 0	$ 0
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]			0	0
Net income (loss) per share, basic (in dollars per share)	[1]			$ 0	$ 0
Numerator:
Net income (loss)				$ 0	$ 0
Denominator:
Weighted-average shares outstanding used in computing net income (loss) per share, basic (in shares)	[1]			0	0
Weighted-average effect of dilutive securities:
Warrants to purchase common stock (in shares)				0	0
Options to purchase common stock (in shares)				0	0
Weighted-average shares outstanding used in computing net income (loss) per share, diluted (in shares)	[1]			0	0
Net income (loss) per share, diluted (in dollars per share)	[1]			$ 0	$ 0
[1] On December 18, 2023, the Company completed its reverse merger, which among other things, resulted in Neurogene OpCo merging with and into a wholly owned subsidiary of Neoleukin Therapeutics, Inc. As the earnings per share information for the pre-merger period is not comparable to the earnings per share information for the post-merger period, the earnings per share information is being presented separately for these periods. See Note 3, Net Income (Loss) Per share , for additional information. (a) Presents information for the pre-merger period for Class A common stock. The pre-merger period is January 1, 2023 through December 17, 2023 for the year ended December 31, 2023 and the full fiscal year ended December 31, 2022. (b) Presents information for the pre-merger period for Class B common stock. The pre-merger period is January 1, 2023 through December 17, 2023 for the year ended December 31, 2023 and the full fiscal year ended December 31, 2022. (c) Presents information for the post-merger period for common stock. The post-merger period is December 18, 2023 through December 31, 2023.

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Potentially Antidilutive Securities (Details) - shares		12 Months Ended
	Dec. 31, 2023	Dec. 18, 2023	Dec. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	541,180
Reverse merger, conversion ratio (in shares)		0.0756
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	541,180
Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0
Series A-1 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0
Series A-2 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0
Series B Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0
Class A Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		614,729	106,776,903
Class A Common Stock | Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		614,729	468,632
Class A Common Stock | Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	6,691
Class A Common Stock | Series A-1 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	18,604,653
Class A Common Stock | Series A-2 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	13,291,208
Class A Common Stock | Series B Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	74,405,719
Class B Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0
Class B Common Stock | Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0
Class B Common Stock | Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0
Class B Common Stock | Series A-1 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0
Class B Common Stock | Series A-2 Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0
Class B Common Stock | Series B Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	0

Reverse Merger - Narrative (Det

Reverse Merger - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 18, 2023	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Asset Acquisition, Bargain Purchase, Gain Recognized, Amount		$ 16,355	$ 0
Neoleukin
Business Acquisition [Line Items]
Contingent consideration liability		1,300
Asset Acquisition, Bargain Purchase, Gain Recognized, Amount	$ 16,355	$ 16,400

Reverse Merger - Calculation of

Reverse Merger - Calculation of Total Purchase Price (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Dec. 18, 2023	Dec. 31, 2023
Business Acquisition [Line Items]
Contingent consideration liability		$ 1,300
Neoleukin
Business Acquisition [Line Items]
Number of common shares and pre-funded warrants of the combined company to be owned by Neoleukin stockholders (in shares)	2,777,017
Multiplied by the fair value per share of Neoleukin common stock (in dollars per share)	$ 13.76
Fair value of Neoleukin common stock issued	$ 38,212
Transaction costs	4,140
Contingent consideration liability	1,287
Total purchase price	$ 43,639

Reverse Merger - Fair Value of

Reverse Merger - Fair Value of Neoleukin Net Assets Acquired at closing and Fair Value Allocation (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 18, 2023	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Fair value allocated to contingent consideration liability		$ 1,300
Fair value allocated to bargain purchase gain		16,355	$ 0
Neoleukin
Business Acquisition [Line Items]
Monetary assets acquired	$ 76,906
Liabilities assumed	(21,052)
Fair value of net assets acquired	55,854
Less: total consideration transferred	(38,212)
Total fair value allocated	17,642
Fair value allocated to contingent consideration liability	1,287
Fair value allocated to bargain purchase gain	$ 16,355	$ 16,400

Reverse Merger - Reconciliation

Reverse Merger - Reconciliation of Allocation to Purchase Price (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 18, 2023	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Fair value allocated to bargain purchase gain		$ (16,355)	$ 0
Neoleukin
Business Acquisition [Line Items]
Fair value of monetary assets acquired	$ 76,906
Transaction costs	4,140
Neoleukin liabilities assumed	(21,052)
Fair value allocated to bargain purchase gain	(16,355)	$ (16,400)
Total purchase price	$ 43,639

Reverse Merger - Other Informat

Reverse Merger - Other Information (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 18, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Common stock, shares, outstanding (in shares)	12,823,665		0
Neoleukin
Business Acquisition [Line Items]
Common stock, shares, outstanding (in shares)		2,351,030
Short term investments		$ 53.9
Asset acquisition, recognized identifiable assets acquired and liabilities assumed, cash and equivalents		22.2
Other assets		0.8
Lease obligation		10.9
Accrued payroll		3.8
Other accrued costs and accounts payable		$ 6.3
Neoleukin | Pre-Funded Warrant
Business Acquisition [Line Items]
Class of warrant or right, outstanding (in shares)		425,987

Investments (Details)

Investments (Details) - U.S. treasury notes - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule of Held-to-Maturity Securities [Line Items]
Amortized cost, as adjusted	$ 48,947	$ 0
Gross unrealized holding gains	16	0
Gross unrealized holding losses	0	0
Estimated fair value	$ 48,963	$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Level 1
Derivative Asset [Abstract]
U.S. treasury notes	$ 48,947
Total	193,305
Level 1 | Money Market Funds
Derivative Asset [Abstract]
Money market funds	144,358	$ 78,749
Level 2
Derivative Asset [Abstract]
U.S. treasury notes	0
Total	0
Level 2 | Money Market Funds
Derivative Asset [Abstract]
Money market funds	0	0
Level 3
Derivative Asset [Abstract]
U.S. treasury notes	0
Total	0
Level 3 | Money Market Funds
Derivative Asset [Abstract]
Money market funds	$ 0	$ 0

Prepaid expenses and other cu_3

Prepaid expenses and other current assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Refunds and other receivables	$ 600	$ 990
Prepaid expenses	1,496	1,078
Other current assets	1,095	630
Total prepaid and other current assets	$ 3,191	$ 2,698

Property and Equipment, Net - P

Property and Equipment, Net - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 25,183	$ 24,882
Less accumulated depreciation and amortization	(8,009)	(4,767)
Property and equipment, net	17,174	20,115
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	3,144	3,088
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	6,142	5,955
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	15,376	15,298
Office Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	19	0
Software
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	268	289
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 234	$ 252

Property and Equipment, Net - N

Property and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization of property and equipment	$ 3,262	$ 3,196

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Compensation and related benefits	$ 3,496	$ 3,357
Research and development	4,895	1,800
Accrued severance, bonus, and retention	2,476	0
Accrued offering costs in connection with pre-closing financing	3,334	0
Accrued transaction costs related to reverse merger	2,557	0
Other	737	167
Total accrued expenses and other current liabilities	$ 17,495	$ 5,324

Commitment and Contingencies -

Commitment and Contingencies - Narrative (Details) $ in Thousands		1 Months Ended				12 Months Ended
	Dec. 18, 2023 USD ($) ft² option	Feb. 28, 2022 USD ($)	Sep. 30, 2020 USD ($) ft²	Sep. 30, 2019 USD ($) ft²	Aug. 31, 2019 USD ($) ft² option	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Lessee, Lease, Description [Line Items]
Finance lease right-of-use assets						$ 98	$ 87
Total finance lease liabilities						107	90
Operating lease right-of-use assets						3,681	4,344
Total operating lease liabilities						14,861	4,599
Asset acquisition, contingent consideration arrangements, range of outcomes, value, low						1,300
Asset acquisition, contingent consideration arrangements, range of outcomes, value, high						19,500
Contingent consideration liability						$ 1,300
Effective term, scenario one						6 months
Effective term, scenario two						30 days
Accrued severance, bonus, and retention						$ 2,476	$ 0
New York Headquarters Lease
Lessee, Lease, Description [Line Items]
Area of real estate property | ft²				6,000
Letters of credit outstanding, amount				$ 400
Operating lease, monthly payments				$ 40
Operating lease right-of-use assets		$ 1,000
Total operating lease liabilities		1,000
Houston Lease
Lessee, Lease, Description [Line Items]
Area of real estate property | ft²			42,342		26,905
Operating lease, monthly payments					$ 30
Number of options to extend | option					2
Security deposit					$ 40
Prepaid rent					$ 40
Renewal term					5 years
Blaine Lease in Seattle
Lessee, Lease, Description [Line Items]
Area of real estate property | ft²	33,300
Number of options to extend | option	2
Renewal term	5 years
Eastlake Lease in Seattle
Lessee, Lease, Description [Line Items]
Area of real estate property | ft²	6,272
Lessor, operating lease, payment to be received	$ 1,600
License | Accipiter | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Lessee, Lease, Description [Line Items]
Contract with customer, liability						200
Collaborative arrangement, rights and obligations, seed financing, minimum						5,000
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product						13,400
Technology Equipment
Lessee, Lease, Description [Line Items]
Finance lease right-of-use assets						100
Total finance lease liabilities						$ 100
Minimum | New York Headquarters Lease
Lessee, Lease, Description [Line Items]
Operating lease, monthly payments		30
Minimum | Houston Lease
Lessee, Lease, Description [Line Items]
Operating lease, monthly payments			$ 50
Minimum | Technology Equipment
Lessee, Lease, Description [Line Items]
Lessee, finance lease, term of contract						36 months
Maximum | New York Headquarters Lease
Lessee, Lease, Description [Line Items]
Operating lease, monthly payments		$ 40
Maximum | Houston Lease
Lessee, Lease, Description [Line Items]
Operating lease, monthly payments			$ 60
Maximum | Technology Equipment
Lessee, Lease, Description [Line Items]
Lessee, finance lease, term of contract						63 months

Commitment and Contingencies _2

Commitment and Contingencies - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,037	$ 1,037
Finance lease cost
Amortization of finance leases	35	4
Interest on finance lease liabilities	12	2
Variable lease cost	178	196
Short-term lease cost	80	74
Total lease cost	$ 1,342	$ 1,313

Commitment and Contingencies _3

Commitment and Contingencies - Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2024	$ 3,862
2025	3,964
2026	3,672
2027	3,235
2028	3,294
2029	616
Total lease payments	18,643
Less: interest	(3,782)
Total operating lease liabilities	$ 14,861	$ 4,599

Commitment and Contingencies _4

Commitment and Contingencies - Maturity of Finance Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2024	$ 51
2025	50
2026	15
2027	6
2028	1
Total lease payments	123
Less: interest	(16)
Total finance lease liabilities	$ 107	$ 90

Commitment and Contingencies _5

Commitment and Contingencies - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 3,681	$ 4,344
Operating lease liabilities, current	2,559	678
Operating lease liabilities, non-current	12,302	3,921
Total operating lease liabilities	14,861	4,599
Finance lease right-of-use assets	98	87
Finance lease liabilities, current	42	24
Finance lease liabilities, non-current	65	66
Total finance lease liabilities	$ 107	$ 90

Commitment and Contingencies _6

Commitment and Contingencies - Other Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Cash paid for amounts included in measurement of operating lease liabilities (in thousands)	$ 1,051	$ 1,039
Cash paid for amounts included in measurement of finance lease liabilities (in thousands)	$ 42	$ 3
Weighted-average remaining lease term - operating leases (in years)	4 years 10 months 17 days	5 years 8 months 19 days
Weighted-average remaining lease term - finance lease (in years)	2 years 6 months 10 days	3 years 5 months 19 days
Weighted-average discount rate - operating leases	9.72%	8.86%
Weighted-average discount rate - finance lease	11.49%	11.45%

Commitment and Contingencies _7

Commitment and Contingencies - Maturity of Lease CVR (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2024	$ 281
2025	598
2026	408
Total lease CVR payments	$ 1,287

License Agreements (Details)

License Agreements (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2023	Dec. 31, 2020	Dec. 31, 2023	Dec. 31, 2022	Jan. 31, 2023	Mar. 31, 2022	Sep. 30, 2020	Dec. 31, 2019
University of North Carolina | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product								$ 1,700
Annual license maintenance fee			$ 4
University of Edinburgh
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative Arrangement, Rights and Obligations, Expense			300
University of Edinburgh | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative Arrangement, Rights and Obligations, Term		40 months
Research Collaboration and License Agreement, Option to Terminate		90 days
Collaborative Arrangement, Rights and Obligations, Expense			1,600	$ 1,100
University of Edinburgh | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Regulatory-Related Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product						$ 5,250
University of Edinburgh | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement | Sales-Related Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product						$ 25,000
Virovek, Inc License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual license maintenance fee			50
Collaborative Arrangement, Rights and Obligations, Expense			100
Virovek, Inc License Agreement | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product							$ 200
Sigma-Aldrich Co
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual license maintenance fee			60
Sigma-Aldrich Co | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product					$ 2,500
University of North Carolina and University of Pennsylvania | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, rights and obligations, maximum aggregate milestone payments, per product				500
Annual license maintenance fee			$ 0	$ 20
Collaborative Arrangement, Rights and Obligations, Additional Term	33 months

Preferred Stock (Details)

Preferred Stock (Details) - USD ($)			12 Months Ended
	Dec. 18, 2023	Mar. 02, 2023	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)			50,000,000	0
Preferred stock, par or stated value per share (in dollars per share)			$ 0.000001	$ 0.000001
Preferred Stock, shares, outstanding (in shares)			0	0
Stock issued during period, shares, new issues (in shares)	13,505,271
Reverse merger, conversion ratio (in shares)	0.0756
Common stock, shares, issued (in shares)	7,231,747		12,823,665	0
Class of warrant or right, issued (in shares)	1,825,635
Convertible preferred stock, non-cumulative dividends, per-dollar-amount (in dollars per share)			$ 0.18
Convertible preferred dividends, net of tax			$ 0
Series B Convertible Preferred Stock
Class of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		27,274,586
Sale of stock, price per share (in dollars per share)		$ 2.44
Proceeds from issuance of redeemable convertible preferred stock		$ 66,500,000
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares, issued (in shares)	12,823,665		0	428,334
Preferred stock, convertible, conversion price (in dollars per share)		$ 2.15
Class A Common Stock | IPO
Class of Stock [Line Items]
Sale of stock, price per share (in dollars per share)			$ 4.30
Sale of stock, consideration received on transaction			$ 75,000,000
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares, issued (in shares)			0	0
Preferred stock, convertible, conversion price (in dollars per share)		$ 2.44
Class B Common Stock | IPO
Class of Stock [Line Items]
Sale of stock, price per share (in dollars per share)			$ 3.66
Sale of stock, consideration received on transaction			$ 50,000,000
Series A-1 Convertible Preferred Stock
Class of Stock [Line Items]
Temporary equity, liquidation preference per share (in dollars per share)			$ 5.38

Stockholders_ Equity (Deficit_2

Stockholders’ Equity (Deficit) - Narrative (Details)		12 Months Ended
	Dec. 18, 2023 shares	Dec. 31, 2023 vote $ / shares shares	Dec. 31, 2022 $ / shares shares
Class of Stock [Line Items]
Common stock, shares authorized (in shares)		450,000,000	0
Common stock, par or stated value per share (in dollars per share) | $ / shares		$ 0.000001	$ 0.000001
Conversion of stock, shares converted (in shares)	10,472,635
Reverse merger, conversion ratio (in shares)	0.0756
Common stock, shares, issued (in shares)	7,231,747	12,823,665	0
Common stock, shares, outstanding (in shares)		12,823,665	0
Stock issued during period, shares, new issues (in shares)	13,505,271
Percentage of outstanding stock per stockholder, maximum		0.0999
Percentage of outstanding stock per stockholder, upon notice, maximum		0.1999
Class of warrant or right, notice period		61 days
Common stock, maximum holding percentage		0.0499
Pre Funded Warrants
Class of Stock [Line Items]
Class of warrant or right, outstanding (in shares)		4,063,361
Class of warrant or right, exercise price of warrants or rights (in dollars per share) | $ / shares		$ 0.000001
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)		0	126,000,000
Common stock, par or stated value per share (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001
Common stock, shares, issued (in shares)	12,823,665	0	428,334
Common stock, shares, outstanding (in shares)	12,823,665	0	428,334
Common stock, number of votes per share | vote		1
Class B Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)		0	120,010,600
Common stock, par or stated value per share (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001
Common stock, shares, issued (in shares)		0	0
Common stock, shares, outstanding (in shares)		0	0
Common stock, number of votes per share | vote		1

Stockholders_ Equity (Deficit_3

Stockholders’ Equity (Deficit) - Reserved Shares for Future Issuance (Details) - shares	Dec. 31, 2023	Dec. 18, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Total common stock reserved (in shares)	3,061,555		107,085,760
Class of warrant or right, number of securities called by each warrant or right (in shares)		0.0756
Options to purchase common stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	823,833		468,632
Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	0		106,301,580
Series A-1 Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	0		18,604,653
Series A-2 Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	0		13,291,208
Series B Convertible Preferred Stock
Class of Stock [Line Items]
Total common stock reserved (in shares)	0		74,405,719
2018 Equity Incentive Plan
Class of Stock [Line Items]
Total common stock reserved (in shares)	0		315,548
2023 Equity Incentive Plan
Class of Stock [Line Items]
Total common stock reserved (in shares)	2,237,722		0

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 18, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total common stock reserved (in shares)	3,061,555	3,061,555	3,061,555	107,085,760
Percentage of outstanding stock maximum			4%
Reverse merger, conversion ratio (in shares)					0.0756
Options outstanding (in shares)	823,833	823,833	823,833	468,632
Outstanding options, intrinsic value	$ 2,600	$ 2,600	$ 2,600
Exercisable options, intrinsic value	2,300	2,300	2,300
Share-based compensation arrangement by share-based payment award, options, exercised, intrinsic value	300	300	$ 300
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value (in dollars per share)			$ 12.99	$ 15.37
Share-based payment arrangement, expense			$ 1,418	$ 1,252
Share-based payment arrangement, nonvested award, option, cost not yet recognized, amount	$ 3,200	$ 3,200	3,200
Restricted stock awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based payment arrangement, expense			$ 20	$ 200
Options to purchase common stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total common stock reserved (in shares)	823,833	823,833	823,833	468,632
Share-based payment arrangement, expense			$ 1,400	$ 1,000
Share-based payment arrangement, nonvested award, cost not yet recognized, period for recognition			2 years 7 months 2 days
2023 EIP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total common stock reserved (in shares)					2,237,722
Share-based compensation arrangement by share-based payment award, shares issued in period	0
2018 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total common stock reserved (in shares)	0	0	0	315,548
Options outstanding (in shares)	609,124	609,124	609,124
2014 Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Options outstanding (in shares)	214,709	214,709	214,709
2023 Employee Stock Purchase Plan | Employee Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total common stock reserved (in shares)	173,223	173,223	173,223
Share-based compensation arrangement by share-based payment award, shares issued in period		0
Share-based compensation arrangement by share-based payment award, maximum contribution amount, percent	15%
Share-based compensation arrangement by share-based payment award, purchase price of common stock, percent	85%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Operating Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total expense	$ 1,418	$ 1,252
Research and development
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total expense	897	732
General and administrative
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total expense	$ 521	$ 520

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of shares
Beginning balance (in shares)	468,632
Assumption of options in connection with the reverse merger (in shares)	215,207
Granted (in shares)	183,391
Exercised (in shares)	(20,348)
Expired/Forfeited (in shares)	(23,049)
Ending balance (in shares)	823,833	468,632
Exercisable at end of period (in shares)	527,053
Weighted average exercise price per share
Beginning balance (in dollars per share)	$ 13.23
Assumption of options in connection with the reverse merger (in dollars per share)	77.20
Granted (in dollars per share)	18.91
Exercised (in dollars per share)	8.24
Expired/Forfeited (in dollars per share)	20.34
Ending balance (in dollars per share)	31.43	$ 13.23
Exercisable at end of period (in dollars per share)	$ 38.42
Weighted average remaining contractual term (years)
Outstanding (years)	5 years 10 months 20 days	7 years 4 months 13 days
Assumption of options in connection with the reverse merger (in dollars per share)	$ 2.50
Exercisable (years)	4 years 8 months 23 days

Stock-Based Compensation - Info

Stock-Based Compensation - Information About Outstanding and Exercisable Options (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Options Outstanding
Intrinsic Value | $	$ 2,600
Options Exercisable
Intrinsic Value | $	$ 2,300
Exercise Price Range One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 5.19
Exercise price range, upper range limit (in dollars per share)	$ 9.99
Options Outstanding
Number Outstanding (in shares) | shares	108,600
Weighted Average Remaining Contractual (in years)	5 years 1 month 13 days
Weighted Average Exercise Price (in dollars per share)	$ 5.86
Intrinsic Value | $	$ 1,469
Options Exercisable
Number Exercisable (in shares) | shares	108,315
Weighted Average Remaining Contractual (in years)	5 years 1 month 13 days
Weighted average Exercise Price (in dollars per share)	$ 5.86
Intrinsic Value | $	$ 1,465
Exercise Price Range Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 10
Exercise price range, upper range limit (in dollars per share)	$ 19.99
Options Outstanding
Number Outstanding (in shares) | shares	365,112
Weighted Average Remaining Contractual (in years)	6 years 11 months 12 days
Weighted Average Exercise Price (in dollars per share)	$ 15.06
Intrinsic Value | $	$ 1,596
Options Exercisable
Number Exercisable (in shares) | shares	184,871
Weighted Average Remaining Contractual (in years)	5 years 4 months 13 days
Weighted average Exercise Price (in dollars per share)	$ 13.42
Intrinsic Value | $	$ 1,120
Exercise Price Range Three
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 20
Exercise price range, upper range limit (in dollars per share)	$ 29.99
Options Outstanding
Number Outstanding (in shares) | shares	196,723
Weighted Average Remaining Contractual (in years)	7 years 1 month 20 days
Weighted Average Exercise Price (in dollars per share)	$ 22.43
Intrinsic Value | $	$ 0
Options Exercisable
Number Exercisable (in shares) | shares	80,817
Weighted Average Remaining Contractual (in years)	7 years 4 months 28 days
Weighted average Exercise Price (in dollars per share)	$ 22.88
Intrinsic Value | $	$ 0
Exercise Price Range Four
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 30
Exercise price range, upper range limit (in dollars per share)	$ 274.80
Options Outstanding
Number Outstanding (in shares) | shares	153,398
Weighted Average Remaining Contractual (in years)	2 years 3 months 7 days
Weighted Average Exercise Price (in dollars per share)	$ 100.05
Intrinsic Value | $	$ 0
Options Exercisable
Number Exercisable (in shares) | shares	153,050
Weighted Average Remaining Contractual (in years)	2 years 3 months 3 days
Weighted average Exercise Price (in dollars per share)	$ 99.86
Intrinsic Value | $	$ 0

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Weighted Average Assumptions (Details) - Options to purchase common stock - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected volatility rate, minimum	82.96%	71.71%
Expected volatility rate, maximum	83.70%	74.01%
Risk-free interest rate, minimum	3.45%	1.47%
Risk-free interest rate, maximum	4.46%	4.22%
Expected dividend yield	0%	0%
Fair value of common stock (in dollars per share)	$ 18.39	$ 20.24
Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected life (in years)	3 years 6 months 29 days	5 years 10 months 13 days
Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected life (in years)	6 years 29 days	6 years 1 month 2 days

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Restricted Stock Awards (Details) - Restricted stock awards - Class A Common Stock	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Number of shares
Beginning balance (in shares) | shares	6,691
Vested (in shares) | shares	(6,691)
Ending balance (in shares) | shares	0
Weighted- average grant date fair value
Beginning balance (in dollars per share) | $ / shares	$ 5.82
Vested (in dollars per share) | $ / shares	5.82
Ending balance (in dollars per share) | $ / shares	$ 0

Income Taxes - Income (Loss) Be

Income Taxes - Income (Loss) Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
United States	$ (36,317)	$ (55,189)
Net income (loss)	$ (36,317)	$ (55,189)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Tax Credit Carryforward [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 60,700,000	$ 13,000,000
Unrecognized tax benefits that would impact effective tax rate	2,600,000	1,100,000
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Income tax expense (benefit)	0	0
Operating loss carryforwards	277,900,000	110,500,000
Domestic Tax Authority | Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	7,500,000	2,900,000
Domestic Tax Authority | Federal Orphan Drug Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount	2,200,000
Domestic Tax Authority | Subject To Expiration
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	2,300,000
Domestic Tax Authority | Carried Forward Indefinitely
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	275,600,000
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Income tax expense (benefit)	0	0
Operating loss carryforwards	35,100,000	36,000,000
State and Local Jurisdiction | Research Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward, amount		$ 100,000
State and Local Jurisdiction | Subject To Expiration
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	33,400,000
State and Local Jurisdiction | Carried Forward Indefinitely
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 1,700,000

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal statutory income tax	21%	21%
State income taxes, net of federal tax benefit	(0.80%)	(0.10%)
Other permanent items	(0.50%)	(0.40%)
Research and development credit	5.80%	3%
Bargain purchase gain	9.50%	0%
Valuation allowance	(35.00%)	(23.50%)
Effective income tax rate	0%	0%

Income Taxes - Significant Comp

Income Taxes - Significant Components of Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 60,287	$ 25,253
Research and development credits	9,765	3,681
Accruals & reserves	802	727
Stock compensation	2,952	107
Amortization	778	298
Lease liability	3,157	995
Capitalized research and development expenses	22,134	8,271
Total deferred tax assets	99,875	39,332
Valuation allowance	(98,926)	(38,168)	$ (25,195)
Net deferred tax assets	949	1,164
Deferred tax liabilities:
Depreciation	(152)	(224)
Right of use asset	(797)	(940)
Total deferred tax liabilities	(949)	(1,164)
Net deferred taxes	$ 0	$ 0

Income Taxes - Change in Valuat

Income Taxes - Change in Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Valuation Allowance [Roll Forward]
Valuation allowance beginning of year	$ 38,168	$ 25,195
Valuation allowance, deferred tax asset, increase (decrease), amount	60,700	13,000
Valuation allowance at end of year	98,926	38,168
Increases recorded to income tax provision
Valuation Allowance [Roll Forward]
Valuation allowance, deferred tax asset, increase (decrease), amount	12,701	12,973
Increase recorded to equity
Valuation Allowance [Roll Forward]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 48,057	$ 0

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 1,108	$ 632
Additions based on tax positions related to current year	574	476
Additions for tax positions of prior years	929	0
Ending Balance	$ 2,611	$ 1,108

Employee Benefit Plan (Details)

Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Retirement Benefits [Abstract]
Defined contribution plan, cost	$ 0.5	$ 0.5
Defined contribution plan, employer contributions vesting period	5 years

Employee Retention Credit (Deta

Employee Retention Credit (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Postemployment Benefits [Abstract]
CARES Act, employee retention credits	$ 0.9

Subsequent Events (Details)

Subsequent Events (Details) - shares	3 Months Ended	12 Months Ended
	Mar. 18, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Grants in period (in shares)		183,391
Exercised (in shares)		20,348
Subsequent Event
Subsequent Event [Line Items]
Grants in period (in shares)	740,752
Exercised (in shares)	29,320
Restricted Stock Units (RSUs) | Subsequent Event
Subsequent Event [Line Items]
Grants in period (in shares)	482,384