Metagenomi, Inc. Common Stock (MGX) 10-Q 13 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 07, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-41949
Entity Registrant Name	Metagenomi, Inc.
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	5959 Horton Street
Entity Address, Address Line Two	7th Floor
Entity Address, City or Town	Emeryville
Entity Address, State or Province	CA
Entity Tax Identification Number	81-3909017
Entity Address, Postal Zip Code	94608
City Area Code	510
Local Phone Number	871-4880
Document Fiscal Year Focus	2024
Title of 12(b) Security	Common stock, par value $0.0001 per share
Trading Symbol	MGX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		37,423,917
Entity Central Index Key	0001785279
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Period Focus	Q3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 25,117,000	$ 140,603,000
Available-for-sale marketable securities	249,470,000	130,579,000
Accounts receivable	589,000	2,451,000
Prepaid expenses and other current assets	7,117,000	4,640,000
Total current assets	282,293,000	278,273,000
Property and equipment, net	19,719,000	21,542,000
Long-term investments	10,577,000	10,676,000
Operating lease right-of-use assets	40,191,000	43,611,000
Other assets	320,000	5,492,000
Restricted cash	5,248,000	5,248,000
Total assets	358,348,000	364,842,000
Current liabilities:
Accounts payable	3,103,000	1,791,000
Income tax payable	0	3,266,000
Accrued expenses and other current liabilities	8,840,000	11,472,000
Current portion of operating lease liabilities	4,696,000	3,427,000
Collaboration advance	0	837,000
Deferred revenue	29,053,000	48,068,000
Total current liabilities	45,692,000	68,861,000
Non-current portion of operating lease liabilities	41,377,000	44,802,000
Deferred revenue, non-current	12,431,000	30,926,000
Other non-current liabilities	3,075,000	5,079,000
Total liabilities	102,575,000	149,668,000
Commitments and contingencies (Note 8)
Redeemable convertible preferred stock: zero shares authorized, issued and outstanding as of September 30, 2024; 41,813,375 shares authorized, issued and outstanding as of December 31, 2023; liquidation preference of $352,044 as of December 31, 2023	0	350,758,000
Stockholders' equity (deficit):
Preferred stock: $0.0001 par value; 10,000,000 shares and zero shares authorized as of September 30, 2024 and December 31, 2023, respectively; zero shares issued and outstanding	0	0
Common stock: $0.0001 par value; 500,000,000 shares and 66,000,000 shares authorized as of September 30, 2024 and December 31, 2023, respectively; 37,432,832 and 3,404,585 shares issued and outstanding as of September 30, 2024 and December 31, 2023, respectively	4,000	0
Additional paid-in-capital	453,734,000	9,457,000
Accumulated other comprehensive income (loss)	1,639,000	(97,000)
Accumulated deficit	(199,604,000)	(144,944,000)
Total stockholders' equity (deficit)	255,773,000	(135,584,000)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	$ 358,348,000	$ 364,842,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Redeemable convertible preferred units, authorized	0	41,813,375
Redeemable convertible preferred units, issued	0	41,813,375
Redeemable convertible preferred units, outstanding	0	41,813,375
Liquidation preference		$ 352,044,000
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, authorized	10,000,000	0
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	500,000,000	66,000,000
Common stock, issued	37,432,832	3,404,585
Common stock, outstanding	37,432,832	3,404,585

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Collaboration revenue	$ 11,514	$ 12,363	$ 42,681	$ 32,357
Operating expenses:
Research and development	26,256	26,837	86,015	69,648
General and administrative	7,641	7,921	24,944	21,005
Total operating expenses	33,897	34,758	110,959	90,653
Loss from operations	(22,383)	(22,395)	(68,278)	(58,296)
Other income (expense):
Interest income	3,616	3,866	11,526	11,836
Change in fair value of long-term investments	(2,055)	0	(2,055)	2,870
Other expense, net	(57)	(85)	(158)	(70)
Total other income, net	1,504	3,781	9,313	14,636
Net loss before benefit (provision) for income taxes	(20,879)	(18,614)	(58,965)	(43,660)
Benefit (provision) for income taxes	2,106	(1,206)	4,305	(5,301)
Net loss	(18,773)	(19,820)	(54,660)	(48,961)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale marketable securities	1,904	70	1,736	(85)
Comprehensive loss	$ (16,869)	$ (19,750)	$ (52,924)	$ (49,046)
Net loss per share attributable to common stockholders - basic	$ (0.51)	$ (5.82)	$ (1.73)	$ (14.38)
Net loss per share attributable to common stockholders - diluted	$ (0.51)	$ (5.82)	$ (1.73)	$ (14.38)
Weighted-average common shares outstanding - basic	36,766,309	3,404,585	31,601,825	3,404,585
Weighted-average common shares outstanding - diluted	36,766,309	3,404,585	31,601,825	3,404,585

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($)	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Redeemable Convertible Preferred Units Preferred Stock
Beginning balance, (in shares) at Dec. 31, 2022						41,478,621
Beginning balance at Dec. 31, 2022						$ 346,103,000
Beginning balance, (in shares) at Dec. 31, 2022		3,404,585
Beginning balance at Dec. 31, 2022	$ (74,428,000)		$ 2,535,000	$ (274,000)	$ (76,689,000)
Issuance of Series B-1 redeemable convertible preferred units (in shares)						334,754
Issuance of Series B-1 redeemable convertible preferred units						$ 4,655,000
Stock-based compensation expense	529,000		529,000
Other comprehensive income (loss)	21,000			21,000
Net loss	(16,133,000)				(16,133,000)
Ending balance, (in shares) at Mar. 31, 2023						41,813,375
Ending balance at Mar. 31, 2023						$ 350,758,000
Ending balance, (in shares) at Mar. 31, 2023		3,404,585
Ending balance at Mar. 31, 2023	(90,011,000)		3,064,000	(253,000)	(92,822,000)
Beginning balance, (in shares) at Dec. 31, 2022						41,478,621
Beginning balance at Dec. 31, 2022						$ 346,103,000
Beginning balance, (in shares) at Dec. 31, 2022		3,404,585
Beginning balance at Dec. 31, 2022	(74,428,000)		2,535,000	(274,000)	(76,689,000)
Net loss	(48,961,000)
Ending balance, (in shares) at Sep. 30, 2023						41,813,375
Ending balance at Sep. 30, 2023						$ 350,758,000
Ending balance, (in shares) at Sep. 30, 2023		3,404,585
Ending balance at Sep. 30, 2023	(119,021)		6,988	(359)	(125,650)
Beginning balance, (in shares) at Mar. 31, 2023						41,813,375
Beginning balance at Mar. 31, 2023						$ 350,758,000
Beginning balance, (in shares) at Mar. 31, 2023		3,404,585
Beginning balance at Mar. 31, 2023	(90,011,000)		3,064,000	(253,000)	(92,822,000)
Stock-based compensation expense	656,000		656,000
Other comprehensive income (loss)	(176,000)			(176,000)
Net loss	(13,008,000)				(13,008,000)
Ending balance, (in shares) at Jun. 30, 2023						41,813,375
Ending balance at Jun. 30, 2023						$ 350,758,000
Ending balance, (in shares) at Jun. 30, 2023		3,404,585
Ending balance at Jun. 30, 2023	(102,539,000)		3,720,000	(429,000)	(105,830,000)
Stock-based compensation expense	3,268		3,268
Other comprehensive income (loss)	70			70
Net loss	(19,820,000)				(19,820,000)
Ending balance, (in shares) at Sep. 30, 2023						41,813,375
Ending balance at Sep. 30, 2023						$ 350,758,000
Ending balance, (in shares) at Sep. 30, 2023		3,404,585
Ending balance at Sep. 30, 2023	$ (119,021)		6,988	(359)	(125,650)
Beginning balance, (in shares) at Dec. 31, 2023	41,813,375					41,813,375
Beginning balance at Dec. 31, 2023	$ 350,758,000					$ 350,758,000
Beginning balance, (in shares) at Dec. 31, 2023		3,404,585
Beginning balance at Dec. 31, 2023	(135,584,000)		9,457,000	(97,000)	(144,944,000)
Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization	1,000	$ 1,000
Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization (in shares)		3,884,740
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (shares)						(41,813,375)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering						$ (350,758,000)
Conversion of redeemable convertible preferred stock to common stock upon initial public offering (shares)		23,935,594
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	350,758,000	$ 2,000	350,756,000
Issuance of common stock in connection with initial public offering, net of issuance costs (in shares)		6,250,000
Issuance of common stock in connection with initial public offering, net of issuance costs	80,730,000	$ 1,000	80,729,000
Forfeiture of unvested common stock (in shares)		(6,841)
Stock-based compensation expense	5,057,000		5,057,000
Other comprehensive income (loss)	(181,000)			(181,000)
Net loss	(25,148,000)				(25,148,000)
Ending balance, (in shares) at Mar. 31, 2024		37,468,078
Ending balance at Mar. 31, 2024	$ 275,633,000	$ 4,000	445,999,000	(278,000)	(170,092,000)
Beginning balance, (in shares) at Dec. 31, 2023	41,813,375					41,813,375
Beginning balance at Dec. 31, 2023	$ 350,758,000					$ 350,758,000
Beginning balance, (in shares) at Dec. 31, 2023		3,404,585
Beginning balance at Dec. 31, 2023	(135,584,000)		9,457,000	(97,000)	(144,944,000)
Net loss	$ (54,660,000)
Ending balance, (in shares) at Sep. 30, 2024	0
Ending balance at Sep. 30, 2024	$ 0
Ending balance, (in shares) at Sep. 30, 2024		37,432,832
Ending balance at Sep. 30, 2024	255,773,000	$ 4,000	453,734,000	1,639,000	(199,604,000)
Beginning balance, (in shares) at Mar. 31, 2024		37,468,078
Beginning balance at Mar. 31, 2024	275,633,000	$ 4,000	445,999,000	(278,000)	(170,092,000)
Forfeiture of unvested common stock (in shares)		(8,225)
Stock-based compensation expense	4,512,000		4,512,000
Other comprehensive income (loss)	13,000			13,000
Net loss	(10,739,000)				(10,739,000)
Ending balance, (in shares) at Jun. 30, 2024		37,459,853
Ending balance at Jun. 30, 2024	269,419,000	$ 4,000	450,511,000	(265,000)	(180,831,000)
Forfeiture of unvested common stock (in shares)		(47,382)
Vesting of restricted stock units		20,361
Stock-based compensation expense	3,223,000		3,223,000
Other comprehensive income (loss)	1,904,000			1,904,000
Net loss	$ (18,773,000)				(18,773,000)
Ending balance, (in shares) at Sep. 30, 2024	0
Ending balance at Sep. 30, 2024	$ 0
Ending balance, (in shares) at Sep. 30, 2024		37,432,832
Ending balance at Sep. 30, 2024	$ 255,773,000	$ 4,000	$ 453,734,000	$ 1,639,000	$ (199,604,000)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net loss	$ (54,660)	$ (48,961)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	12,792	4,453
Depreciation	3,946	3,006
Loss on fixed assets write-off	290	9
Non-cash lease expense	3,432	3,107
Amortization of premiums and discounts on available-for-sale marketable securities	(4,827)	(6,852)
Amortization of non-cash collaboration revenue	(1,613)	(654)
Change in fair value of long-term investments	2,055	(2,870)
Changes in operating assets and liabilities:
Accounts receivable	1,862	(3,924)
Contract assets		1,274
Prepaid expenses and other assets	(1,159)	389
Accounts payable	1,464	2,439
Income tax payable	(3,266)	632
Deferred revenue and collaboration advance	(38,366)	(25,039)
Accrued expenses and other current liabilities	(575)	727
Operating lease liabilities	(2,168)	(972)
Other non-current liabilities	(2,004)	2,419
Net cash used in operating activities	(82,797)	(70,817)
Cash flows from investing activities
Purchases of property and equipment	(2,780)	(8,077)
Purchases of available-for-sale marketable securities	(293,755)	(168,977)
Maturities of available-for-sale marketable securities	180,157	162,156
Purchases of long-term investments	(324)
Net cash used in investing activities	(116,702)	(14,898)
Cash flows from financing activities
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs	84,013
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs		4,295
Payments of initial public offering costs		(1,949)
Net cash provided by financing activities	84,013	2,346
Net decrease in cash, cash equivalents and restricted cash	(115,486)	(83,369)
Cash, cash equivalents and restricted cash at beginning of period	145,851	190,514
Cash, cash equivalents and restricted cash at end of period	30,365	107,145
Supplemental disclosure of non-cash information
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	350,758
Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization	9,457
Reclassification of deferred offering costs paid in prior year to stockholders' equity	3,283
Common shares of Affini-T received for collaboration revenue	1,632
Purchases of property and equipment included in accounts payable, accrued expenses and other current liabilities	271	876
Operating lease right-of-use assets obtained in exchange for new lease liabilities		30,608
Deferred initial public offering costs included in accounts payable, accrued expenses and other current liabilities		2,456
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	25,117	101,897
Restricted cash	5,248	5,248
Cash, cash equivalents and restricted cash at end of period	$ 30,365	$ 107,145

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (18,773)	$ (10,739)	$ (25,148)	$ (19,820)	$ (13,008)	$ (16,133)	$ (54,660)	$ (48,961)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
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

Description of Business, Organi

Description of Business, Organization and Liquidity	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business, Organization and Liquidity	1. Description of Business, Organization and Liquidity Organization and business Metagenomi, Inc. (“Metagenomi” or the “Company”) is a precision genetic medicines company committed to developing curative therapeutics for patients using our proprietary, comprehensive metagenomics-derived genome editing toolbox. Formation and group reorganizations Metagenomi.co was incorporated in September 2016 in the State of Delaware and is headquartered in Emeryville, California. In September 2018, Metagenomi.co formed a subsidiary, Metagenomi Technologies, LLC (“Metagenomi LLC”) as its sole member. In November 2018, the two companies completed a reorganization where Metagenomi LLC became the parent of Metagenomi.co. The reorganization was a transaction of entities under common control and did not change the group. In December 2018, Metagenomi LLC formed another wholly owned subsidiary, Metagenomi IP Technologies, LLC. Metagenomi IP Technologies, LLC did not have any operations except for the initial transfer of IP from Metagenomi.co and an ongoing license of its technology to Metagenomi.co. Key activities of Metagenomi LLC were raising capital to support operations of Metagenomi.co. In April 2020, Metagenomi.co changed its name to Metagenomi, Inc. In December 2021, the group completed another tax-free reorganization, whereby Metagenomi IP Technologies, LLC merged with and into Metagenomi, Inc. Reorganization and Reverse Stock Split On January 24, 2024, the Company completed a series of transactions pursuant to which Metagenomi LLC merged with and into Metagenomi, Inc., with Metagenomi, Inc. continuing as the surviving corporation (the “Reorganization”). In connection with the Reorganization, (i) all of the outstanding common unitholders received shares of common stock of Metagenomi, Inc., (ii) all of the outstanding preferred unitholders received shares of redeemable convertible preferred stock of Metagenomi, Inc. with the same rights and privileges and (iii) certain holders of profits interest units received shares of common stock and unvested restricted common stock in Metagenomi, Inc. as determined by the applicable provisions of the Amended and Restated Limited Liability Company Agreement dated December 20, 2022, as amended on July 31, 2023 (the “LLC Agreement”) in effect immediately prior to the Reorganization. In connection with the Reorganization, by operation of law, Metagenomi, Inc. acquired all assets of Metagenomi LLC, and assumed all of its liabilities and obligations. The Reorganization is expected to be a non-taxable transaction to Metagenomi, Inc. for United States (“U.S.”) income tax purposes. On January 26, 2024, following the Reorganization, Metagenomi, Inc. effected a reverse stock split of the shares of common stock at a ratio of 1-for- 1.74692 (the “Reverse Stock Split”). The number of authorized shares and par value per share were not adjusted as a result of the Reverse Stock Split. The Reorganization and the Reverse Stock Split was accounted for as a reorganization of entities under common control. All redeemable convertible preferred stock, common stock, additional paid-in-capital and per share amounts for all periods presented in the accompanying condensed consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect this Reorganization and Reverse Stock Split. In connection with the Reorganization and also effecting the reverse stock split: • holders of Metagenomi LLC’s outstanding Series A-1 redeemable convertible preferred units (“Series A-1 preferred units”) received one share of Series A-1 redeemable convertible preferred stock (“Series A-1 preferred stock”) of Metagenomi, Inc. for each Series A-1 preferred unit, with an aggregate of 7,501,002 shares of Series A-1 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series A-1 preferred stock shall become convertible into an aggregate of 4,293,867 shares of common stock; • holders of Metagenomi LLC’s outstanding Series A-2 redeemable convertible preferred units (“Series A-2 preferred units”) received one share of Series A-2 redeemable convertible preferred stock (“Series A-2 preferred stock”) of Metagenomi, Inc. for each Series A-2 preferred unit, with an aggregate of 774,473 shares of Series A-2 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series A-2 preferred stock shall become convertible into an aggregate of 443,338 shares of common stock; • holders of Metagenomi LLC’s outstanding Series A-3 redeemable convertible preferred units (“Series A-3 preferred units”) received one share of Series A-3 redeemable convertible preferred stock (“Series A-3 preferred stock”) of Metagenomi, Inc. for each Series A-3 preferred unit, with an aggregate of 1,513,860 shares of Series A-3 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series A-3 preferred stock shall become convertible into an aggregate of 866,589 shares of common stock; • holders of Metagenomi LLC’s outstanding Series A-4 redeemable convertible preferred units (“Series A-4 preferred units”) received one share of Series A-4 redeemable convertible preferred stock (“Series A-4 preferred stock”) of Metagenomi, Inc. for each Series A-4 preferred unit, with an aggregate of 8,280,360 shares of Series A-4 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series A-4 preferred stock shall become convertible into an aggregate of 4,740,000 shares of common stock; • holders of Metagenomi LLC’s outstanding Series A-5 redeemable convertible preferred units (“Series A-5 preferred units”) received one share of Series A-5 redeemable convertible preferred stock (“Series A-5 preferred stock”) of Metagenomi, Inc. for each Series A-5 preferred unit, with an aggregate of 1,580,937 shares of Series A-5 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series A-5 preferred stock shall become convertible into an aggregate of 904,990 shares of common stock; • holders of Metagenomi LLC’s outstanding Series B redeemable convertible preferred units (“Series B preferred units”) received one share of Series B redeemable convertible preferred stock (“Series B preferred stock”) of Metagenomi, Inc. for each Series B preferred unit, with an aggregate of 15,054,263 shares of Series B preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series B preferred stock shall become convertible into an aggregate of 8,617,649 shares of common stock; • holders of Metagenomi LLC’s outstanding Series B-1 redeemable convertible preferred units (“Series B-1 preferred units”) received one share of Series B-1 redeemable convertible preferred stock (“Series B-1 preferred stock”) of Metagenomi, Inc. for each Series B-1 preferred unit, with an aggregate of 7,108,480 shares of Series B-1 preferred stock outstanding, and after giving effect to the reverse stock split, such shares of Series B-1 preferred stock shall become convertible into an aggregate of 4,069,161 shares of common stock; • holders of Metagenomi LLC’s outstanding common units received one share of common stock of Metagenomi, Inc. for each common unit, with an aggregate of 3,404,585 shares of common stock outstanding, after giving effect to the reverse stock split; and • holders of Metagenomi LLC’s outstanding profits interests received 0 - 0.997816 shares of common stock in accordance with the Metagenomi LLC operating agreement for each profits interest, with an aggregate of 3,884,740 shares of common stock outstanding (which includes 1,036,833 shares of unvested restricted common stock), after giving effect to the reverse stock split. Vesting terms of outstanding profits interests did not change. Initial Public Offering On February 8, 2024, Metagenomi, Inc.’s Form S-1 Registration Statement for its initial public offering (the “IPO”) was declared effective and the common stock of Metagenomi, Inc. began trading on the Nasdaq Global Select Market under the symbol “MGX.” On February 13, 2024, the closing date of IPO, the Company issued 6,250,000 shares of common stock at a price to the public of $ 15.00 per share. In connection with the closing of the IPO, the Company received gross proceeds of approximately $ 93.8 million and net proceeds of approximately $ 80.7 million , after deducting underwriting discounts and commissions and other offering costs totaling approximately $ 13.0 million . Immediately prior to the IPO closing , each share of Metagenomi, Inc.’s redeemable convertible preferred stock then outstanding converted into shares of common stock at a conversion ratio of 1.74692 , based on the formula set forth in Metagenomi, Inc.’s amended and restated certificate of incorporation in effect immediately prior to the closing of the IPO and giving effect to the reverse stock split. In connection with the closing of the IPO, Metagenomi, Inc. increased the authorized number of shares of common stock to 500,000,000 shares, $ 0.0001 par value per share, and 10,000,000 shares of preferred stock, $ 0.0001 par value per share. Liquidity and going concern The Company has incurred significant losses from operations since its inception. As of September 30, 2024, the Company had an accumulated deficit of $ 199.6 million . The Company has historically financed its operations primarily through issuance of redeemable convertible preferred stock, convertible promissory notes, its collaboration agreements, and sales of its common stock. In February 2024, the Company completed its IPO for aggregate net proceeds of approximately $ 80.7 million , after deducting underwriting discounts and commissions and other offering costs totaling approximately $ 13.0 million. The Company expects to continue to incur substantial losses, and its ability to achieve and sustain profitability will depend on the successful development, approval, and commercialization of any product candidates it may develop, and on the achievement of sufficient revenue to support its cost structure. The Company may never achieve profitability and, unless and until it does, it will need to continue to raise additional capital. Management believes that existing cash, cash equivalents and available-for-sale marketable securities as of September 30, 2024 of $ 274.6 million will be sufficient to fund its current operating plan for at least the next 12 months from the date of issuance of these unaudited condensed consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 2, “Summary of Significant Accounting Policies” to the consolidated financial statements included in the Annual Report for the year ended December 31, 2023. There have been no material changes to these policies during the nine months ended September 30, 2024. Basis of presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchanges Commission (“SEC”). Accordingly, these financial statements do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements include all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair statement of the Company’s condensed consolidated financial statements for the periods presented. These interim financial results are not necessarily indicative of results to be expected for the full fiscal year ending December 31, 2024, or any other future period. Readers should read these interim unaudited condensed consolidated financial statements in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2023, included in the Company’s Annual Report on Form 10-K filed with the SEC. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying condensed consolidated financial statements include the accounts of Metagenomi, Inc. and the accounts of Metagenomi LLC, retroactively adjusted for the Reorganization and Reverse Stock Split (see Note 1). All intercompany balances and transactions have been eliminated in consolidation. Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates estimates and assumptions, including but not limited to those related to revenue recognition under its collaboration agreements, the fair value of its common stock, stock-based compensation expense, accruals for research and development expenses, the fair value of long-term investments, the valuation of deferred tax assets and uncertain income tax positions. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates. Recently issued accounting pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This ASU requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280 on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its financial statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its financial statements. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires, among other things, more detailed disclosures about specified categories of expense (purchases of inventory, employee compensation, depreciation, amortization, and depletion) included in certain expense captions presented on the face of the income statement. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. This ASU may be applied prospectively with the option for retrospective application. The Company is currently evaluating the impact of the adoption of this standard on its financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the condensed consolidated balance sheets, are categorized based upon the level of judgment associated with inputs used to measure their fair values. The accounting guidance for fair value provides a framework for measuring fair value and requires certain disclosures about how fair value is determined. The accounting guidance establishes a three-level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1 — Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 — Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 — Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. An assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. The Company recognizes transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. The Company’s financial instruments measured at fair value on a recurring basis consist of Level 1, Level 2, and Level 3 financial instruments. Usually, marketable securities are considered Level 2 when their fair values are determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis. U.S. Government bonds, corporate debt obligations, commercial paper, government agency obligations and asset-backed securities are valued primarily using market prices of comparable securities, bid/ask quotes, interest rate yields and prepayment spreads and are included in Level 2. Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies, or similar techniques, and at least one significant model assumption or input is unobservable. The Company’s investments in preferred stock, common stock and warrants of Affini-T Therapeutics, Inc. (“ Affini-T”) (see Note 5) are Level 3 financial assets. The following tables summarize financial assets that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2024 Total Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash equivalents) $ 23,846 $ 23,846 $ — $ — U.S. government bonds 121,824 — 121,824 — Government agency obligations 40,537 — 40,537 — Corporate debt obligations 31,270 — 31,270 — Commercial paper 42,673 — 42,673 — Asset-backed securities 10,691 — 10,691 — Foreign debt securities 2,475 — 2,475 — Long-term investments (Note 5) 8,422 — — 8,422 Total fair value of assets $ 281,738 $ 23,846 $ 249,470 $ 8,422 December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash equivalents) $ 137,216 $ 137,216 $ — $ — U.S. Treasury bills 9,831 — 9,831 — U.S. Government bonds 2,989 — 2,989 — Government agency obligations 46,409 — 46,409 — Corporate debt obligations 10,973 — 10,973 — Commercial paper 54,727 — 54,727 — Asset-backed securities 2,171 — 2,171 — Foreign debt securities 3,479 — 3,479 — Long-term investments (Note 5) 8,521 — — 8,521 Total fair value of assets $ 276,316 $ 137,216 $ 130,579 $ 8,521 In addition, restricted cash of $ 5.2 million as of September 30, 2024 and December 31, 2023, collateralized by the Company’s cash equivalents, are financial assets measured at fair value and are Level 1 financial instruments under the fair value hierarchy. The Company accounts for its investments in Affini-T by applying an option-pricing model backsolve method for inferring the total equity value implied by a recent Series B preferred stock financing round of Affini-T. Key assumptions used in the valuation model as of September 30, 2024 included an expected holding period of two years , a risk free interest rate of 4.05 %, a dividend yield of 0.0 % and an estimated volatility of 88.5 %. Key assumptions used in the valuation model as of December 31, 2023 included an expected holding period of two years , a risk free interest rate of 4.87 %, a dividend yield of 0.0 % and an estimated volatility of 83.0 %. Estimated volatility was calculated based on the historical volatility of a selected peer group of public companies comparable to Affini-T. The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial assets (in thousands): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Beginning balance $ 8,521 $ 8,521 $ 8,521 $ 5,651 Fair value of investment received as collaboration consideration 1,632 — 1,632 — Fair value of investment purchased in preferred stock purchase agreement 324 — 324 — Change in fair value included in other income (expense) ( 2,055 ) — ( 2,055 ) 2,870 Ending balance $ 8,422 $ 8,521 $ 8,422 $ 8,521

Available-For-Sale Marketable S

Available-For-Sale Marketable Securities	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Available-For-Sale Marketable Securities	4. Available-For-Sale Marketable Securities The following tables summarize the amortized cost, unrealized gains (losses) and fair value of available-for-sale marketable securities (in thousands): September 30, 2024 Amortized Unrealized Unrealized Fair value Money market funds $ 23,846 $ — $ — $ 23,846 U.S. government bonds 120,666 1,160 ( 2 ) 121,824 Government agency obligations 40,240 297 — 40,537 Corporate debt obligations 31,182 88 — 31,270 Commercial paper 42,600 73 — 42,673 Asset-backed securities 10,668 23 — 10,691 Foreign debt securities 2,475 — — 2,475 Total 271,677 1,641 ( 2 ) 273,316 Less: amounts classified as cash equivalents ( 23,846 ) — — ( 23,846 ) Total available-for-sale marketable securities $ 247,831 $ 1,641 $ ( 2 ) $ 249,470 December 31, 2023 Amortized Unrealized Unrealized Fair value Money market funds $ 137,216 $ — $ — $ 137,216 U.S. treasury bills 9,826 5 — 9,831 U.S. government bonds 3,005 — ( 16 ) 2,989 Government agency obligations 46,446 4 ( 41 ) 46,409 Corporate debt obligations 11,014 — ( 41 ) 10,973 Commercial paper 54,724 4 ( 1 ) 54,727 Asset-backed securities 2,177 — ( 6 ) 2,171 Foreign debt securities 3,484 — ( 5 ) 3,479 Total 267,892 13 ( 110 ) 267,795 Less: amounts classified as cash equivalents ( 137,216 ) — — ( 137,216 ) Total available-for-sale marketable securities $ 130,676 $ 13 $ ( 110 ) $ 130,579 As of September 30, 2024 and December 31, 2023 , no significant facts or circumstances were present to indicate a deterioration in the creditworthiness of the issuers of the available-for-sale securities, and the Company has no requirement or intention to sell these securities before maturity or recovery of their amortized cost basis. The Company considered the current and expected future economic and market conditions and determined that its investments were not significantly impacted. For all securities with a fair value less than its amortized cost basis, the Company determined the decline in fair value below amortized cost basis to be immaterial and non-credit related, and therefore no allowance for losses has been recorded. During the three and nine months ended September 30, 2024 and 2023 , the Company did no t recognize any impairment losses on its investments. Accrued interest receivable included in prepaid expenses and other current assets as of September 30, 2024 and December 31, 2023 was $ 1.6 million and $ 1.0 million , respectively. The company has no t written off any accrued interest receivable during the three and nine months ended September 30, 2024 and 2023. The amortized cost and fair value of available-for-sale marketable securities by contractual maturity were as follows (in thousands): September 30, 2024 December 31, 2023 Amortized Fair Value Amortized Fair Value Maturing within one year $ 154,228 $ 154,702 $ 129,823 $ 129,728 Maturing in one to five years 93,603 94,768 853 851 Total available-for-sale marketable securities $ 247,831 $ 249,470 $ 130,676 $ 130,579

Long-Term Investments

Long-Term Investments	9 Months Ended
	Sep. 30, 2024
Disclosure Text Block [Abstract]
Long-Term Investments	5. Long-Term Investments Affini-T investment In July 2024, pursuant to the terms of the Development, Option and License Agreement with Affini-T (the “Affini-T Agreement”), the Company received equity consideration of 933,650 shares of Affini-T common stock upon the achievement of a regulatory milestone related to the submission of drug master files to the Food and Drug Administration (“FDA”) in support of an investigational new drug (“IND”) application for Affini-T’s T-cell receptor-based therapy. Refer to Note 7 for further discussion of the Affini-T Agreement to perform research and development activities. In August 2024, in connection with Affini-T’s Series B extension, the Company entered into a Joinder to Series B Preferred Stock Purchase Agreement (the “Series B Purchase Agreement”), pursuant to which the Company purchased 33,383 shares of Series B convertible preferred stock of Affini-T (the “Affini-T Series B Preferred Stock”) at a purchase price of $ 9.714 per share and received warrants to purchase up to 16,691 shares of common stock at an exercise price of $ 0.01 per share, for an aggregate purchase price of approximately $ 0.3 million. The Series B Purchase Agreement also provides for the purchase of up to an additional 16,691 shares of Affini-T Series B Preferred Stock at a purchase price of $ 9.714 per share and warrants to purchase up to 8,345 shares of common stock at an exercise price of $ 0.01 per share in a subsequent milestone closing (the “Milestone Closing”), upon Affini-T achi eving certain milestone conditions. The Milestone Closing has not occurred as of September 30, 2024. As of September 30, 2024, the Company had investments in Affini-T consisting of 527,035 shares of Series A convertible preferred stock, 33,383 shares of Series B Preferred Stock, 1,867,300 shares of common stock, and a warrant exercisable for 16,691 shares of common stock . As of December 31, 2023 , the Company had investments in Affini-T consisting of 527,035 shares of Series A convertible preferred stock and 933,650 shares of common stock . The Company performed a VIE analysis and concluded that it was not a primary beneficiary of Affini-T as of September 30, 2024 and December 31, 2023. The Company is using the fair value method to account for its investments in Affini-T using an option-pricing valuation model and recent Affini-T financing transactions (see Note 3) with changes in fair value recorded to other income (expense) in the condensed consolidated statements of operations and comprehensive loss . The estimated fair value of its investments in Affini-T was $ 8.4 million as of September 30, 2024 and $ 8.5 million as of December 31, 2023. The Company recognized a loss related to the change in fair value of $ 2.1 million during the three and nine months ended September 30, 2024, and recognized a gain related to the change in fair value of zero and $ 2.9 million during the three and nine months ended September 30, 2023, respectively. ViTToria investment As of September 30, 2024 and December 31, 2023, the Company had an investment in shares of preferred stock of ViTToria Biotherapeutics, Inc. (“Vittoria”), a private biotechnology company. During the nine months ended September 30, 2024 and year ended December 31, 2023 , the Company did not have a board seat and owned less than 20 % of the outstanding voting shares of Vittoria. The investment in Vittoria does not provide the Company the ability to control or have significant influence over Vittoria’s operations. The Company accounts for its investment in Vittoria using the measurement alternative method. As of September 30, 2024 and December 31, 2023, the carrying value of Vittoria’s investm ent was $ 2.2 million and no impairment was recognized .

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): September 30, 2024 December 31, 2023 Accrued personnel related expenses $ 5,574 $ 7,263 Accrued legal and professional services 1,350 2,627 Accrued research and development expenses 1,376 856 Accrued purchases of property and equipment 174 445 Other accrued liabilities 366 281 Total accrued expenses and other current liabilities $ 8,840 $ 11,472

Significant Agreements

Significant Agreements	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant Agreements	7. Significant Agreements Moderna strategic collaboration and license agreement Terms of the agreement On October 29, 2021, the Company entered into a Strategic Collaboration and License Agreement with ModernaTX, Inc. (“ Moderna”) (the “Moderna Agreement”). On April 26, 2024, the Company and Moderna mutually terminated the Moderna Agreement (the “Termination”). The Moderna Agreement was terminated pursuant to a Mutual Termination Agreement (the “Termination Agreement”), dated as of April 26, 2024, by and between the Company and Moderna. Pursuant to the Termination Agreement, the Company regained full development and commercialization rights to its wholly-owned base editing and RNA-mediated integration systems (“RIGS”) that were subject to the Moderna Agreement. Prior to the Termination, the parties collaborated on the research and development of in vivo genome editing therapies directed at certain targets and the commercialization of such genome editing therapies. The collaboration provided Moderna with exclusive access to the Company’s technology platform during the research period in (1) the field of in vivo genome editing technology for a therapeutic, ameliorative or prophylactic application by way of knock-out through InDel formation or base editing or insertion of an exogenous DNA template (such field, “DT Field”) and (2) the field of in vivo genome editing technology for a therapeutic, ameliorative or prophylactic application outside the use of (a) DNA donor templates and (b) no exogenous template at all but including (c) correction by base editing (such field, “RT Field”). The use of RIGS with messenger RNA (“mRNA”) and base editing correction with mRNA was within the RT Field exclusive to Moderna within the term. The parties formed a joint steering committee, a joint research subcommittee and a joint patent subcommittee to oversee the collaboration activities. Under the terms of the Moderna Agreement, the parties agreed to collaborate on one or more programs in the RT Field (the “Moderna RT program”) and two programs in the DT Field (the “Moderna DT program” and the “DT Co-Co program”). With respect to the Moderna RT program and Moderna DT program, the parties agreed to collaborate on the research and development of product candidates under the approved research plans. The initial research term of the Moderna RT program was four years , which could have been extended by Moderna for an additional three years upon written notice and a payment of extension fees. The initial research term of the Moderna DT program was four years . The Company granted Moderna an option to obtain an exclusive license to develop, manufacture and commercialize up to ten Moderna RT program candidates and up to two Moderna DT program candidates at any time during the research term and prior to filing of an IND application with the FDA or any similar application filed with a regulatory authority in a country other than the U.S., subject to Moderna’s payment of an option exercise fee of $ 10.0 million per target. With respect to the DT Co-Co program, the parties agreed to work together on the co-development and commercialization of products and shared costs and profits equally. The Company maintained commercialization rights in the U.S. (subject to Moderna’s right to appoint up to 50 % of the U.S. sales force for the DT Co-Co program), while Moderna maintained these rights in countries other than the U.S. The initial research term for the DT Co-Co program was four years , and each party had a right to opt-out of the DT Co-Co program at any time, at which point the other party had the right to solely continue the development and commercialization activities. If there was no development candidate nomination by the end of the initial research term, the DT Co-Co program would have expired, unless the parties had mutually agreed to continue the program. During the year ended December 31, 2021, the Company received a non-refundable upfront payment of $ 40.0 million and a $ 5.0 million payment for the first year of research costs. Concurrent with the Moderna Agreement, Moderna also provided $ 30.0 million in cash in the form of a convertible promissory note pursuant to a convertible promissory note agreement dated October 29, 2021 (the “Moderna Convertible Promissory Note Agreement”). The convertible promissory note was converted into shares of Series B redeemable convertible preferred units in January 2022. Moderna rei mbursed the Company up to $ 5.0 million in annual research and development costs related to the Moderna RT program and Moderna DT program, or up to the agreed amount of expenses per the budget. As of September 30, 2024, the Company has received a total of $ 56.6 million under the Moderna Agreement, not including cost-sharing payments under the DT Co-Co program. For the Moderna RT program and Moderna DT program, the Company was eligible to receive (i) technology milestone fees related to the achievement of certain preclinical research objectives, of up to $ 75.0 million, (ii) development and regulatory milestones of up to $ 100.0 million per target, (iii) sales milestones of up to $ 200.0 million per target and (iv) royalties ranging from a mid-single digit to a low-teens percentage of annual net sales of a licensed product. Any profits and losses from the co-development and commercialization of the DT Co-Co program were shared equally between the Company and Moderna. With respect to the DT Co-Co program for which the opt-out party had exercised its opt-out right, the continuing party would have paid to the opt-out party, certain development, regulatory and sales milestone payments that would not have exceeded an aggregate $ 239.0 million per DT Co-Co target, and opt-out royalties ranging from a high-single digit to a low-teens percentage of annual net sales of a licensed product. Accounting analysis and revenue recognition The Company concluded that the Moderna RT program and Moderna DT program are in the scope of ASC 606. The Company determined that the licenses granted to Moderna, and its participation in the joint steering committee are not capable of being distinct from the preclinical research and development services and therefore concluded that there are two performance obligations: (1) the Moderna RT program and (2) the Moderna DT program. The Company also concluded that the option to obtain an exclusive license and options to extend the Moderna RT program term do not include significant incremental discounts, and as such, the options do not provide material rights. The Company concluded that the DT Co-Co program research activities are within the scope of ASC 808, as the Company and Moderna were both active participants in the research, development and commercialization activities, were exposed to significant risks and rewards that were dependent on the success of the DT Co-Co program activities and share costs and profits equally. The Company determined that the guidance in ASC 730, Research and Development , was appropriate to apply to the DT Co-Co program research activities by analogy, based on the nature of the cost sharing provisions of the agreement. The Company concluded that DT Co-Co program is one unit of accounting, as the co-exclusive license is not distinct from the research and development and the participation in joint steering committee activities. The Company recognized payments to or from Moderna related to the DT Co-Co program cost sharing research activities as an increase to or reduction of research and development expenses, respectively. The Company concluded that the Moderna Agreement and the Moderna Convertible Promissory Note Agreement should be combined and treated as a sin gle arrangement for accounting purposes as the agreements were entered into contemporaneously and in contemplation of one another. The Company estimated the contract consideration to be $ 90.0 million, which consisted of: 1) the non-refundable upfront collaboration payment of $ 40.0 million received in 2021, 2) $ 30.0 million in cash received in 2021 in exchange for the convertible promissory note and 3) the estimated cost reimbursements for the Moderna RT program and Moderna DT program of $ 20.0 million. The Company constrained future milestones, as it assessed that it was probable that the inclusion of such variable consideration could result in a significant reversal of cumulative revenue in future periods. During the year ended December 31, 2021, the Company recorded $ 30.0 million of the contract consideration for the convertible promissory note based on the fair value and allocated the transaction price of $ 60.0 million to each of the following programs on a relative standalone selling price basis: 1) $ 49.5 million to the Moderna RT program, 2) $ 5.5 million to the Moderna DT program and 3) $ 5.0 million to the DT Co-Co program. The variable consideration is reevaluated at each reporting period and as changes in circumstances occur. The Company recognized revenue for each of the Moderna RT program and Moderna DT program as collaboration revenue based on the measure of progress using an estimated cost-based input method each reporting period. The Company also amortized the allocation consideration for the DT Co-C o program of $ 5.0 million as a credit to research and development expenses during the discovery and lead optimization phases for the DT Co-Co program. Due to the Termination of the Moderna Agreement, the Company recognized all remaining deferred revenue as revenue during the nine months ended September 30, 2024 . The final $ 5.0 million payment related to the fourth year of research costs was forfeited. The Company recognized collaboration revenue of zero and $ 18.7 million in the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2024, respectively, and $ 5.3 million and $ 14.2 million for the three and nine months ended September 30, 2023, respectively, which was included in deferred revenue as of December 31, 2023 and 2022, respectively. The Company recorded no accounts receivable on the condensed consolidated balance sheets as of September 30, 2024 and $ 0.5 million as of December 31, 2023, related to services performed. As of September 30, 2024 and December 31, 2023, deferred revenue related to the Moderna Agreement was zero and $ 18.7 million , respectively. As of September 30, 2024 , there were no remaining unsatisfied performance obligations. During the three and nine months ended September 30, 2023, the Company recognized zero and $ 0.3 million in credits to research and development expenses related to the cost sharing allocation, respectively, and $ 0.1 million and $ 0.5 million in credits related to the amortization of the collaboration advance, respectively. During the three and nine months ended September 30, 2024 , the Company recognized zero and $ 0.1 million in credits related to the cost sharing allocation, respectively, and zero and $ 0.7 million in credits related to the amortization of the collaboration advance, respectively. As of September 30, 2024 and December 31, 2023, the collaboration advance balance was zero and $ 0.7 million , respectively, and the cost-sharing payable balance was zero and $ 0.1 million , which were presented as a collaboration advance on the Company’s condensed consolidated balance sheets. Affini-T development, option and license agreement Terms of the agreement Pursuant to the Affini-T Agreement entered into on June 14, 2022, the parties have agreed to identify, develop or optimize certain reagents using the Company’s proprietary technology for Affini-T to use such reagents to develop and commercialize gene edited T-cell receptor (“TCR”)-based therapeutic products exclusively in the field of treatment, prevention or diagnosis of any human cancer using products with any engineered primary TCR alpha/beta T cells and non-exclusively in the field of treatment, prevention or diagnosis of any human cancer using products with certain other engineered immune cells worldwide. A joint steering committee was established by both parties to assign alliance managers and project leaders to oversee the collaboration activities. Pursuant to the Affini-T Agreement, the Company granted Affini-T options to receive, on a pre-specified target-by-pre-specified target basis, for up to six pre-specified targets, either (i) an exclusive, royalty-bearing, sublicensable worldwide license under all of the Company’s applicable intellectual property to research, develop, manufacture, use, commercialize and otherwise exploit any TCR-based therapy, preventative treatment, or diagnostic for humans that is directed to such pre-specified target, contains or comprises Primary TCR alpha/beta T Cells and is derived from ex vivo application of a Company reagent (the “Exclusive Option”) or a non-exclusive, royalty-bearing, sublicensable worldwide license under all of the Company’s applicable intellectual property to research, develop, manufacture, use, commercialize and otherwise exploit any TCR-based therapy, preventative treatment, or diagnostic for humans that is directed to such pre-specified target, contains or comprises TCR natural killer (“NK”) cells derived from iPSC immune cells or TCR T cells derived from donor-derived or iPSC immune cells. Affini-T can exercise its options for either an exclusive license or a non-exclusive license, or both, for each pre-specified target by providing written notice prior to the earlier of (x) the end of the Affini-T Agreement term or (y) 90 days following the filing of an IND for a licensed product directed to a pre-specified target, subject to the payment of certain fees per each option exercised. After the option exercise, Affini-T has agreed to use commercially reasonable efforts to conduct all development and commercialization activities for a licensed product, and development and commercialization of all licensed products will be at Affini-T’s sole cost and expense. In connection with the Affini-T Agreement, the Company received upfront equity consideration of 719,920 shares of Affini-T’s common stock with an estimated fair value of $ 1.3 million in June 2022. Upon achievement of a regulatory milestone in July 2024 r elated to the submission of drug master files to the FDA in support of an IND for Affini-T’s T-cell receptor-based therapy, the Company received additional equity consideration of 933,650 shares of Affini-T common stock with an estimated fair value of $ 1.6 million in July 2024 . The fair value of Affini-T’s shares of common stock was estimated by management, considering the most recent third-party valuation at the time of each grant. Affini-T has also agreed to reimburse the Company for expenses incurred while performing research activities under the research plans. As of September 30, 2024, the Company has received a total of $ 7.4 million from Affini-T related to reimbursable expenses. Additionally, the Company is eligible to receive (i) up to $ 18.8 million in future developmental milestone payments depending on the completion of or the number of patients dosed in, the relevant human clinical trial, or the initiation of a pivotal trial, and $ 40.6 million in future regulatory approval milestone payments, which include regulatory approvals in the U.S. and other markets for licensed products directed to a pre-specified target if options for both exclusive and non-exclusive licenses are exercised with respect to such target, (ii) up to $ 250.0 million in sales-based milestones for aggregate sales of all licensed products directed to a given pre-specified target and (iii) royalties ranging from a low-single digit to high-single digit percentage of worldwide annual net sales of licensed products. The initial term of the Affini-T Agreement is five years from the effective date. If Affini-T exercises an Exclusive Option with respect to any pre-specified target during the initial term, the initial term will be extended by an additional five years. Following the expiration of the extended term, if any, the agreement will continue on a target-by-target basis and expire with respect to such target upon the expiration of the royalty term for all licensed products directed to such target. The Affini-T Agreement may be terminated during the term by either party for an uncured material breach by, or bankruptcy of, the other party. Additionally, Affini-T may terminate the Affini-T Agreement for convenience, in its entirety, on a research plan-by-research plan basis, on a target-by-target basis or on a licensed product-by-licensed product basis, by providing prior written notice. Accounting analysis and revenue recognition The Company concluded that the Affini-T Agreement is in the scope of ASC 606 and that there is one performance obligation to perform research activities under the Affini-T Agreement. Exclusive and non-exclusive licenses are optional contingent purchases that do not include significant incremental discounts, and therefore do not provide a material right. At the effective date, the transaction price consisted of the upfront equity consideration with an estimated fair value of $ 1.3 million and estimated research reimbursement costs. Research reimbursement costs represent variable consideration, and the Company’s management estimates what portion to include in total consideration at the end of each reporting period. Other payments under the Affini-T Agreement, including additional equity consideration and development and regulatory milestones, also represent variable consideration, and were constrained at the effective date to the extent that the inclusion of such variable consideration could result in a significant reversal of cumulative revenue in future periods. In June 2023, the joint steering committee approved the budget for estimated research reimbursement costs for the Affini-T Agreement, which resulted in a $ 2.4 million reduction to variable consideration. In July 2024, the Company included previously constrained additional equity consideration related to the regulatory milestone with an estimated fair value of $ 1.6 million in the transaction price, resulting in an increase to variable consideration. As of September 30, 2024 and December 31, 2023, future development and regulatory milestone payments were excluded from the estimated total transaction price as they were considered constrained. In addition, the equity consideration related to the regulatory milestone was also excluded from the estimated total transaction price as of December 31, 2023, as it was also considered constrained. The transaction price is reevaluated in each reporting period and as changes in circumstances occur. The Company recognizes revenue each reporting period based on the measure of progress using an estimated cost-based input method. The Company recognized collaboration revenue of $ 1.6 million and $ 2.9 million for the three and nine months ended September 30, 2024, respectively, and $ 1.1 million and $ 3.7 million for the three and nine months ended September 30, 2023, respectively. As of September 30, 2024 and December 31, 2023, the Company recorded $ 0.1 million and $ 2.0 million in accounts receivable on the condensed consolidated balance sheet, respectively, related to services performed. There was no contract asset related to services performed as of September 30, 2024 and December 31, 2023. As of September 30, 2024 and December 31, 2023, deferred revenue related to the Affini-T Agreement was $ 0.3 million and $ 0.2 million , respectively. The value of the transaction price allocated to the remaining unsatisfied portion of the performance obligation was approximately $ 0.9 million as of September 30, 2024 , which the Company expects to recognize as revenue over the next four -to-five years. Ionis collaboration and license agreement Terms of the agreement On November 10, 2022 the Company entered into a Collaboration and License Agreement with Ionis Pharmaceuticals, Inc. (“ Ionis”) (the “Ionis Agreement”) to collaborate on drug discovery and exploratory research activities to advance new medicines using genome editing strategies, with the goal of discovering novel medicines. Pursuant to the terms of the Ionis Agreement, the Company granted Ionis and its affiliates a worldwide exclusive, royalty-bearing license, with the right to grant sublicenses, to use all licensed systems and licensed products in the field of in vivo genome editing for all therapeutic, prophylactic, palliative, and analgesic uses in humans. In connection with the Ionis Agreement, the Company also has the right to exercise an exclusive option to co-develop and co-commercialize certain products under a drug discovery program. A joint steering committee was established by both parties to coordinate, oversee and monitor the research and drug discovery activities under the Ionis Agreement. The parties will collaborate to discover therapeutic products under a drug discovery program and develop a drug discovery plan for each target, selected by Ionis. The target selection is divided into two waves: up to four targets in Wave 1 and up to four targets in Wave 2. For each drug discovery program, once the parties identify a development candidate that is suitable for further development, Ionis will be responsible for the development and commercialization of products resulting from such program. Per the terms of the Ionis Agreement, at any time prior to the designation of a development candidate for a drug discovery program and for any reason, Ionis may replace the collaboration target, provided such target has not previously been substituted out. Ionis may substitute (i) up to two Wave 1 targets and (ii) up to two Wave 2 targets. The drug discovery activities for a program commence on the selection of a target and expire upon the earlier of (a) completion of all drug discovery activities for such program, (b) the fifth anniversary of the effective date and (c) selection of a development candidate for such drug discovery program. If one or more Wave 2 targets become collaboration targets as a result of the parties achieving enabled delivery and less than two years are remaining in the drug discovery term, then the term will be extended to the earlier of (i) the time that the Company completes all of its activities under the applicable drug discovery plan and (ii) the seventh anniversary of the effective date, subject to the Company’s consent. The parties will also conduct an exploratory research program, and will jointly optimize gRNA and select delivery technologies and other activities. The exploratory research activities commence on the effective date and expire upon the earlier of (a) completion of all exploratory research activities established in the exploratory research plan, and (b) the fifth anniversary of the effective date. The Company has the exclusive option to co-develop and co-commercialize the licensed products under a drug discovery program (the “Co-Co Option”) with Ionis. The Co-Co Option may be exercised for (a) the initial Wave 1 target (“Target 1”), (b) no more than one of the other three discovery programs for the Wave 1 targets, and (c) no more than two drug discovery programs for the Wave 2 targets that become collaboration targets. If the Company exercises the Co-Co Option for a particular drug discovery program, that drug discovery program will automatically be deemed a “Co-Co Program”, all corresponding licensed products be deemed “Co-Co Products,” the Company will be obligated to pay Ionis an option exercise fee, and the parties will enter into a separate co-development and co-c ommercialization agreement. The Co-Co Option exercise fee will equal 50% of Ionis’ internal costs and out-of-pocket costs incurred in the conduct of the drug discovery activities prior to the exercise of the Co-Co Option and be reduced by 50% of the Company’s corresponding costs incurred. Future development and commercialization costs will be shared equally. The Company may elect to reduce its cost-share percentage anywhere between 50% and 25% on a go-forward basis, provided the Company will continue to bear 50% of the costs of any clinical trials ongoing at the time of the election through the completion of the clinical trials. The Company will manufacture all licensed systems and certain components of the applicable licensed products that are needed by Ionis for use in its development activities and all of the Company’s manufactured components needed by Ionis for use in its commercialization activities. The Company will provide the manufactured components at a price that represents the cost of goods plus 15 %. Pursuant to the terms of the Ionis Agreement, the Company has also been granted an option to obtain a non-exclusive, royalty-bearing license, with the right to grant sublicenses, for certain Ionis’ background technology to use in up to eight therapeutic products discovered by the Company in the field of in vivo genome editing and directed to a Collaboration Target (each such product, a “Metagenomi Product” and each such option an “Ionis IP Option”), but subject to encumbrance checks with respect to particular targets. A Collaboration Target is a target that is selected by Ionis, and, with respect to the Company is not the subject of discussions with a third party, is not the subject of a contractual grant of rights to a third party nor the subject to an internal research and development program. If the Company exercises its Ionis IP Option, the Company will pay to Ionis up to several million dollars per Metagenomi Product upon achievement of certain clinical and regulatory milestones. The Company is also obligated to pay Ionis royalties in an amount equal to a low single-digit royalty on the net sales of the applicable Metagenomi Product on product-by-product and country-by-country basis. In November 2022, the Company received an $ 80.0 million upfront payment from Ionis for the Wave 1 drug discovery research collaboration and selected Target 1. Ionis selected its second target (“Target 2”) in Wave 1 in December 2022, its third target (“Target 3”) in Wave 1 in November 2023, and its fourth target (“Target 4”) in Wave 1 in February 2024. Ionis has an option to select up to four Wave 2 targets at any time during the drug discovery term, if (a) an IND for any licensed product directed to a Wave 1 target is filed with the applicable regulatory authority or (b) the parties achieve enabled delivery for a non-liver target under the exploratory research activities, by providing written notice and by paying a Wave 2 target selection fee of $ 15.0 million or $ 30.0 million, depending on and per the selected target. Ionis is obligated to reimburse the Company for all internal costs and out-of-pocket costs incurred in the performance of the exploratory research activities, up to an aggregate of $ 10.0 million, which is pay able in quarterly installments of $ 0.5 million during the exploratory research term. As of September 30, 2024, the Company received a total of $ 3.8 million related to the reimbursable expenses. The Company is also eligible to receive (a) up to $ 29.0 million in future development milestone payments for each licensed product; (b) up to $ 60.0 million in future regulatory milestone payments for each licensed product; (c) up to $ 250.0 million in sales-based milestones for each licensed product; and (d) royalties on annual net sales of licensed products from a mid-single-digit to low-teens percentage, subject to customary reductions. The term of the Ionis Agreement will continue (i) with respect to the drug discovery programs, until the expiration of all applicable royalty terms for a licensed product, (ii) with respect to the Co-Co Programs, until the parties cease all exploitation for the Co-Co Products that are the subject to such Co-Co Program, and with respect to the Metagenomi Products, until the expiration of the royalty term for a Metagenomi Product. The royalty term ends on the latest of the following two dates: (i) the expiration of (A) the last claim of any issued and unexpired patent, or (B) a claim within a patent application that has not been pending for more than seven years from the earliest date to which the claim or applicable patent application is entitled to claim priority and which claim has not been revoked, canceled, withdrawn, held invalid, or abandoned, or (ii) 12 years following the first commercial sale of a licensed product. The Ionis Agreement may be terminated during the term by either party for an uncured material breach or bankruptcy by the other party. Additionally, Ionis may terminate the Ionis Agreement for convenience and without penalty, in its entirety or on a licensed product-by-licensed product basis, by providing 90 days’ written notice. Accounting analysis and revenue recognition The Company concluded that the Ionis Agreement is in the scope of ASC 606 at the effective date and until the Company exercises its Co-Co Option for any drug discovery program, which was determined to not be probable at the effective date and as of September 30, 2024 and December 31, 2023. The Company also concluded that exclusive licenses and participation in a joint steering committee are not distinct from discovery research services and should thus be combined into one performance obligation (the “discovery program”). The Company also concluded that exploratory research services are a separate and distinct performance obligation (the “exploratory program”). The Ionis options for Wave 2 targets are optional purchases and do not have significant incremental discounts, as such, the options do not provide material rights. The Company allocated the total estimated transaction price of $ 90.0 million, which consisted of an $ 80.0 million upfront payment received in November 2022 and $ 10.0 million in reimbursements for research costs, into two performance obligations, which was determined based on their estimated standalone selling prices. The Company concluded that future development and commercial supply agreements are at market terms, as the terms were consistent with industry standards as of the effective date. The Company constrains future milestone payments under the arrangement to the extent that the inclusion of such variable consideration could result in a significant reversal of cumulative revenue in future periods. The Company constrained all development and regulatory milestone payments at the effective date and as of September 30, 2024 and December 31, 2023 . The Company is recognizing revenue of $ 80.0 million related to the discovery program and $ 10.0 million related to exploratory program over the research terms using an estimated cost-based input method as a measure of progress for each obligation. In June 2024, the Company included previously constrained estimated manufacturing costs in the transaction price, resulting in a $ 3.4 million increase to variable consideration. The Company recognized collaboration revenue of $ 9.9 million and $ 21.0 million for the three and nine months ended September 30, 2024, respectively, of which $ 9.5 million and $ 19.4 million , respectively, was included in deferred revenue as of December 31, 2023. The Company recognized collaboration revenue of $ 6.0 million and $ 14.4 million for the three and nine months ended September 30, 2023, respectively, which was included in deferred revenue as of December 31, 2022 for both periods. As of September 30, 2024 and December 31, 2023, deferred revenue related to the Ionis Agreement was $ 41.2 million and $ 60.0 million , respectively. The value of the transaction price allocated to the remaining performance obligations was approximately $ 50.3 million as of September 30, 2024, which the Company expects to recognize as revenue over the next three-to- four years.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Operating leases For more information about the Company’s Operating Leases, see “Note 8. Commitments and Contingencies – Operating Leases” of the “Notes to Consolidated Financial Statements” included in Part II, Item 8 of its Annual Report on Form 10-K for the year ended December 31, 2023. Legal contingencies On September 26, 2024, a class action complaint was filed in the U.S. District Court for the Northern District of California against the Company and certain of the Company’s officers and certain of its current and former directors, captioned Vreeland v. Metagenomi Inc. et al. , No. 5:24-cv-06765 (the “Securities Action”). The Securities Action alleges violations of Section 11 of the Securities Act against all defendants and control person violations of Section 15 against the individuals. The Securities Action alleges that the defendants made misleading statements and omitted to disclose material information concerning the Company’s collaboration with Moderna in the Company’s registration statement and final prospectus materials filed in January 2024 and February 2024. The Securities Action seeks, among other things, compensatory damages as well as costs and expenses, including attorneys’ fees and expert fees. The Company intends to defend vigorously against this litigation. From time to time, the Company may become involved in legal proceedings arising from the ordinary course of business. The Company records a liability for such matters when it is probable that future losses will be incurred and that such losses can be reasonably estimated. Significant judgment by the Company is required to determine both probability and the estimated amount. Other than the Securities Action, the Company is currently not aware of any legal matters that could have a material adverse effect on the Company’s financial position, results of operations or cash flows. Guarantees and indemnifications In the normal course of business, the Company enters into agreements that contain a variety of representations and provide for general indemnification. Its exposure under these agreements is unknown because it involves claims that may be made against the Company in the future. To the extent permitted under Delaware law, the Company has agreed to indemnify its directors and officers for certain events or occurrences while the director or officer is, or was serving, at a request in such capacity. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. As of September 30, 2024 and December 31, 2023 , the Company did not have any material indemnification claims that were probable or reasonably possible and consequently has not recorded related liabilities.

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Redeemable Convertible Preferred Stock	9. Redeemable Convertible Preferred Stock On December 20, 2022, the Company entered into a Series B-1 redeemable convertible preferred unit purchase agreement to sell up to 7,108,480 shares of Series B-1 redeemable convertible preferred units (“Series B-1”) at the purchase price of $ 14.07 . In December 2022, the Company sold and issued 6,773,726 Series B-1 shares for gross cash proceeds of $ 95.3 million in the initial closing and incurred $ 0.4 million issuance costs. In January 2023, the Company sold an additional 334,751 Series B-1 shares and received gross cash proceeds of $ 4.7 million and incurred $ 0.1 million in issuance costs. The redeemable convertible preferred stock as of December 31, 2023, consisted of the following (in thousands, except unit data): Shares Shares Original Issue Price Aggregate Net Series A-1 7,501,002 7,501,002 $ 3.23 $ 24,247 $ 24,067 Series A-2 774,473 774,473 0.65 500 581 Series A-3 1,513,860 1,513,860 1.17 1,773 1,892 Series A-4 8,280,360 8,280,360 4.85 40,149 40,007 Series A-5 1,580,937 1,580,937 6.33 10,000 9,948 Series B 15,054,263 15,054,263 11.65 175,375 174,678 Series B-1 7,108,480 7,108,480 14.07 100,000 99,585 41,813,375 41,813,375 $ 352,044 $ 350,758 On January 24, 2024, in connection with the Reorganization, all outstanding redeemable convertible preferred units were converted into an equal number of shares of redeemable convertible preferred stock. Immediately prior to the closing of the IPO, all of the then-outstanding shares of redeemable convertible preferred stock converted into 23,935,594 shares of common stock .

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	10. Stock-Based Compensation Profits Interests Plan Prior to the Reorganization, the Company granted profits interests under the 2019 Equity Incentive Plan, adopted on March 13, 2019 (the “2019 Plan”). The Company granted profits interests with a threshold amount established by the Board of Managers on the date of issuance. The 2019 Plan allows for grants of profits interests to the Company’s officers, employees, directors and consultants. The LLC Agreement provides each profits interest with a distribution threshold amount, which is determined on the date of issuance and represents the amount that would be distributed if, immediately after issuance, the Company sold all of its assets at fair market value and distributed the net proceeds in liquidation. A profits interest does not participate in Company distributions until an amount equal to its distribution threshold amount has been distributed to other members of the Company with units that either have a lower threshold amount or no threshold amount. The Company’s LLC Agreement was amended on July 31, 2023 to provide for “catch-up” distributions for profits interests once the applicable catch-up threshold amount for such profits interests was met (the “Amendment to the LLC Agreement”). In accordance with the Amendment to the LLC Agreement, once the applicable distribution threshold amount has been met for a particular profits interest, such profits interest will participate in Company distributions on a pro rata basis until the catch-up threshold amount has been met. Once the catch-up threshold amount has been met, subsequent “catch-up” distributions will be made solely to holders of profits interests until such holders have received an amount equal to the amount such holders would have received had the distribution threshold not existed. Once the profits interest holders have received distributions in an amount equal to what they would have received had the distribution threshold not existed, all subsequent distributions are made on a pro rata basis with common unitholders. As a result of the Amendment to the LLC Agreement, the Board approved an $ 11.84 catch-up threshold amount, which was based on the estimated fair value of the Company’s common unit as of July 31, 2023. After giving the effect to the Amendment to the LLC Agreement, the grant date fair value of profits interests issued after July 31, 2023 and profits interests at the modification date was estimated using the valuation model based on the Probability Weighted Expected Return Method (“PWERM”). The estimated equity fair value was allocated via the distribution waterfall in accordance with the Amendment to the LLC Agreement to all outstanding redeemable convertible preferred units, common units and profits interests. The PWERM is the hybrid method, where the equity value in one or more scenarios is calculated using an option pricing model. The PWERM is a scenario based methodology that estimates the fair value of common unit based upon an analysis of future values for the company, assuming various outcomes. The common unit value is based on the probability-weighted present value of expected future investment returns considering each of the possible outcomes available as well as the rights of each class of members’ units. The future value of the common unit under each outcome is discounted back to the valuation date at an appropriate risk-adjusted discount rate and probability weighted to arrive at an indication of value for the common unit. A discount for lack of marketability of the common unit is then applied to arrive at an indication of value for the common unit. As part of the catch-up and Amendment to the LLC Agreement, the Company modified the terms and conditions of the profits interest, which resulted in a change in the fair value of the awards. The change was treated as a modification under ASC 718, Stock Compensation, in which the fair value of the profits interest s was remeasured at the modification date and compared to the fair value of the modified award immediately prior to the modification, with the difference resulting in incremental compensation expense. The Company estimated total modification expense of $ 10.3 million. As part of the Reorganization, 282,660 profits interest units were canceled without a concurrent grant of a replacement award and were accounted for as a repurchase for no consideration and accordingly previously unrecognized compensation of $ 3.0 million was recognized at the cancelation date. Immediately after the Reorganization, all of the outstanding 9,142,176 profits interes t units were exchanged for 3,884,870 shares of common stock, of which 1,036,833 were subject to certain vesting conditions. The table below presents a summary of profits interests units activity: Profits Weighted-Average Outstanding as of December 31, 2023 9,488,776 $ 2.63 Forfeited and expired ( 63,940 ) 1.17 Canceled in connection with the Reorganization ( 282,660 ) 11.84 Exchanged for vested and unvested common stock in connection with the Reorganization ( 9,142,176 ) 2.36 Outstanding as of September 30, 2024 — $ — The following table presents a summary of the unvested common stock activity for the nine months ended September 30, 2024: Restricted Stock Awards Number of Shares Weighted-Average Outstanding as of December 31, 2023 — $ — Exchange of profits interests units for unvested common stock 1,036,833 18.80 Vested ( 381,048 ) 14.06 Forfeited ( 62,448 ) 13.80 Outstanding as of September 30, 2024 593,337 $ 22.36 (1) Weighted-average grant date fair value includes amount related to the modification as a result of the catch-up and Amendment to the LLC Agreement 2024 Stock Option and Incentive Plan In January 2024, the board of directors adopted and the stockholders approved the 2024 Stock Option and Incentive Plan (“2024 Plan”), which became effective immediately prior to the closing of the IPO. The 2024 Plan allows the Company to make equity-based and cash-based incentive awards to its officers, employees, directors, and consultants. The 2024 Plan provides for the grant of incentive stock options, non-qualified stock options, restricted stock units, restricted stock awards, and other stock-based awards. The Company initially reserved 6,690,000 shares of common stock for future issuance under the 2024 Plan. The number of shares of common stock reserved and available for issuance under the 2024 Plan will automatically increase on each January 1, commencing on January 1, 2025 and through 2034, by five percent of the number of shares of the Company’s common stock issued and outstanding on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s compensation committee. Awards granted under the 2024 Plan expire no later than ten years from the date of grant. For the Incentive Stock Options and Non-Qualified Stock Options, the option price shall not be less than 100 % of the estimated fair value on the date of grant. Options and restricted stock units typically vest over a four-year time period but may be granted with different vesting terms. As of September 30, 2024, there were 3,216,835 shares available for future issuance under the 2024 Plan. Stock Option Activity The following table presents a summary of the stock option activity for the nine months ended September 30, 2024: Stock Options Number of Shares Weighted-Average Outstanding as of December 31, 2023 — $ — Granted 3,585,904 10.73 Forfeited ( 529,494 ) 10.82 Outstanding as of September 30, 2024 3,056,410 $ 10.72 Exercisable as of September 30, 2024 118,954 $ 10.69 Restricted Stock Unit Activity The following table presents a summary of the restricted stock unit activity for the nine months ended September 30, 2024: Restricted Stock Units Number of Weighted-Average Outstanding as of December 31, 2023 — $ — Granted 508,490 10.68 Vested ( 20,361 ) 10.82 Forfeited ( 91,735 ) 10.02 Outstanding as of September 30, 2024 396,394 $ 10.82 2024 Employee Stock Purchase Plan In January 2024, the board of directors adopted and the stockholders approved the 2024 Employee Stock Purchase Plan (“ESPP”), which become effective upon the date immediately preceding the date on which the Company’s registration statement was declared effective by the SEC. The Company initially reserved 375,000 shares of common stock for future issuance under the ESPP. The number of shares of common stock reserved and available for issuance under the ESPP will automatically increase on each January 1, commencing on January 1, 2025 and through 2034, by the least of (i) 750,000 shares of common stock; (ii) one percent of the number of shares of the Company’s common stock issued and outstanding on the immediately preceding December 31, or (iii) such lesser number of shares as determined by the Company’s compensation committee. Under the ESPP, employees, subject to certain restrictions, may purchase shares of common stock at 85 % of the fair market value at either the first business day or the last business day of the offering period, whichever is lower. Purchases are limited to the lesser of 15 % of each employee’s eligible annual compensation or $ 25,000 . As of September 30, 2024 , the Company has issued no shares under the ESPP as the first offering period has not begun. As of September 30, 2024 , there were 375,000 shares available for issuance under the ESPP. Compensation Expense The following table presents the classification of share-based compensation expense for the periods presented (in thousands): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Research and development expenses $ 1,024 $ 1,552 $ 7,326 $ 2,166 General and administrative expenses 2,199 1,716 5,466 2,287 Total $ 3,223 $ 3,268 $ 12,792 $ 4,453 As of September 30, 2024, there was $ 13.7 million of unrecognized compensation expense (including modification expense related to the catch-up) related to restricted stock awards that is expected to be recognized over a weighted-average period of 2.1 years, $ 19.7 million of unrecognized compensation expense related to stock options that is expected to be recognized over a weighted-average period of 3.3 years and $ 3.9 million of unrecognized compensation expense related to restricted stock units that is expected to be recognized over a weighted-average period of 3.6 years.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share	11. Net Loss Per Share Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands except share and per share amounts): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Numerator: Net loss attributable to common stockholders $ ( 18,773 ) $ ( 19,820 ) $ ( 54,660 ) $ ( 48,961 ) Denominator: Weighted-average common shares outstanding 37,431,688 3,404,585 32,267,642 3,404,585 Less: Weighted-average unvested shares of common stock ( 665,379 ) — ( 665,817 ) — Weighted-average common shares outstanding—basic and diluted 36,766,309 3,404,585 31,601,825 3,404,585 Net loss per share attributable to common stockholders—basic and diluted $ ( 0.51 ) $ ( 5.82 ) $ ( 1.73 ) $ ( 14.38 ) The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect would have been anti-dilutive: Three and Nine Months Ended 2024 2023 Common stock issuable upon conversion of redeemable convertible preferred stock — 23,935,594 Common stock issuable upon settlement of profits interests — 3,937,500 Restricted stock subject to future vesting 593,337 — Options to purchase common stock 3,056,410 — Restricted stock units 396,394 — Total 4,046,141 27,873,094

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchanges Commission (“SEC”). Accordingly, these financial statements do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, these financial statements include all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair statement of the Company’s condensed consolidated financial statements for the periods presented. These interim financial results are not necessarily indicative of results to be expected for the full fiscal year ending December 31, 2024, or any other future period. Readers should read these interim unaudited condensed consolidated financial statements in conjunction with the audited consolidated financial statements and the related notes thereto for the year ended December 31, 2023, included in the Company’s Annual Report on Form 10-K filed with the SEC. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The accompanying condensed consolidated financial statements include the accounts of Metagenomi, Inc. and the accounts of Metagenomi LLC, retroactively adjusted for the Reorganization and Reverse Stock Split (see Note 1). All intercompany balances and transactions have been eliminated in consolidation.
Use of estimates	Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates estimates and assumptions, including but not limited to those related to revenue recognition under its collaboration agreements, the fair value of its common stock, stock-based compensation expense, accruals for research and development expenses, the fair value of long-term investments, the valuation of deferred tax assets and uncertain income tax positions. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those estimates.
Recently issued accounting pronouncements	Recently issued accounting pronouncements In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This ASU requires public entities to disclose information about their reportable segments’ significant expenses and other segment items on an interim and annual basis. Public entities with a single reportable segment are required to apply the disclosure requirements in ASU 2023-07, as well as all existing segment disclosures and reconciliation requirements in ASC 280 on an interim and annual basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its financial statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU requires public entities, on an annual basis, to provide disclosure of specific categories in the rate reconciliation, as well as disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its financial statements. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires, among other things, more detailed disclosures about specified categories of expense (purchases of inventory, employee compensation, depreciation, amortization, and depletion) included in certain expense captions presented on the face of the income statement. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. This ASU may be applied prospectively with the option for retrospective application. The Company is currently evaluating the impact of the adoption of this standard on its financial statements.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on Recurring Basis	The following tables summarize financial assets that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands): September 30, 2024 Total Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash equivalents) $ 23,846 $ 23,846 $ — $ — U.S. government bonds 121,824 — 121,824 — Government agency obligations 40,537 — 40,537 — Corporate debt obligations 31,270 — 31,270 — Commercial paper 42,673 — 42,673 — Asset-backed securities 10,691 — 10,691 — Foreign debt securities 2,475 — 2,475 — Long-term investments (Note 5) 8,422 — — 8,422 Total fair value of assets $ 281,738 $ 23,846 $ 249,470 $ 8,422 December 31, 2023 Total Level 1 Level 2 Level 3 Assets: Money market funds (included in cash and cash equivalents) $ 137,216 $ 137,216 $ — $ — U.S. Treasury bills 9,831 — 9,831 — U.S. Government bonds 2,989 — 2,989 — Government agency obligations 46,409 — 46,409 — Corporate debt obligations 10,973 — 10,973 — Commercial paper 54,727 — 54,727 — Asset-backed securities 2,171 — 2,171 — Foreign debt securities 3,479 — 3,479 — Long-term investments (Note 5) 8,521 — — 8,521 Total fair value of assets $ 276,316 $ 137,216 $ 130,579 $ 8,521
Summary of Changes in Fair Value of Company's Level 3 Financial Assets	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial assets (in thousands): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Beginning balance $ 8,521 $ 8,521 $ 8,521 $ 5,651 Fair value of investment received as collaboration consideration 1,632 — 1,632 — Fair value of investment purchased in preferred stock purchase agreement 324 — 324 — Change in fair value included in other income (expense) ( 2,055 ) — ( 2,055 ) 2,870 Ending balance $ 8,422 $ 8,521 $ 8,422 $ 8,521

Available-For-Sale Marketable_2

Available-For-Sale Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost, Unrealized Gains (Losses) and Fair Value of Available-for-sale Marketable Securities	The following tables summarize the amortized cost, unrealized gains (losses) and fair value of available-for-sale marketable securities (in thousands): September 30, 2024 Amortized Unrealized Unrealized Fair value Money market funds $ 23,846 $ — $ — $ 23,846 U.S. government bonds 120,666 1,160 ( 2 ) 121,824 Government agency obligations 40,240 297 — 40,537 Corporate debt obligations 31,182 88 — 31,270 Commercial paper 42,600 73 — 42,673 Asset-backed securities 10,668 23 — 10,691 Foreign debt securities 2,475 — — 2,475 Total 271,677 1,641 ( 2 ) 273,316 Less: amounts classified as cash equivalents ( 23,846 ) — — ( 23,846 ) Total available-for-sale marketable securities $ 247,831 $ 1,641 $ ( 2 ) $ 249,470 December 31, 2023 Amortized Unrealized Unrealized Fair value Money market funds $ 137,216 $ — $ — $ 137,216 U.S. treasury bills 9,826 5 — 9,831 U.S. government bonds 3,005 — ( 16 ) 2,989 Government agency obligations 46,446 4 ( 41 ) 46,409 Corporate debt obligations 11,014 — ( 41 ) 10,973 Commercial paper 54,724 4 ( 1 ) 54,727 Asset-backed securities 2,177 — ( 6 ) 2,171 Foreign debt securities 3,484 — ( 5 ) 3,479 Total 267,892 13 ( 110 ) 267,795 Less: amounts classified as cash equivalents ( 137,216 ) — — ( 137,216 ) Total available-for-sale marketable securities $ 130,676 $ 13 $ ( 110 ) $ 130,579
Summary of Amortized Cost and Fair Value of Available-for-sale Marketable Securities by Contractual Maturity	The amortized cost and fair value of available-for-sale marketable securities by contractual maturity were as follows (in thousands): September 30, 2024 December 31, 2023 Amortized Fair Value Amortized Fair Value Maturing within one year $ 154,228 $ 154,702 $ 129,823 $ 129,728 Maturing in one to five years 93,603 94,768 853 851 Total available-for-sale marketable securities $ 247,831 $ 249,470 $ 130,676 $ 130,579

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): September 30, 2024 December 31, 2023 Accrued personnel related expenses $ 5,574 $ 7,263 Accrued legal and professional services 1,350 2,627 Accrued research and development expenses 1,376 856 Accrued purchases of property and equipment 174 445 Other accrued liabilities 366 281 Total accrued expenses and other current liabilities $ 8,840 $ 11,472

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2024
Equity [Abstract]
Summary of Redeemable Convertible Preferred Stock	The redeemable convertible preferred stock as of December 31, 2023, consisted of the following (in thousands, except unit data): Shares Shares Original Issue Price Aggregate Net Series A-1 7,501,002 7,501,002 $ 3.23 $ 24,247 $ 24,067 Series A-2 774,473 774,473 0.65 500 581 Series A-3 1,513,860 1,513,860 1.17 1,773 1,892 Series A-4 8,280,360 8,280,360 4.85 40,149 40,007 Series A-5 1,580,937 1,580,937 6.33 10,000 9,948 Series B 15,054,263 15,054,263 11.65 175,375 174,678 Series B-1 7,108,480 7,108,480 14.07 100,000 99,585 41,813,375 41,813,375 $ 352,044 $ 350,758

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Summary of Profits Units Activity and Stock Option Activity	The table below presents a summary of profits interests units activity: Profits Weighted-Average Outstanding as of December 31, 2023 9,488,776 $ 2.63 Forfeited and expired ( 63,940 ) 1.17 Canceled in connection with the Reorganization ( 282,660 ) 11.84 Exchanged for vested and unvested common stock in connection with the Reorganization ( 9,142,176 ) 2.36 Outstanding as of September 30, 2024 — $ —
Summary of Unvested Common Stock Activity	The following table presents a summary of the unvested common stock activity for the nine months ended September 30, 2024: Restricted Stock Awards Number of Shares Weighted-Average Outstanding as of December 31, 2023 — $ — Exchange of profits interests units for unvested common stock 1,036,833 18.80 Vested ( 381,048 ) 14.06 Forfeited ( 62,448 ) 13.80 Outstanding as of September 30, 2024 593,337 $ 22.36
Summary of Restricted Stock Unit Activity	The following table presents a summary of the restricted stock unit activity for the nine months ended September 30, 2024: Restricted Stock Units Number of Weighted-Average Outstanding as of December 31, 2023 — $ — Granted 508,490 10.68 Vested ( 20,361 ) 10.82 Forfeited ( 91,735 ) 10.02 Outstanding as of September 30, 2024 396,394 $ 10.82
Summary of Classification of Share-based Compensation Expense	The following table presents the classification of share-based compensation expense for the periods presented (in thousands): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Research and development expenses $ 1,024 $ 1,552 $ 7,326 $ 2,166 General and administrative expenses 2,199 1,716 5,466 2,287 Total $ 3,223 $ 3,268 $ 12,792 $ 4,453
Employee Stock Option
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Summary of Profits Units Activity and Stock Option Activity	The following table presents a summary of the stock option activity for the nine months ended September 30, 2024: Stock Options Number of Shares Weighted-Average Outstanding as of December 31, 2023 — $ — Granted 3,585,904 10.73 Forfeited ( 529,494 ) 10.82 Outstanding as of September 30, 2024 3,056,410 $ 10.72 Exercisable as of September 30, 2024 118,954 $ 10.69

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share Attributable To Common Stockholders	Basic and diluted net loss per share attributable to common stockholders is calculated as follows (in thousands except share and per share amounts): Three Months Ended Nine Months Ended 2024 2023 2024 2023 Numerator: Net loss attributable to common stockholders $ ( 18,773 ) $ ( 19,820 ) $ ( 54,660 ) $ ( 48,961 ) Denominator: Weighted-average common shares outstanding 37,431,688 3,404,585 32,267,642 3,404,585 Less: Weighted-average unvested shares of common stock ( 665,379 ) — ( 665,817 ) — Weighted-average common shares outstanding—basic and diluted 36,766,309 3,404,585 31,601,825 3,404,585 Net loss per share attributable to common stockholders—basic and diluted $ ( 0.51 ) $ ( 5.82 ) $ ( 1.73 ) $ ( 14.38 )
Summary of Outstanding Potentially Dilutive Securities that have been Excluded from Calculation of Diluted Net Loss Per Unit	The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect would have been anti-dilutive: Three and Nine Months Ended 2024 2023 Common stock issuable upon conversion of redeemable convertible preferred stock — 23,935,594 Common stock issuable upon settlement of profits interests — 3,937,500 Restricted stock subject to future vesting 593,337 — Options to purchase common stock 3,056,410 — Restricted stock units 396,394 — Total 4,046,141 27,873,094

Description of Business, Orga_2

Description of Business, Organization and Liquidity - Additional Information (Details) $ / shares in Units, $ in Thousands			9 Months Ended
	Feb. 13, 2024 USD ($) $ / shares shares	Jan. 26, 2024	Sep. 30, 2024 USD ($) $ / shares shares	Feb. 12, 2024 $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Entity incorporation date			Sep. 30, 2016
Reverse stock split		1-for-1.74692
Reverse stock split conversion ratio		0.5724
Shares of common stock outstanding			37,432,832		3,404,585
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs | $			$ 84,013
Common stock, authorized			500,000,000		66,000,000
Common stock, par value | $ / shares			$ 0.0001		$ 0.0001
Preferred stock, authorized			10,000,000		0
Preferred stock, par value | $ / shares			$ 0.0001		$ 0.0001
Accumulated deficit | $			$ (199,604)		$ (144,944)
Cash, cash equivalents and available-for-sale marketable securities | $			$ 274,600
Profits Interests
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Shares of common stock outstanding			3,884,740
Profits Interests | Unvested Restricted Common Stock
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Shares of common stock outstanding			1,036,833
Profits Interests | Minimum
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Shares of common stock received by holders of outstanding profits interests			0
Profits Interests | Maximum
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Shares of common stock received by holders of outstanding profits interests			0.997816
Initial Public Offering
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs | $	$ 80,700
Payments of initial public offering costs | $	$ 13,000
Metagenomi LLC
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Shares of common stock outstanding			3,404,585
Metagenomi LLC | Series A-1 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			7,501,002
Number of shares after reverse stock split			4,293,867
Metagenomi LLC | Series A-2 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			774,473
Number of shares after reverse stock split			443,338
Metagenomi LLC | Series A-3 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			1,513,860
Number of shares after reverse stock split			866,589
Metagenomi LLC | Series A-4 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			8,280,360
Number of shares after reverse stock split			4,740,000
Metagenomi LLC | Series A-5 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			1,580,937
Number of shares after reverse stock split			904,990
Metagenomi LLC | Series B Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			15,054,263
Number of shares after reverse stock split			8,617,649
Metagenomi LLC | Series B-1 Preferred Units
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of shares issued			7,108,480
Number of shares after reverse stock split			4,069,161
Metagenomi Inc | Initial Public Offering
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Sale of stock, number of shares issued	6,250,000
Purchase price | $ / shares	$ 15
Gross proceeds from issuance initial public offering | $	$ 93,800
Proceeds from issuance of common stock upon initial public offering, net of underwriting discounts and commissions and other offering costs | $	80,700
Payments of initial public offering costs | $	$ 13,000
Common stock, authorized				500,000,000
Common stock, par value | $ / shares				$ 0.0001
Preferred stock, authorized				10,000,000
Preferred stock, par value | $ / shares				$ 0.0001
Preferred stock, conversion ratio				1.74692

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	$ 281,738	$ 276,316
Money Market Funds (Included in Cash and Cash Equivalents)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	23,846	137,216
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	42,673	54,727
U.S. Treasury Bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets		9,831
U.S. Government Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	121,824	2,989
Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	8,422	8,521
Government Agency Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	40,537	46,409
Corporate Debt Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	31,270	10,973
Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	10,691	2,171
Foreign Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	2,475	3,479
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	23,846	137,216
Level 1 | Money Market Funds (Included in Cash and Cash Equivalents)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	23,846	137,216
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	249,470	130,579
Level 2 | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	42,673	54,727
Level 2 | U.S. Treasury Bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets		9,831
Level 2 | U.S. Government Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	121,824	2,989
Level 2 | Government Agency Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	40,537	46,409
Level 2 | Corporate Debt Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	31,270	10,973
Level 2 | Asset-backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	10,691	2,171
Level 2 | Foreign Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	2,475	3,479
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	8,422	8,521
Level 3 | Long-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	$ 8,422	$ 8,521

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands		9 Months Ended
	Dec. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash		$ 5,248	$ 5,248
Affini-T
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Valuation model		us-gaap:ValuationTechniqueOptionPricingModelMember
Expected holding period	2 years	2 years
Risk free interest rate	4.87%	4.05%
Dividend yield	0%	0%
Estimated volatility	83%	88.50%
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash	$ 5,200	$ 5,200

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Changes in Fair Value of Company's Level 3 Financial Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Beginning balance	$ 8,521	$ 8,521	$ 8,521	$ 5,651
Fair value of investment received as collaboration consideration	1,632	0	1,632	0
Fair value of investment purchased in preferred stock purchase agreement	324	0	324	0
Change in fair value included in other income (expense)	(2,055)	0	(2,055)	2,870
Ending balance	$ 8,422	$ 8,521	$ 8,422	$ 8,521

Available-For-Sale Marketable_3

Available-For-Sale Marketable Securities - Summary of Amortized Cost, Unrealized Gains (Losses) and Fair Value of Available-for-sale Marketable Securities (Details) - USD ($) $ in Thousands		9 Months Ended
	Dec. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	$ 267,892	$ 271,677
Unrealized gains	13	1,641
Unrealized losses	(110)	(2)
Fair value	267,795	273,316
Amortized cost	(140,603)	(25,117)	$ (101,897)
Money Market Funds
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	137,216	23,846
Fair value	137,216	23,846
U.S. Treasury Bills
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	9,826
Unrealized gains	5
Fair value	9,831
U.S. Government Bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	3,005	120,666
Unrealized gains		1,160
Unrealized losses	(16)	(2)
Fair value	2,989	121,824
Government Agency Obligations
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	46,446	40,240
Unrealized gains	4	297
Unrealized losses	(41)
Fair value	46,409	40,537
Corporate Debt Obligations
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	11,014	31,182
Unrealized gains		88
Unrealized losses	(41)
Fair value	10,973	31,270
Commercial Paper
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	54,724	42,600
Unrealized gains	4	73
Unrealized losses	(1)
Fair value	54,727	42,673
Asset-backed Securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	2,177	10,668
Unrealized gains		23
Unrealized losses	(6)
Fair value	2,171	10,691
Foreign Debt Securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	3,484	2,475
Unrealized losses	(5)
Fair value	3,479	2,475
Less: Amounts Classified as Cash Equivalents
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	(137,216)	(23,846)
Fair value	(137,216)	(23,846)
Total Available-for-sale Marketable Securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	130,676	247,831
Unrealized gains	13	1,641
Unrealized losses	(110)	(2)
Fair value	$ 130,579	$ 249,470

Available-For-Sale Marketable_4

Available-For-Sale Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Deterioration in creditworthiness of issuers of available-for-sale securities			$ 0		$ 0
Allowance for losses	$ 0		0
Impairment losses on investments	0	$ 0	0	$ 0
Accrued interest receivable included in prepaid expenses and other current assets	1,600,000		1,600,000		$ 1,000,000
Written off accrued interest receivable	$ 0	$ 0	$ 0	$ 0

Available-For-Sale Marketable_5

Available-For-Sale Marketable Securities - Summary of Amortized Cost and Fair Value of Available-for-sale Marketable Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Available-for-Sale Securities, Debt Maturities [Abstract]
Amortized Cost, Maturing within one year	$ 154,228	$ 129,823
Amortized Cost, Maturing in one to five years	93,603	853
Amortized Cost, Total available-for-sale marketable securities	247,831	130,676
Fair Value, Maturing within one year	154,702	129,728
Fair Value, Maturing in one to five years	94,768	851
Fair Value, Total available-for-sale marketable securities	$ 249,470	$ 130,579

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2024	Jul. 31, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Aggregate share purchase amount	$ 300,000
Carrying value of investment			$ 10,577,000		$ 10,577,000		$ 10,676,000
Affini-T investment
Debt Instrument [Line Items]
Estimated fair value of investments			8,400,000		8,400,000		$ 8,500,000
Gain (loss) related to changes in fair value of investments			$ (2,100,000)	$ 0	$ (2,100,000)	$ 2,900,000
Affini-T investment | Series A convertible preferred stock
Debt Instrument [Line Items]
Number of shares invested			527,035		527,035		527,035
Affini-T investment | Series B Preferred Stock
Debt Instrument [Line Items]
Number of shares invested			33,383		33,383
Development, Option and License Agreement | Affini-T investment
Debt Instrument [Line Items]
Equity consideration shares received		933,650
Preferred Stock | Affini-T investment | Series B Preferred Stock
Debt Instrument [Line Items]
Preferred shares purchased	33,383
Preferred stock purchase price per share	$ 9.714
Additional purchase of preferred stock	16,691
Preferred Stock | ViTToria investment
Debt Instrument [Line Items]
Impairment loss recognized					$ 0		$ 0
Carrying value of investment			$ 2,200,000		$ 2,200,000		$ 2,200,000
Preferred Stock | ViTToria investment | Maximum
Debt Instrument [Line Items]
Percentage of voting shares			20%		20%		20%
Common Stock | Affini-T investment
Debt Instrument [Line Items]
Common stock exercise price	$ 0.01
Additional purchase of common stock	8,345
Number of shares invested			1,867,300		1,867,300		933,650
Warrant exercisable					16,691
Common Stock | Affini-T investment | Maximum
Debt Instrument [Line Items]
Purchase of common stock	16,691

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued personnel related expenses	$ 5,574	$ 7,263
Accrued legal and professional services	1,350	2,627
Accrued research and development expenses	1,376	856
Accrued purchases of property and equipment	174	445
Other accrued liabilities	366	281
Total accrued expenses and other current liabilities	$ 8,840	$ 11,472

Significant Agreements - Additi

Significant Agreements - Additional Information (Details) - USD ($)			1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Nov. 10, 2022	Jul. 31, 2024	Jun. 30, 2024	Jun. 30, 2023	Nov. 30, 2022	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2021	Jun. 14, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborations revenue							$ 9,900,000	$ 6,000,000	$ 21,000,000	$ 14,400,000
Deferred revenue							9,500,000		19,400,000
Collaboration advance	$ 0						0		0		$ 837,000
Remaining performance obligation as revenue	0						0		0
Increase in variable consideration				$ 3,400,000
Moderna TX, Inc | Strategic Collaboration and License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Option exercise fee paid per target									10,000,000
Non-refundable upfront payment received												$ 40,000,000
Research and development costs received	56,600,000											5,000,000
Collaborations revenue							0	5,300,000	18,700,000	14,200,000
Accounts receivable	0						0		0		500,000
Deferred revenue									0		18,700,000
Collaboration advance	0						0		0		700,000
Cost sharing payables	0						0		0		100,000
Final payment to be forfeited									5,000,000
Moderna TX, Inc | Strategic Collaboration and License Agreement | Research and Development Expenses
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cost sharing allocation expense							0	0	100,000	300,000
Amortization of collaboration advance							0	100,000	$ 700,000	500,000
Moderna TX, Inc | Strategic Collaboration and License Agreement | Moderna RT Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial research term									4 years
Extended research term									3 years
Moderna TX, Inc | Strategic Collaboration and License Agreement | Moderna DT Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial research term									4 years
Moderna TX, Inc | Strategic Collaboration and License Agreement | DT Co-Co Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Initial research term									4 years
Moderna TX, Inc | Strategic Collaboration and License Agreement | DT Co-Co Program | Research and Development Expenses
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Amortization of contract consideration amount									$ 5,000,000
Moderna TX, Inc | Strategic Collaboration and License Agreement | DT Co-Co Program | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of appointment right									50%
Development, regulatory and sales milestone payments									$ 239,000,000
Moderna TX, Inc | Strategic Collaboration and License Agreement | Moderna DT and Moderna RT Programs | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual research and development costs reimbursement												5,000,000
Technology milestone fees related to preclinical research objectives									75,000,000
Development and regulatory milestones payment received									100,000,000
Sales based milestones received									200,000,000
Moderna TX, Inc | Convertible Promissory Note Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash received in the form of convertible promissory note												30,000,000
Moderna TX, Inc | Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Cash received in the form of convertible promissory note												30,000,000
Estimated contract consideration									90,000,000
Non refundable upfront collaboration payment received												40,000,000
Contract consideration amount												30,000,000
Transaction cost												60,000,000
Moderna TX, Inc | Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement | Moderna RT Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transaction cost												49,500,000
Moderna TX, Inc | Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement | Moderna DT Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transaction cost												5,500,000
Moderna TX, Inc | Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement | DT Co-Co Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Transaction cost												5,000,000
Moderna TX, Inc | Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement | Moderna DT and Moderna RT Programs
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Annual research and development costs reimbursement												$ 20,000,000
Affini-T Therapeutics, Inc. | Development, Option and License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborations revenue							1,600,000	$ 1,100,000	2,900,000	$ 3,700,000
Accounts receivable	100,000						100,000		100,000		2,000,000
Deferred revenue									300,000		200,000
Upfront equity consideration received									$ 7,400,000
Upfront equity consideration shares received									719,920
Additional equity consideration shares received									933,650
Equity consideration estimated fair value													$ 1,300,000
Remaining performance obligation as revenue	900,000						900,000		$ 900,000
Future regulatory approval milestone payments received									$ 40,600,000
Agreement term description									The initial term of the Affini-T Agreement is five years from the effective date. If Affini-T exercises an Exclusive Option with respect to any pre-specified target during the initial term, the initial term will be extended by an additional five years. Following the expiration of the extended term, if any, the agreement will continue on a target-by-target basis and expire with respect to such target upon the expiration of the royalty term for all licensed products directed to such target. The Affini-T Agreement may be terminated during the term by either party for an uncured material breach by, or bankruptcy of, the other party. Additionally, Affini-T may terminate the Affini-T Agreement for convenience, in its entirety, on a research plan-by-research plan basis, on a target-by-target basis or on a licensed product-by-licensed product basis, by providing prior written notice.
Reduction in variable consideration					$ 2,400,000
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Common Stock
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront equity consideration received									$ 1,300,000
Equity consideration estimated fair value, additional			$ 1,600,000						1,600,000
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront equity consideration received									18,800,000
Sales based milestones received									250,000,000
Ionis
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Deferred revenue									41,200,000		$ 60,000,000
Ionis | Collaboration and License Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Remaining performance obligation as revenue	50,300,000						$ 50,300,000		$ 50,300,000
Reimbursable expenses received	$ 3,800,000
Upfront payment received						$ 80,000,000
Reimbursement for research costs						10,000,000
Estimated transaction price						90,000,000
Collaboration agreement upfront payment received						80,000,000
Percentage added to cost of goods that represents price of manufactured components		15%
Reimbursable internal costs and out-of-pocket costs payable in quarterly installments		$ 500,000
Ionis | Collaboration and License Agreement | Wave 2 Target
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Target selection fee						15,000,000
Ionis | Collaboration and License Agreement | Selected Target
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Target selection fee						30,000,000
Ionis | Collaboration and License Agreement | Maximum
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Reimbursable internal costs and out-of-pocket costs		10,000,000
Future development milestone payments to be received		29,000,000
Future regulatory milestone payments to be received		60,000,000
Sales-based milestones to be received		$ 250,000,000
Ionis | Co-Develop and Co-Commercialize Licensed Products
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Exercise fee description									The Co-Co Option exercise fee will equal 50% of Ionis’ internal costs and out-of-pocket costs incurred in the conduct of the drug discovery activities prior to the exercise of the Co-Co Option and be reduced by 50% of the Company’s corresponding costs incurred.
Cost - share percentage description									The Company may elect to reduce its cost-share percentage anywhere between 50% and 25% on a go-forward basis, provided the Company will continue to bear 50% of the costs of any clinical trials ongoing at the time of the election through the completion of the clinical trials.
Ionis | Discovery Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue						80,000,000
Ionis | Exploratory Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue						$ 10,000,000

Significant Agreements - Addi_2

Significant Agreements - Additional Information (Details1)	Sep. 30, 2024 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 0
Affini-T Therapeutics, Inc. | Development, Option and License Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 900,000
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Affini-T Therapeutics, Inc. | Development, Option and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Ionis | Collaboration and License Agreement
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Transaction price allocated to remaining performance obligations	$ 50,300,000
Ionis | Collaboration and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Ionis | Collaboration and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Ionis | Collaboration and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Ionis | Collaboration and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Ionis | Collaboration and License Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year

Redeemable Convertible Prefer_3

Redeemable Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Jan. 31, 2023	Dec. 31, 2022	Feb. 12, 2024	Dec. 20, 2022
Preferred Units [Line Items]
Redeemable convertible preferred stock converted into common stock			23,935,594
Series B-1 Redeemable Convertible Preferred Unit Purchase Agreement | Series B-1 Redeemable Convertible Preferred Units
Preferred Units [Line Items]
Units to be sold				7,108,480
Purchase price				$ 14.07
Shares sold and issued		6,773,726
Gross cash proceeds		$ 95.3
Issuance costs		$ 0.4
Series B-1 Redeemable Convertible Preferred Unit Purchase Agreement | Additional Series B-1 shares
Preferred Units [Line Items]
Shares sold and issued	334,751
Gross cash proceeds	$ 4.7
Issuance costs	$ 0.1

Redeemable Convertible Prefer_4

Redeemable Convertible Preferred Stock - Summary of Redeemable Convertible Preferred Stock (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Temporary Equity [Line Items]
Shares Authorized	0	41,813,375
Shares Issued	0	41,813,375
Shares Outstanding	0	41,813,375
Aggregate Liquidation Preference		$ 352,044,000
Net Carrying Value	$ 0	$ 350,758,000
Series A-1
Temporary Equity [Line Items]
Shares Authorized		7,501,002
Shares Issued		7,501,002
Shares Outstanding		7,501,002
Original Issue Price		$ 3.23
Aggregate Liquidation Preference		$ 24,247,000
Net Carrying Value		$ 24,067,000
Series A-2
Temporary Equity [Line Items]
Shares Authorized		774,473
Shares Issued		774,473
Shares Outstanding		774,473
Original Issue Price		$ 0.65
Aggregate Liquidation Preference		$ 500,000
Net Carrying Value		$ 581,000
Series A-3
Temporary Equity [Line Items]
Shares Authorized		1,513,860
Shares Issued		1,513,860
Shares Outstanding		1,513,860
Original Issue Price		$ 1.17
Aggregate Liquidation Preference		$ 1,773,000
Net Carrying Value		$ 1,892,000
Series A-4
Temporary Equity [Line Items]
Shares Authorized		8,280,360
Shares Issued		8,280,360
Shares Outstanding		8,280,360
Original Issue Price		$ 4.85
Aggregate Liquidation Preference		$ 40,149,000
Net Carrying Value		$ 40,007,000
Series A-5
Temporary Equity [Line Items]
Shares Authorized		1,580,937
Shares Issued		1,580,937
Shares Outstanding		1,580,937
Original Issue Price		$ 6.33
Aggregate Liquidation Preference		$ 10,000,000
Net Carrying Value		$ 9,948,000
Series B
Temporary Equity [Line Items]
Shares Authorized		15,054,263
Shares Issued		15,054,263
Shares Outstanding		15,054,263
Original Issue Price		$ 11.65
Aggregate Liquidation Preference		$ 175,375,000
Net Carrying Value		$ 174,678,000
Series B-1
Temporary Equity [Line Items]
Shares Authorized		7,108,480
Shares Issued		7,108,480
Shares Outstanding		7,108,480
Original Issue Price		$ 14.07
Aggregate Liquidation Preference		$ 100,000,000
Net Carrying Value		$ 99,585,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Addition Information (Details) - USD ($)			1 Months Ended		3 Months Ended		9 Months Ended
	Jan. 25, 2024	Jan. 24, 2024	Jan. 31, 2024	Jul. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Recognized compensation expense							$ 12,792,000	$ 4,453,000
Recognized compensation expense		$ 3,000,000			$ 3,223,000	$ 3,268,000	12,792,000	$ 4,453,000
Restricted Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation expense					13,700,000		$ 13,700,000
Weighted-average period							2 years 1 month 6 days
Employee Stock Option
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation expense					19,700,000		$ 19,700,000
Weighted-average period							3 years 3 months 18 days
Restricted Stock Units
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unrecognized compensation expense					$ 3,900,000		$ 3,900,000
Weighted-average period							3 years 7 months 6 days
2024 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock shares reserved/available for future issuance			6,690,000		3,216,835		3,216,835
Common stock for future issuance description							The number of shares of common stock reserved and available for issuance under the 2024 Plan will automatically increase on each January 1, commencing on January 1, 2025 and through 2034, by five percent of the number of shares of the Company’s common stock issued and outstanding on the immediately preceding December 31, or such lesser number of shares as determined by the Company’s compensation committee.
Expiration period	10 years
Vesting period	4 years
Incentive Stock Options and Non-Qualified Stock Options | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Option price estimated fair value percentage on date of grant			100%
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares issued under ESPP plan							0
Common stock shares reserved/available for future issuance			375,000		375,000		375,000
Common stock for future issuance description							The number of shares of common stock reserved and available for issuance under the ESPP will automatically increase on each January 1, commencing on January 1, 2025 and through 2034, by the least of (i) 750,000 shares of common stock; (ii) one percent of the number of shares of the Company’s common stock issued and outstanding on the immediately preceding December 31, or (iii) such lesser number of shares as determined by the Company’s compensation committee.
Number of shares of common stock			750,000
Purchase price of common stock percentage of fair value			85%
Employee's eligible annual compensation			$ 25,000
ESPP | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Purchases percentage on employee's eligible annual compensation			15%
Profit Interest Unit
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares canceled		282,660
Shares outstanding	9,142,176
Outstanding shares converted	3,884,870
Profit Interest Unit | Certain Vesting Conditions
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Outstanding shares converted	1,036,833
Amendment To LLC Agreement | Catch-Up | Modification Under ASC 718
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Estimated total modification expense				$ 10,300,000
Board of Directors | Amendment To LLC Agreement
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Catch-up threshold amount based on estimated fair value of common unit				$ 11.84

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Profits Units Activity (Details)	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Profit Interests, Outstanding, Beginning balance | shares	9,488,776
Profits Interests, Forfeited and expired | shares	(63,940)
Profits Interests, Canceled in connection with the Reorganization | shares	(282,660)
Profits Interests, Exchanged for vested and unvested common stock in connection with the Reorganization | shares	(9,142,176)
Weighted-Average Threshold Amount, Outstanding, Beginning balance | $ / shares	$ 2.63
Weighted-Average Threshold Amount, Forfeited and expired | $ / shares	1.17
Weighted-average Threshold amount, Canceled in connection with the Reorganization | $ / shares	11.84
Weighted-average Threshold amount, Exchanged for vested and unvested common stock in connection with the Reorganization | $ / shares	$ 2.36

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Unvested Common Stock Activity (Details) - Restricted Stock	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Shares, Exchange of profits interests units for unvested common stock | shares	1,036,833
Number of Shares, Vested | shares	(381,048)
Number of Shares, Forfeited | shares	(62,448)
Number of Shares, Outstanding, Ending balance | shares	593,337
Weighted- Average Grant Date Fair Value, Exchange of profits interests units for unvested common stock | $ / shares	$ 18.8
Weighted- Average Grant Date Fair Value, Vested | $ / shares	14.06
Weighted- Average Grant Date Fair Value, Forfeited | $ / shares	13.8
Weighted- Average Grant Date Fair Value, Outstanding, Ending balance | $ / shares	$ 22.36

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Common Stock Option Activity (Details) - Employee Stock Option	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock options, number of shares granted | shares	3,585,904
Stock options, number of shares forfeited | shares	(529,494)
Stock options, number of shares outstanding ending balance | shares	3,056,410
Stock options, number of shares exercisable as of June 30, 2024 | shares	118,954
Stock options, weighted average exercise price granted | $ / shares	$ 10.73
Stock options, weighted average exercise price forfeited | $ / shares	10.82
Stock options, weighted average exercise price outstanding ending balance | $ / shares	10.72
Stock options, weighted average exercise price exercisable as of June 30, 2024 | $ / shares	$ 10.69

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Common Restricted Stock Unit Activity (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Shares, Granted | shares	508,490
Number of Shares, Vested | shares	(20,361)
Number of Shares, Forfeited | shares	(91,735)
Number of Shares, Outstanding, Ending balance | shares	396,394
Weighted- Average Grant Date Fair Value, Granted | $ / shares	$ 10.68
Weighted- Average Grant Date Fair Value, Vested | $ / shares	10.82
Weighted- Average Grant Date Fair Value, Forfeited | $ / shares	10.02
Weighted- Average Grant Date Fair Value, Outstanding, Ending balance | $ / shares	$ 10.82

Stock-based Compensation - Su_5

Stock-based Compensation - Summary of Classification of Share-based Compensation Expense (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 24, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 3,000	$ 3,223	$ 3,268	$ 12,792	$ 4,453
Research and Development Expenses
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense		1,024	1,552	7,326	2,166
General and Administrative Expenses
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense		$ 2,199	$ 1,716	$ 5,466	$ 2,287

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable To Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss attributable to common stockholders	$ (18,773)	$ (19,820)	$ (54,660)	$ (48,961)
Denominator
Weighted-average common shares outstanding	37,431,688	3,404,585	32,267,642	3,404,585
Less: Weighted-average unvested shares of common stock	(665,379)		(665,817)
Weighted-average common shares outstanding - basic	36,766,309	3,404,585	31,601,825	3,404,585
Weighted-average common shares outstanding - diluted	36,766,309	3,404,585	31,601,825	3,404,585
Net loss per share attributable to common stockholders - basic	$ (0.51)	$ (5.82)	$ (1.73)	$ (14.38)
Net loss per share attributable to common stockholders - diluted	$ (0.51)	$ (5.82)	$ (1.73)	$ (14.38)

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Outstanding Potentially Dilutive Securities that have been Excluded from Calculation of Diluted Net Loss Per Unit (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	4,046,141	27,873,094	4,046,141	27,873,094
Common Stock Issuable Upon Conversion of Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities		23,935,594		23,935,594
Common Stock Issuable Upon Settlement of Profits Interests
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities		3,937,500		3,937,500
Restricted Stock Subject to Future Vesting
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	593,337		593,337
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	3,056,410		3,056,410
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	396,394		396,394