Foghorn Therapeutics (FHTX) 10-Q 6 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	Apr. 30, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-39634
Entity Registrant Name	Foghorn Therapeutics Inc.
Entity Incorporation, State	DE
Entity Tax Identification Number	47-5271393
Entity Address, Street Name	500 Technology Square, Ste 700
Entity Address, City	Cambridge
Entity Address, State	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	586-3100
Title of each class	Common Stock, $0.0001 par value per share
Trading Symbol(s)	FHTX
Name of each exchange on which registered	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		42,585,616
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001822462
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 79,253	$ 80,336
Marketable securities	127,408	153,721
Prepaid expenses and other current assets	4,859	6,124
Total current assets	211,520	240,181
Property and equipment, net	12,187	12,956
Restricted cash	1,708	1,708
Other assets	1,052	1,115
Operating lease right-of-use assets	28,537	29,956
Total assets	255,004	285,916
Current liabilities:
Accounts payable	5,631	6,260
Accrued expenses and other current liabilities	6,265	9,108
Operating lease liabilities	8,668	8,518
Deferred revenue	31,501	34,550
Total current liabilities	52,065	58,436
Operating lease liabilities, net of current portion	34,311	36,555
Deferred revenue, net of current portion	266,114	268,115
Total liabilities	352,490	363,106
Commitments and contingencies (Note 9)
Stockholders’ deficit:
Preferred stock, $0.0001 par value; 25,000,000 shares authorized at March 31, 2024 and December 31, 2023; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.0001 par value; 175,000,000 shares authorized at March 31, 2024 and December 31, 2023; 42,585,616 shares issued and outstanding at March 31, 2024 and 42,282,040 shares issued and outstanding at December 31, 2023	4	4
Additional paid-in capital	399,587	395,196
Accumulated other comprehensive loss	(497)	(826)
Accumulated deficit	(496,580)	(471,564)
Total stockholders’ deficit	(97,486)	(77,190)
Total liabilities and stockholders’ deficit	$ 255,004	$ 285,916

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	175,000,000	175,000,000
Common stock, shares issued (in shares)	42,585,616	42,282,040
Common stock, shares outstanding (in shares)	42,585,616	42,282,040

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Collaboration revenue	$ 5,050	$ 5,309
Operating expenses:
Research and development	25,534	29,985
General and administrative	7,710	8,641
Total operating expenses	33,244	38,626
Loss from operations	(28,194)	(33,317)
Other income, net:
Interest income	2,439	2,669
Other income, net	739	720
Total other income, net	3,178	3,389
Loss before income taxes	(25,016)	(29,928)
Provision for income taxes	0	(560)
Net loss	$ (25,016)	$ (30,488)
Net loss per share attributable to common stockholders—basic (in dollars per share)	$ (0.59)	$ (0.73)
Net loss per share attributable to common stockholders—diluted (in dollars per share)	$ (0.59)	$ (0.73)
Weighted average common shares outstanding—basic (in shares)	42,428,813	41,811,087
Weighted average common shares outstanding—diluted (in shares)	42,428,813	41,811,087
Comprehensive loss:
Net loss	$ (25,016)	$ (30,488)
Other comprehensive gain:
Unrealized gains on marketable securities	329	1,116
Total other comprehensive gain	329	1,116
Total comprehensive loss	$ (24,687)	$ (29,372)
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	Collaboration Revenue [Member]	Collaboration Revenue [Member]

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders’ Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2022	$ 112	$ 4	$ 377,232	$ (3,986)	$ (373,138)
Beginning balance (in shares) at Dec. 31, 2022		41,803,436
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options and employee stock purchase plan	102		102
Issuance of common stock upon exercise of stock options and employee stock purchase plan (in shares)		21,322
Stock-based compensation expense	4,572		4,572
Unrealized gains on marketable securities	1,116			1,116
Net loss	(30,488)				(30,488)
Ending balance at Mar. 31, 2023	(24,586)	$ 4	381,906	(2,870)	(403,626)
Ending balance (in shares) at Mar. 31, 2023		41,824,758
Beginning balance at Dec. 31, 2023	$ (77,190)	$ 4	395,196	(826)	(471,564)
Beginning balance (in shares) at Dec. 31, 2023	42,282,040	42,282,040
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of stock options and employee stock purchase plan	$ 1,167		1,167
Issuance of common stock upon exercise of stock options and employee stock purchase plan (in shares)		303,576
Stock-based compensation expense	3,224		3,224
Unrealized gains on marketable securities	329			329
Net loss	(25,016)				(25,016)
Ending balance at Mar. 31, 2024	$ (97,486)	$ 4	$ 399,587	$ (497)	$ (496,580)
Ending balance (in shares) at Mar. 31, 2024	42,585,616	42,585,616

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (25,016)	$ (30,488)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	3,224	4,572
Depreciation and amortization expense	835	859
Noncash lease expense	1,419	1,200
Accretion of discount on marketable securities	(554)	(770)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,328	887
Accounts payable	(629)	1,691
Accrued expenses and other liabilities	(2,808)	(2,154)
Operating lease liabilities	(2,094)	(1,668)
Deferred revenue	(5,050)	(5,309)
Net cash used in operating activities	(29,345)	(31,180)
Cash flows from investing activities:
Purchases of property and equipment	(101)	(636)
Purchases of marketable securities	(31,263)	(26,232)
Proceeds from maturities of marketable securities	58,459	56,373
Net cash provided by investing activities	27,095	29,505
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options and employee stock purchase plan	1,167	102
Net cash provided by financing activities	1,167	102
Net decrease in cash, cash equivalents and restricted cash	(1,083)	(1,573)
Cash, cash equivalents and restricted cash at beginning of period	82,044	53,922
Cash, cash equivalents and restricted cash at end of period	80,961	52,349
Supplemental disclosure of noncash investing and financing information:
Cash paid for taxes	49	0
Purchases of property and equipment included in accounts payable and accrued expenses	0	298
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	79,253	50,641
Restricted cash (current and non-current)	1,708	1,708
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 80,961	$ 52,349

Nature of Business, Going Conce

Nature of Business, Going Concern and Basis of Presentation	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business, Going Concern and Basis of Presentation	Nature of Business, Going Concern and Basis of Presentation Foghorn Therapeutics Inc. (the “Company”) is a clinical-stage biopharmaceutical company discovering and developing a new class of medicines targeting genetically determined dependencies within the chromatin regulatory system. The Company uses its proprietary Gene Traffic Control platform to identify, validate and potentially drug targets within the system. The Company was founded in October 2015 as a Delaware corporation. The Company is headquartered in Cambridge, Massachusetts. The Company is subject to risks similar to those of other early-stage companies in the biopharmaceutical industry, including dependence on key individuals, the need to develop commercially viable products, competition from other companies, many of whom are larger and better capitalized, and the need to obtain adequate additional financing to fund the development of its products. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be maintained, that any products developed will obtain required regulatory approval or that any approved products will be commercially viable. Even if the Company’s development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from the sale of its products. Going concern The accompanying condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations primarily with proceeds from sales of preferred stock, upfront and milestone payments from collaboration agreements, a public offering and a stock purchase agreement. The Company has incurred recurring losses, including net losses of $25.0 million and $30.5 million for the three months ended March 31, 2024 and 2023, respectively. As of March 31, 2024, the Company had an accumulated deficit of $496.6 million. The Company expects to continue to generate operating losses in the foreseeable future. As of the issuance date of these interim condensed consolidated financial statements the Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months. The Company will need to obtain additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements to continue to fund its operations. The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into collaborative or strategic alliances or licensing arrangements. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. Arrangements with collaborators or others may require the Company to relinquish rights to certain of its technologies or programs. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, pipeline expansion or commercialization efforts, which could adversely affect its business prospects. Although management will continue to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding in the future on terms acceptable to the Company to fund continuing operations when needed or at all. Basis of presentation The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany accounts and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The accounting policies of the Company are set forth in Note 2 to the consolidated financial statements contained in the Company’s 2023 Annual Report on Form 10-K, and the accounting policies followed by the Company for interim financial reporting are consistent with the accounting policies therein .

Marketable Securities and Fair

Marketable Securities and Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Marketable Securities and Fair Value Measurements	Marketable Securities and Fair Value Measurements As of March 31, 2024, available for sale marketable securities by security type consisted of (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury notes (due within one year) $ 7,468 $ — $ (1) $ 7,467 U.S. government agencies (due within one year) 7,833 — (13) 7,820 Commercial paper (due within one year) 6,972 2 (15) 6,959 Corporate notes and bonds (due within one year) 92,063 3 (416) 91,650 Corporate notes and bonds (due after one year through two 13,569 — (57) 13,512 Total $ 127,905 $ 5 $ (502) $ 127,408 As of December 31, 2023, available for sale marketable securities by security type consisted of (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. government agencies (due within one year) 11,823 — (26) 11,797 Commercial paper (due within one year) 5,901 7 (2) 5,906 Corporate notes and bonds (due within one year) 130,933 11 (784) 130,160 Corporate notes and bonds (due after one year through two 5,890 — (32) 5,858 Total $ 154,547 $ 18 $ (844) $ 153,721 The following tables present the Company’s fair value hierarchy for its assets and liabilities, which are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at March 31, 2024 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 62,312 $ — $ — $ 62,312 U.S. treasury notes — 16,941 — 16,941 Marketable securities: U.S. treasury notes — 7,467 — 7,467 U.S. government agencies — 7,820 — 7,820 Commercial paper — 6,959 — 6,959 Corporate notes and bonds — 105,162 — 105,162 Total $ 62,312 $ 144,349 $ — $ 206,661 Fair Value Measurements at December 31, 2023 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 53,336 $ — $ — $ 53,336 U.S. treasury notes — 27,000 — 27,000 Marketable securities: U.S. government agencies — 11,797 — 11,797 Commercial paper — 5,906 — 5,906 Corporate notes and bonds — 136,018 — 136,018 Total $ 53,336 $ 180,721 $ — $ 234,057 For the three months ended March 31, 2024 and 2023, there were no transfers between Level 1, Level 2 and Level 3.

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): March 31, 2024 December 31, 2023 Laboratory equipment $ 6,869 $ 6,804 Furniture and fixtures 815 815 Computer equipment and software 74 115 Leasehold improvements 17,239 17,239 24,997 24,973 Less: Accumulated depreciation and amortization (12,810) (12,017) $ 12,187 $ 12,956 Depreciation and amortization expense was $0.8 million and $0.9 million for the three months ended March 31, 2024 and 2023, respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses consisted of the following (in thousands): March 31, 2024 December 31, 2023 Accrued external research and development expenses $ 3,355 $ 3,646 Accrued employee compensation and benefits 1,619 4,347 Accrued income taxes 674 674 Accrued professional fees 617 441 $ 6,265 $ 9,108

Common Stock and Net Loss Per S

Common Stock and Net Loss Per Share	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Common Stock and Net Loss Per Share	Common Stock and Net Loss Per Share Common Stock Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are not entitled to receive dividends, unless declared by the board of directors. Net Loss Per Share The following common stock equivalents presented based on amounts outstanding at each period end have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: March 31, 2024 2023 Stock options to purchase common stock 9,597,719 9,666,311 Warrants to purchase common stock 18,445 18,445 9,616,164 9,684,756

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2020 Equity Incentive Plan The Company’s 2020 Equity Incentive Plan (the “2020 Plan”) provides for the grant of incentive stock options, non-qualified options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares initially reserved for issuance under the 2020 Plan was (i) 2,200,000 shares (the “share pool”), plus (ii) the number of shares of common stock available for issuance under the Company’s 2016 Stock Incentive Plan (the “2016 Plan”) as of the effective date of the 2020 Plan, plus the number of shares of common stock underlying awards under the 2016 Plan that on or after the date of adoption expire or become unexercisable without delivery of shares, are forfeited to, or repurchased for cash, are settled in cash, or otherwise become available again for grant under the 2016 Plan, in each case, in accordance with its terms (up to an aggregate of 5,078,295 shares). As of March 31, 2024, 2,391,808 shares remained available for future grant under the 2020 Plan. The share pool will automatically increase on January 1 of each year from 2021 to 2030 by the lesser of (i) four percent of the number of shares of our common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the board of directors on or prior to such date for such year. The number of shares reserved for issuance under the 2020 Plan was increased by 1,691,281 shares effective January 1, 2024. The 2020 Plan is administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. The exercise prices, vesting and other restrictions are determined at the discretion of the board of directors, or its committee if so delegated. Stock options granted with service-based vesting conditions generally vest over four years and expire after ten years. The exercise price for stock options granted is not less than the fair value of common stock on the date of grant. The Company bases fair value of common stock on the quoted market price. 2020 Employee Stock Purchase Plan On October 21, 2020, the Company’s board of directors adopted and its stockholders approved the 2020 Employee Stock Purchase Plan (the “ESPP”), which became effective on October 21, 2020. The aggregate number of shares of common stock available for purchase pursuant to the exercise of options under the ESPP is 360,000 shares, plus an automatic annual increase, as of January 1 of each year from 2021 to 2030, equal to the lesser of one percent of the number of shares of common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the board of directors on or prior to such date for such year (up to a maximum of 3,220,520 shares). The number of shares reserved for issuance under the ESPP was increased by 422,820 shares to 1,566,120 shares effective January 1, 2024. As of March 31, 2024, 1,554,086 shares remained available for future grant under the ESPP. Eligible employees may authorize payroll deductions of up to 15% of their eligible compensation during an offering period. The purchase of shares is done at a 15% discount on the lesser of (i) the Fair Market Value of a share of Stock on the first day of the offering period and (ii) the Fair Market Value of a share of Stock on the last day of the offering period. The Company currently holds two offering periods, September 1 and March 1, respectively. The Company recognized a de minimis amount of expense related to the ESPP for the three months ended March 31, 2024 and 2023, respectively. Stock-Based Compensation Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development expenses $ 1,341 $ 2,039 General and administrative expenses 1,883 2,533 $ 3,224 $ 4,572 As of March 31, 2024, total unrecognized compensation cost related to unvested options was $23.3 million, which is expected to be recognized over a weighted average period of 2.3 years.

Collaboration Agreements

Collaboration Agreements	3 Months Ended
	Mar. 31, 2024
Collaboration Agreement [Abstract]
Collaboration Agreements	Collaboration Agreements Lilly Collaboration Agreement and Stock Purchase Agreement In December 2021, the Company entered into a collaboration agreement (the “Lilly Collaboration Agreement”) with Loxo Oncology at Eli Lilly and Company (“Lilly”) to create novel oncology medicines by applying Foghorn’s proprietary Gene Traffic Control platform. The collaboration includes a co-development and co-commercialization agreement for the Company’s selective BRM oncology target, consisting of two programs, and one additional undisclosed oncology target (collectively, the “Joint Programs”). The collaboration also includes three additional discovery targets or programs (collectively, the “Discovery Programs”) for a total of six programs directed at five targets. With respect to the Joint Programs, the Company will lead discovery and early research activities through the successful completion of dose finding toxicity studies for the identified compound, while Lilly will lead development and commercialization activities of the identified compound with participation from the Company in development activities and 50% cost sharing until registrational clinical trials. The Company and Lilly may jointly develop and commercialize the Joint Program compound though the Company may, in its sole discretion, opt-out on a program-by-program basis of further participation in the development and commercialization efforts prior to the first registrational clinical trial. If the Company does not opt-out, Lilly and the Company will continue to share in the costs to further develop and commercialize the Joint Program compound on a worldwide basis, equally share in the U.S. profits on product sales, subject to certain adjustments and receive royalties on sales outside of the United States (“Ex-U.S.”) at royalty rates ranging from low double digits to high twenties. If the Company opts-out of further development and commercialization efforts, it will have no further obligations to share in the development and commercialization costs, will receive royalties rather than profit share on U.S. sales and will receive royalties at a lower rate on Ex-U.S. sales. With respect to the Discovery Programs, the Company will lead discovery and early research activities through the successful completion of dose finding toxicity studies for the identified compounds. The Company may, in its sole discretion, opt-in on a program-by-program basis after the successful completion of dose finding toxicity to participate in the further development and commercialization efforts of the Discovery Program compounds. If the Company opts-in to the development and commercialization of the Discovery Program compounds, it will be eligible to receive milestone payments of up to $10.0 million per program upon specified research and development milestones and up to $180.0 million per program upon achievement of specified regulatory and commercial milestones and will also be eligible to share in the U.S. profits at pre-determined percentages on product sales. The Company would also be eligible to receive tiered Ex-U.S. royalty rates, calculated on a product-by-product and country-by-country basis, on net sales outside of the United States, if any, ranging from low single digits to low double digits, but less then teens. If the Company does not opt-in to further development and commercialization efforts for the Discovery Programs, it will be eligible to receive milestone payments of up to $70.0 million per program upon specified research and development milestones and up to $360.0 million per program upon achievement of specified regulatory and commercial milestones per approved product, if any. The Company would also be eligible to receive tiered royalties on net sales of products worldwide at royalty rates ranging from low single digits to low double digits, but less than teens. Lilly has the right to make substitutions for each of the five targets during the research term of each program, subject to certain limitations. Pursuant to the Lilly Collaboration Agreement, the Company will also participate in joint decision-making through the joint steering committee and subcommittees. Unless terminated earlier, the Lilly Collaboration Agreement will continue on a product-by-product basis until the expiration of all royalty obligations under the Lilly Collaboration Agreement and when neither the Company nor Lilly is developing, commercializing or manufacturing any product under the Lilly Collaboration Agreement. The Company or Lilly may terminate the Lilly Collaboration Agreement upon an uncured material breach by the other party. Lilly may also terminate the Lilly Collaboration Agreement in its entirety or on a target-by-target, program-by-program or product-by-product basis for any reason upon certain notice to the Company. The Company determined that (1) the research activities performed by the Company for both the Joint Programs and the Discovery Programs (2) the development activities and cost sharing for the Joint Program development efforts after dose finding toxicity until registrational clinical trials (3) the research, development, manufacture and commercialization licenses and (4) service on the joint steering committee and subcommittees represent a single performance obligation under the Lilly Collaboration Agreement. The Company determined that Lilly cannot benefit from the licenses separately from the research activities, the development activities until registrational clinical trials and participation on the joint steering committee and subcommittees because these services are specialized and rely on the Company’s expertise such that these activities are highly interrelated and therefore not distinct. Accordingly, the promised goods and services represent one combined performance obligation, and the entire transaction price was allocated to that single combined performance obligation. The performance obligation will be satisfied over time as the Company performs the research activities, participates and shares in the cost of the development activities for the Joint Programs and participates in a joint steering committee and subcommittees to oversee these activities. The Company’s options to share in further development and commercialization efforts via its opt-in/opt-out rights will be assessed and accounted for as separate units of accounting under the relevant guidance if, and when, such options are exercised by the Company. During the third quarter of 2023, the Company has transitioned the BRM Selective inhibitor program into development activities for which Lilly will lead and the Company will participate and share in 50% of the costs until at least registrational trials. Costs incurred will continue to be included in research and development expenses on the condensed consolidated statements of operations and comprehensive loss. As of March 31, 2024, the aggregate amount of the transaction price related to the unsatisfied portion of the performance obligation was $297.6 million, which is expected to be recognized as revenue through 2029 or beyond depending on the timing of certain clinical development activities. The Company does not expect collaboration revenue to be recognized evenly over this period as it will be recognized on a percentage of completion basis (using a cost-to-cost method) as the Company performs the research and development activities and participates on the joint steering committee and subcommittees, which will likely vary from period to period. In estimating the total costs to satisfy its single performance obligation pursuant to the Lilly Collaboration Agreement, the Company is required to make significant estimates including an estimate of the number of target substitutions Lilly may elect to make and the expected time and expected costs to fulfill the performance obligation. The cumulative effect of revisions to the total estimated costs to complete the Company’s single performance obligation will be recorded in the period in which the changes are identified, and amounts can be reasonably estimated. While such revisions will have no impact on the Company’s cash flows, a significant change in these assumptions and estimates could have a material impact on the timing and amount of revenue recognized in future periods and the classification of deferred revenue between short-term and long-term. For the three months ended March 31, 2024 and 2023, the Company had recorded $5.1 million and $4.7 million, respectively, of revenue under the Lilly Collaboration Agreement, which was included in deferred revenue at the beginning of the respective periods. As of March 31, 2024 and December 31, 2023, the Company had a payable to Lilly of $1.2 million and $1.5 million recorded in accrued expenses and other current liabilities on the Company’s consolidated balance sheets. Merck Collaboration Agreement In July 2020, the Company entered into the Merck Collaboration Agreement with Merck, pursuant to which the Company and Merck applied Foghorn’s proprietary Gene Traffic Control platform to discover and develop novel therapeutics. Under the terms of the Merck Collaboration Agreement, the Company and Merck were each responsible to perform certain research activities in accordance with a mutually-agreed upon research plan. For the three months ended March 31, 2023, the Company had recorded $0.6 million of the revenue under the Merck Collaboration Agreement, which was included in deferred revenue at the beginning of the respective periods and the classification of deferred revenue between short term and long term.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company leases office space under a non-cancelable operating lease. There have been no material changes to the Company's lease during the three months ended March 31, 2024. For additional information, see Note 10, Leases , to the consolidated financial statements in the Company's Annual Report on Form 10-K for the year ended December 31, 2023. License agreements The Company has entered into various exclusive and non-exclusive license agreements for certain technologies. Under the terms of these license agreements, the Company could be required to reimburse the licensors for patent expenses and remit amounts in the low single-digit as sales-based royalties upon the occurrence of specific events as outlined in the corresponding license agreements. The Company is also required to make annual license maintenance fees of less than $0.3 million and pay up to $1.1 million in regulatory milestones on each licensed product upon the occurrence of specific events as outlined in one of the license agreements. None of our product candidates utilize technologies covered by these licenses. Indemnification agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, contract research organizations, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. The Company has not incurred any material costs as a result of such indemnifications and is not currently aware of any indemnification claims. Legal Proceedings From time to time, the Company may become involved in litigation or other legal proceedings. The Company is not currently a party to any material litigation or legal proceedings.

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Parties	Related Parties In October 2015, the Company entered into a five-year consulting agreement with a scientific founder of the Company who is also a shareholder. This agreement was amended and extended to January 1, 2025 and is subject to automatic one-year renewal terms until terminated if notice is provided more than 30 days before the current end of term date. During the three months ended March 31, 2024 and 2023, the Company paid the scientific founder a de minimis amount. As of March 31, 2024 and December 31, 2023, the Company had less than $0.1 million, respectively, of accounts payable due to the scientific founder. On December 10, 2021, we entered into the Lilly Collaboration Agreement with Lilly. Concurrent with the Lilly Collaboration Agreement the Company also entered into a stock purchase agreement with Lilly (the “Lilly SPA”) where the Company issued and sold Lilly 4,000,000 shares of our common stock at a price of $20.00 per share, making them a 5% or greater shareholder in the Company for the three months ended March 31, 2024 and 2023. We are obligated to make certain payments to Lilly pursuant to the Lilly Collaboration Agreement. During the three months ended March 31, 2024, the Company paid Lilly $1.7 million. The Company made no payments to Lilly during the three months ended March 31, 2023. As of March 31, 2024 and December 31, 2023, the Company had a payable of $1.2 million and $1.5 million, respectively, due to Lilly.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net loss	$ (25,016)	$ (30,488)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Steven Bellon [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On March 11, Steven Bellon, our Chief Scientific Officer, adopted a Rule 10b5-1 trading arrangement. Dr. Bellon’s trading arrangement provides for the sale of up to 60,000 shares of our common stock through March 10, 2025.
Name	Steven Bellon
Title	Chief Scientific Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 11
Arrangement Duration	364 days
Aggregate Available	60,000
Carlos Costa [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	On March 11, Carlos Costa, our Chief People Officer, adopted a Rule 10b5-1 trading arrangement. Mr. Costa’s trading arrangement provides for the sale of up to 213,106 shares of our common stock through March 10, 2025. During the three months ended March 31, 2024, none of our directors or officers (as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934, as amended) entered into, modified (as to amount, price or timing of trades) or terminated any non-Rule 10b5-1 trading arrangements.
Name	Carlos Costa
Title	Chief People Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	March 11
Arrangement Duration	364 days
Aggregate Available	213,106

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany accounts and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).

Marketable Securities and Fai_2

Marketable Securities and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Summary of Available for Sale Marketable Securities by Security Type	As of March 31, 2024, available for sale marketable securities by security type consisted of (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. treasury notes (due within one year) $ 7,468 $ — $ (1) $ 7,467 U.S. government agencies (due within one year) 7,833 — (13) 7,820 Commercial paper (due within one year) 6,972 2 (15) 6,959 Corporate notes and bonds (due within one year) 92,063 3 (416) 91,650 Corporate notes and bonds (due after one year through two 13,569 — (57) 13,512 Total $ 127,905 $ 5 $ (502) $ 127,408 As of December 31, 2023, available for sale marketable securities by security type consisted of (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value U.S. government agencies (due within one year) 11,823 — (26) 11,797 Commercial paper (due within one year) 5,901 7 (2) 5,906 Corporate notes and bonds (due within one year) 130,933 11 (784) 130,160 Corporate notes and bonds (due after one year through two 5,890 — (32) 5,858 Total $ 154,547 $ 18 $ (844) $ 153,721
Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present the Company’s fair value hierarchy for its assets and liabilities, which are measured at fair value on a recurring basis (in thousands): Fair Value Measurements at March 31, 2024 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 62,312 $ — $ — $ 62,312 U.S. treasury notes — 16,941 — 16,941 Marketable securities: U.S. treasury notes — 7,467 — 7,467 U.S. government agencies — 7,820 — 7,820 Commercial paper — 6,959 — 6,959 Corporate notes and bonds — 105,162 — 105,162 Total $ 62,312 $ 144,349 $ — $ 206,661 Fair Value Measurements at December 31, 2023 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 53,336 $ — $ — $ 53,336 U.S. treasury notes — 27,000 — 27,000 Marketable securities: U.S. government agencies — 11,797 — 11,797 Commercial paper — 5,906 — 5,906 Corporate notes and bonds — 136,018 — 136,018 Total $ 53,336 $ 180,721 $ — $ 234,057

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment Net	Property and equipment, net consisted of the following (in thousands): March 31, 2024 December 31, 2023 Laboratory equipment $ 6,869 $ 6,804 Furniture and fixtures 815 815 Computer equipment and software 74 115 Leasehold improvements 17,239 17,239 24,997 24,973 Less: Accumulated depreciation and amortization (12,810) (12,017) $ 12,187 $ 12,956

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses consisted of the following (in thousands): March 31, 2024 December 31, 2023 Accrued external research and development expenses $ 3,355 $ 3,646 Accrued employee compensation and benefits 1,619 4,347 Accrued income taxes 674 674 Accrued professional fees 617 441 $ 6,265 $ 9,108

Common Stock and Net Loss Per_2

Common Stock and Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Summary of Earnings Per Share Diluted Anti Dilutive Impact	The following common stock equivalents presented based on amounts outstanding at each period end have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: March 31, 2024 2023 Stock options to purchase common stock 9,597,719 9,666,311 Warrants to purchase common stock 18,445 18,445 9,616,164 9,684,756

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Expense	Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development expenses $ 1,341 $ 2,039 General and administrative expenses 1,883 2,533 $ 3,224 $ 4,572

Nature of Business, Going Con_2

Nature of Business, Going Concern and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ 25,016	$ 30,488
Accumulated deficit	$ 496,580		$ 471,564

Marketable Securities and Fai_3

Marketable Securities and Fair Value Measurements - Summary of Available for Sale Marketable Securities by Security Type (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	$ 127,905	$ 154,547
Gross Unrealized Gains	5	18
Gross Unrealized Losses	(502)	(844)
Estimated Fair Value	127,408	153,721
U.S. treasury notes (due within one year)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	7,468
Gross Unrealized Gains	0
Gross Unrealized Losses	(1)
Estimated Fair Value	7,467
U.S. government agencies (due within one year)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	7,833	11,823
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(13)	(26)
Estimated Fair Value	7,820	11,797
Commercial paper (due within one year)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	6,972	5,901
Gross Unrealized Gains	2	7
Gross Unrealized Losses	(15)	(2)
Estimated Fair Value	6,959	5,906
Corporate notes and bonds (due within one year)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	92,063	130,933
Gross Unrealized Gains	3	11
Gross Unrealized Losses	(416)	(784)
Estimated Fair Value	91,650	130,160
Corporate notes and bonds (due after one year through two years)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Amortized Cost	13,569	5,890
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(57)	(32)
Estimated Fair Value	$ 13,512	$ 5,858

Marketable Securities and Fai_4

Marketable Securities and Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	$ 127,408	$ 153,721
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	6,959	5,906
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	206,661	234,057
Recurring | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	7,467
Recurring | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	7,820	11,797
Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	6,959	5,906
Recurring | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	105,162	136,018
Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	62,312	53,336
Recurring | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	16,941	27,000
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	62,312	53,336
Recurring | Level 1 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0
Recurring | Level 1 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 1 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 1 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	62,312	53,336
Recurring | Level 1 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	144,349	180,721
Recurring | Level 2 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	7,467
Recurring | Level 2 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	7,820	11,797
Recurring | Level 2 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	6,959	5,906
Recurring | Level 2 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	105,162	136,018
Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Recurring | Level 2 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	16,941	27,000
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	0	0
Recurring | Level 3 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0
Recurring | Level 3 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 3 | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 3 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Marketable securities	0	0
Recurring | Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	0	0
Recurring | Level 3 | U.S. treasury notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash equivalents	$ 0	$ 0

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment Net (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Property plant and equipment including finance right of use assets, gross	$ 24,997	$ 24,973
Less: Accumulated depreciation and amortization	(12,810)	(12,017)
Property and equipment, net	12,187	12,956
Laboratory equipment
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Property plant and equipment including finance right of use assets, gross	6,869	6,804
Furniture and fixtures
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Property plant and equipment including finance right of use assets, gross	815	815
Computer equipment and software
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Property plant and equipment including finance right of use assets, gross	74	115
Leasehold improvements
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Property plant and equipment including finance right of use assets, gross	$ 17,239	$ 17,239

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 835	$ 859

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued external research and development expenses	$ 3,355	$ 3,646
Accrued employee compensation and benefits	1,619	4,347
Accrued income taxes	674	674
Accrued professional fees	617	441
Total	$ 6,265	$ 9,108

Common Stock and Net Loss Per_3

Common Stock and Net Loss Per Share - Narrative (Details)	Mar. 31, 2024 vote
Equity [Abstract]
Voting rights per share (per share)	1

Common Stock and Net Loss Per_4

Common Stock and Net Loss Per Share - Summary of Earnings Per Share Diluted Anti Dilutive Impact (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive shares excluded from the calculation of earnings per share (in shares)	9,616,164	9,684,756
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive shares excluded from the calculation of earnings per share (in shares)	9,597,719	9,666,311
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive shares excluded from the calculation of earnings per share (in shares)	18,445	18,445

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ in Millions			3 Months Ended
	Jan. 01, 2024 shares	Oct. 21, 2020 shares	Mar. 31, 2024 USD ($) period shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 shares
Share-based Payment Arrangement
Number of shares authorized (in shares)	1,566,120
Unrecognized compensation costs related to unvested options and unvested restricted stock | $			$ 23.3
Weighted average period of unrecognized compensation costs			2 years 3 months 18 days
2020 Equity Incentive Plan
Share-based Payment Arrangement
Number of shares authorized (in shares)			2,200,000
Common stock shares available for grant (in shares)			2,391,808
Percentage of automatic annual increase in number of shares			4%
Number of additional shares authorized (in shares)	1,691,281
Vesting period (years)			4 years
Stock option expiry period (years)			10 years
2016 Stock Incentive Plan
Share-based Payment Arrangement
Number of shares authorized (in shares)			5,078,295
2020 Employee Stock Purchase Plan
Share-based Payment Arrangement
Number of shares authorized (in shares)		360,000
Common stock shares available for grant (in shares)					1,554,086
Percentage of automatic annual increase in number of shares		1%
Number of additional shares authorized (in shares)	422,820
Maximum aggregate number of shares added to plan (in shares)		3,220,520
Percentage of payroll deductions			15%
Discount of shares rate, percent			15%
Number of offering periods (period) | period			2
Share-based payment arrangement, expense | $			$ 0	$ 0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Payment Arrangement
Stock-based compensation expense	$ 3,224	$ 4,572
Research and development expenses
Share-based Payment Arrangement
Stock-based compensation expense	1,341	2,039
General and administrative expenses
Share-based Payment Arrangement
Stock-based compensation expense	$ 1,883	$ 2,533

Collaboration Agreements (Detai

Collaboration Agreements (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Dec. 31, 2021 USD ($) target program	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023
Collaborative Arrangement and Arrangement Other than Collaborative
Collaboration revenue		$ 5,050	$ 5,309
Accrued expenses and other current liabilities		6,265		$ 9,108
Eli Lilly
Collaborative Arrangement and Arrangement Other than Collaborative
Number of additional targets | target	3
Number of programs | program	6
Number of targets | target	5
Cost sharing allocation	50%				50%
Deferred revenue		297,600
Collaboration revenue		5,100	4,700
Accrued expenses and other current liabilities		1,200		1,500
Eli Lilly | Sales Based Milestone
Collaborative Arrangement and Arrangement Other than Collaborative
Amount receivable for achievement of milestones	$ 180,000
Optout milestone receivable upon achievement	360,000
Eli Lilly | Maximum | Research Development And Regulatory
Collaborative Arrangement and Arrangement Other than Collaborative
Amount receivable for achievement of milestones	10,000
Optout milestone receivable upon achievement	$ 70,000
Merck
Collaborative Arrangement and Arrangement Other than Collaborative
Unsatisfied portion of the performance obligation		$ 0		$ 0
Merck | Merck Collaboration Agreement
Collaborative Arrangement and Arrangement Other than Collaborative
Collaboration revenue			$ 600

Commitments and Contingencies (

Commitments and Contingencies (Details) - Stanford License Agreement - Maximum $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Commitments And Contingencies
Annual license maintenance fees	$ 0.3
Milestones payable upon event	$ 1.1

Related Parties (Details)

Related Parties (Details) - USD ($)		1 Months Ended	3 Months Ended
	Dec. 10, 2021	Oct. 31, 2015	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Related Party Transaction
Accounts payable			$ 5,631,000		$ 6,260,000
Revenue			5,050,000	$ 5,309,000
Accrued expenses and other current liabilities			6,265,000		9,108,000
Eli Lilly
Related Party Transaction
Revenue			5,100,000	4,700,000
Accrued expenses and other current liabilities			1,200,000		1,500,000
Related Party | Eli Lilly
Related Party Transaction
Revenue			1,700,000	$ 0
Accrued expenses and other current liabilities			$ 1,200,000		1,500,000
Related Party | Eli Lilly | Share Purchase Agreement
Related Party Transaction
Sale of stock, number of shares issued in transaction (in shares)	4,000,000
Sale of stock issue price per share (in dollars per share)			$ 20
Related Party | Scientific Founder
Related Party Transaction
Service agreement term		5 years
Service agreement, renewal term		1 year
Accounts payable			$ 100,000		$ 100,000