Entrada Therapeutics (TRDA) 10-Q 7 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	001-40969
Entity Registrant Name	ENTRADA THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-3983399
Entity Address, Address Line One	One Design Center Place
Entity Address, Address Line Two	Suite 17-500
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210
City Area Code	857
Local Phone Number	520-9158
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	TRDA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		33,758,976
Entity Central Index Key	0001689375
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 68,436	$ 67,602
Marketable securities	258,978	284,367
Collaboration receivable	77,514	5,878
Prepaid expenses and other current assets	9,244	11,924
Total current assets	414,172	369,771
Property and equipment, net	11,002	11,191
Restricted cash	3,950	3,950
Right-of-use assets, operating leases	78,958	81,490
Other non-current assets	2,762	2,790
Total assets	510,844	469,192
Current liabilities:
Accounts payable	2,527	3,277
Accrued expenses and other current liabilities	8,792	11,325
Income taxes payable	5,855	4,024
Operating lease obligations, current portion	8,301	7,909
Deferred revenue, current portion	148,463	132,261
Total current liabilities	173,938	158,796
Operating lease obligations, net of current portion	58,131	60,321
Deferred revenue, net of current portion	9,408	7,715
Total liabilities	241,477	226,832
Commitments and contingencies (Note 11)
Stockholders’ equity:
Common stock, par value $0.0001; 150,000,000 shares authorized; $33,625,117 shares issued and $33,604,053 shares outstanding as of March 31, 2024 and 33,461,771 shares issued and 33,437,296 shares outstanding as of December 31, 2023	3	3
Additional paid‑in capital	441,084	437,132
Accumulated other comprehensive (loss) income	(246)	195
Accumulated deficit	(171,474)	(194,970)
Total stockholders’ equity	269,367	242,360
Total liabilities and stockholders’ equity	$ 510,844	$ 469,192

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares, authorized (in shares)	150,000,000	150,000,000
Common stock, shares, issued (in shares)	33,625,117	33,461,771
Common stock, shares, outstanding (in shares)	33,604,053	33,437,296

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Collaboration revenue	$ 59,120	$ 25,260
Operating expenses:
Research and development	28,608	23,102
General and administrative	9,399	7,938
Total operating expenses	38,007	31,040
Income (loss) from operations	21,113	(5,780)
Other income:
Interest and other income	4,214	2,657
Total other income	4,214	2,657
Income (loss) before provision for income taxes	25,327	(3,123)
Provision for income taxes	(1,831)	(3,551)
Net income (loss)	$ 23,496	$ (6,674)
Net income (loss) per share, basic (in dollars per share)	$ 0.70	$ (0.21)
Net income (loss) per share, diluted (in dollars per share)	$ 0.68	$ (0.21)
Weighted-average common shares outstanding, basic (in shares)	33,497,072	32,374,299
Weighted-average common shares outstanding, diluted (in shares)	34,790,925	32,374,299
Other comprehensive (loss) income:
Unrealized (loss) gain on marketable securities	$ (441)	$ 1,415
Total other comprehensive (loss) income	(441)	1,415
Total comprehensive income (loss)	$ 23,055	$ (5,259)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid‑in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balances (in shares) at Dec. 31, 2022		31,394,767
Beginning balances at Dec. 31, 2022	$ 212,554	$ 3	$ 402,893	$ (2,057)	$ (188,285)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		18,344
Issuance of common stock upon exercise of stock options	129		129
Vesting of early exercised options (in shares)		10,153
Vesting of early exercised options	26		26
Vesting of restricted stock units (in shares)		91,859
Issuance of common stock in connection with the Vertex Agreement (in shares)		1,618,613
Issuance of common stock in connection with the Vertex Agreement	19,407		19,407
Stock‑based compensation	2,755		2,755
Other comprehensive income	1,415			1,415
Net income (loss)	(6,674)				(6,674)
Ending balances (in shares) at Mar. 31, 2023		33,133,736
Ending balances at Mar. 31, 2023	229,612	$ 3	425,210	(642)	(194,959)
Beginning balances (in shares) at Dec. 31, 2022		31,394,767
Beginning balances at Dec. 31, 2022	$ 212,554	$ 3	402,893	(2,057)	(188,285)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of early exercised options (in shares)	14,745
Ending balances (in shares) at Dec. 31, 2023	33,437,296	33,437,296
Ending balances at Dec. 31, 2023	$ 242,360	$ 3	437,132	195	(194,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	30,888	30,888
Issuance of common stock upon exercise of stock options	$ 206		206
Vesting of early exercised options (in shares)	11,334	3,411
Vesting of early exercised options	$ 13		13
Vesting of restricted stock units (in shares)		132,458
Stock‑based compensation	3,733		3,733
Other comprehensive income	(441)			(441)
Net income (loss)	$ 23,496				23,496
Ending balances (in shares) at Mar. 31, 2024	33,604,053	33,604,053
Ending balances at Mar. 31, 2024	$ 269,367	$ 3	$ 441,084	$ (246)	$ (171,474)

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 income (loss)	$ 23,496	$ (6,674)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation expense	934	541
Stock‑based compensation expense	3,733	2,755
Net amortization of premium (accretion of discount) on marketable securities	(2,037)	(237)
Changes in operating assets and liabilities:
Collaboration receivable	(71,636)	(6,297)
Prepaid expenses and other current assets	2,680	4,339
Right-of-use assets, operating leases	2,532	3,332
Other non-current assets	28	(8,633)
Accounts payable	(655)	534
Accrued expenses and other current liabilities	(2,522)	4,107
Income tax payable	1,831	0
Operating lease liabilities	(1,798)	(1,950)
Deferred revenue	17,895	211,582
Net cash (used in) provided by operating activities	(25,519)	203,399
Cash flows from investing activities:
Purchases of property and equipment	(838)	(1,668)
Purchases of marketable securities	(96,935)	(101,776)
Maturities of marketable securities	123,920	63,000
Net cash provided by (used in) investing activities	26,147	(40,444)
Cash flows from financing activities:
Proceeds from issuance of common stock in connection with the Vertex Agreement	0	19,407
Proceeds from exercise of stock options	206	129
Net cash provided by financing activities	206	19,536
Net increase in cash, cash equivalents, and restricted cash	834	182,491
Cash, cash equivalents, and restricted cash at beginning of period	71,552	49,107
Cash, cash equivalents, and restricted cash at end of period	72,386	231,598
Supplemental cash flow disclosures:
Purchases of property and equipment included in accounts payable and accrued expenses	115	57
Right-of-use assets surrendered as part of lease modification	0	7,761
Transfer of deposits for equipment from operating to investing cash flows	0	617
Vesting of options early exercised subject to repurchase	$ 13	$ 26

Nature of the Business

Nature of the Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Organization Entrada Therapeutics, Inc. ("Entrada" or the "Company") is a clinical-stage biopharmaceutical company aiming to transform the lives of patients by e stablishing a new class of medicines which engage intracellular targets that have long been considered inaccessible . The Company’s Endosomal Escape Vehicle ("EEV™")-therapeutics are designed to enable the efficient delivery of a wide range of therapeutics into a variety of organs and tissues, resulting in an improved therapeutic index. The Company was incorporated in Delaware on September 22, 2016 and its principal offices are located in Boston, Massachusetts. Liquidity and Capital Resources Since its inception, the Company has devoted substantially all of its resources to its research and development efforts relating to its proprietary, highly versatile and modular EEV platform ("EEV Platform"), advancing development of its portfolio of programs and general and administrative support for these operations, including raising capital. The Company is subject to risks and uncertainties common to earlier stage companies in the biotechnology industry, including, but not limited to, technical risks associated with the successful research, development and manufacturing of therapeutic candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, and the ability to secure additional capital to fund operations. Therapeutic candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel and infrastructure. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize revenue from product sales. In accordance with Accounting Standards Codification ("ASC") 205-40, Going Concern, the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. Since its inception, the Company has incurred significant net losses. As of March 31, 2024, the Company had an accumulated deficit of $171.5 million. To date, the Company has funded its operations primarily through the sale of equity securities and collaboration payments. Other than the recognition of revenue related to collaboration payments, the Company expects to continue to generate operating losses and negative operating cash flows for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities of $327.4 million as of March 31, 2024 will be sufficient to fund its operations and capital expenditure requirements for at least the next twelve months from the date of issuance of these condensed consolidated financial statements. The Company will need additional financing to support its continuing operations and pursue its business strategy and may pursue additional cash resources through a combination of equity offerings, debt financings, collaborations, strategic alliances, licensing, or other arrangements. The Company may be unable to raise additional funds or enter into such other agreements when needed or on favorable terms or at all. The inability to raise capital as and when needed would have a negative impact on the Company’s financial condition and its ability to pursue its business strategy. The Company will need to generate significant revenue to achieve profitability, and it may never do so.

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 significant accounting policies used in preparation of these condensed consolidated financial statements as of and for the three months ended March 31, 2024 are consistent with those discussed in Note 2 to the consolidated financial statements included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2023, which was filed with the Securities and Exchange Commission (the "SEC") on March 13, 2024 (the "Annual Report") . Basis of Presentation The accompanying condensed consolidated financial statements are unaudited and have been prepared in conformity with generally accepted accounting principles in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the ASC and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted, as is permitted by GAAP. These condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position as of March 31, 2024, and results of operations for the interim periods ended March 31, 2024 and 2023 . The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These condensed consolidated financial statements should be read in conjunction with the audited financial statements as of and for the years ended December 31, 2023 and 2022, and the notes thereto, included in the Annual Report. Recently Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all highly liquid investments with an original maturity of 90 days or less at the date of purch ase to be cash equivalents. At March 31, 2024 and December 31, 2023 , cash and cash equivalents include standard checking accounts and money market account funds that invest primarily in U.S. government-backed securities and treasuries. As of March 31, 2024 and December 31, 2023 , restricted cash represents collateral provided for a letter of credit issued as a security deposi t in connection with the Company’s lease of its corporate facilities located at One Design Center Place, Boston, Massachusetts. A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows (in thousands): March 31, December 31, Cash and cash equivalents $ 68,436 $ 67,602 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 72,386 $ 71,552

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The following are summaries of the Company's marketable securities at March 31, 2024 and December 31, 2023 (in thousands). March 31, 2024 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 195,594 $ 4 $ (84) $ 195,514 Corporate debt securities 15,268 3 (33) 15,238 Total securities with a maturity of one year or less $ 210,862 $ 7 $ (117) $ 210,752 U.S. government agency securities and treasuries 38,641 — (155) 38,486 Corporate debt securities 9,721 29 (10) 9,740 Total securities with a maturity of more than one year $ 48,362 $ 29 $ (165) $ 48,226 Total available-for-sale securities $ 259,224 $ 36 $ (282) $ 258,978 December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 235,500 $ 127 $ (41) $ 235,586 Corporate debt securities 25,466 — (29) 25,437 Total securities with a maturity of one year or less $ 260,966 $ 127 $ (70) $ 261,023 U.S. government agency securities and treasuries 15,537 45 — 15,582 Corporate debt securities 7,669 93 — 7,762 Total securities with a maturity of more than one year $ 23,206 $ 138 $ — $ 23,344 Total available-for-sale securities $ 284,172 $ 265 $ (70) $ 284,367 As of March 31, 2024, the Company had 42 marketable securities with a total fair market value of $244.2 million in an unrealized loss position . All of the Company’s investments are classified as available-for-sale and are carried at fair value with unrealized gains and losses recorded as a component of accumulated other comprehensive income (loss). The Company considers all available-for-sale securities, including those with maturity dates beyond 12 months, as available to support current operational liquidity needs and therefore classifies all securities as available for sale. The Company believes that any unrealized losses associated with the decline in value of its securities are temporary and believes that it is more likely than not that it will be able to hold its debt securities to maturity and that there was no material change in the credit risk of the above instruments since January 1, 2024. Therefore, the Company anticipates a full recovery of the amortized cost basis of its debt securities at maturity and no allowance for credit losses was recognized. As of March 31, 2024 and December 31, 2023, $1.0 million and $1.7 million , respectively, of accrued interest receivable was included in prepaid expenses and other current assets

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables present the Company’s fair value hierarchy for its assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value (in thousands): Fair Value Measurements at March 31, 2024 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 60,006 $ — $ — $ 60,006 U.S. government agency securities and treasuries (2) $ — $ 7,931 $ — $ 7,931 Marketable securities: U.S. government agency securities and treasuries — 234,000 — 234,000 Corporate bonds — 24,978 — 24,978 Total $ 60,006 $ 266,909 $ — $ 326,915 Fair Value Measurements at December 31, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 67,102 $ — $ — $ 67,102 Marketable securities: U.S. government agency securities and treasuries $ — $ 251,168 $ — $ 251,168 Corporate bonds — 33,199 — 33,199 Total $ 67,102 $ 284,367 $ — $ 351,469 (1) The cash equivalent amounts above do not include $0.5 million of cash related to checking accounts included in cash and cash equivalents as of March 31, 2024 and December 31, 2023. These amounts are excluded as no valuation is needed for cash in checking accounts . (2) The amortized cost of debt securities classified as cash equivalents approximated fair value. Money market funds are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active

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 at March 31, 2024 and December 31, 2023 (in thousands): March 31, December 31, Laboratory equipment $ 13,229 $ 12,596 Furniture and fixtures 2,228 2,228 Computer equipment 431 431 Leasehold improvements 1,859 1,859 Total property and equipment 17,747 17,114 Less: accumulated depreciation (6,745) (5,923) Property and equipment, net $ 11,002 $ 11,191

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2024
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following at March 31, 2024 and December 31, 2023 (in thousands): March 31, December 31, Employee compensation and benefits $ 3,038 $ 6,660 External research and development expenses 3,716 2,894 General and administrative professional service expenses 1,297 767 Other 741 1,004 Total accrued expenses and other current liabilities $ 8,792 $ 11,325

Common Stock and Preferred Stoc

Common Stock and Preferred Stock	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Common Stock and Preferred Stock	Common Stock and Preferred Stock Common Stock As of March 31, 2024 and December 31, 2023, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 150,000,000 shares of common stock, par value $0.0001 per share. In February 2023, in connection with the closing of the Vertex Agreement (as defined in Note 12, Collaboration and License Agreements ), the Company and Vertex also closed their Stock Purchase Agreement (the "Stock Purchase Agreement") for the sale and issuance of 1,618,613 shares of Entrada's common stock (the “Shares”) to Vertex for an aggregate purchase price of approximately $26.3 million or $16.26 per share. See Note 12, Collaboration and License Agreements, for further discussion of the Company's accounting for the Shares sold in connection with the closing of the Vertex Agreement. In September 2023, the Company entered into a sales agreement (the "Sales Agreement") with Cowen and Company, LLC, acting as the Company's agent and/or principal (the "Sales Agent"), with respect to an "at the market offering" program under which the Company may, from time to time, at its sole discretion, issue and sell shares of its common stock having an aggregate offering price of up to $150.0 million through the Sales Agent. During the three months ended March 31, 2024, there have been no sales of common stock pursuant to the Sales Agreement. Shares Reserved for Future Issuance The Company has reserved the following shares of common stock for future issuance as of: March 31, December 31, Exercise of outstanding stock options 5,730,951 5,414,360 Vesting of outstanding restricted stock 2,005,889 1,268,461 Future awards under the 2021 Stock Option and Incentive Plan 1,818,548 1,697,832 Future awards under the 2021 Employee Stock Purchase Plan 1,174,059 839,539 Total shares of authorized common stock reserved for future issuance 10,729,447 9,220,192 Preferred Stock As of March 31, 2024 and December 31, 2023, the Company was authorized to issue 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share, in one or more series and to fix the rights, preferences, privileges and restrictions thereof. As of March 31, 2024 and December 31, 2023, there were no shares of undesignated preferred stock issued or outstanding.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2021 Plan The total remaining shares of common stock authorized for issuance under the 2021 Stock Option and Incentive Plan (the "2021 Plan") increased from 6,336,068 as of December 31, 2023 to 7,585,585 as of March 31, 2024 primarily due to the automatic annual increase provision of the 2021 Plan. 2016 Plan The total remaining shares of common stock authorized for issuance under the 2016 Stock Incentive Plan as of March 31, 2024 and December 31, 2023 were 1,969,803 shares and 2,206,655 shares, respectively. 2021 Employee Stock Purchase Plan The total remaining shares of common stock authorized for issuance under the 2021 Employee Stock Purchase Plan (the "2021 ESPP") increased from 839,539 as of December 31, 2023 to 1,174,059 as of March 31, 2024 due to the automatic annual increase provision of the 2021 ESPP. Stock-Based Compensation Stock-based compensation expense recorded in the condensed consolidated statements of operations and comprehensive loss is as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development expenses $ 1,613 $ 1,298 General and administrative expenses 2,120 1,457 Total $ 3,733 $ 2,755 Stock Option Valuation The following table presents, on a weighted-average basis, the assumptions used in the Black-Scholes option-pricing model to determine the fair value of stock options granted during the three months ended March 31, 2024 and 2023: March 31, March 31, Risk‑free interest rate 4.14 % 4.13 % Expected volatility 75 % 71 % Expected dividend yield — — Expected term (in years) 6.08 6.08 Early Exercise of Unvested Stock Options Shares purchased by employees pursuant to the early exercise of stock options are not deemed, for accounting purposes, to be outstanding shares until those shares vest according to their respective vesting schedules. Cash received from employee exercises of unvested options is included in current liabilities on the balance sheet. Amounts recorded are reclassified to common stock and additional paid-in capital as the shares vest. Vesting can occur in the year of exercise and thereafter. There were 11,334 and 14,745 unvested shares related to early exercises of stock options as of March 31, 2024 and December 31, 2023, respectively. As of March 31, 2024 and December 31, 2023, the liability associated with the unvested early exercise of stock options was $0.1 million. Stock Options The following table summarizes the Company’s stock option activity during the three months ended March 31, 2024: Number of Weighted‑ Outstanding as of December 31, 2023 5,414,360 $ 11.42 Granted 542,700 13.73 Exercised (30,888) 6.68 Forfeited (195,221) 11.77 Outstanding as of March 31, 2024 5,730,951 $ 11.65 Exercisable as of March 31, 2024 (1) 3,453,494 $ 9.91 (1) This represents the number of vested and unvested options exercisable as of March 31, 2024. The weighted-average grant-date fair value of stock options granted during the three months ended March 31, 2024 and 2023 was $9.43 per share and $8.17 per share, respectively. As of March 31, 2024, there was $22.0 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.39 years. Restricted Stock Units During the three months ended March 31, 2024, restricted stock units ("RSUs") were granted to employees with vesting conditions based on continued service over time. Accordingly, stock-based compensation expense for such awards is recognized using a straight-line attribution model over the vesting term of each RSU. The fair value of each RSU is based on the closing price of the Company's common stock on the date of grant. A summary of restricted stock activity during the three months ended March 31, 2024 is as follows : Shares Weighted‑ Unvested as of December 31, 2023 1,268,461 $ 13.83 Granted 928,290 $ 13.76 Vested (132,458) $ 11.92 Forfeited (58,404) $ 13.65 Unvested as of March 31, 2024 2,005,889 $ 13.93 As of March 31, 2024, there was $25.8 million of unrecognized stock-based compensation expense related to restricted stock that is expected to vest. These costs are expected to be recognized over a weighted-average remaining vesting period of 3.37 years.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company records income tax expense in any interim period based on the estimated effective tax rate for the fiscal year for those tax jurisdictions in which the Company can reliably estimate the effective tax rate. The calculation of the estimated effective tax rate requires an estimate of pre-tax income by tax jurisdiction as well as total tax expense for the fiscal year. Accordingly, the annual estimated effective tax rate is subject to adjustment if there are changes to the initial estimates of total tax expense or pre-tax income. Provision for Income Taxes The Company recorded income tax expense of $1.8 million for the three months ended March 31, 2024 and $3.6 million for the three months ended March 31, 2023 . For both periods, the income tax expense recorded was driven largely by the projected current tax liabilities associated with the tax recognition of payments received pursuant to the Vertex Agreement. Despite the collaboration revenue, the Company continues to maintain a valuation allowance against all remaining deferred tax assets. The Company believes that it is more likely than not that it will not realize a future tax benefit of these attributes as the Company expects to continue to generate operating losses. Ultimate realization of any deferred tax asset is dependent on the Company’s ability to generate sufficient future taxable income in the appropriate tax jurisdiction before the expiration of carryforward periods, if any. The Company currently anticipates that there will be no change in its unrecognized tax benefits in the next twelve months. As of March 31, 2024 , the Company had no unrecognized tax benefits. The Company has not yet conducted a study of its research and development credit carryforwards. Such a study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amount is being presented as an uncertain tax position.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company's commitments, including significant license agreements, are disclosed in Note 10 Commitments and Contingencies in the audited financial statements for the year ended December 31, 2023, and notes thereto, included in the Annual Report. Since the date of those financial statements, there have been no material changes to its commitments except those discussed below. Concurrently with the Company entering into and later amending the Vertex Agreement, the Company entered into a sublicense agreement with Vertex, which was amended in October 2023 (the "Sublicense Agreement"). Pursuant to the Sublicense Agreement, the Company granted to Vertex an exclusive sublicense under certain intellectual property licensed to the Company under the Ohio State Innovation Foundation (the "OSIF License Agreement"). The material terms of the Sublicense Agreement mirror those of the Vertex Agreement, and the payments described in connection with the Vertex Agreement in Note 12, Collaboration and License Agreements , in our Annual Report, are in consideration for the rights granted under both the Vertex Agreement and Sublicense Agreement. Pursuant to the OSIF License Agreement, as of March 31, 2024, the Company accrued a $1.0 million sublicense fee related to the Vertex Agreement milestone achieved in the first quarter of 2024. The expense associated with the sublicense fee was recorded in research and development expenses for the three months ended March 31, 2024 .

Collaboration and License Agree

Collaboration and License Agreements	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Collaboration and License Agreements	Collaboration and License Agreements Vertex Agreement - Overview T he Company and Vertex closed their Strategic Collaboration and License Agreement in February 2023, as amended in October 2023 (the "Vertex Agreement"), pursuant to which the Company granted Vertex an exclusive worldwide license to research, develop, manufacture and commercialize VX-670, the Company’s intracellular EEV-based therapeutic candidate for the treatment of myotonic dystrophy type 1 ("DM1"), as well as any additional EEV-based therapeutic candidates that may be identified by the Company for the potential treatment of DM1 in the course of the parties’ global research collaboration. In October 2023, the Company and Vertex amended the Vertex Agreement to clarify a milestone and related payment terms. The Vertex Agreement provides for a four-year global research collaboration under which Entrada will continue to perform preclinical development of the Company's partnered candidate VX-670 pursuant to the mutually agreed-upon research plan (the "Research Plan"). The Research Plan is overseen by a Joint Research Committee ("JRC") as detailed in the Vertex Agreement. Pursuant to the terms of the Vertex Agreement, the JRC may amend the Research Plan to include additional DM1-related research activities with a goal of identifying other EEV-based therapeutic product candidates for the potential treatment of DM1. Vertex is obligated to reimburse the Company’s research expenses incurred in performing activities under the Research Plan. Pursuant to the Vertex Agreement, the Company received an upfront payment of $223.7 million , and Vertex made an equity investment of $26.3 million by purchasing 1,618,613 shares of the Company's common stock, pursuant to the Stock Purchase Agreement. Under the terms of the Vertex Agreement, the Company is eligible to receive up to $485.0 million upon the achievement of certain research, development, regulatory and commercial milestones. The Company will also receive tiered royalties, from the mid to high single digits based on potential future net sales of licensed products as set forth in the Vertex Agreement. In October 2023, the Company achieved a milestone pursuant to the Vertex Agreement related to preclinical IND-enabling Good Laboratory Practices (" GLP") toxicology studies of VX-670 that triggered a $17.5 million milestone payment, which the Company received in the fourth quarter of 2023. In the first quarter of 2024, the Company achieved a milestone related to the clinical advancement of VX-670, which triggered a $75.0 million payment. The Company expects to receive this payment in the second quarter of 2024. The term of the Vertex Agreement will expire in its entirety upon expiration of the royalty term as set forth in the Vertex Agreement. Vertex may terminate the Vertex Agreement for convenience by providing adequate written notice to the Company. The Company may terminate the Vertex Agreement under certain specified circumstances, including in the event Vertex or any of its affiliates or sublicensees challenges directly or indirectly in a legal or administrative proceeding the patentability, enforceability, or validity of any licensed patent as set forth in the Vertex Agreement. Either party may terminate the Vertex Agreement for an uncured material breach by the other party or upon the bankruptcy or insolvency of the other party. Neither party may assign the agreement without the prior written consent of the other party, except that a party may assign its rights and obligations to an affiliate or third party that acquires all or substantially all of the business or assets to which the Vertex Agreement relates and agrees in writing to be bound by the terms of the Vertex Agreement. Vertex Agreement - Accounting Analysis The Company determined that the Vertex Agreement should be accounted for in accordance with ASC 606 as Vertex was deemed to be a customer. The Company assessed the promised goods and services under the Vertex Agreement in accordance with ASC 606. At inception, the Vertex Agreement included one performance obligation which was the combination of the exclusive license and the performance of the research activities for VX-670 ("Performance Obligation One"). The Company concluded that the license is not distinct from the research and development services for VX-670 during the research collaboration as Vertex cannot fully exploit the value of the license without receipt of such services. The Company also determined that Vertex's ability to engage Entrada to perform work on additional EEV-based therapeutic candidates for the potential treatment of DM1 through the JRC represented customer options. The Company concluded that these customer options do not represent a material right as these services will be reimbursed by Vertex at a price that represents standalone selling price for such services. In the second quarter of 2023, pursuant to the terms of the Vertex Agreement, Vertex amended the Research Plan (the "Amended Research Plan") to engage the Company to perform work on additional EEV-based therapeutic candidates for the potential treatment of DM1 ("Performance Obligation Two"). Such work is treated as a separate contract for accounting purposes and represents a separate performance obligation as the activities are distinct from the research activities for VX-670. Determination of Transaction Price At the commencement of the arrangement, the Vertex Agreement had a fixed transaction price of $232.0 million , primarily consisting of the $223.7 million upfront fee plus a premium of $6.9 million related to the 1,618,613 shares sold to Vertex under the Stock Purchase Agreement when measured at fair value on the date of issuance. The shares issued to Vertex pursuant to the Stock Purchase Agreement were unregistered and therefore considered restricted securities at the time of issuance. As a result, the fair value of the shares issued to Vertex of $19.4 million was calculated using the closing price of the Company's unrestricted shares of common stock on February 8, 2023, adjusted to reflect a discount for lack of marketability ("DLOM") due to the shares issued being unregistered and therefore subject to related sale restrictions. The Company is also entitled to reimbursement of costs incurred associated with the delivery of services under the Research Plan. The Company utilized the most likely amount approach to estimate the expected cost reimbursement. The Company concluded that these amounts do not require a constraint and are included in the transaction price at inception. The Company considers this estimate at each reporting date and updates the estimate based on information available. In October 2023, the Company achieved a milestone related to preclinical IND-enabling GLP toxicology studies of VX-670, which triggered a $17.5 million payment. In the first quarter of 2024 the Company achieved a milestone related to the clinical advancement of VX-670, which triggered a $75.0 million payment . The Company expects to receive this payment in the second quarter of 2024. Upon the achievement of this milestone in the first quarter of 2024, which resulted in an increase in variable consideration, the Company recorded a $38.7 million cumulative catch-up entry to collaboration revenue for the three months ended March 31, 2024. No additional milestones were deemed probable of being achieved as of March 31, 2024 and, therefore, all remaining milestone payments were fully constrained and excluded from the transaction price as of March 31, 2024. The Company re-evaluates the probability of achievement of development milestones and any related constraint at each period end, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration revenue in the period of adjustment. Allocation and Recognition As of March 31, 2024, the transaction price for the combination of the exclusive license and the performance of the research activities for VX-670 consists of (i) the upfront payment, (ii) the milestone achieved in October 2023, (iii) the milestone achieved in the first quarter of 2024 and (iv) reimbursement of costs incurred in connection with the delivery of services under the Amended Research Plan associated with VX-670. The transaction price for the work on additional EEV-based therapeutic candidates consists of the reimbursement of costs incurred in connection with the delivery of services under the Amended Research Plan associated with such work. The Company recognizes revenue associated with both performance obligations as the related research and development services are provided using an input method, according to the costs incurred as related to the respective research services and the costs expected to be incurred in the future to satisfy the performance obligations in accordance with the Amended Research Plan. The transfer of control occurs over this time period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligations. The estimated costs associated with the remaining effort required to complete the performance obligations in accordance with the research plans may change, which may materially impact revenue recognition. The Company regularly evaluates and, when necessary, updates the costs associated with the remaining effort pursuant to the performance obligations under the Vertex Agreement and records any necessary adjustment to revenue for the change in estimate. During the three months ended March 31, 2024, the Company made revisions to its forecasted costs primarily to reflect manufacturing efficiencies that reduced its remaining estimated costs to satisfy its performance obligation. During the three months ended March 31, 2024, the revenue recorded by the Company includes a cumulative catch-up adjustment of $12.2 million as a result of such revisions to its estimated costs. The amounts received that have not yet been recognized as revenue are deferred on the Company’s consolidated balance sheet and will be recognized over the remaining research and development period until the performance obligation is satisfied. The performance obligations have not been fully satisfied as of March 31, 2024. During the three months ended March 31, 2024, the Company recognized $58.1 million in revenue under the Vertex Agreement, including $2.0 million of cost reimbursements, $38.7 million related to a cumulative catch-up adjustment for the milestone and $17.4 million from amounts that were recorded in deferred revenue as of December 31, 2023. The aggregate amount of the transaction price allocated to the Company’s unsatisfied performance obligations recorded in deferred revenue at March 31, 2024 is $157.9 million. The Company will recognize the deferred revenue related to the research and development services based on a cost input method, over the remaining term of the Amended Research Plan. Pierrepont Agreement

Net Income (Loss) per Share

Net Income (Loss) per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Income (Loss) per Share	Net Income (Loss) per Share The computation of basic net income (loss) per share is based on the weighted-average number of our common shares outstanding. The computation of diluted net income (loss) per share is based on the weighted-average number of our common shares outstanding and potential dilutive common shares outstanding during the period as determined by using the treasury stock method. The following table illustrates the determination of basic and diluted net income (loss) per share for each period presented (in thousands, except share and per share date): Three Months Ended March 31, 2024 2023 Numerator: Net income (loss) $ 23,496 $ (6,674) Denominator: Weighted‑average common shares outstanding, basic 33,497,072 32,374,299 Effect of dilutive securities 1,293,853 — Weighted‑average common shares outstanding, diluted 34,790,925 32,374,299 Net income (loss) per share, basic $ 0.70 $ (0.21) Net income (loss) per share, diluted $ 0.68 $ (0.21) The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net income (loss) per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2024 2023 Unvested restricted common stock 69,080 671,308 Unvested shares from early exercises — 43,588 Stock options to purchase common stock 3,842,929 5,349,166 3,912,009 6,064,062

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the condensed consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. The Company has concluded that no subsequent events have occurred that require disclosure.

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 income (loss)	$ 23,496	$ (6,674)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	From time to time, our officers (as defined in Rule 16a–1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the three months ended March 31, 2024, our officers and directors took the following actions with respect to 10b5-1 trading arrangements: Trading Arrangement Name (Title) Action Date Type of Trading Arrangement Nature of Trading Arrangement Aggregate Maximum Number of Shares that may be Sold Expiration Date Kory Wentworth (Chief Financial Officer) Adopt 3/15/2024 Trading plan intended to satisfy the affirmative defense conditions of Securities Exchange Act Rule 10b5-1(c) Sale of the Company's common stock pursuant to the terms of the plan 48,018(1) 6/15/2025 (1) For purposes of this disclosure, the shares included in this table reflect the aggregate maximum number of shares that may be sold under the 10b5-1 trading arrangement. The 10b5-1 trading arrangement covers RSUs, shares underlying stock options exercisable, and shares held by the officer. The actual number of shares that may be sold under the 10b5-1 trading arrangement will be calculated as RSU vesting to satisfy tax withholding obligations pursuant to the Company’s non-discretionary sell-to-cover requirement occurs.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Kory Wentworth [Member]
Trading Arrangements, by Individual
Name	Kory Wentworth
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	3/15/2024
Arrangement Duration	457 days
Aggregate Available	48,018

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 accompanying condensed consolidated financial statements are unaudited and have been prepared in conformity with generally accepted accounting principles in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the ASC and Accounting Standards Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted, as is permitted by GAAP. These condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position as of March 31, 2024, and results of operations for the interim periods ended March 31, 2024 and 2023 . The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full year. These condensed consolidated financial statements should be read in conjunction with the audited financial statements as of and for the years ended December 31, 2023 and 2022, and the notes thereto, included in the Annual Report.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows (in thousands): March 31, December 31, Cash and cash equivalents $ 68,436 $ 67,602 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 72,386 $ 71,552
Restrictions on Cash and Cash Equivalents	A reconciliation of the cash, cash equivalents, and restricted cash reported within the balance sheet that sum to the total of the same amounts shown in the statement of cash flows is as follows (in thousands): March 31, December 31, Cash and cash equivalents $ 68,436 $ 67,602 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 72,386 $ 71,552

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-sale	The following are summaries of the Company's marketable securities at March 31, 2024 and December 31, 2023 (in thousands). March 31, 2024 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 195,594 $ 4 $ (84) $ 195,514 Corporate debt securities 15,268 3 (33) 15,238 Total securities with a maturity of one year or less $ 210,862 $ 7 $ (117) $ 210,752 U.S. government agency securities and treasuries 38,641 — (155) 38,486 Corporate debt securities 9,721 29 (10) 9,740 Total securities with a maturity of more than one year $ 48,362 $ 29 $ (165) $ 48,226 Total available-for-sale securities $ 259,224 $ 36 $ (282) $ 258,978 December 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 235,500 $ 127 $ (41) $ 235,586 Corporate debt securities 25,466 — (29) 25,437 Total securities with a maturity of one year or less $ 260,966 $ 127 $ (70) $ 261,023 U.S. government agency securities and treasuries 15,537 45 — 15,582 Corporate debt securities 7,669 93 — 7,762 Total securities with a maturity of more than one year $ 23,206 $ 138 $ — $ 23,344 Total available-for-sale securities $ 284,172 $ 265 $ (70) $ 284,367

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of fair value hierarchy for assets and liabilities measured at fair value on recurring basis	The following tables present the Company’s fair value hierarchy for its assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value (in thousands): Fair Value Measurements at March 31, 2024 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 60,006 $ — $ — $ 60,006 U.S. government agency securities and treasuries (2) $ — $ 7,931 $ — $ 7,931 Marketable securities: U.S. government agency securities and treasuries — 234,000 — 234,000 Corporate bonds — 24,978 — 24,978 Total $ 60,006 $ 266,909 $ — $ 326,915 Fair Value Measurements at December 31, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 67,102 $ — $ — $ 67,102 Marketable securities: U.S. government agency securities and treasuries $ — $ 251,168 $ — $ 251,168 Corporate bonds — 33,199 — 33,199 Total $ 67,102 $ 284,367 $ — $ 351,469 (1) The cash equivalent amounts above do not include $0.5 million of cash related to checking accounts included in cash and cash equivalents as of March 31, 2024 and December 31, 2023. These amounts are excluded as no valuation is needed for cash in checking accounts . (2)

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Schedule of Property and equipment, Net	Property and equipment, net consisted of the following at March 31, 2024 and December 31, 2023 (in thousands): March 31, December 31, Laboratory equipment $ 13,229 $ 12,596 Furniture and fixtures 2,228 2,228 Computer equipment 431 431 Leasehold improvements 1,859 1,859 Total property and equipment 17,747 17,114 Less: accumulated depreciation (6,745) (5,923) Property and equipment, net $ 11,002 $ 11,191

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2024
Accrued Expenses and Other Current Liabilities [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following at March 31, 2024 and December 31, 2023 (in thousands): March 31, December 31, Employee compensation and benefits $ 3,038 $ 6,660 External research and development expenses 3,716 2,894 General and administrative professional service expenses 1,297 767 Other 741 1,004 Total accrued expenses and other current liabilities $ 8,792 $ 11,325

Common Stock and Preferred St_2

Common Stock and Preferred Stock (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Shares Reserved for Future Issuance	The Company has reserved the following shares of common stock for future issuance as of: March 31, December 31, Exercise of outstanding stock options 5,730,951 5,414,360 Vesting of outstanding restricted stock 2,005,889 1,268,461 Future awards under the 2021 Stock Option and Incentive Plan 1,818,548 1,697,832 Future awards under the 2021 Employee Stock Purchase Plan 1,174,059 839,539 Total shares of authorized common stock reserved for future issuance 10,729,447 9,220,192

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Stock-based compensation expense	Stock-based compensation expense recorded in the condensed consolidated statements of operations and comprehensive loss is as follows (in thousands): Three Months Ended March 31, 2024 2023 Research and development expenses $ 1,613 $ 1,298 General and administrative expenses 2,120 1,457 Total $ 3,733 $ 2,755
Schedule of assumptions used in the Black-Scholes option-pricing model to determine the fair value of stock options granted	The following table presents, on a weighted-average basis, the assumptions used in the Black-Scholes option-pricing model to determine the fair value of stock options granted during the three months ended March 31, 2024 and 2023: March 31, March 31, Risk‑free interest rate 4.14 % 4.13 % Expected volatility 75 % 71 % Expected dividend yield — — Expected term (in years) 6.08 6.08
Summary of the stock option activity	The following table summarizes the Company’s stock option activity during the three months ended March 31, 2024: Number of Weighted‑ Outstanding as of December 31, 2023 5,414,360 $ 11.42 Granted 542,700 13.73 Exercised (30,888) 6.68 Forfeited (195,221) 11.77 Outstanding as of March 31, 2024 5,730,951 $ 11.65 Exercisable as of March 31, 2024 (1) 3,453,494 $ 9.91 (1) This represents the number of vested and unvested options exercisable as of March 31, 2024.
Summary of unvested restricted stock	A summary of restricted stock activity during the three months ended March 31, 2024 is as follows : Shares Weighted‑ Unvested as of December 31, 2023 1,268,461 $ 13.83 Granted 928,290 $ 13.76 Vested (132,458) $ 11.92 Forfeited (58,404) $ 13.65 Unvested as of March 31, 2024 2,005,889 $ 13.93

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of basic and diluted net (income) loss per share attributable to common stockholders	The following table illustrates the determination of basic and diluted net income (loss) per share for each period presented (in thousands, except share and per share date): Three Months Ended March 31, 2024 2023 Numerator: Net income (loss) $ 23,496 $ (6,674) Denominator: Weighted‑average common shares outstanding, basic 33,497,072 32,374,299 Effect of dilutive securities 1,293,853 — Weighted‑average common shares outstanding, diluted 34,790,925 32,374,299 Net income (loss) per share, basic $ 0.70 $ (0.21) Net income (loss) per share, diluted $ 0.68 $ (0.21)
Schedule of antidilutive securities excluded from computation of net loss per share	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net income (loss) per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended March 31, 2024 2023 Unvested restricted common stock 69,080 671,308 Unvested shares from early exercises — 43,588 Stock options to purchase common stock 3,842,929 5,349,166 3,912,009 6,064,062

Nature of the Business (Details

Nature of the Business (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 171,474	$ 194,970
Cash, cash equivalents, and short-term investments	$ 327,400

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 68,436	$ 67,602
Restricted cash	3,950	3,950
Total cash, cash equivalents and restricted cash	$ 72,386	$ 71,552	$ 231,598	$ 49,107

Marketable Securities - Amortiz

Marketable Securities - Amortized cost (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Amortized Cost
Total available-for-sale securities	$ 259,224	$ 284,172
Unrealized Gains (Losses)
Unrealized Gains	36	265
Unrealized Losses	(282)	(70)
Fair Value
Marketable securities	258,978	284,367
One Year or Less
Amortized Cost
Total securities with a maturity of one year or less	210,862	260,966
Unrealized Gains (Losses)
Unrealized Gains	7	127
Unrealized Losses	(117)	(70)
Fair Value
Total securities with a maturity of one year or less	210,752	261,023
One to Two Years
Amortized Cost
Total securities with a maturity of more than one year	48,362	23,206
Unrealized Gains (Losses)
Unrealized Gains	29	138
Unrealized Losses	(165)	0
Fair Value
Total securities with a maturity of more than one year	48,226	23,344
U.S. government agency securities and treasuries | One Year or Less
Amortized Cost
Total securities with a maturity of one year or less	195,594	235,500
Unrealized Gains (Losses)
Unrealized Gains	4	127
Unrealized Losses	(84)	(41)
Fair Value
Total securities with a maturity of one year or less	195,514	235,586
U.S. government agency securities and treasuries | One to Two Years
Amortized Cost
Total securities with a maturity of more than one year	38,641	15,537
Unrealized Gains (Losses)
Unrealized Gains	0	45
Unrealized Losses	(155)	0
Fair Value
Total securities with a maturity of more than one year	38,486	15,582
Corporate debt securities | One Year or Less
Amortized Cost
Total securities with a maturity of one year or less	15,268	25,466
Unrealized Gains (Losses)
Unrealized Gains	3	0
Unrealized Losses	(33)	(29)
Fair Value
Total securities with a maturity of one year or less	15,238	25,437
Corporate debt securities | One to Two Years
Amortized Cost
Total securities with a maturity of more than one year	9,721	7,669
Unrealized Gains (Losses)
Unrealized Gains	29	93
Unrealized Losses	(10)	0
Fair Value
Total securities with a maturity of more than one year	$ 9,740	$ 7,762

Marketable Securities - Additio

Marketable Securities - Additional Information (Details)	Mar. 31, 2024 USD ($) security	Dec. 31, 2023 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of securities | security	42
Market value of marketable securities	$ 244,200,000
Allowance for credit loss	0
Interest receivable	$ 1,000,000	$ 1,700,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Current, Statement of Financial Position [Extensible Enumeration]	Prepaid expenses and other current assets	Prepaid expenses and other current assets

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	$ 258,978	$ 284,367
Cash	500	500
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		67,102
Total	326,915	351,469
Fair Value, Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	60,006
Fair Value, Recurring | U.S. government agency securities and treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	7,931
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		67,102
Total	60,006	67,102
Fair Value, Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	60,006
Fair Value, Recurring | Level 1 | U.S. government agency securities and treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Total	266,909	284,367
Fair Value, Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Fair Value, Recurring | Level 2 | U.S. government agency securities and treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	7,931
Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Total	0	0
Fair Value, Recurring | Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Fair Value, Recurring | Level 3 | U.S. government agency securities and treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Fair Value, Recurring | U.S. government agency securities and treasuries
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	234,000	251,168
Fair Value, Recurring | U.S. government agency securities and treasuries | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Fair Value, Recurring | U.S. government agency securities and treasuries | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	234,000	251,168
Fair Value, Recurring | U.S. government agency securities and treasuries | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Fair Value, Recurring | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	24,978	33,199
Fair Value, Recurring | Corporate bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Fair Value, Recurring | Corporate bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	24,978	33,199
Fair Value, Recurring | Corporate bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	$ 0	$ 0

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 17,747		$ 17,114
Less: accumulated depreciation	(6,745)		(5,923)
Property and equipment, net	11,002		11,191
Depreciation expense	934	$ 541
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	13,229		12,596
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	2,228		2,228
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	431		431
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 1,859		$ 1,859

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accrued Expenses and Other Current Liabilities [Abstract]
Employee compensation and benefits	$ 3,038	$ 6,660
External research and development expenses	3,716	2,894
General and administrative professional service expenses	1,297	767
Other	741	1,004
Total accrued expenses and other current liabilities	$ 8,792	$ 11,325

Common Stock and Preferred St_3

Common Stock and Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended
	Sep. 30, 2023	Feb. 28, 2023	Mar. 31, 2024	Dec. 31, 2023
Class of Stock
Common stock, shares, authorized (in shares)			150,000,000	150,000,000
Common stock, par value per share (in dollars per share)			$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)			10,000,000	10,000,000
Preferred stock, par or stated value per share (in dollars per share)			$ 0.0001	$ 0.0001
Preferred stock shares issued (in shares)			0	0
Preferred stock shares outstanding (in shares)			0	0
Vertex Agreement
Class of Stock
Number of shares purchases in equity investment (in shares)		1,618,613
Net proceeds from issuance of common stock		$ 26.3
Offering price per share (in dollars per share)		$ 16.26
Sales Agreement
Class of Stock
Number of shares purchases in equity investment (in shares)			0
Sales Agreement | Maximum
Class of Stock
Aggregate ofering price	$ 150

Common Stock and Preferred St_4

Common Stock and Preferred Stock - Schedule of Shares Reserved for Future Issuance under Equity Compensation Plans (Details) - shares	Mar. 31, 2024	Dec. 31, 2023
Class of Stock
Shares of common stock reserved for issuance (in shares)	10,729,447	9,220,192
Future awards under the 2021 Stock Option and Incentive Plan
Class of Stock
Shares of common stock reserved for issuance (in shares)	1,818,548	1,697,832
Exercise of outstanding stock options
Class of Stock
Shares of common stock reserved for issuance (in shares)	5,730,951	5,414,360
Vesting of outstanding restricted stock
Class of Stock
Shares of common stock reserved for issuance (in shares)	2,005,889	1,268,461
Future awards under the 2021 Employee Stock Purchase Plan
Class of Stock
Shares of common stock reserved for issuance (in shares)	1,174,059	839,539

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Stock-based compensation
Vesting of early exercised options (in shares)	11,334		14,745
Unvested early exercises of stock options	$ 0.1		$ 0.1
Future awards under the 2021 Employee Stock Purchase Plan
Stock-based compensation
Stock authorized for issuance (in shares)	1,174,059		839,539
Exercise of outstanding stock options
Stock-based compensation
Weighted-average grant-date fair value of stock options granted (in dollars per share)	$ 9.43	$ 8.17
Unrecognized compensation cost	$ 22
Unrecognized compensation cost, weighted-average period for recognition	2 years 4 months 20 days
Vesting of outstanding restricted stock
Stock-based compensation
Unrecognized compensation cost	$ 25.8
Unrecognized compensation cost, weighted-average period for recognition	3 years 4 months 13 days
Future awards under the 2021 Stock Option and Incentive Plan
Stock-based compensation
Stock authorized for issuance (in shares)	7,585,585		6,336,068
2016 Stock Plan
Stock-based compensation
Stock authorized for issuance (in shares)	1,969,803		2,206,655

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock-based compensation
Share-based compensation expense	$ 3,733	$ 2,755
Research and development expenses
Stock-based compensation
Share-based compensation expense	1,613	1,298
General and administrative expenses
Stock-based compensation
Share-based compensation expense	$ 2,120	$ 1,457

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Valuation (Details) - Exercise of outstanding stock options	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Assumptions used to determine the fair value of stock options granted
Risk‑free interest rate	4.14%	4.13%
Expected volatility	75%	71%
Expected dividend yield	0%	0%
Expected term (in years)	6 years 29 days	6 years 29 days

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock option activity (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Number of Shares
Outstanding at beginning of period (in shares) | shares	5,414,360
Granted (in shares) | shares	542,700
Exercised (in shares) | shares	(30,888)
Forfeited (in shares) | shares	(195,221)
Outstanding at end period (in shares) | shares	5,730,951
Exercisable (in shares) | shares	3,453,494
Weighted‑ Average Exercise Price
Outstanding at beginning period (in dollars per share) | $ / shares	$ 11.42
Granted (in dollars per share) | $ / shares	13.73
Exercised (in dollars per share) | $ / shares	6.68
Forfeited (in dollars per share) | $ / shares	11.77
Outstanding at end period (in dollars per share) | $ / shares	11.65
Exercisable (in dollars per share) | $ / shares	$ 9.91

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Shares
Unvested balance, at beginning of period (in shares) | shares	1,268,461
Granted (in shares) | shares	928,290
Vested (in shares) | shares	(132,458)
Forfeited (in shares) | shares	(58,404)
Unvested balance, at end of period (in shares) | shares	2,005,889
Weighted‑ Average Grant‑Date Fair Value
Beginning of period (in dollars per share) | $ / shares	$ 13.83
Granted (in dollars per share) | $ / shares	13.76
Vested (in dollars per share) | $ / shares	11.92
Forfeited (in dollars per share) | $ / shares	13.65
End of period (in dollars per share) | $ / shares	$ 13.93

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Provision for income tax expense	$ 1,831	$ 3,551

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Mar. 31, 2024 USD ($)
License agreement with a third-party
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential milestone payment obligation	$ 1

Collaboration and License Agr_2

Collaboration and License Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Oct. 31, 2023	Feb. 28, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			$ 59,120	$ 25,260
Vertex
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Strategic collaboration agreement, term		4 years
Milestone payment	$ 17,500		75,000
Stock Issued		$ 19,400
Cumulative catch-up adjustment			38,700
Revenue			58,100
Vertex | Private Placement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Net proceeds from issuance of common stock		$ 26,300
Number of shares purchases in equity investment (in shares)		1,618,613
Consideration amount		$ 485,000
Vertex | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment		223,700
Revenue, remaining performance obligation, amount		232,000	157,900		$ 17,400
Premium		$ 6,900
Cumulative catch-up adjustment			12,200
Vertex | Collaboration service revenue
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			2,000
Vertex | Recognition of upfront and milestone payments
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue			38,700
Pierrepont Therapeutics, Inc
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue recognized			$ 1,000

Net Income (Loss) per Share - C

Net Income (Loss) per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net income (loss)	$ 23,496	$ (6,674)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	33,497,072	32,374,299
Effect of dilutive securities (in shares)	1,293,853	0
Weighted-average common shares outstanding, diluted (in shares)	34,790,925	32,374,299
Net income (loss) per share, basic (in dollars per share)	$ 0.70	$ (0.21)
Net income (loss) per share, diluted (in dollars per share)	$ 0.68	$ (0.21)

Net Income (Loss) per Share - A

Net Income (Loss) per Share - Antidilutive securities (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive securities excluded from common stock
Antidilutive securities excluded from common stock (in shares)	3,912,009	6,064,062
Unvested restricted common stock
Antidilutive securities excluded from common stock
Antidilutive securities excluded from common stock (in shares)	69,080	671,308
Unvested shares from early exercises
Antidilutive securities excluded from common stock
Antidilutive securities excluded from common stock (in shares)	0	43,588
Stock options to purchase common stock
Antidilutive securities excluded from common stock
Antidilutive securities excluded from common stock (in shares)	3,842,929	5,349,166