Entrada Therapeutics (TRDA) 10-Q 10 May 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	Apr. 30, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
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)		33,197,018
Entity Central Index Key	0001689375
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Former Address
Document Information [Line Items]
Entity Address, Address Line One	6 Tide Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02210

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 227,648	$ 45,157
Marketable securities	183,983	143,555
Collaboration receivable	6,297	0
Prepaid expenses and other current assets	16,207	21,163
Total current assets	434,135	209,875
Property and equipment, net	9,394	7,681
Restricted cash	3,950	3,950
Right-of-use assets, operating leases	14,247	25,340
Other non-current assets	13,843	5,210
Total assets	475,569	252,056
Current liabilities:
Accounts payable	6,474	5,990
Accrued expenses and other current liabilities	11,676	7,576
Operating lease obligations, current portion	7,103	8,406
Deferred revenue, current portion	122,341	0
Total current liabilities	147,594	21,972
Operating lease obligations, net of current portion	9,122	17,530
Deferred revenue, net of current portion	89,241	0
Total liabilities	245,957	39,502
Commitments and contingencies (Note 11)
Stockholders’ equity:
Common stock, par value $0.0001; 150,000,000 shares authorized; 33,177,324 shares issued and 33,133,736 shares outstanding as of March 31, 2023 and 31,448,508 shares issued and 31,394,767 shares outstanding as of December 31, 2022	3	3
Additional paid‑in capital	425,210	402,893
Accumulated other comprehensive loss	(642)	(2,057)
Accumulated deficit	(194,959)	(188,285)
Total stockholders’ equity	229,612	212,554
Total liabilities and stockholders’ equity	$ 475,569	$ 252,056

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
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)	33,177,324	31,448,508
Common stock, shares, outstanding (in shares)	33,133,736	31,394,767

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Revenue from contract with customer	$ 25,260	$ 0
Operating expenses:
Research and development	23,102	15,718
General and administrative	7,938	6,433
Total operating expenses	31,040	22,151
Loss from operations	(5,780)	(22,151)
Other income:
Interest and other income	2,657	480
Total other income	2,657	480
Loss before provision for income taxes	(3,123)	(21,671)
Provision for income taxes	(3,551)	0
Net loss	$ (6,674)	$ (21,671)
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.21)	$ (0.69)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.21)	$ (0.69)
Weighted-average common shares outstanding, basic (in shares)	32,374,299	31,246,916
Weighted-average common shares outstanding, diluted (in shares)	32,374,299	31,246,916
Other comprehensive loss:
Unrealized gain (loss) on marketable securities	$ 1,415	$ (1,535)
Total other comprehensive gain (loss)	1,415	(1,535)
Total comprehensive loss	$ (5,259)	$ (23,206)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid‑in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balances (in shares) at Dec. 31, 2021		31,224,336
Beginning balances at Dec. 31, 2021	$ 298,718	$ 3	$ 392,384	$ 0	$ (93,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		24,891
Issuance of common stock upon exercise of stock options	50		50
Vesting of early exercised options (in shares)		15,224
Vesting of early exercised options	35		35
Stock-based compensation	1,794		1,794
Other comprehensive loss	(1,535)			(1,535)
Net loss	(21,671)				(21,671)
Ending balances (in shares) at Mar. 31, 2022		31,264,451
Ending balances at Mar. 31, 2022	277,391	$ 3	394,263	(1,535)	(115,340)
Beginning balances (in shares) at Dec. 31, 2021		31,224,336
Beginning balances at Dec. 31, 2021	$ 298,718	$ 3	392,384	0	(93,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of early exercised options (in shares)	53,741
Ending balances (in shares) at Dec. 31, 2022	31,394,767	31,394,767
Ending 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	18,344
Issuance of common stock upon exercise of stock options	$ 129		129
Vesting of early exercised options (in shares)	43,588	10,153
Vesting of early exercised options	$ 26		26
Vesting of restricted common stock (in shares)		91,859
Shares issued (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 loss	1,415			1,415
Net loss	$ (6,674)				(6,674)
Ending balances (in shares) at Mar. 31, 2023	33,133,736	33,133,736
Ending balances at Mar. 31, 2023	$ 229,612	$ 3	$ 425,210	$ (642)	$ (194,959)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (6,674)	$ (21,671)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	541	390
Stock‑based compensation expense	2,755	1,794
Amortization of premiums and discounts on marketable securities, net	(237)	142
Changes in operating assets and liabilities:
Collaboration receivable	(6,297)	0
Prepaid expenses and other current assets	4,339	(1,670)
Right-of-use assets, operating leases	3,332	1,582
Other non-current assets	(8,633)	(562)
Accounts payable	534	2,061
Accrued expenses and other current liabilities	4,107	(1,526)
Operating lease liabilities	(1,950)	(1,531)
Deferred revenue	211,582	0
Net cash provided by (used in) operating activities	203,399	(20,991)
Cash flows from investing activities:
Purchases of property and equipment	(1,668)	(594)
Purchases of marketable securities	(101,776)	(182,653)
Maturities of marketable securities	63,000	1,714
Net cash used in investing activities	(40,444)	(181,533)
Cash flows from financing activities:
Proceeds from issuance of common stock in connection with the Vertex Agreement	19,407	0
Proceeds from exercise of stock options	129	50
Net cash provided by financing activities	19,536	50
Net increase (decrease) in cash, cash equivalents, and restricted cash	182,491	(202,474)
Cash, cash equivalents, and restricted cash at beginning of period	49,107	291,064
Cash, cash equivalents, and restricted cash at end of period	231,598	88,590
Supplemental cash flow disclosures:
Purchases of property and equipment included in accounts payable and accrued expenses	57	391
Right-of-use assets surrendered as part of lease modification	7,761	0
Recognition of right-of use asset upon adoption of ACS 842	0	32,991
Transfer of deposits for equipment from operating to investing cash flows	617	495
Vesting of options early exercised subject to repurchase	$ 26	$ 35

Nature of the Business

Nature of the Business	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business Organization Entrada Therapeutics, Inc. (Entrada or the Company) aims to transform the lives of patients by establishing Endosomal Escape Vehicle (EEV TM ) therapeutics as a new class of medicines and to become the world’s foremost intracellular therapeutics company. 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 early-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. The Company has incurred losses since its inception, including losses of $6.7 million and $21.7 million for the three months ended March 31, 2023 and 2022, respectively. As of March 31, 2023, the Company had an accumulated deficit of $195.0 million. To date, the Company has funded its operations primarily through the sale of equity securities and collaboration payments. Other than the upfront collaboration payment received during the three months ended March 31, 2023 which resulted in positive cash flows for the period ended March 31, 2023, 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 $411.6 million as of March 31, 2023 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, 2023
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, 2023 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, 2022, which was filed with the Securities and Exchange Commission (the SEC) on March 6, 2023 (Annual Report) , except as noted immediately below. 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 Accounting Standards Codification (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, 2023, and results of operations for the interim periods ended March 31, 2023 and 2022 . 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, 2022 and 2021, and the notes thereto, included in the Company’s Annual Report. Revenue Recognition The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements (“ASC 808”) to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and those that are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, generally by analogy to Topic 606. For those elements of the arrangement that are accounted for pursuant to Topic 606, the Company applies the five-step model described below. To date all revenue has been generated from the Company's Strategic Collaboration and License Agreement (the Vertex Agreement) with Vertex Pharmaceuticals Incorporated (Vertex) which closed in February 2023 and falls within the scope of ASC Topic 606, "Revenue from Contracts with Customers" (“ASC 606”), under which the Company licensed rights to ENTR-701 and performs research and development services. The terms of this arrangement includes a non-refundable upfront payment, reimbursement for research and development costs; development, regulatory, and commercial milestone payments; and royalties on net sales of licensed products. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. For contracts within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered separate performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying license relative to the option exercise price, including assumptions about technical feasibility and the probability of developing a candidate that would be subject to the option rights. The exercise of a material right is accounted for as a contract modification for accounting purposes. The Company assesses whether each promised good or service is distinct for the purpose of identifying the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such promised goods or services are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). In assessing whether a promised good or service is distinct, the Company considers factors such as the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. The transaction price is then determined and allocated to the identified performance obligations in proportion to their standalone selling prices (SSP) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations may require significant judgment. In developing the SSP for a performance obligation, the Company considers applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. The Company validates the SSP for performance obligations by evaluating whether changes in the key assumptions used to determine the SSP will have a significant effect on the allocation of arrangement consideration between multiple performance obligations. If the consideration promised in a contract includes a variable amount, the Company estimates the amount of consideration to which it will be entitled in exchange for transferring the promised goods or services to a customer. The Company determines the amount of variable consideration by using the expected value method or the most likely amount method. The Company includes the unconstrained amount of estimated variable consideration in the transaction price. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the period of adjustment. If an arrangement includes development and regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or a customer's control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied. Up-front and milestone payments are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as a collaboration receivable when the Company's right to consideration is unconditional. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires that credit losses for financial instruments measured at amortized cost be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2023
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 three months or less at the date of purch ase to be cash equivalents. At March 31, 2023 and December 31, 2022 , 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, 2023 and December 31, 2022 , 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 $ 227,648 $ 45,157 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 231,598 $ 49,107

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The following are summaries of the Company's marketable securities at March 31, 2023 and December 31, 2022 (in thousands). March 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 79,580 $ 65 $ (605) $ 79,040 Corporate debt securities 45,996 2 (593) 45,405 Total securities with a maturity of one year or less $ 125,576 $ 67 $ (1,198) $ 124,445 U.S. government agency securities and treasuries 49,960 439 — 50,399 Corporate debt securities 9,089 50 — 9,139 Total securities with a maturity of more than one year $ 59,049 $ 489 $ — $ 59,538 Total available-for-sale securities $ 184,625 $ 556 $ (1,198) $ 183,983 December 31, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 100,555 $ — $ (1,159) $ 99,396 Corporate debt securities 41,615 — (774) 40,841 Total securities with a maturity of one year or less $ 142,170 $ — $ (1,933) $ 140,237 U.S. government agency securities and treasuries — — — — Corporate debt securities 3,442 — (124) 3,318 Total securities with a maturity of more than one year $ 3,442 $ — $ (124) $ 3,318 Total available-for-sale securities $ 145,612 $ — $ (2,057) $ 143,555 As of March 31, 2023, the Company had 23 marketable securities with a total fair market value of $95.2 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 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, 2023. 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, 2023 and December 31, 2022, $0.9 million and $0.6 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, 2023
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, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 227,321 $ — $ — $ 227,321 Marketable securities: U.S. government agency securities and treasuries — 129,439 — 129,439 Corporate bonds — 54,544 — 54,544 Total $ 227,321 $ 183,983 $ — $ 411,304 Fair Value Measurements at December 31, 2022 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 44,907 $ — $ — $ 44,907 Marketable securities: U.S. government agency securities and treasuries $ — $ 99,396 $ — $ 99,396 Corporate bonds — 44,159 — 44,159 Total $ 44,907 $ 143,555 $ — $ 188,462 (1) The cash equivalent amounts above do not include $0.3 million of cash related to checking accounts included in cash and cash equivalents as of March 31, 2023 and December 31, 2022. These amounts are excluded as no valuation is needed for cash in checking accounts .

Property and Equipment, Net

Property and Equipment, Net	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment, net consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, Laboratory equipment $ 8,512 $ 8,335 Furniture and fixtures 161 161 Computer equipment 43 43 Leasehold improvements 1,859 1,859 Construction in progress 2,659 584 Total property and equipment 13,234 10,982 Less: accumulated depreciation (3,840) (3,301) Property and equipment, net $ 9,394 $ 7,681 Depreciation expense for the three months ended March 31, 2023 and 2022 was $0.5 million and $0.4 million, respectively. The construction in progress amount in the table above represents costs for capital assets not yet placed into service as of March 31, 2023.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2023
Accrued Expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current LiabilitiesAccrued expenses and other current liabilities consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, Employee compensation and benefits $ 2,049 $ 5,063 External research and development expenses 4,057 1,157 General and administrative professional service expenses 837 925 Accrued income tax liability 3,551 — Other 1,182 431 Total accrued expenses and other current liabilities $ 11,676 $ 7,576

Common Stock and Preferred Stoc

Common Stock and Preferred Stock	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Common Stock and Preferred Stock	Common Stock and Preferred Stock Common Stock As of March 31, 2023 and December 31, 2022, 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, the Company and Vertex also closed their 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 13, 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. 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 5,349,166 5,028,850 Vesting of outstanding restricted stock 671,308 463,964 Future awards under the 2021 Stock Option and Incentive Plan 2,596,835 1,976,758 Future awards under the 2021 Employee Stock Purchase Plan 877,600 563,115 Total shares of authorized common stock reserved for future issuance 9,494,909 8,032,687 Preferred Stock As of March 31, 2023 and December 31, 2022, 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, 2023 and December 31, 2022, there were no shares of undesignated preferred stock issued or outstanding.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2021 Plan The total shares of common stock authorized for issuance under the 2021 Stock Option and Incentive Plan increased from 5,262,917 as of December 31, 2022 to 6,425,669 as of March 31, 2023 primarily due to the automatic annual increase provision. 2016 Plan The total shares of common stock authorized for issuance under the 2016 Stock Incentive Plan as of March 31, 2023 and December 31, 2022 were 2,191,640 shares and 2,206,655 shares, respectively. 2021 Employee Stock Purchase Plan The total shares of common stock authorized for issuance under the 2021 Employee Stock Purchase Plan (2021 ESPP) increased from 563,115 as of December 31, 2022 to 877,600 as of March 31, 2023 due to the automatic annual increase provision within 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, 2023 2022 Research and development expenses $ 1,298 $ 704 General and administrative expenses 1,457 1,090 Total $ 2,755 $ 1,794 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, 2023 and 2022: March 31, March 31, Risk‑free interest rate 4.13 % 1.61 % Expected volatility 71 % 70 % Expected dividend yield — — Expected term (in years) 6.08 6.06 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 43,588 and 53,741 unvested shares related to early exercises of stock options as of March 31, 2023 and December 31, 2022, respectively. As of March 31, 2023 and December 31, 2022, the liability associated with the unvested early exercise of stock options was $0.2 million. Stock Options The following table summarizes the Company’s stock option activity during the three months ended March 31, 2023: Number of Weighted‑ Outstanding as of December 31, 2022 5,028,850 $ 10.95 Granted 350,396 12.24 Exercised (18,344) 6.39 Forfeited (11,736) 13.69 Outstanding as of March 31, 2023 5,349,166 $ 11.04 Exercisable as of March 31, 2023 (1) 2,878,389 $ 8.37 (1) This represents the number of vested and unvested options exercisable as of March 31, 2023. The weighted-average grant-date fair value of stock options granted during the three months ended March 31, 2023 and 2022 was $8.17 per share and $7.39 per share, respectively. As of March 31, 2023, there was $25.2 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.71 years. Restricted Stock Units During the three months ended March 31, 2023, 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, 2023 is as follows : Shares Weighted‑ Unvested as of December 31, 2022 463,964 $ 12.26 Issued 303,262 $ 12.25 Vested (91,859) $ 11.57 Forfeited (4,059) $ 12.06 Unvested as of March 31, 2023 671,308 $ 12.35 As of March 31, 2023, there was $7.8 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 3.42 years.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
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 an income tax expense of $3.6 million for the three months ended March 31, 2023 . In the three months ended March 31, 2023 , the income tax expense recorded was driven largely by the projected current tax liability associated with the tax recognition of the Vertex Agreement upfront payment received in 2023. A significant portion of the taxable income related to the collaboration payment is projected to be offset by current year expenses and prior year accumulated losses. A current tax liability has been projected for the remaining taxable income. The Company reported no income tax provision in the three months ended March 31, 2022, as the Company generated a taxable loss, offset by an increase to the Company’s valuation allowance. 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, 2023 , 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, 2023
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, 2022, and notes thereto, included in the Company’s 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 closing of the Vertex Agreement in February 2023, the Company entered into a sublicense agreement (the Sublicense Agreement) with Vertex. Pursuant to the Sublicense Agreement, the Company granted to Vertex an exclusive sublicense under certain intellectual property licensed to the Company under the license agreement (OSIF License Agreement), dated December 14, 2018, by and between Company and Ohio State Innovation Foundation (OSIF), as amended. See Note 10, Commitments and Contingencies, in the Company's audited financial statements for the year ended December 31, 2022 for further discussion of 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 above are in consideration for the rights granted under both the Vertex Agreement and Sublicense Agreement. Pursuant to the OSIF License Agreement, in April 2023, the Company paid OSIF a sublicense fee of $2.8 million . The sublicense fee was accrued for in accrued expenses and other current liabilities as of March 31, 2023 and recorded in research and development expenses for the three months ended March 31, 2023 . No other sublicense fees were owed to OSIF as of March 31, 2023. If the Company receives any additional sublicensing consideration, it will owe additional fees to OSIF pursuant to the terms of the OSIF License Agreement.

Leases

Leases	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Leases	Leases The Company’s operating lease activity is comprised of non-cancelable facility leases for office and laboratory space in Boston, Massachusetts. 6 Tide Street Lease The Company entered into an operating lease for office and laboratory space in Boston, Massachusetts in February 2020 (6 Tide Street Lease), and entered into subsequent amendments through 2023. The amendments run co-terminus with the existing lease. The Company has a total of 42,046 square feet licensed at this facility. The Company has the option to terminate the lease and amendments after November 30, 2023 without penalty. At the adoption of ASC 842, the Company concluded that it is not reasonably certain that it will exercise this option to terminate the lease early. In January 2023, the Company entered into an amendment to the 6 Tide Street Lease pursuant to which the Company will cease making lease payments for a portion of the leased space no later than November 30, 2023. The term for the remainder of the lease will end on November 30, 2025. Following the amendment, the fixed rental payment will be approximately $0.8 million per month through November 30, 2023, and $0.5 million per month after November 30, 2023. Subsequent to the amendment, the Company continues to classify the 6 Tide Street Lease as an operating lease. Upon the lease modification, the Company reassessed its incremental borrowing rate and remeasured the lease liability and right-of-use asset. In connection with entering into the 6 Tide Street Lease, the Company paid a security deposit of $0.8 million, of which $0.5 million is recorded as a component of other non-current assets and $0.3 million is recorded as a component of other current assets as of March 31, 2023. The components of operating lease cost were as follows (in thousands): Three Months Ended March 31, 2023 Operating lease cost $ 3,665 Variable lease cost — Total lease cost $ 3,665 Supplemental information related to operating leases was as follows: Other information Three Months Ended March 31, 2023 Operating cash flows used for operating leases (in thousands) $ 2,282 Weighted average remaining lease term 2.7 years Weighted average discount rate 7.95% Future payments due under operating leases as of March 31, 2023 were as follows (in thousands): Maturity of Lease Liability As of March 31, 2023 2023 (excluding the three-months ended March 31, 2023) 6,627 2024 5,741 2025 5,396 Thereafter — Total lease payments $ 17,764 Less: imputed interest (1,539) Present value of operating lease liabilities $ 16,225 IDB Lease On March 16, 2022, the Company and IDB 17-19 Drydock Limited Partnership, as landlord (Landlord), entered into a lease agreement (IDB Lease) with respect to approximately 81,229 square feet of office and laboratory space (Premises) in Boston, Massachusetts, which, when available for occupancy, will become the Company’s new consolidated headquarters location and supplement its existing space in Massachusetts. The term of the IDB Lease commences the date upon which the Landlord tenders possession of the Premises to the Company following the Landlord’s substantial completion of the initial build-out of the Premises (Commencement Date) and shall continue for a period of approximately 10 years, unless earlier terminated in accordance with the terms of the IDB Lease. The Company has (i) the option to extend the IDB Lease for an additional period of five (5) years, and (ii) a right of first offer on adjacent space to the Premises, subject to the terms and conditions of the IDB Lease. As these options are not reasonably certain of occurring, they will not be included in the initial calculation of the Company's right-of-use asset upon lease commencement. The initial fixed rental rate is $0.5 million per month, which is for a 12 month period during which the base rent is payable for 65,000 square feet, and will increase 3% per annum thereafter for the entire 81,229 square feet leased. Base rent becomes due upon the earlier of (i) the Company’s occupancy of the Premises for use in its regular operations, or (ii) 10 months following the Commencement Date, provided that in the event the Landlord’s build-out of the Premises is not complete on such date, base rent becomes due upon substantial completion of such build-out. Under the terms of the IDB Lease, the Landlord will provide an allowance in an amount not to exceed $19.5 million (calculated at a rate of $240.00 per rentable square foot of the Premises) toward the cost of completing tenant improvements for the Premises. In addition, the Company has the right to require the Landlord to provide an additional contribution in an amount not to exceed $1.6 million (calculated at a rate of $20.00 per rentable square foot of the Premises) toward the cost of tenant improvements to the Premises, which amount shall be repaid by the Company in an amount of equal monthly payments of principal and interest as would be necessary to repay a loan in the full amount of the additional contribution used by the Company, subject to an 8% annual interest charge, on a level direct reduction basis over a 120 month period. The Company will be required to pay its share of operating expenses, taxes and any other expenses payable under the IDB Lease. In connection with the execution of the IDB Lease, the Company executed a cash-collateralized letter of credit, which may be reduced in the future subject to reduction requirements specified in the IDB Lease therein. The cash collateralizing the letter of credit is classified as restricted cash on the Company's condensed consolidated balance sheets. The Company concluded that the improvements resulting from both the Landlord's build-out and the tenant improvements are the Landlord's assets for accounting purposes. Costs incurred by the Company related to the tenant improvements up to the Landlord's allowance are pass-through costs and will be reimbursed. Costs incurred by the Company related to the tenant improvements in excess of the Landlord's allowance will be treated as prepaid rent and will increase the right-of-use asset upon occurrence of the accounting commencement date. As of March 31, 2023, the Company had incurred $21.2 million of refundable pass-through costs, of which $14.4 million was reimbursed by the Landlord as of March 31, 2023 , and $13.3 million of prepaid rent amounts. Net pass-through cost associated with the IDB Lease are included in other current assets as the Company expects to receive the remaining reimbursement for such costs in the next 12 months. Prepaid rent amounts associated with the IDB Lease are included in other non-current assets. The accounting commencement date occurred in April 2023 when both the Landlord's build-out and the tenant improvements were substantially completed. As the accounting commencement date had not occurred as of March 31, 2023, the IDB Lease is excluded from the table above. IDB Sublease In December 2022, the Company entered into a sublease agreement to sublease a portion of the office and laboratory space leased under the IDB Lease to a third-party (subtenant). The sublease term is 3 years and the subtenant has an option to extend the lease term for 6 months. The initial fixed rental rate is approximately $0.2 million per month, and will increase 3% per annum thereafter. The sublessee is obligated to pay its ratable portion of operating expenses during the sublease term. The Company received a letter of credit of $0.5 million in place of a security deposit. As of March 31, 2023 , no amounts have been drawn on the letter of credit. The sublease accounting commencement date occurred in April 2023 and therefore no sublease income was recorded during the three months ended March 31, 2023 and no amounts were owed from the subtenant as of March 31, 2023.
Leases	Leases The Company’s operating lease activity is comprised of non-cancelable facility leases for office and laboratory space in Boston, Massachusetts. 6 Tide Street Lease The Company entered into an operating lease for office and laboratory space in Boston, Massachusetts in February 2020 (6 Tide Street Lease), and entered into subsequent amendments through 2023. The amendments run co-terminus with the existing lease. The Company has a total of 42,046 square feet licensed at this facility. The Company has the option to terminate the lease and amendments after November 30, 2023 without penalty. At the adoption of ASC 842, the Company concluded that it is not reasonably certain that it will exercise this option to terminate the lease early. In January 2023, the Company entered into an amendment to the 6 Tide Street Lease pursuant to which the Company will cease making lease payments for a portion of the leased space no later than November 30, 2023. The term for the remainder of the lease will end on November 30, 2025. Following the amendment, the fixed rental payment will be approximately $0.8 million per month through November 30, 2023, and $0.5 million per month after November 30, 2023. Subsequent to the amendment, the Company continues to classify the 6 Tide Street Lease as an operating lease. Upon the lease modification, the Company reassessed its incremental borrowing rate and remeasured the lease liability and right-of-use asset. In connection with entering into the 6 Tide Street Lease, the Company paid a security deposit of $0.8 million, of which $0.5 million is recorded as a component of other non-current assets and $0.3 million is recorded as a component of other current assets as of March 31, 2023. The components of operating lease cost were as follows (in thousands): Three Months Ended March 31, 2023 Operating lease cost $ 3,665 Variable lease cost — Total lease cost $ 3,665 Supplemental information related to operating leases was as follows: Other information Three Months Ended March 31, 2023 Operating cash flows used for operating leases (in thousands) $ 2,282 Weighted average remaining lease term 2.7 years Weighted average discount rate 7.95% Future payments due under operating leases as of March 31, 2023 were as follows (in thousands): Maturity of Lease Liability As of March 31, 2023 2023 (excluding the three-months ended March 31, 2023) 6,627 2024 5,741 2025 5,396 Thereafter — Total lease payments $ 17,764 Less: imputed interest (1,539) Present value of operating lease liabilities $ 16,225 IDB Lease On March 16, 2022, the Company and IDB 17-19 Drydock Limited Partnership, as landlord (Landlord), entered into a lease agreement (IDB Lease) with respect to approximately 81,229 square feet of office and laboratory space (Premises) in Boston, Massachusetts, which, when available for occupancy, will become the Company’s new consolidated headquarters location and supplement its existing space in Massachusetts. The term of the IDB Lease commences the date upon which the Landlord tenders possession of the Premises to the Company following the Landlord’s substantial completion of the initial build-out of the Premises (Commencement Date) and shall continue for a period of approximately 10 years, unless earlier terminated in accordance with the terms of the IDB Lease. The Company has (i) the option to extend the IDB Lease for an additional period of five (5) years, and (ii) a right of first offer on adjacent space to the Premises, subject to the terms and conditions of the IDB Lease. As these options are not reasonably certain of occurring, they will not be included in the initial calculation of the Company's right-of-use asset upon lease commencement. The initial fixed rental rate is $0.5 million per month, which is for a 12 month period during which the base rent is payable for 65,000 square feet, and will increase 3% per annum thereafter for the entire 81,229 square feet leased. Base rent becomes due upon the earlier of (i) the Company’s occupancy of the Premises for use in its regular operations, or (ii) 10 months following the Commencement Date, provided that in the event the Landlord’s build-out of the Premises is not complete on such date, base rent becomes due upon substantial completion of such build-out. Under the terms of the IDB Lease, the Landlord will provide an allowance in an amount not to exceed $19.5 million (calculated at a rate of $240.00 per rentable square foot of the Premises) toward the cost of completing tenant improvements for the Premises. In addition, the Company has the right to require the Landlord to provide an additional contribution in an amount not to exceed $1.6 million (calculated at a rate of $20.00 per rentable square foot of the Premises) toward the cost of tenant improvements to the Premises, which amount shall be repaid by the Company in an amount of equal monthly payments of principal and interest as would be necessary to repay a loan in the full amount of the additional contribution used by the Company, subject to an 8% annual interest charge, on a level direct reduction basis over a 120 month period. The Company will be required to pay its share of operating expenses, taxes and any other expenses payable under the IDB Lease. In connection with the execution of the IDB Lease, the Company executed a cash-collateralized letter of credit, which may be reduced in the future subject to reduction requirements specified in the IDB Lease therein. The cash collateralizing the letter of credit is classified as restricted cash on the Company's condensed consolidated balance sheets. The Company concluded that the improvements resulting from both the Landlord's build-out and the tenant improvements are the Landlord's assets for accounting purposes. Costs incurred by the Company related to the tenant improvements up to the Landlord's allowance are pass-through costs and will be reimbursed. Costs incurred by the Company related to the tenant improvements in excess of the Landlord's allowance will be treated as prepaid rent and will increase the right-of-use asset upon occurrence of the accounting commencement date. As of March 31, 2023, the Company had incurred $21.2 million of refundable pass-through costs, of which $14.4 million was reimbursed by the Landlord as of March 31, 2023 , and $13.3 million of prepaid rent amounts. Net pass-through cost associated with the IDB Lease are included in other current assets as the Company expects to receive the remaining reimbursement for such costs in the next 12 months. Prepaid rent amounts associated with the IDB Lease are included in other non-current assets. The accounting commencement date occurred in April 2023 when both the Landlord's build-out and the tenant improvements were substantially completed. As the accounting commencement date had not occurred as of March 31, 2023, the IDB Lease is excluded from the table above. IDB Sublease In December 2022, the Company entered into a sublease agreement to sublease a portion of the office and laboratory space leased under the IDB Lease to a third-party (subtenant). The sublease term is 3 years and the subtenant has an option to extend the lease term for 6 months. The initial fixed rental rate is approximately $0.2 million per month, and will increase 3% per annum thereafter. The sublessee is obligated to pay its ratable portion of operating expenses during the sublease term. The Company received a letter of credit of $0.5 million in place of a security deposit. As of March 31, 2023 , no amounts have been drawn on the letter of credit. The sublease accounting commencement date occurred in April 2023 and therefore no sublease income was recorded during the three months ended March 31, 2023 and no amounts were owed from the subtenant as of March 31, 2023.

Collaboration and License Agree

Collaboration and License Agreements	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Collaboration and License Agreements	Collaboration and License Agreements Vertex Agreement - Overview In February 2023, the Company and Vertex closed the Vertex Agreement pursuant to which the Company granted Vertex an exclusive worldwide license to research, develop, manufacture and commercialize ENTR-701, the Company’s intracellular Endosomal Escape Vehicle (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. The Vertex Agreement provides for a four-year global research collaboration under which Entrada will continue to perform pre-clinical development of the Company's partnered candidate ENTR-701 pursuant to the mutually agreed-upon research plan (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 a separate but simultaneously executed stock purchase agreement. The Company will be 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. 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 ENTR-701 (the Research Services). The Company concluded that the license is not distinct from the research and development services for ENTR-701 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. These customer options will be accounted for as separate contracts for accounting purposes upon Vertex's election. At the commencement of the arrangement, the Vertex Agreement has 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. To determine the fair value of the common stock issued to Vertex, the Company utilized the fair value of the Company’s common stock as of the effective date of the Vertex Agreement and applied a discount for lack of marketability. 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. Additional consideration to be paid to the Company upon reaching certain milestones are excluded from the transaction price as they are fully constrained as the Company concluded that they are not probable of being achieved as of March 31, 2023. 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. The transaction price is fully allocated to the one performance obligation. The Company recognizes revenue associated with the performance obligation as the research and development services are provided using an input method, according to the costs incurred as related to the research services and the costs expected to be incurred in the future to satisfy the performance obligation in accordance with the 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 obligation. As the Company progresses towards satisfaction of performance obligations under the Vertex Agreement, the estimated costs associated with the remaining effort required to complete the performance obligation in accordance with the research plan 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 obligation under the Vertex Agreement. 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 obligation has not been fully satisfied as of March 31, 2023. During the three months ended March 31, 2023, the Company recognized $25.3 million in revenue under the Vertex Agreement including $4.9 million in cost reimbursements and $20.4 million from amounts that were recorded in deferred revenue at inception of the agreement. The aggregate amount of the transaction price allocated to the Company’s unsatisfied performance obligation and recorded in deferred revenue at March 31, 2023 is $211.6 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 research plan.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2023 2022 Numerator: Net loss attributable to common stockholders $ (6,674) $ (21,671) Denominator: Weighted‑average common shares outstanding, basic and diluted 32,374,299 31,246,916 Net loss per share attributable to common stockholders, basic and diluted $ (0.21) $ (0.69) The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net 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, 2023 2022 Unvested restricted common stock 671,308 297,754 Unvested shares from early exercises 43,588 96,532 Stock options to purchase common stock 5,349,166 4,412,667 6,064,062 4,806,953

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsThe 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
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 Accounting Standards Codification (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, 2023, and results of operations for the interim periods ended March 31, 2023 and 2022 . 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, 2022 and 2021, and the notes thereto, included in the Company’s Annual Report.
Revenue Recognition	The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements (“ASC 808”) to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of ASC 808 and those that are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, generally by analogy to Topic 606. For those elements of the arrangement that are accounted for pursuant to Topic 606, the Company applies the five-step model described below.
Revenue Recognition	To date all revenue has been generated from the Company's Strategic Collaboration and License Agreement (the Vertex Agreement) with Vertex Pharmaceuticals Incorporated (Vertex) which closed in February 2023 and falls within the scope of ASC Topic 606, "Revenue from Contracts with Customers" (“ASC 606”), under which the Company licensed rights to ENTR-701 and performs research and development services. The terms of this arrangement includes a non-refundable upfront payment, reimbursement for research and development costs; development, regulatory, and commercial milestone payments; and royalties on net sales of licensed products. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer. For contracts within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations. Arrangements that include rights to additional goods or services that are exercisable at a customer’s discretion are generally considered options. The Company assesses if these options provide a material right to the customer and if so, they are considered separate performance obligations. The identification of material rights requires judgments related to the determination of the value of the underlying license relative to the option exercise price, including assumptions about technical feasibility and the probability of developing a candidate that would be subject to the option rights. The exercise of a material right is accounted for as a contract modification for accounting purposes. The Company assesses whether each promised good or service is distinct for the purpose of identifying the performance obligations in the contract. This assessment involves subjective determinations and requires management to make judgments about the individual promised goods or services and whether such promised goods or services are separable from the other aspects of the contractual relationship. Promised goods and services are considered distinct provided that: (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (that is, the good or service is capable of being distinct) and (ii) the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (that is, the promise to transfer the good or service is distinct within the context of the contract). In assessing whether a promised good or service is distinct, the Company considers factors such as the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. The Company also considers the intended benefit of the contract in assessing whether a promised good or service is separately identifiable from other promises in the contract. If a promised good or service is not distinct, an entity is required to combine that good or service with other promised goods or services until it identifies a bundle of goods or services that is distinct. The transaction price is then determined and allocated to the identified performance obligations in proportion to their standalone selling prices (SSP) on a relative SSP basis. SSP is determined at contract inception and is not updated to reflect changes between contract inception and when the performance obligations are satisfied. Determining the SSP for performance obligations may require significant judgment. In developing the SSP for a performance obligation, the Company considers applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer and estimated costs. The Company validates the SSP for performance obligations by evaluating whether changes in the key assumptions used to determine the SSP will have a significant effect on the allocation of arrangement consideration between multiple performance obligations. If the consideration promised in a contract includes a variable amount, the Company estimates the amount of consideration to which it will be entitled in exchange for transferring the promised goods or services to a customer. The Company determines the amount of variable consideration by using the expected value method or the most likely amount method. The Company includes the unconstrained amount of estimated variable consideration in the transaction price. The amount included in the transaction price is constrained to the amount for which it is probable that a significant reversal of cumulative revenue recognized will not occur. At the end of each subsequent reporting period, the Company re-evaluates the estimated variable consideration included in the transaction price and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis in the period of adjustment. If an arrangement includes development and regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or a customer's control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. For arrangements with licenses of intellectual property that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes royalty revenue and sales-based milestones at the later of (i) when the related sales occur, or (ii) when the performance obligation to which the royalty has been allocated has been satisfied. Up-front and milestone payments are recorded as deferred revenue upon receipt or when due until the Company performs its obligations under these arrangements. Amounts are recorded as a collaboration receivable when the Company's right to consideration is unconditional. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) each performance obligation is satisfied, either at a point in time or over time, and if over time recognition is based on the use of an output or input method.
Recently Adopted Accounting Pronouncements	In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU requires that credit losses for financial instruments measured at amortized cost be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2023
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 $ 227,648 $ 45,157 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 231,598 $ 49,107
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 $ 227,648 $ 45,157 Restricted cash 3,950 3,950 Total cash, cash equivalents and restricted cash $ 231,598 $ 49,107

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-sale	The following are summaries of the Company's marketable securities at March 31, 2023 and December 31, 2022 (in thousands). March 31, 2023 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 79,580 $ 65 $ (605) $ 79,040 Corporate debt securities 45,996 2 (593) 45,405 Total securities with a maturity of one year or less $ 125,576 $ 67 $ (1,198) $ 124,445 U.S. government agency securities and treasuries 49,960 439 — 50,399 Corporate debt securities 9,089 50 — 9,139 Total securities with a maturity of more than one year $ 59,049 $ 489 $ — $ 59,538 Total available-for-sale securities $ 184,625 $ 556 $ (1,198) $ 183,983 December 31, 2022 Amortized Cost Unrealized Gains Unrealized Losses Fair Value U.S. government agency securities and treasuries $ 100,555 $ — $ (1,159) $ 99,396 Corporate debt securities 41,615 — (774) 40,841 Total securities with a maturity of one year or less $ 142,170 $ — $ (1,933) $ 140,237 U.S. government agency securities and treasuries — — — — Corporate debt securities 3,442 — (124) 3,318 Total securities with a maturity of more than one year $ 3,442 $ — $ (124) $ 3,318 Total available-for-sale securities $ 145,612 $ — $ (2,057) $ 143,555

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
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, 2023 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 227,321 $ — $ — $ 227,321 Marketable securities: U.S. government agency securities and treasuries — 129,439 — 129,439 Corporate bonds — 54,544 — 54,544 Total $ 227,321 $ 183,983 $ — $ 411,304 Fair Value Measurements at December 31, 2022 Level 1 Level 2 Level 3 Total Cash equivalents: (1) Money market funds $ 44,907 $ — $ — $ 44,907 Marketable securities: U.S. government agency securities and treasuries $ — $ 99,396 $ — $ 99,396 Corporate bonds — 44,159 — 44,159 Total $ 44,907 $ 143,555 $ — $ 188,462 (1) The cash equivalent amounts above do not include $0.3 million of cash related to checking accounts included in cash and cash equivalents as of March 31, 2023 and December 31, 2022. These amounts are excluded as no valuation is needed for cash in checking accounts

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and equipment, Net	Property and equipment, net consisted of the following at March 31, 2023 and December 31, 2022 (in thousands): March 31, December 31, Laboratory equipment $ 8,512 $ 8,335 Furniture and fixtures 161 161 Computer equipment 43 43 Leasehold improvements 1,859 1,859 Construction in progress 2,659 584 Total property and equipment 13,234 10,982 Less: accumulated depreciation (3,840) (3,301) Property and equipment, net $ 9,394 $ 7,681

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2023
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, 2023 and December 31, 2022 (in thousands): March 31, December 31, Employee compensation and benefits $ 2,049 $ 5,063 External research and development expenses 4,057 1,157 General and administrative professional service expenses 837 925 Accrued income tax liability 3,551 — Other 1,182 431 Total accrued expenses and other current liabilities $ 11,676 $ 7,576

Common Stock and Preferred St_2

Common Stock and Preferred Stock (Tables)	3 Months Ended
	Mar. 31, 2023
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 5,349,166 5,028,850 Vesting of outstanding restricted stock 671,308 463,964 Future awards under the 2021 Stock Option and Incentive Plan 2,596,835 1,976,758 Future awards under the 2021 Employee Stock Purchase Plan 877,600 563,115 Total shares of authorized common stock reserved for future issuance 9,494,909 8,032,687

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
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, 2023 2022 Research and development expenses $ 1,298 $ 704 General and administrative expenses 1,457 1,090 Total $ 2,755 $ 1,794
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, 2023 and 2022: March 31, March 31, Risk‑free interest rate 4.13 % 1.61 % Expected volatility 71 % 70 % Expected dividend yield — — Expected term (in years) 6.08 6.06
Summary of the stock option activity	The following table summarizes the Company’s stock option activity during the three months ended March 31, 2023: Number of Weighted‑ Outstanding as of December 31, 2022 5,028,850 $ 10.95 Granted 350,396 12.24 Exercised (18,344) 6.39 Forfeited (11,736) 13.69 Outstanding as of March 31, 2023 5,349,166 $ 11.04 Exercisable as of March 31, 2023 (1) 2,878,389 $ 8.37 (1) This represents the number of vested and unvested options exercisable as of March 31, 2023.
Summary of unvested restricted stock	A summary of restricted stock activity during the three months ended March 31, 2023 is as follows : Shares Weighted‑ Unvested as of December 31, 2022 463,964 $ 12.26 Issued 303,262 $ 12.25 Vested (91,859) $ 11.57 Forfeited (4,059) $ 12.06 Unvested as of March 31, 2023 671,308 $ 12.35

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Leases [Abstract]
Lease, Cost	The components of operating lease cost were as follows (in thousands): Three Months Ended March 31, 2023 Operating lease cost $ 3,665 Variable lease cost — Total lease cost $ 3,665 Supplemental information related to operating leases was as follows: Other information Three Months Ended March 31, 2023 Operating cash flows used for operating leases (in thousands) $ 2,282 Weighted average remaining lease term 2.7 years Weighted average discount rate 7.95%
Lessee, Operating Lease, Liability, Maturity	Future payments due under operating leases as of March 31, 2023 were as follows (in thousands): Maturity of Lease Liability As of March 31, 2023 2023 (excluding the three-months ended March 31, 2023) 6,627 2024 5,741 2025 5,396 Thereafter — Total lease payments $ 17,764 Less: imputed interest (1,539) Present value of operating lease liabilities $ 16,225

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of basic and diluted net loss per share attributable to common stockholders	Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended March 31, 2023 2022 Numerator: Net loss attributable to common stockholders $ (6,674) $ (21,671) Denominator: Weighted‑average common shares outstanding, basic and diluted 32,374,299 31,246,916 Net loss per share attributable to common stockholders, basic and diluted $ (0.21) $ (0.69)
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 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, 2023 2022 Unvested restricted common stock 671,308 297,754 Unvested shares from early exercises 43,588 96,532 Stock options to purchase common stock 5,349,166 4,412,667 6,064,062 4,806,953

Nature of the Business (Details

Nature of the Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net loss	$ (6,674)	$ (21,671)
Accumulated deficit	194,959		$ 188,285
Cash, cash equivalents, and short-term investments	$ 411,600

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 227,648	$ 45,157
Restricted cash	3,950	3,950
Total cash, cash equivalents and restricted cash	$ 231,598	$ 49,107	$ 88,590	$ 291,064

Marketable Securities - Amortiz

Marketable Securities - Amortized Cost (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale, Amortized Cost [Abstract]
Amortized Cost	$ 125,576	$ 142,170
Total securities with a maturity of more than one year	59,049	3,442
Total available-for-sale securities	184,625	145,612
Unrealized Gains (Losses)
Unrealized Gains	556	0
Unrealized Losses	(1,198)	(2,057)
Fair Value
Total securities with a maturity of one year or less	124,445	140,237
Total securities with a maturity of more than one year	59,538	3,318
Total available-for-sale securities	183,983	143,555
One Year or Less
Unrealized Gains (Losses)
Unrealized Gains	67	0
Unrealized Losses	(1,198)	(1,933)
One to Two Years
Unrealized Gains (Losses)
Unrealized Gains	489	0
Unrealized Losses	0	(124)
U.S. government agency securities and treasuries
Debt Securities, Available-for-Sale, Amortized Cost [Abstract]
Amortized Cost	79,580	100,555
Total securities with a maturity of more than one year	49,960	0
Fair Value
Total securities with a maturity of one year or less	79,040	99,396
Total securities with a maturity of more than one year	50,399	0
U.S. government agency securities and treasuries | One Year or Less
Unrealized Gains (Losses)
Unrealized Gains	65	0
Unrealized Losses	(605)	(1,159)
U.S. government agency securities and treasuries | One to Two Years
Unrealized Gains (Losses)
Unrealized Gains	439	0
Unrealized Losses	0	0
Corporate debt securities
Debt Securities, Available-for-Sale, Amortized Cost [Abstract]
Amortized Cost	45,996	41,615
Total securities with a maturity of more than one year	9,089	3,442
Fair Value
Total securities with a maturity of one year or less	45,405	40,841
Total securities with a maturity of more than one year	9,139	3,318
Corporate debt securities | One Year or Less
Unrealized Gains (Losses)
Unrealized Gains	2	0
Unrealized Losses	(593)	(774)
Corporate debt securities | One to Two Years
Unrealized Gains (Losses)
Unrealized Gains	50	0
Unrealized Losses	$ 0	$ (124)

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) $ in Thousands	Mar. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Number of securities | security	23
Market value of marketable securities	$ 95,200
Allowance for credit loss	0
Interest receivable	900	$ 600
Fair Value, Recurring
Schedule of Held-to-maturity Securities [Line Items]
Money market funds	227,321	44,907
Level 2 | Fair Value, Recurring
Schedule of Held-to-maturity Securities [Line Items]
Money market funds	$ 0	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities:	$ 183,983	$ 143,555
Cash	300	300
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	227,321	44,907
Total	411,304	188,462
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	227,321	44,907
Total	227,321	44,907
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Total	183,983	143,555
Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0	0
Total	0	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:	129,439	99,396
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:	129,439	99,396
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:	54,544	44,159
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:	54,544	44,159
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, 2023	Mar. 31, 2022	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 13,234		$ 10,982
Less: accumulated depreciation	(3,840)		(3,301)
Property and equipment, net	9,394		7,681
Depreciation expense	541	$ 390
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,512		8,335
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	161		161
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	43		43
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,859		1,859
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,659		$ 584

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accrued Expenses and Other Current Liabilities [Abstract]
Employee compensation and benefits	$ 2,049	$ 5,063
External research and development expenses	4,057	1,157
General and administrative professional service expenses	837	925
Accrued income tax liability	3,551	0
Other	1,182	431
Total accrued expenses and other current liabilities	$ 11,676	$ 7,576

Common Stock and Preferred St_3

Common Stock and Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
	Feb. 28, 2023	Mar. 31, 2023	Dec. 31, 2022
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
Shares of common stock reserved for issuance (in shares)		9,494,909	8,032,687
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
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 (usd per share)	$ 16.26
2021 Plan
Class of Stock
Shares of common stock reserved for issuance (in shares)		2,596,835	1,976,758
Exercise of outstanding stock options
Class of Stock
Shares of common stock reserved for issuance (in shares)		5,349,166	5,028,850
Restricted Stock
Class of Stock
Shares of common stock reserved for issuance (in shares)		671,308	463,964
Future awards under the 2021 Employee Stock Purchase Plan
Class of Stock
Shares of common stock reserved for issuance (in shares)		877,600	563,115

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Stock-based compensation
Vesting of early exercised options (in shares)	43,588		53,741
Unvested early exercises of stock options	$ 0.2		$ 0.2
Future awards under the 2021 Employee Stock Purchase Plan
Stock-based compensation
Stock authorized for issuance (in shares)	877,600		563,115
Stock options to purchase common stock
Stock-based compensation
Weighted-average grant-date fair value of stock options granted (in dollars per share)	$ 8.17	$ 7.39
Unrecognized compensation cost	$ 25.2
Unrecognized compensation cost, weighted-average period for recognition	2 years 8 months 15 days
Restricted Stock
Stock-based compensation
Unrecognized compensation cost	$ 7.8
Unrecognized compensation cost, weighted-average period for recognition	3 years 5 months 1 day
2021 Plan
Stock-based compensation
Stock authorized for issuance (in shares)	6,425,669		5,262,917
2016 Stock Plan
Stock-based compensation
Stock authorized for issuance (in shares)	2,191,640		2,206,655

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Stock-based compensation
Share-based compensation expense	$ 2,755	$ 1,794
Research and development expenses
Stock-based compensation
Share-based compensation expense	1,298	704
General and administrative expenses
Stock-based compensation
Share-based compensation expense	$ 1,457	$ 1,090

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Valuation (Details) - Stock options to purchase common stock	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Assumptions used to determine the fair value of stock options granted
Risk‑free interest rate	4.13%	1.61%
Expected volatility	71%	70%
Expected dividend yield	0%	0%
Expected term (in years)	6 years 29 days	6 years 21 days

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock option activity (Details)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Number of Shares
Outstanding at beginning of period (in shares) | shares	5,028,850
Granted (in shares) | shares	350,396
Exercised (in shares) | shares	(18,344)
Forfeited (in shares) | shares	(11,736)
Outstanding at end period (in shares) | shares	5,349,166
Exercisable (in shares) | shares	2,878,389
Weighted Average Exercise Price
Outstanding at beginning period (in dollars per share) | $ / shares	$ 10.95
Granted (in dollars per share) | $ / shares	12.24
Exercised (in dollars per share) | $ / shares	6.39
Forfeited (in dollars per share) | $ / shares	13.69
Outstanding at end period (in dollars per share) | $ / shares	11.04
Exercisable (in dollars per share) | $ / shares	$ 8.37

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards (Details) - Restricted Stock	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Shares
Unvested balance, at beginning of period (in shares) | shares	463,964
Issued (in shares) | shares	303,262
Vested (in shares) | shares	(91,859)
Forfeited (in shares) | shares	(4,059)
Unvested balance, at end of period (in shares) | shares	671,308
Weighted- Average Grant -Date Fair Value
Beginning of period (in dollars per share) | $ / shares	$ 12.26
Issued (in dollars per share) | $ / shares	12.25
Vested (in dollars per share) | $ / shares	11.57
Forfeited (in dollars per share) | $ / shares	12.06
End of period (in dollars per share) | $ / shares	$ 12.35

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Provision for income taxes	$ (3,551)	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Mar. 31, 2023 USD ($)
License agreement with a third-party
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Potential milestone payment obligation	$ 2.8

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions		1 Months Ended	12 Months Ended	24 Months Ended
	Mar. 16, 2022 USD ($) sqft $ / sqft	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Nov. 30, 2025 USD ($)	Mar. 31, 2023 USD ($) sqft
Lessee, Lease, Description [Line Items]
Number of square feet | sqft	65,000
Fixed rental payments			$ 0.5
Security deposit					$ 0.8
Term of contract	10 years
Lease term	5 years
Fixed monthly rental payments	$ 0.5
Rental expenses annual increase	3%
Tenant improvements allowance	$ 19.5
Calculated rentable square foot of premises | $ / sqft	240
Operating leases additional allowance	$ 1.6
Tenant allowance rentable square foot of premises per annum | $ / sqft	20
Interest rate for additional improvements allowance	8%
Level direct reduction basis, term	120 months
Refundable pass-through costs					21.2
Pass-through costs reimbursed by landlord					14.4
Prepaid rent					13.3
Sublease term		3 years	3 years
Lease term extension		6 months
Sublease income		$ 0.2
Sublease fixed rental rate, percentage increase per annum		3%
Letter of credit received in place of a security deposit		$ 0.5	$ 0.5
Forecast
Lessee, Lease, Description [Line Items]
Fixed rental payments				$ 0.8
Other Noncurrent Assets
Lessee, Lease, Description [Line Items]
Security deposit					0.5
Other Current Assets
Lessee, Lease, Description [Line Items]
Security deposit					$ 0.3
Massachusetts
Lessee, Lease, Description [Line Items]
Number of square feet | sqft					42,046
Massachusetts | IDB
Lessee, Lease, Description [Line Items]
Number of square feet | sqft	81,229

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Leases [Abstract]
Operating lease cost	$ 3,665
Variable lease cost	0
Total lease cost	$ 3,665

Leases - Cash flow information

Leases - Cash flow information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Leases [Abstract]
Operating cash flows used for operating leases (in thousands)	$ 2,282
Weighted average remaining lease term	2 years 8 months 12 days
Weighted average discount rate	7.95%

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Maturity of Lease Liability
2023 (excluding the three-months ended March 31, 2023)	$ 6,627
2024	5,741
2025	5,396
Thereafter	0
Total lease payments	17,764
Less: imputed interest	(1,539)
Present value of operating lease liabilities	$ 16,225

Collaboration and License Agr_2

Collaboration and License Agreements (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 28, 2023	Mar. 31, 2023	Mar. 31, 2022
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Strategic collaboration agreement, term	4 years
Revenue from contract with customer		$ 25,260	$ 0
Vertex
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from contract with customer		4,900
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
Vertex | License
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Up-front payment	$ 223,700
Premium	6,900
Consideration amount	485,000
Revenue, remaining performance obligation, amount	$ 232,000	211,600
Revenue from contract with customer		25,300
Agreement deferred revenue		$ 20,400

Net Loss per Share - Computatio

Net Loss per Share - Computation of EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net loss attributable to common stockholders	$ (6,674)	$ (21,671)
Denominator:
Weighted-average common shares outstanding, basic (in shares)	32,374,299	31,246,916
Weighted-average common shares outstanding, diluted (in shares)	32,374,299	31,246,916
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.21)	$ (0.69)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.21)	$ (0.69)

Net Loss per Share - Antidiluti

Net Loss per Share - Antidilutive securities (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net Loss per Share
Antidilutive securities excluded from common stock (in shares)	6,064,062	4,806,953
Unvested restricted common stock
Net Loss per Share
Antidilutive securities excluded from common stock (in shares)	671,308	297,754
Unvested shares from early exercises
Net Loss per Share
Antidilutive securities excluded from common stock (in shares)	43,588	96,532
Stock options to purchase common stock
Net Loss per Share
Antidilutive securities excluded from common stock (in shares)	5,349,166	4,412,667