Form 10-Q - Quarterly report [Sections 13 or 15(d)]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q


☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2025


☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 001-39319

GENERATION BIO CO.

(Exact name of registrant as specified in its charter)



Delaware		81-4301284
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification Number)

301 Binney Street Cambridge, Massachusetts		02142
(Address of principal executive offices)		(Zip Code)

(617) 655-7500

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:



Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, $0.0001 Par Value	GBIO	Nasdaq Global Select Market

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.



Large accelerated filer	☐	Accelerated filer	☐

Non-accelerated filer	☒	Smaller reporting company	☒

		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of April 30, 2025 there were 67,035,236 shares of Common Stock, $0.0001 par value per share, outstanding.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q, or this Quarterly Report, of Generation Bio Co. contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that involve substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this Quarterly Report, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans and objectives of management, are forward-looking statements. The words “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” or the negative of these words or other similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

The forward-looking statements in this Quarterly Report include, among other things, statements about:

●

our estimates regarding expenses, future revenue, capital requirements, need for additional financing and the period over which we believe that our existing cash, cash equivalents and marketable securities will be sufficient to fund our operating expenses and capital expenditure requirements;

●

the potential achievement of milestones and receipt of payments under our collaboration with ModernaTX, Inc., or Moderna;

●

the potential advantages of our technologies;

●

the initiation, timing, progress and results of our research and development programs and preclinical studies and clinical trials;

●

the timing of and our ability to submit applications and obtain and maintain regulatory approvals for any product candidates we may develop;

●

our plans to develop and, if approved, subsequently commercialize any product candidates we may develop;

●

our commercialization, marketing and manufacturing capabilities and strategy;

●

our expectations regarding our ability to obtain and maintain intellectual property protection;

●

our intellectual property position;

●

our ability to identify additional products, product candidates or technologies with significant commercial potential that are consistent with our commercial objectives;

●

the impact of government laws and regulations;

●

our competitive position and expectations regarding developments and projections relating to our competitors and any competing therapies that are or may become available; and

●

our ability to maintain and establish collaborations or obtain additional funding.

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and stockholders should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important factors in the cautionary statements included in this Quarterly Report, particularly in the “Risk Factors” section in this Quarterly Report and our most recent Annual Report on Form 10-K, or our 2024 Annual Report, filed with the Securities and Exchange Commission, or SEC, that we believe could cause actual results or events to differ materially

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from the forward-looking statements that we make. Moreover, we operate in a competitive and rapidly changing environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, collaborations, joint ventures, or investments we may make or enter into.

Stockholders should read this Quarterly Report and the documents that we file with the SEC with the understanding that our actual future results may be materially different from what we expect. The forward-looking statements contained in this Quarterly Report are made as of the date of this Quarterly Report, and we do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by applicable law.

Except where the context otherwise requires or where otherwise indicated, the terms “we,” “us,” “our,” “our company,” “the company,” and “our business” in this Quarterly Report refer to Generation Bio Co. and its consolidated subsidiary.

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Generation Bio Co.

INDEX

		Page(s)
PART I – FINANCIAL INFORMATION
Item 1.	Financial Statements (unaudited)	5
	Condensed Consolidated Balance Sheets	5
	Condensed Consolidated Statements of Operations and Comprehensive Loss	6
	Condensed Consolidated Statements of Stockholders’ Equity	7
	Condensed Consolidated Statements of Cash Flows	8
	Notes to Condensed Consolidated Financial Statements	9
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	21
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	31
Item 4.	Controls and Procedures	31
PART II – OTHER INFORMATION
Item 1.	Legal Proceedings	32
Item 1A.	Risk Factors	32
Item 5.	Other Information	32
Item 6.	Exhibits	33
	Signatures	34

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PART I—FINANCIAL INFORMATION

Item 1. Financial Statements (unaudited)

Generation Bio Co.

Condensed Consolidated Balance Sheets

(In thousands, except share and per share amounts)

(Unaudited)


	March 31,		December 31,
	2025		2024
Assets
Current assets:
Cash and cash equivalents	$	50,891	$	76,301
Marketable securities		106,668		108,922
Collaboration receivable		1,392		1,224
Prepaid expenses and other current assets		6,168		6,456
Total current assets		165,119		192,903
Property and equipment, net		14,432		15,293
Operating lease right-of-use assets		19,375		20,310
Restricted cash		2,152		2,152
Other long-term assets		270		539
Total assets	$	201,348	$	231,197
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	2,262	$	1,408
Accrued expenses and other current liabilities		5,765		10,059
Deferred revenue		2,107		10,582
Operating lease liabilities		9,463		13,006
Total current liabilities		19,597		35,055
Deferred revenue, net of current portion		30,305		29,161
Operating lease liabilities, net of current portion		78,114		80,554
Other liabilities, net of current portion		—		223
Total liabilities		128,016		144,993
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 5,000,000 shares authorized and no shares issued or outstanding at March 31, 2025 and December 31, 2024		—		—
Common stock, $0.0001 par value; 150,000,000 shares authorized at March 31, 2025 and December 31, 2024; 67,008,511 and 66,971,977 shares issued and outstanding at March 31, 2025 and December 31, 2024, respectively		7		7
Additional paid-in capital		791,087		789,083
Accumulated other comprehensive income		85		159
Accumulated deficit		(717,847)		(703,045)
Total stockholders’ equity		73,332		86,204
Total liabilities and stockholders’ equity	$	201,348	$	231,197

The accompanying notes are an integral part of these condensed consolidated financial statements.

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Generation Bio Co.

Condensed Consolidated Statements of Operations and Comprehensive Loss

(In thousands, except share and per share amounts)

(Unaudited)


	Three Months Ended March 31,
	2025		2024
Revenues:
Collaboration revenue	$	8,723	$	4,059
Operating expenses:
Research and development		15,357		14,335
General and administrative		8,834		10,428
Loss on lease termination		1,138		56,930
Total operating expenses		25,329		81,693
Loss from operations		(16,606)		(77,634)
Other income:
Other income and interest income, net		1,804		3,093
Net loss	$	(14,802)	$	(74,541)
Net loss per share, basic and diluted	$	(0.22)	$	(1.12)
Weighted average common shares outstanding, basic and diluted		67,002,511		66,433,640

Comprehensive loss:
Net loss	$	(14,802)	$	(74,541)
Other comprehensive loss:
Unrealized losses on marketable securities		(74)		(471)
Comprehensive loss	$	(14,876)	$	(75,012)

The accompanying notes are an integral part of these condensed consolidated financial statements.

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Generation Bio Co.

Condensed Consolidated Statements of Stockholders’ Equity

(In thousands, except share amounts)

(Unaudited)


						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholders’
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity
Balances at December 31, 2024	66,971,977	$	7	$	789,083	$	159	$	(703,045)	$	86,204
Vesting of restricted common stock	36,534		—		(7)		—		—		(7)
Stock-based compensation expense	—		—		2,011		—		—		2,011
Unrealized losses on marketable securities	—		—		—		(74)		—		(74)
Net loss	—		—		—		—		(14,802)		(14,802)
Balances at March 31, 2025	67,008,511	$	7	$	791,087	$	85	$	(717,847)	$	73,332


						Accumulated
				Additional		Other				Total
	Common Stock			Paid-in		Comprehensive		Accumulated		Stockholders’
	Shares	Amount		Capital		Income (Loss)		Deficit		Equity
Balances at December 31, 2023	66,205,550	$	7	$	774,224	$	274	$	(571,377)	$	203,128
Vesting of restricted common stock	273,550		—		(125)		—		—		(125)
Stock-based compensation expense	—		—		4,000		—		—		4,000
Unrealized losses on marketable securities	—		—		—		(471)		—		(471)
Net loss	—		—		—		—		(74,541)		(74,541)
Balances at March 31, 2024	66,479,100	$	7	$	778,099	$	(197)	$	(645,918)	$	131,991

The accompanying notes are an integral part of these condensed consolidated financial statements.

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Generation Bio Co.

Condensed Consolidated Statements of Cash Flows

(In thousands)

(Unaudited)


	Three Months Ended March 31,
	2025		2024
Cash flows from operating activities:
Net loss	$	(14,802)	$	(74,541)
Adjustments to reconcile net loss to net cash used in operating activities:
Loss on lease termination		1,138		56,930
Stock-based compensation expense		2,011		4,000
Depreciation and amortization expense		1,136		1,312
Accretion of discount on marketable securities, net		(993)		(2,328)
Other		2		(7)
Changes in operating assets and liabilities:
Collaboration receivable		(168)		—
Prepaid expenses and other current assets		469		(878)
Operating lease right-of-use assets		935		1,050
Other noncurrent assets		269		13
Accounts payable		643		(242)
Accrued expenses and other current liabilities		(4,319)		(10,032)
Deferred revenue		(7,331)		(4,059)
Other noncurrent liabilities		(223)		—
Operating lease liabilities		(7,127)		(2,915)
Net cash used in operating activities		(28,360)		(31,697)
Cash flows from investing activities:
Purchases of property and equipment		(246)		(1,918)
Proceeds from sale of property and equipment		30		—
Purchases of marketable securities		(41,827)		(86,635)
Maturities of marketable securities		45,000		88,000
Net cash provided by (used in) investing activities		2,957		(553)
Cash flows from financing activities:
Tax withholding payments related to net share settlements of restricted stock units		(7)		(125)
Net cash used in financing activities		(7)		(125)
Net decrease in cash, cash equivalents and restricted cash		(25,410)		(32,375)
Cash, cash equivalents and restricted cash at beginning of period		78,453		72,237
Cash, cash equivalents and restricted cash at end of period	$	53,043	$	39,862
Supplemental disclosure of noncash investing and financing information:
Purchases of property and equipment included in accounts payable and accrued expenses	$	420	$	—
Unrealized losses on marketable securities	$	(74)	$	(471)

Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	$	50,891	$	35,526
Restricted cash (included in current assets)		—		2,184
Restricted cash (included in non-current assets)		2,152		2,152
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$	53,043	$	39,862

The accompanying notes are an integral part of these condensed consolidated financial statements.

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Generation Bio Co.

Notes to Condensed Consolidated Financial Statements

(Unaudited)

1. Nature of the Business and Basis of Presentation

Generation Bio Co., or Generation Bio, was incorporated on October 21, 2016 as Torus Therapeutics, Inc. and subsequently changed its name to Generation Bio Co. Generation Bio Co. and its consolidated subsidiary, or the company, we, our or us, are working to change what’s possible for people living with T cell-driven autoimmune diseases. Our strategy is to discover, develop, and commercialize redosable therapeutics that reprogram T cells in vivo to reduce or eliminate the production and persistence of autoreactive T cells, which erroneously recognize and attack the body’s own tissues, causing autoimmune disease. We are leveraging our cell-targeted lipid nanoparticle, or ctLNP, to selectively deliver small interfering RNA, or siRNA, to T cells, and we believe that the combination of selective delivery and an intracellular, genetically precise mechanism of target engagement unlocks a series of high-value historically undruggable disease-driving genes in autoimmunity. We are headquartered in Cambridge, Massachusetts.

We are subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations, the ability to establish clinical- and commercial-scale manufacturing processes and the ability to secure additional capital to fund operations. Programs currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization of a product. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if our development efforts are successful, it is uncertain when, if ever, we will realize significant revenue from product sales.

The accompanying condensed consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, we have funded our operations with proceeds from the sale of instruments convertible into convertible preferred stock, sales of convertible preferred stock, and sales of common stock in underwritten public offerings, “at-the-market” offerings, and in a private placement, as well as collaboration revenue under our collaboration with ModernaTX, Inc., or Moderna. We have incurred recurring losses, including net losses of $14.8 million for the three months ended March 31, 2025 and $74.5 million for the three months ended March 31, 2024. As of March 31, 2025 we had an accumulated deficit of $717.8 million. We expect to continue to generate operating losses in the foreseeable future. As of the issuance date of these condensed consolidated financial statements, we expect that our cash, cash equivalents, and marketable securities will be sufficient to fund our operating expenses and capital expenditure requirements for at least 12 months.

We will need to obtain additional funding through public or private equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements. We may not be able to obtain financing on acceptable terms, or at all, and we may not be able to enter into additional collaborative or strategic alliances or licensing arrangements. The terms of any financing may adversely affect the holdings or the rights of our stockholders. Arrangements with collaborators or others may require us to relinquish rights to certain of our technologies or programs. If we are unable to obtain funding, we could be forced to delay, reduce or eliminate some or all of our research and development programs, pipeline expansion or commercialization efforts, which could adversely affect our business prospects. Although management will continue to pursue these plans, there is no assurance that we will be successful in obtaining sufficient funding on terms acceptable to us to fund continuing operations when needed or at all.

The accompanying condensed consolidated financial statements reflect the operations of Generation Bio and our wholly owned subsidiary, Generation Bio Securities Corporation. Intercompany balances and transactions have been eliminated in consolidation. The accompanying condensed consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America, or GAAP. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification, or ASC, and Accounting Standards Update, or ASU, of the Financial Accounting Standards Board, or FASB.

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2. Summary of Significant Accounting Policies

Use of estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the measurement of proportional performance of the combined license and research services performance obligation of our collaboration agreement and to a lesser extent, our accrual of research and development expenses. We base our estimates on historical experience, known trends and other market-specific or other relevant factors that we believe to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates, as there are changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results may differ from those estimates or assumptions.

Unaudited interim financial information

The condensed consolidated balance sheet as of December 31, 2024 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited financial statements as of March 31, 2025 and for the three months ended March 31, 2025 and 2024 have been prepared by us pursuant to the rules and regulations of the Securities and Exchange Commission, or SEC, for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These financial statements should be read in conjunction with our audited financial statements included in our Annual Report on Form 10-K that was most recently filed with the SEC, or our 2024 Annual Report. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair presentation of our financial position as of March 31, 2025, the results of operations for the three months ended March 31, 2025 and 2024, and cash flows for the three months ended March 31, 2025 and 2024 have been made. The results of operations for the three months ended March 31, 2025 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2025 or any other period.

Our significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements included in our 2024 Annual Report.

Recently issued accounting pronouncements

In December 2023, the FASB issued its final standard to improve income tax disclosures. This standard, issued as ASU 2023-09, requires public business entities to annually disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. This update is effective for us as of and for the year ended December 31, 2025. We are currently evaluating the impact the guidance will have on our consolidated financial statements.

In November 2024, the FASB issued its final standard on expense disaggregation disclosures. This standard, issued as ASU 2024-03, requires public business entities to disclose, on an annual and interim basis, disaggregated information about certain income statement line items in a tabular format in the notes to the financial statements. This update is effective for annual periods beginning after December 15, 2026. We are currently evaluating the impact the guidance will have on our consolidated financial statements.

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3. Marketable Securities and Fair Value Measurements

The following tables present our marketable securities by security type:

As of March 31, 2025

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

106,583

(4)

106,668

As of December 31, 2024

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

108,763

159

—

108,922

Our marketable securities as of March 31, 2025 consisted of investments that mature within one year.

We assess our available-for-sale securities under the available-for-sale security impairment model in ASC 326 Financial Instruments - Credit Losses, as of each reporting date in order to determine if a portion of any decline in fair value below carrying value recognized on our available-for-sale securities is the result of a credit loss. We also evaluate our available-for-sale securities for impairment using a variety of factors including our intent to sell the underlying securities prior to maturity and whether it is more likely than not that we would be required to sell the securities before the recovery of their amortized basis. During the three months ended March 31, 2025 and 2024, we did not recognize any impairment or realized gains or losses on sales of available-for-sale securities, and we did not record an allowance for, or recognize, any expected credit losses.

The following tables present our assets that are measured at fair value on a recurring basis and indicate the level within the fair value hierarchy of the valuation techniques that we utilized to determine such fair value:


	Fair Value Measurements at March 31, 2025 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	25,616	$	—	$	—	$	25,616
U.S. Treasury securities		—		14,959		—		14,959
Marketable securities:
U.S. Treasury securities		—		106,668		—		106,668
Totals	$	25,616	$	121,627	$	—	$	147,243


	Fair Value Measurements at December 31, 2024 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	46,802	$	—	$	—	$	46,802
Marketable securities:
U.S. Treasury securities		—		108,922		—		108,922
Totals	$	46,802	$	108,922	$	—	$	155,724

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4. Collaboration and License Agreement

Moderna Collaboration and License Agreement

In March 2023, we entered into a Collaboration and License Agreement, or the Collaboration Agreement, with Moderna to collaborate on developing treatments for certain diseases by targeting delivery of nucleic acids to liver cells and certain cells outside of the liver.

Under the Collaboration Agreement, the parties agreed to collaborate on preclinical research programs relating to lipid nanoparticle, or LNP, delivery systems and nucleic acid payloads, with each party obtaining certain rights to intellectual property used in and arising out of such research programs. Each party is solely responsible for its own clinical development and commercialization of products under the Collaboration Agreement. Moderna reimburses us for the internal and external costs incurred by us in conducting the research programs, to the extent consistent with such research plans and budgets.

Moderna has exclusive options, upon payment of option exercise fees, to obtain worldwide, exclusive, sublicensable licenses under specified company intellectual property to develop, manufacture and commercialize (a) products comprising LNP delivery systems and nucleic acid payloads that are directed to (i) up to two liver targets, (ii) up to two non-liver targets and (iii) a third liver or non-liver target and (b) Exclusive Targets, which are Independent Program Products (as defined below) that include messenger RNA, or mRNA, that are directed to gene and protein targets in any of certain agreed-upon immune cell types, referred to as the Cell Target Types. Subject to the exclusivity obligations described below, each party has granted to the other a worldwide, non-exclusive, sublicensable license under certain LNP-related intellectual property arising out of the non-liver ctLNP program, or the Joint Collaboration ctLNP Intellectual Property, to develop, manufacture and commercialize products comprising LNP delivery systems and nucleic acid payloads directed to gene and protein targets in any of the Cell Target Types, or Independent Program Products.

Each party is obligated to use commercially reasonable efforts to complete the activities assigned to it under the research plans, and Moderna is further obligated to use commercially reasonable efforts to develop, seek regulatory approval for and commercialize at least one product directed to each target for which Moderna exercises its exclusive license option in at least one indication in the United States and in specified European countries.

We have agreed not to, directly or indirectly, alone or with, for or through any third party, develop, manufacture, commercialize or exploit (a) products containing mRNA that are directed to any of the Cell Target Types, during an agreed-upon exclusivity period, which may be extended by payment of extension fees, (b) products directed to any liver target or non-liver target during the option periods for those targets, (c) products directed to any liver target or non-liver target for which Moderna has exercised its exclusive license option or (d) products containing mRNA that are directed to any Exclusive Target for which Moderna has exercised its exclusive license option.

Under the terms of the Collaboration Agreement, in April 2023, Moderna made an upfront payment to us of $40.0 million, and paid us $7.5 million in prepaid research funding. In addition, we are eligible to receive up to $1.8 billion in milestone payments upon the achievement of specified development, regulatory, commercial, and sales milestone events, research term extension fees and exclusivity extension fees. Subject to reductions in specified circumstances, we will also be entitled to receive tiered royalties: (i) ranging from high-single-digits to low-double-digits on sales of licensed products that are directed to any liver target or non-liver target with respect to which Moderna has exercised its exclusive license option, and (ii) in the single digits on sales of Independent Program Products, including the exclusively licensed Independent Program Products directed to the Exclusive Targets. In consideration for the non-exclusive license granted by Moderna to us under the Joint Collaboration ctLNP Intellectual Property, we have agreed to pay Moderna tiered royalties in the single digits on sales of Independent Program Products that include mRNA, subject to reductions in specified circumstances. Royalties will be paid by each party, on a licensed product-by-licensed product and country-by-country basis, until the latest to occur of: (i) expiration of the last-to-expire of specified licensed patent rights; (ii) expiration of regulatory exclusivity; or (iii) ten years after the first commercial sale of the applicable licensed product.

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In addition, in connection with the execution of the Collaboration Agreement, we entered into a Share Purchase Agreement, or the Share Purchase Agreement, with Moderna, pursuant to which we issued and sold 5,859,375 shares of our common stock to Moderna, at a price of $6.14 per share, for an aggregate purchase price of $36.0 million, which closed concurrently with the execution of the Collaboration Agreement, and resulted in Moderna becoming a related party. Under the Share Purchase Agreement, Moderna has the right, subject to certain terms and conditions, to purchase up to 3.06% of the outstanding shares of our common stock (on a post-closing basis) in connection with a future equity financing of at least $25.0 million by us.

Moderna Agreement Assessment

We assessed the promised goods and services under the Collaboration Agreement, in accordance with ASC 606 Revenue from Contracts with Customers, or ASC 606. At inception, the Collaboration Agreement included one combined performance obligation, which includes the license to the ctLNP technology to target indications outside of the liver and the related research services to develop such technology, as the two items are not distinct in context of the contract. The Collaboration Agreement also provides Moderna with options to receive additional research services and options to receive exclusive licenses. The options to receive exclusive licenses allow Moderna to develop and commercialize product candidates that utilize our ctLNP and closed-ended DNA, or ceDNA, technology for targets within the liver, as well as utilizing the ctLNP technology to be developed as part of the Collaboration Agreement and our ceDNA, technology for targets outside the liver. These options are considered to be priced at a discount to its standalone selling price and therefore are considered to be material rights.

The initial transaction price included a $40.0 million upfront fee, premium paid over the fair value of the common stock of $13.3 million in connection with shares issued and sold to Moderna under the Share Purchase Agreement, and estimated revenue associated with the payment for research services, including $7.5 million in prepaid research services. We utilized the expected amount method to determine the amount of reimbursement for these activities. We utilized the most likely amount method to determine the amount of consideration to include in the transaction price related to any variable consideration related to exclusivity fees, and milestones, and the royalty payments are constrained based on the royalty constraint. No amounts are included in the transaction price related to these elements.

We initially allocated the transaction price to each unit of account as follows:


Performance Obligations (in thousands)	Standalone Selling Price		Transaction Price Allocated
ctLNP technology and research license	$	52,500	$	42,576
First liver program commercialization option license		7,000		5,677
Second liver program commercialization option license		7,000		5,677
First non-liver program commercialization option license		11,700		9,488
Second non-liver program commercialization option license		11,700		9,488
Third liver or non-liver program commercialization option license		6,150		4,987
Total	$	96,050	$	77,893

The transaction price was allocated to each unit of account based on the relative estimated standalone selling prices, over which management has applied significant judgment, of each element. We developed the estimated standalone selling price for combined performance obligation and each of the options to receive licenses primarily based on the probability-weighted present value of expected future cash flows associated with each license related to each specific program and an estimate of the costs to provide services including a reasonable return. In developing such estimate, we also considered applicable market conditions and relevant entity-specific factors, including those factors contemplated in negotiating the agreement, the probability of success and the time needed to commercialize a product candidate pursuant to the associated license.

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On a quarterly basis, we measure proportional performance of the combined performance obligation over time using an input method based on cost incurred relative to the total estimated costs by determining the proportion of effort incurred as a percentage of total effort we expect to expend. This ratio is then applied to the transaction price allocated to the combined performance obligation and each of the options to receive licenses. Any changes to these estimates are recognized in the period in which they change as a cumulative catch up. All allocated consideration for the material rights is deferred until such time that Moderna exercises its options or the right to exercise the options expires.

During the three months ended March 31, 2025, we recorded additional revenue related to a change in estimate due to revisions in the research plan. The change in estimate resulted in a $3.5 million decrease in the allocated transaction price, a $5.3 million increase in collaboration revenue, a $5.3 million decrease in deferred revenue and a $0.08 decrease in net loss per share, basic and diluted, for the three months ended March 31, 2025.

The following table provides a summary of the transaction price allocated to each unit of account, in addition to revenue activity during the period:


	Transaction Price Allocated		Revenue Recognized During
	as of		Three Months Ended		Deferred Revenue as of
Performance Obligations (in thousands)	March 31, 2025		March 31, 2025		March 31, 2025
ctLNP technology and research license	$	37,112	$	8,629	$	2,109
First liver program commercialization option license		4,948		—		4,871
Second liver program commercialization option license		4,948		—		4,871
First non-liver program commercialization option license		8,271		—		8,141
Second non-liver program commercialization option license		8,271		—		8,141
Third liver or non-liver program commercialization option license		4,347		—		4,279
Total	$	67,897	$	8,629	$	32,412

The following table presents the balance of our collaboration receivable and contract liabilities related to the Collaboration Agreement:


	Balance at						Balance at
(in thousands)	December 31, 2024		Additions		Deductions		March 31, 2025
Collaboration receivable	$	1,224	$	1,298	$	(1,224)	$	1,298
Contract liabilities:
Deferred revenue	$	39,743	$	1,298	$	(8,629)	$	32,412

On January 21, 2025, Moderna exercised an option to receive additional services under the Agreement on a time and materials basis. The Company accounts for these services as a separate contract under ASC 606 and recognizes revenue as services are performed. During the three months ended March 31, 2025, the Company recognized revenue of $0.1 million, which amount is included in collaboration receivable as of March 31, 2025.

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5. Accrued Expenses

Accrued expenses and other current liabilities consisted of the following:


	March 31,		December 31,
(in thousands)	2025		2024
Accrued employee compensation and benefits	$	2,345	$	5,975
Accrued external research and development expenses		848		720
Accrued professional fees		950		597
Property and equipment		140		109
Other		1,482		2,658
Total	$	5,765	$	10,059

Accrued employee compensation and benefits as of each of March 31, 2025 and December 31, 2024 includes salary continuation and severance costs of $0.4 million related to our strategic reorganization. For additional information, refer to Note 11, Reduction in Force.

6. Leases

Office and Lab Lease

We lease our office and laboratory space under a noncancelable operating lease that expires in 2029, or the Office and Lab Lease. There have been no material changes to our Office and Lab Lease during the three months ended March 31, 2025. For additional information, refer to Note 7, Leases, to the consolidated financial statements in our 2024 Annual Report.

Seyon Lease

In July 2021, we entered into a lease agreement for a manufacturing facility in Waltham, Massachusetts, or the Seyon Lease. The Seyon Lease commenced in December 2021, when we were granted access to the facility and monthly rent payments began in September 2022, and the total rent payment was expected to be approximately $104.3 million for the 12-year lease term. We had an option to extend the Seyon Lease term for two additional terms of five years each at the greater of the then-current base rent or the then-current fair market value. Exercise of this option was not determined to be reasonably certain and thus was not considered in determining the operating lease liability. In connection with the Seyon Lease, we provided a security deposit of $3.6 million in the form of a letter of credit. We paid an initial monthly base rent of approximately $0.4 million that increased annually, up to a monthly base rent of $0.6 million. We were obligated to pay operating costs, taxes and utilities applicable to the facility. We were responsible for costs of constructing interior improvements within the facility that exceed a construction allowance of $26.0 million provided by Waltham CenterPoint I Investment Group, LLC, or the Landlord. On January 31, 2024, we notified the Landlord of termination of the Seyon Lease due to the Landlord’s breach of its obligations to us under the Seyon Lease and returned possession of the premises to the Landlord, effective January 31, 2024. On February 20, 2024, the Landlord served us with a complaint, filed in Massachusetts Superior Court, or the Court, with respect to the Seyon Lease. The complaint seeks declaratory judgment that we unlawfully terminated the Seyon Lease and also asserts a claim for breach of contract damages. As of December 31, 2024, the Landlord had collected $3.6 million from our security deposit in lieu of monthly payments and has fully utilized such deposit.

In connection with the termination of the Seyon Lease, during the three months ended March 31, 2024, we recorded a material impairment loss of non-cash charges of $45.8 million in an impairment of the Seyon Lease right-of-use asset, $6.2 million in an impairment of construction in progress, and the write-off of $3.9 million in tenant improvement allowance receivable from the Landlord. In addition, during the three months ended March 31, 2024, we recognized $1.0 million in accretion and other related expenses, which resulted in a $56.9 million loss on termination of lease in our condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2024.

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During the three months ended March 31, 2025, we recognized $1.1 million in accretion and other related expenses. Accretion and other related expenses will continue to be recognized in loss on lease termination in our condensed consolidated statements of operations and comprehensive loss. After the Court’s preliminary injunction ruling in January 2025, we began making monthly payments to the Landlord. During the three months ended March 31, 2025, we paid $7.1 million to the Landlord, which included $4.9 million due from July through December 2024.

As of March 31, 2025 and December 31, 2024, we have not met the criteria to extinguish the lease liability pursuant to ASC 405 Liabilities. Accordingly, we had a total operating lease liability related to the Seyon Lease of $58.5 million and $63.1 million as of March 31, 2025 and December 31, 2024, respectively, of which $3.4 million and $7.1 million were included in current liabilities on our consolidated balance sheets as of March 31, 2025 and December 31, 2024, respectively. Additionally, in accordance with ASC 450 Contingencies, we have assessed the probability of realizing a material loss contingency for the potential losses, including obligations to pay any future variable lease costs, under the Seyon Lease. Based on this assessment, we have determined that it is not probable that we will be obligated to pay any such material amounts.

For additional information, refer to Note 9 Commitments and Contingencies.

7. Equity

As of March 31, 2025, our amended and restated certificate of incorporation authorizes us to issue 150,000,000 shares of common stock, par value $0.0001 per share, and 5,000,000 shares of preferred stock, par value $0.0001 per share, all of which preferred stock is undesignated.

In August 2024, we entered into an “at-the-market” sales agreement pursuant to which we may, from time to time, sell shares of our common stock having an aggregate offering price of up to $237.0 million. As of the issuance date of these condensed consolidated financial statements, we have not issued and sold any shares of our common stock pursuant to the August 2024 sales agreement.

Each share of common stock entitles the holder to one vote on all matters submitted to a vote of our stockholders. Holders of common stock are not entitled to receive dividends, unless declared by the board of directors.

8. Stock-Based Compensation

Stock incentive plans

Our 2017 Stock Incentive Plan, or the 2017 Plan, provided for us to grant incentive or nonstatutory stock options, restricted stock, restricted stock units and other equity awards to employees, non-employees, and directors.

In May 2020, our board of directors adopted, and in June 2020, our stockholders approved, the 2020 Stock Incentive Plan, or the 2020 Plan, and, together with the 2017 Plan, the Plans, which became effective on June 11, 2020. The 2020 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares of common stock reserved for issuance under the 2020 Plan is the sum of (1) 2,547,698 shares; plus (2) the number of shares (up to a maximum of 7,173,014 shares) as was equal to the sum of (x) the number of shares of common stock reserved for issuance under the 2017 Plan that remained available for grant under the 2017 Plan on June 11, 2020 and (y) the number of shares of common stock subject to outstanding awards granted under the 2017 Plan that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase, to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2021 and continuing until, and including, the fiscal year ending December 31, 2030, equal to the lesser of (i) 4% of the number of shares of common stock outstanding on such date, and (ii) an amount determined by the board of directors. In January 2025, the number of shares of common stock authorized for issuance under the 2020 Plan was increased from 19,462,688 shares to 22,141,904 shares. Upon the effectiveness of the 2020 Plan, we ceased granting additional awards under the 2017 Plan.

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The Plans are administered by the board of directors or, at the discretion of the board of directors, by a committee of the board of directors. The exercise prices, vesting and other restrictions on any award under the Plans are determined at the discretion of the board of directors, or its committee if so delegated. Stock options granted under the Plans with service-based vesting conditions generally vest over four years and expire after ten years. The exercise price for stock options granted is not less than the fair value of common stock as of the date of grant.

As of March 31, 2025, 700,090 shares remained available for future issuance under the 2020 Plan. Shares subject to outstanding awards granted under the Plans that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right will be available for future awards under the 2020 Plan.

Grant of stock options

During the three months ended March 31, 2025, we granted time-based options to certain employees for the purchase of an aggregate of 3,681,752 shares of common stock with a weighted average grant date fair value of $0.77 per share that vest over a weighted average period of approximately four years.

Employee stock purchase plan

In May 2020, our board of directors adopted, and in June 2020, our stockholders approved, the 2020 Employee Stock Purchase Plan, or the 2020 ESPP, which became effective June 11, 2020. The 2020 ESPP is administered by our board of directors or by a committee appointed by the board of directors. The number of shares of common stock authorized for issuance under the 2020 ESPP automatically increases on the first day of each fiscal year, beginning with the fiscal year that commenced on January 1, 2021 and continuing for each fiscal year until, and including the fiscal year commencing on, January 1, 2030, in an amount equal to the lowest of (1) 1,302,157 shares of common stock, (2) 1% of the number of shares of common stock outstanding on such date, and (3) an amount determined by the board of directors. In January 2025, the number of shares of common stock authorized for issuance under the 2020 ESPP was increased from 2,777,974 shares to 3,447,778 shares. As of March 31, 2025, 2,698,529 shares remained available for issuance under the 2020 ESPP.

Stock-based compensation

Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows:


	Three Months Ended March 31,
(in thousands)	2025		2024
Research and development expenses	$	714	$	1,521
General and administrative expenses		1,297		2,479
Total	$	2,011	$	4,000

As of March 31, 2025, total unrecognized compensation cost related to unvested time-based stock options and restricted stock units was $10.3 million, with $9.4 million expected to be recognized over a weighted average period of 2.5 years and $0.9 million expected to be recognized over a weighted average period of 1.8 years.

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9. Commitments and Contingencies

401(k) Plan

We have a defined-contribution plan under Section 401(k) of the Internal Revenue Code of 1986, as amended, or the 401(k) Plan. The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to contribute a portion of their annual compensation on a pre-tax and/or after-tax basis. In September 2020, we adopted a match program, beginning on January 1, 2021, for employee contributions to the 401(k) Plan up to a maximum of four percent of the employee’s salary, subject to the maximums established under the U.S. Internal Revenue Code of 1986, as amended.

Indemnification agreements

In the ordinary course of business, we may provide indemnification of varying scope and terms to vendors, lessors, contract research organizations, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, we have entered into indemnification agreements with members of our board of directors and our officers that will require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments we could be required to make under these indemnification agreements is, in many cases, unlimited. We have not incurred any material costs as a result of such indemnifications and are not currently aware of any indemnification claims.

Legal proceedings

We, from time to time, may be party to litigation arising in the ordinary course of business. On February 20, 2024, the Landlord served us with a complaint, filed in the Court with respect to the Seyon Lease. The complaint sought declaratory judgment that we unlawfully terminated the Seyon Lease and also asserted a claim for breach of contract damages. Following receipt of the complaint, we filed a counterclaim against the Landlord asserting breach of contract and violation of Massachusetts General Law Chapter 93A. On October 29, 2024, the Court determined that although we did not have the right to terminate the Seyon Lease, the Landlord’s subsequent termination was effective, and that we had alleged sufficient facts to state a claim for breach of contract and violation of Massachusetts General Law Chapter 93A by the Landlord. On January 21, 2025, the Court granted the Landlord’s motion for preliminary injunction and ordered us to pay, until further notice, monthly amounts equal to the rent and other charges that would have been due to the Landlord under the Seyon Lease had it not been terminated. On February 14, 2025, we filed a notice of appeal of the Court’s preliminary injunction ruling and our appeal is pending before the Massachusetts Appeals Court. On March 28, 2025, we filed a petition for direct appellate review with the Massachusetts Supreme Judicial Court. We are continuing to make monthly payments under the Seyon Lease during the pendency of the appeal. We will continue to vigorously defend the action and prosecute our counterclaims against the Landlord with respect to this matter. As a result, we may continue to incur costs and expenses relating to this facility, and we may remain responsible for payments under the Seyon Lease, which may have a material adverse effect on our business, results of operations or financial condition.

10. Net Loss per Share

We have generated a net loss in all periods presented, therefore the basic and diluted net loss per share attributable to common stockholders are the same as the inclusion of the potentially dilutive securities would be anti-dilutive. We 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:


	March 31,
	2025	2024
Unvested restricted stock units	225,341	497,121
Stock options to purchase common stock	16,041,622	12,514,950
Total	16,266,963	13,012,071

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11. Reduction in Force

In January 2025, our management and board of directors approved a reduction in force, or the January 2025 RIF, to support our new focus on applying our ctLNP delivery technology to develop siRNA therapeutics to silence disease-driving targets in T cells. In connection with the January 2025 RIF, affected employees are eligible to receive one-time severance benefits, including cash severance, temporary healthcare coverage, to the extent they are eligible for and elect such coverage, and transition support services, subject to each such employee entering into an effective separation agreement, which will include a general release of claims against us. We also offered a retention bonus to certain affected employees if such employees remain in continuous employment with us through their respective separation dates and execute a general release of claims against us. Retention amounts are expensed as services are performed.

During the three months ended March 31, 2025, we recorded $0.6 million of restructuring expenses related to the January 2025 RIF in our condensed consolidated statements of operation and comprehensive loss, of which $0.4 million was classified as research and development expense and $0.2 million was classified as general and administrative expense. During the three months ended March 31, 2024, we recorded $0.3 million of restructuring expenses in our condensed consolidated statements of operation and comprehensive loss, all of which was classified as general and administrative expense, and related to our prior strategic reorganization that commenced in November 2023 and was completed during the second quarter of 2024, or the November 2023 RIF.

Below is a summary of accrued restructuring costs recorded and included in accrued expenses and other current liabilities on our condensed consolidated balance sheets:


(in thousands)	Payroll-Related Costs		Stock-Based Compensation		Total
Balance at December 31, 2024	$	446	$	—	$	446
Restructuring expenses		618		13		631
Cash payments		(690)		—		(690)
Non-cash expenses		—		(13)		(13)
Adjustments		(5)		—		(5)
Balance at March 31, 2025	$	369	$	—	$	369

12. Reportable Segments

Our Chief Executive Officer is our chief operating decision maker, or CODM and we operate as one reportable segment related to the research and development of therapeutics that can deliver siRNA, leveraging our ctLNP delivery system, to T cells. The measure of segment profit or loss is the Company’s consolidated net loss.

Resource allocation decisions are based on the best use of our resources to advance our ctLNP delivery system with the goal of selecting and advancing a drug candidate into clinical development. These decisions are informed by our cash resources, reflected in the balance of cash, cash equivalents and marketable securities on our consolidated balance sheets, forecasted financial results, the actual results included in our consolidated balance sheets, consolidated statements of operations and comprehensive loss, and significant segment expenses included in the table below.

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Significant segment revenues and expenses include the following:


	Three Months Ended March 31,
(in thousands)	2025		2024
Revenue:
Collaboration revenue	$	8,723	$	4,059

Operating expenses:
Personnel-related		8,947		6,735
Preclinical and manufacturing		3,489		3,296
Facilities-related		4,753		5,757
Stock-based compensation		2,011		4,000
Lab supplies		803		915
Consulting and professional services		3,234		2,598
Loss on lease termination		1,138		56,930
Other (1)		954		1,462
Total operating expenses		25,329		81,693
Loss from operations		(16,606)		(77,634)
Other income:
Other income and interest income, net		1,804		3,093
Net Loss	$	(14,802)	$	(74,541)

(1)

Other segment items include depreciation, amortization, license fees and other costs. Depreciation and amortization expense for the three months ended March 31, 2025 and 2024 were $1.1 million and $1.3 million, respectively, and are included in facilities-related and other segment operating expenses.

All collaboration revenue recognized to date which has been entirely in connection to our License and Collaboration Agreement with Moderna and long-lived assets are attributable solely to our operations in the United States.

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion and analysis of our financial condition and results of operations is meant to provide material information relevant to an assessment of the financial condition and results of operations of our company, including an evaluation of the amounts and uncertainties of cash flows from operations and from outside resources, so as to allow investors to better view our company from management’s perspective. It should be read in conjunction with our condensed consolidated financial statements and related notes appearing elsewhere in this Quarterly Report and our consolidated financial statements and related notes appearing in our 2024 Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Quarterly Report, in our 2024 Annual Report and in the other documents filed with the SEC, our actual results could differ materially from the results described in, or implied by, the forward-looking statements contained in the following discussion and analysis.

Overview

We are a biotechnology company working to change what’s possible for people living with T cell-driven autoimmune diseases. Our strategy is to discover, develop, and commercialize redosable therapeutics that reprogram T cells in vivo to reduce or eliminate the production and persistence of autoreactive T cells, which erroneously recognize and attack the body’s own tissues, causing autoimmune disease. We are leveraging our cell-targeted lipid nanoparticle, or ctLNP, to selectively deliver small interfering RNA, or siRNA, to T cells, and we believe that the combination of selective delivery and an intracellular, genetically precise mechanism of target engagement unlocks a series of high-value historically undruggable disease-driving genes in autoimmunity.

T cells are central to the normal function of the immune system, but when inactivated or naïve T cells are inappropriately activated against proteins or molecules naturally present in the body, known as autoantigens, they expand, differentiate, and drive tissue inflammation that results in the development of autoimmune disease. Modulating T cell activity has historically been limited by a lack of selectivity along two dimensions – selective delivery to T cells while sparing other immune cell types, and precisely inhibiting or silencing the intended genetic sequence to block disease causing pathways.

We believe that the advantage of our approach to combatting T cell-driven autoimmune disease is in the combination of highly selective delivery and precise gene silencing in T cells to drive potency while sparing broader immune cells, thus potentially expanding the therapeutic margin of safety, or index. We achieve selective delivery using our modular, redosable ctLNP delivery system, which is designed to reach cell type targets of interest selectively through active ligand-mediated uptake. We are leveraging our T cell-selective LNP to deliver siRNA, a cargo that can potently and precisely regulate protein expression in T cells without off-target effects. The intracellular mechanism of action of siRNA means that our T cell-selective LNP-siRNA has the potential to reach targets inaccessible by other modalities, creating a large and new target space for autoimmune disease.

Selective and potent siRNA delivery to T cells opens a broad landscape of protein targets to address T cell-driven autoimmune disease indications, including targets that are undruggable or poorly drugged by conventional modalities. We intend to build a portfolio of therapeutic candidates for T cell-driven autoimmune indications, selecting those with a strong link to protein target biology, high unmet need, a clear clinical/regulatory pathway, and path to demonstrate clinical superiority. We are prioritizing protein target selection for these indications based on the following:

-targets in T cells that are undruggable or poorly drugged with conventional modalities;

-well-characterized biology;

-superiority of mechanism of action (selective delivery and intracellular knockdown); and

-clear target engagement in early clinical development.

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We expect to announce the target and indication of our lead T cell-selective LNP-siRNA program for autoimmune disease by mid-year 2025. We expect to submit our investigational new drug, or IND, application for our lead program in the second half of 2026.

We are collaborating with Moderna under a Collaboration and License Agreement, or the Collaboration Agreement, entered into in March 2023 to develop treatments for certain diseases by targeting delivery of nucleic acids to liver cells and certain cells outside of the liver. Under the Collaboration Agreement, we and Moderna have agreed to collaborate on preclinical research programs relating to lipid nanoparticle, or LNP, delivery systems and nucleic acid payloads, with each party obtaining certain rights to intellectual property used in and arising out of such research programs.

Since our inception in October 2016, we have focused substantially all of our resources on building our technologies, establishing and protecting our intellectual property portfolio, conducting research and development activities, developing our manufacturing process, organizing and staffing our company, business planning, raising capital and providing general and administrative support for these operations. We do not have any products approved for sale and have not generated any revenue from product sales. We expect that any revenue recognized for the next several years will be derived primarily from our current collaboration with Moderna and any additional collaborations that we may enter into in the future. Historically, we have funded our operations with proceeds from the sale of instruments convertible into convertible preferred stock, sales of convertible preferred stock, and sales of common stock in underwritten public offerings, “at-the-market” offerings, and in a private placement, as well as collaboration revenue under our collaboration with Moderna.

Historically, we have incurred significant operating losses. Our ability to generate any product revenue or product revenue sufficient to achieve profitability will depend on the successful development and eventual commercialization of one or more product candidates we may develop. For the three months ended March 31, 2025 and 2024, we reported net losses of $14.8 million and $74.5 million, respectively. As of March 31, 2025, we had an accumulated deficit of $717.8 million. We expect to continue to incur significant expenses and increasing operating losses for at least the next several years. We expect that our expenses and capital requirements will increase substantially in connection with our ongoing activities, particularly if and as we:

●	continue our current research programs and conduct additional research programs, including pursuant to our collaboration with Moderna;

●	expand the capabilities of our proprietary technologies;

●	advance any product candidates we identify into preclinical and clinical development;

●	obtain, expand, maintain, defend and enforce our intellectual property portfolio;

●	seek marketing approvals for any product candidates that successfully complete clinical trials;

●	hire additional clinical, regulatory and scientific personnel;

●	establish additional manufacturing sources and secure supply chain capacity sufficient to provide necessary quantities of any product candidates we may develop for clinical or commercial use;

●	ultimately establish a sales, marketing and distribution infrastructure to commercialize any products for which we may obtain marketing approval; and

●	add operational, legal, compliance, financial and management information systems and personnel to support our research, product development, and future commercialization efforts.

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We will not generate revenue from product sales unless and until we successfully complete clinical development and obtain regulatory approval for any product candidates we may develop. If we obtain regulatory approval for any product candidates we may develop, we expect to incur significant expenses related to developing our commercial capability to support product sales, marketing and distribution.

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of equity offerings, debt financings, collaborations, strategic alliances and/or licensing arrangements, including our collaboration with Moderna. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed on favorable terms, or at all. If we fail to raise capital or enter into such agreements when needed or on terms acceptable to us, we would be required to delay, limit, reduce or terminate our product development or future commercialization of one or more of our product candidates.

Because of the numerous risks and uncertainties associated with pharmaceutical product development, we are unable to accurately predict the timing or amount of increased expenses or when, or if, we will be able to achieve or maintain profitability. Even if we are able to generate product sales, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce or terminate our operations.

Components of Our Results of Operations

Collaboration revenue

Our revenue consists of collaboration revenue, including amounts recognized as payments for licenses, research funding and milestone payments earned under our collaboration and license agreements.

In March 2023, we entered into the Collaboration Agreement, with Moderna, to collaborate on developing treatments for certain diseases by targeting delivery of nucleic acids to liver cells and certain cells outside of the liver. Under the Collaboration Agreement, the parties have agreed to collaborate on preclinical research programs relating to lipid nanoparticle, or LNP, delivery systems and nucleic acid payloads, with each party obtaining certain rights to intellectual property used in and arising out of such research programs.

The research programs will be conducted pursuant to research plans and associated research budgets established by governance committees formed by the parties. Moderna will reimburse us for the internal and external costs we incur in conducting the research programs, to the extent consistent with such research plans and budgets. Each party will be solely responsible for its own clinical development and commercialization of products under the Collaboration Agreement.

In addition, Moderna has exclusive options, upon payment of option exercise fees, to obtain worldwide, exclusive, sublicensable licenses under certain of our specified intellectual property to develop, manufacture and commercialize (a) products comprising LNP delivery systems and nucleic acid payloads that are directed to (i) up to two liver targets, (ii) up to two agreed-upon non-liver targets and (iii) a third liver or non-liver target and (b) Independent Program Products, which are products comprising LNP delivery systems that include mRNA that are directed to gene and protein targets in any of the agreed-upon immune cell types, or Cell Targets Types.

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Under the terms of the Collaboration Agreement, in April 2023, Moderna made an upfront payment to us of $40.0 million, and paid us $7.5 million in prepaid research funding. In addition, we are eligible to receive up to $1.8 billion in milestone payments upon the achievement of specified development, regulatory, commercial, and sales milestone events, research term extension fees and exclusivity extension fees. Subject to reduction in specified circumstances, we will also be entitled to receive tiered royalties: (i) ranging from high-single-digits to low-double-digits on sales of licensed products that are directed to the liver targets and non-liver targets with respect to which Moderna has exercised its exclusive license options, and (ii) in the single digits on sales of Independent Program Products, including the exclusively licensed Independent Program Products. In consideration for the non-exclusive license granted by Moderna to us under the LNP-related intellectual property arising out of the research program focused on the discovery and development of ctLNPs directed to agreed-upon immune cell types, we have agreed to pay Moderna tiered royalties ranging from low-single-digits to mid-single-digits on sales of Independent Program Products that include mRNA, subject to reductions in specified circumstances.

In connection with the Collaboration Agreement, we entered into a Share Purchase Agreement with Moderna, pursuant to which we issued and sold 5,859,375 shares of our common stock to Moderna, at a price of $6.14 per share, for an aggregate purchase price of $36.0 million. In addition, under the Share Purchase Agreement, Moderna has the right, subject to certain terms and conditions, to purchase up to 3.06% of the outstanding shares of our common stock (on a post-closing basis) in connection with a future equity financing of at least $25.0 million by us. For additional information on our collaboration with Moderna and the accounting thereunder, refer to Note 4, Collaboration and License Agreement.

Operating expenses

Research and development expenses

Research and development expenses consist primarily of costs incurred for our research activities, including our discovery efforts, and the development of our programs, which include:

●	personnel-related costs, including salaries, benefits, stock-based compensation and severance expense, for employees engaged in research and development functions;

●	expenses incurred in connection with our research programs, including under agreements with third parties, such as consultants, contractors and contract research organizations, or CROs, and regulatory agency fees;

●

the cost of developing and scaling our manufacturing process and capabilities and manufacturing drug substance and drug product for use in our research and preclinical studies, including under agreements with third parties, such as consultants, contractors and contract development organizations, or CDOs;

●	laboratory supplies and research materials;

●	facilities, depreciation and amortization and other expenses, which include direct and allocated expenses for rent and maintenance of facilities and insurance; and

●	payments made under third-party licensing agreements.

We expense research and development costs as incurred. Advance payments that we make for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed.

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Our external research and development expenses consist of costs that include fees and other costs paid to consultants, contractors, CDOs and CROs in connection with our research, preclinical and manufacturing activities. We do not allocate our research and development costs to specific programs because costs are deployed across multiple programs and our technologies and, as such, are not separately classified. We expect that our research and development expenses will increase substantially as we advance our programs into clinical development and expand our discovery, research and preclinical activities in the near term and in the future. At this time, we cannot accurately estimate or know the nature, timing and costs of the efforts that will be necessary to complete the preclinical and clinical development of any product candidates we may develop. The successful development of any of our product candidates is highly uncertain. This is due to the numerous risks and uncertainties associated with product development, including the following:

●	the timing and progress of preclinical studies, including IND-enabling studies;

●	the number and scope of preclinical and clinical programs we decide to pursue;

●	our ability to raise additional funds necessary to complete preclinical and clinical development of any product candidates we may develop;

●	the timing of the submission and acceptance of IND applications or comparable foreign applications that allow commencement of future clinical trials for any product candidates we may develop;

●	the successful initiation, enrollment and completion of clinical trials, including under Good Clinical Practices;

●	our ability to achieve positive results from our future clinical programs that support a finding of safety and effectiveness and an acceptable risk-benefit profile in the intended patient populations of any product candidates we may develop;

●	our ability to establish arrangements with third-party manufacturers for preclinical, clinical and initial commercial supply;

●	the availability of specialty raw materials for use in production of any product candidates we may develop;

●	our ability to establish new licensing or collaboration arrangements;

●	the receipt and related terms of regulatory approvals from the U.S. Food and Drug Administration and other applicable regulatory authorities;

●	our ability to establish, obtain, maintain, enforce and defend patent, trademark, trade secret protection and other intellectual property rights or regulatory exclusivity for any product candidates we may develop and our technology;

●	our ability to maintain a continued acceptable safety, tolerability and efficacy profile of our product candidates following approval; and

●	the terms and timing of any existing or future collaboration, license or other arrangement, including the terms and timing of any achievement of milestones and the receipt of payments thereunder.

A change in the outcome of any of these variables with respect to any product candidates we may develop could significantly change the costs and timing associated with the development of that product candidate. We may never succeed in obtaining regulatory approval for any product candidates we may develop.

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General and administrative expenses

General and administrative expenses consist primarily of personnel-related costs, including salaries, benefits, stock-based compensation and severance expense, for employees engaged in executive, legal, finance and accounting and other administrative functions. General and administrative expenses also include professional fees for legal, patent, consulting, investor and public relations and accounting and audit services as well as direct and allocated facility-related costs.

We anticipate that our general and administrative expenses will increase in the future as our research progresses towards clinical studies and will increase our headcount to support our operational growth. We also anticipate that we will continue to incur substantial accounting, audit, legal, regulatory, compliance, director and officer insurance costs and investor and public relations expenses associated with operating as a public company.

Loss on lease termination

Loss on lease termination consists of expenses recognized for the impairment of the right-of-use asset and construction in progress, the write-off of the related tenant improvement allowance receivable, accretion and other related expenses in connection with the termination of our lease for a manufacturing facility in Waltham, Massachusetts, or the Seyon Lease.

Other income and interest income, net

Other income and interest income, net consists of interest income earned on our invested cash balances and miscellaneous income and expenses unrelated to our core operations.

Results of Operations

Comparison of the three months ended March 31, 2025 and 2024

The following table summarizes our results of operations for the three months ended March 31, 2025 and 2024:


	Three Months Ended March 31,				Change
(in thousands)	2025		2024		2025 vs. 2024
Revenues:
Collaboration revenue	$	8,723	$	4,059	$	4,664
Operating expenses:
Research and development		15,357		14,335		1,022
General and administrative		8,834		10,428		(1,594)
Loss on lease termination		1,138		56,930		(55,792)
Total operating expenses		25,329		81,693		(56,364)
Loss from operations		(16,606)		(77,634)		61,028
Other income:
Other income and interest income, net		1,804		3,093		(1,289)
Net loss	$	(14,802)	$	(74,541)	$	59,739

Collaboration revenue

During the three months ended March 31, 2025, we recognized $8.7 million in collaboration revenue, compared to $4.1 million for the three months ended March 31, 2024. The increase in collaboration revenue of $4.7 million during the three months ended March 31, 2025 was primarily due to $5.3 million of additional revenue related to a change in the total estimated research services due to revisions in the research plan, partially offset by decreased reimbursable activity. For additional information on our collaboration with Moderna and the accounting thereunder, refer to Note 4, Collaboration and License Agreement.

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Research and development expenses

The following table summarizes our research and development expenses for the three months ended March 31, 2025 and 2024:


	Three Months Ended March 31,				Change
(in thousands)	2025		2024		2025 vs. 2024
Personnel-related	$	5,637	$	3,722	$	1,915
Facilities-related		3,611		3,531		80
Preclinical and manufacturing		3,489		3,296		193
Stock-based compensation		714		1,521		(807)
Lab supplies		803		915		(112)
Consulting and professional services		363		387		(24)
License fees		17		89		(72)
Other		723		874		(151)
Total research and development expenses	$	15,357	$	14,335	$	1,022

Research and development expenses were $15.4 million for the three months ended March 31, 2025, compared to $14.3 million for the three months ended March 31, 2024. The increase in personnel-related costs of $1.9 million was driven primarily by an employee tax credit in the first quarter of 2024 that did not recur in the first quarter of 2025 as well as severance expenses, partially offset by a decrease in headcount. The decrease in stock-based compensation costs of $0.8 million was driven primarily by decreased headcount.

General and administrative expenses

The following table summarizes our general and administrative expenses for the three months ended March 31, 2025 and 2024:


	Three Months Ended March 31,				Change
(in thousands)	2025		2024		2025 vs. 2024
Personnel-related	$	3,310	$	3,013	$	297
Stock-based compensation		1,297		2,479		(1,182)
Facilities-related		1,142		2,226		(1,084)
Consulting and professional services		2,871		2,211		660
Other		214		499		(285)
Total general and administrative expenses	$	8,834	$	10,428	$	(1,594)

General and administrative expenses were $8.8 million for the three months ended March 31, 2025, compared to $10.4 million for the three months ended March 31, 2024. The decrease in stock-based compensation costs of $1.2 million was driven primarily by decreased headcount. The decrease in facilities-related costs of $1.1 million was driven primarily by the termination of the Seyon Lease in in the first quarter of 2024. The increase in consulting and professional services of $0.7 million was driven primarily by higher legal fees and recruiting expenses.

Loss on lease termination

During the three months ended March 31, 2025, we recognized a non-cash charge of $1.1 million in accretion and other related expenses in connection with the termination of the Seyon Lease. During the three months ended March 31, 2024, we recognized a non-cash charge of $56.9 million in connection with the termination of the Seyon Lease which included impairments of $45.8 million on the right-of-use asset and $6.2 million on construction in progress, a write-off of $3.9 million in tenant improvement allowance receivable from the landlord and $1.0 million in accretion and other related expenses.

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Other income and interest income, net

Other income and interest income, net for the three months ended March 31, 2025 was $1.8 million as compared to $3.1 million for the three months ended March 31, 2024. The decrease in other income and interest income, net during the three months ended March 31, 2025 was primarily due to decreases in interest yields and invested cash balances.

Liquidity and Capital Resources

Sources of Liquidity

Since our inception, we have incurred significant operating losses. We expect to incur significant expenses and operating losses for the foreseeable future as we support our continued research activities and development of our programs and technologies. We have not yet commercialized any product candidates and we do not expect to generate revenue from sales of any product candidates for several years, if at all. We expect that any revenue recognized for the next several years will be derived primarily from our current collaboration with Moderna and any additional collaborations that we may enter into in the future.

Historically, we have funded our operations with proceeds from the sale of instruments convertible into convertible preferred stock, sales of convertible preferred stock and sales of common stock in underwritten public offerings, “at-the-market” offerings and in a private placement, as well as collaboration revenue under our collaboration with Moderna. In August 2024, we entered into an “at-the-market” sales agreement pursuant to which we may, from time to time, sell shares of our common stock having an aggregate offering price of up to $237.0 million. As of the date of this Quarterly Report, we have not issued and sold any shares of our common stock pursuant to the August 2024 sales agreement. As of March 31, 2025, we had cash, cash equivalents, and marketable securities of $157.6 million.

Cash flows

The following table summarizes our sources and uses of cash for each of the periods presented:


	Three Months Ended March 31,
(in thousands)	2025		2024
Net cash used in operating activities	$	(28,360)	$	(31,697)
Net cash provided by (used in) investing activities		2,957		(553)
Net cash used in financing activities		(7)		(125)
Net decrease in cash, cash equivalents and restricted cash	$	(25,410)	$	(32,375)

Operating activities

During the three months ended March 31, 2025, operating activities used $28.4 million of cash, primarily resulting from our net loss of $14.8 million and the net changes in our operating assets and liabilities of $16.9 million, partially offset by net non-cash charges of $3.3 million. Net changes in our operating assets and liabilities for the three months ended March 31, 2025 consisted of a $7.3 million decrease in deferred revenue, a $7.1 million decrease of operating lease liabilities due primarily to payments for the Seyon Lease, a $3.7 million decrease of accrued expense and other current liabilities and accounts payable, due primarily to payments of accrued employee bonus, partially offset by a $0.9 million decrease in operating lease right-of-use assets and a $0.5 million decrease in prepaid expenses and other current assets.

During the three months ended March 31, 2024, operating activities used $31.7 million of cash, primarily resulting from our net loss of $74.5 million and the net changes in our operating assets and liabilities of $17.1 million and offset by the net of non-cash charges of $59.9 million. Net changes in our operating assets and liabilities for the three months ended March 31, 2024 consisted of a $4.1 million decrease of deferred revenue, a $1.1 million decrease in operating lease right of-use assets, a $0.9 million increase in prepaid expenses and other current assets, a $10.3 million decrease of accrued expense and other current liabilities and accounts payable and a $2.9 million decrease in operating lease liability.

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Changes in deferred revenue relate to the recognition of revenue for consideration allocated to research activities performed under our Collaboration Agreement with Moderna. Changes in prepaid expenses and other current assets and accrued expenses and other current liabilities and accounts payable are generally due to the timing of employee compensation and vendor invoicing and payments.

Investing activities

During the three months ended March 31, 2025, net cash provided by investing activities was $3.0 million, primarily due to $45.0 million in maturities of marketable securities, partially offset by purchases of marketable securities of $41.8 million. During the three months ended March 31, 2024, net cash used in investing activities was $0.6 million, due to purchases of marketable securities of $86.6 million and property and equipment of $1.9 million during the period, partially offset by $88.0 million in maturities of marketable securities.

Financing activities

During the three months ended March 31, 2025, net cash used in financing activities was less than $0.1 million, consisting of payments for repurchases of common stock for employee tax withholdings. During the three months ended March 31, 2024, net cash used in financing activities was $0.1 million, consisting of payments for repurchase of common stock for employee tax withholdings.

Funding requirements

We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we advance preclinical activities and initiate clinical trials for our product candidates in development. The timing and amount of our operating expenditures will depend largely on:

●

the costs and scope of the continued development of our technologies;

●

the identification of additional research programs and product candidates;

●

the costs and timing of preparing, filing and prosecuting applications for patents; obtaining, maintaining, defending and enforcing our intellectual property rights and defending against any intellectual property-related claims, including claims of infringement, misappropriation or other violation of third-party intellectual property;

●

the scope, progress, costs and results of preclinical and clinical development for any product candidates we may develop;

●

our research and development costs and the receipt of milestone payments under our collaboration with Moderna;

●

the costs, timing and outcome of regulatory review of any product candidates we may develop;

●

the cost and timing of completion of commercial-scale manufacturing activities;

●

the costs and timing of future commercialization activities, including product manufacturing, marketing, sales and distribution, for any product candidates we may develop for which we receive marketing approval;

●

the costs of satisfying any post-marketing requirements;

●

the revenue, if any, received from commercial sales of product candidates we may develop for which we receive marketing approval;

●

the costs of operational, financial and management information systems and associated personnel;

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●

the associated costs in connection with any acquisition of in-licensed products, intellectual property and technologies; and

●

the costs of operating as a public company.

In July 2021, we entered into the Seyon Lease for a manufacturing facility in Waltham, Massachusetts. On January 31, 2024, we notified the Landlord of termination of the Seyon Lease due to the Landlord’s breach of its obligations to us under the Seyon Lease and returned possession of the premises to the Landlord, effective January 31, 2024. On February 20, 2024, the Landlord served us with a complaint, filed in Massachusetts Superior Court, or the Court, with respect to the Seyon Lease. The complaint seeks declaratory judgment that we unlawfully terminated the Seyon Lease and also asserts a claim for breach of contract damages. Following receipt of the complaint, we filed a counterclaim against the Landlord asserting breach of contract and violation of Massachusetts General Law Chapter 93A. On October 29, 2024, the Court determined that although we did not have the right to terminate the Seyon Lease, the Landlord’s subsequent termination was effective, and that we had alleged sufficient facts to state a claim for breach of contract and violation of Massachusetts General Law Chapter 93A by the Landlord. On January 21, 2025, the Court granted the Landlord’s motion for preliminary injunction and ordered us to pay, until further notice, monthly amounts equal to the rent and other charges that would have been due to the Landlord under the Seyon Lease had it not been terminated. On February 14, 2025, we filed a notice of appeal of the Court’s preliminary injunction ruling and our appeal is pending before the Massachusetts Appeals Court. On March 28, 2025, we filed a petition for direct appellate review with the Massachusetts Supreme Judicial Court. We are continuing to make monthly payments under the Seyon Lease during the pendency of the appeal. We will continue to vigorously defend the action and prosecute our counterclaims against the Landlord with respect to this matter.

We believe that our existing cash, cash equivalents, and marketable securities will enable us to fund our operating expenses and capital expenditures into the second half of 2027. We have based our estimates as to how long we expect we will be able to fund our operations on assumptions that may prove to be wrong. We could use our available capital resources sooner than we currently expect, in which case we would be required to obtain additional financing, which may not be available to us on acceptable terms, or at all. Our failure to raise capital as and when needed would have a negative impact on our financial condition and our ability to pursue our business strategy. Although we may receive potential future payments under our collaboration with Moderna, we do not have any committed external source of funds. Accordingly, we will be required to obtain further funding through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources. If we raise additional funds by issuing equity securities, our stockholders may experience dilution. Any future debt financing into which we enter would result in fixed payment obligations and may involve agreements that include grants of security interests on our assets and restrictive covenants that limit our ability to take specific actions, such as incurring additional debt, making capital expenditures, granting liens over our assets, redeeming stock or declaring dividends, that could adversely impact our ability to conduct our business. Any debt financing or additional equity that we raise may contain terms that could adversely affect the holdings or the rights of our common stockholders.

If we are unable to raise sufficient capital as and when needed, we may be required to significantly curtail, delay or discontinue one or more of our research or development programs or the commercialization of any product candidate we may develop, or be unable to expand our operations or otherwise capitalize on our business opportunities. If we raise additional funds through collaborations or licensing arrangements with third parties, we may have to relinquish valuable rights to future revenue streams or product candidates or grant licenses on terms that may not be favorable to us.

See the “Risk Factors” section of this Quarterly Report and in our 2024 Annual Report for additional risks associated with our substantial capital requirements.

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Critical Accounting Policies and Significant Judgments and Estimates

Our condensed consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States of America, or GAAP. The preparation of our condensed consolidated financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses and the disclosure of contingent assets and liabilities in our condensed consolidated financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions. There have been no material changes to our critical accounting policies and estimates from those disclosed in our 2024 Annual Report.

Item 3. Quantitative and Qualitative Disclosures about Market Risks.

Interest Rate Market Risk

We are exposed to market risk related to changes in interest rates. We had marketable securities of $106.7 million as of March 31, 2025. We did not record any impairment charges to our marketable securities during the three months ended March 31, 2025. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates, particularly because a majority of our investments are generally invested in short-term securities. Interest rate changes would result in a change in the net fair value of these financial instruments due to the difference between the current market interest rate and the market interest rate at the date of purchase of the financial instrument. As of March 31, 2025, a hypothetical increase in interest rates of 100 basis points across the entire yield curve on our holdings would have resulted in a $0.4 million decrease to the fair value of our holdings. We currently do not seek to hedge this exposure to fluctuations in interest rates. We have not been exposed to, nor do we anticipate being exposed to, material risks due to changes in interest rates.

Item 4. Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

Our management, under the supervision and with the participation of our President and Chief Executive Officer and our Chief Financial Officer, our principal executive officer and principal financial and accounting officer, respectively, evaluated the effectiveness of our disclosure controls and procedures as of March 31, 2025. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended, or the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any disclosure controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives, and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of March 31, 2025, our President and Chief Executive Officer and our Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control over Financial Reporting

There were no other changes in our internal control over financial reporting (as defined in Rules 13a–15(f) and 15d–15(f) under the Exchange Act) during the three months ended March 31, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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PART II—OTHER INFORMATION

Item 1. Legal Proceedings.

For a discussion of material legal proceedings, see Note 9. Commitments and Contingencies—Legal Proceedings in Part I, Item 1, Financial Statements of this Quarterly Report.

Item 1A. Risk Factors.

In addition to the other information set forth in this Quarterly Report, you should carefully consider the factors discussed in Part I, Item 1A Risk Factors in our 2024 Annual Report, which could materially affect our business, financial condition, or future results.

Item 5. Other Information.

Director and Officer Trading Arrangements

The following table describes, for the period covered by this Quarterly Report, each trading arrangement for the sale or purchase of Company securities adopted or terminated by our directors and officers that is a contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) (a “Rule 10b5-1 trading arrangement”):


Name	Title	Action taken	Date	Shares to be sold	Expiration Date
Kevin Conway	Chief Financial Officer	Adopted	January 28, 2025	111,397	May 29, 2026

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Item 6. Exhibits.

Exhibit Number		Description of Exhibit

31.1*		Certification of Principal Executive Officer pursuant to Rule 13a-14(a) of the Securities Exchange Act, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

31.2*		Certification of Principal Financial Officer pursuant to Rule 13a-14(a) of the Securities Exchange Act, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

32.1**		Certification of Principal Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

32.2**		Certification of Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

101.SCH		Inline XBRL Taxonomy Extension Schema Document

101.CAL		Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF		Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB		Inline XBRL Taxonomy Extension Label Linkbase Document

101.PRE		Inline XBRL Taxonomy Extension Presentation Linkbase Document

104		Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101)

*	Filed herewith.

**	Furnished herewith.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	GENERATION BIO CO.

Date: May 7, 2025	By:	/s/ Geoff McDonough
		Geoff McDonough, M.D.
		President and Chief Executive Officer
		(Principal Executive Officer)

Date: May 7, 2025	By:	/s/ Kevin Conway
		Kevin Conway
		Chief Financial Officer
		(Principal Financial and Accounting Officer)

Exhibit 31.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Geoff McDonough, hereby certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Generation Bio Co.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 7, 2025

/s/ Geoff McDonough

Geoff McDonough, M.D.

President and Chief Executive Officer

(Principal Executive Officer)

Exhibit 31.2

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Kevin Conway, hereby certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Generation Bio Co.;

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 7, 2025

/s/ Kevin Conway

Kevin Conway

Chief Financial Officer

(Principal Financial and Accounting Officer)

Exhibit 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Geoff McDonough, certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge, the Quarterly Report on Form 10-Q of Generation Bio Co. for the quarter ended March 31, 2025 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and the information contained in such Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of Generation Bio Co.

/s/ Geoff McDonough

Geoff McDonough, M.D.

President and Chief Executive Officer

(Principal Executive Officer)

May 7, 2025

Exhibit 32.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Kevin Conway, certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge, the Quarterly Report on Form 10-Q of Generation Bio Co. for the quarter ended March 31, 2025 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and the information contained in such Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of Generation Bio Co.

/s/ Kevin Conway

Kevin Conway

Chief Financial Officer

(Principal Financial and Accounting Officer)

May 7, 2025

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2025	Apr. 30, 2025
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2025
Document Fiscal Year Focus	2025
Document Transition Report	false
Securities Act File Number	001-39319
Entity Registrant Name	GENERATION BIO CO.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4301284
Entity Address, Address Line One	301 Binney Street
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	617
Local Phone Number	655-7500
Title of 12(b) Security	Common Stock, $0.0001 Par Value
Trading Symbol	GBIO
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	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		67,035,236
Entity Central Index Key	0001733294
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 50,891,000	$ 76,301,000
Marketable securities	106,668,000	108,922,000
Collaboration receivable	1,392,000	1,224,000
Prepaid expenses and other current assets	6,168,000	6,456,000
Restricted cash	0
Total current assets	165,119,000	192,903,000
Property and equipment, net	14,432,000	15,293,000
Operating lease right-of-use assets	19,375,000	20,310,000
Restricted cash	2,152,000	2,152,000
Other long-term assets	270,000	539,000
Total assets	201,348,000	231,197,000
Current liabilities:
Accounts payable	2,262,000	1,408,000
Accrued expenses and other current liabilities	5,765,000	10,059,000
Deferred revenue	2,107,000	10,582,000
Operating lease liabilities	9,463,000	13,006,000
Total current liabilities	19,597,000	35,055,000
Deferred revenue, net of current portion	30,305,000	29,161,000
Operating lease liabilities, net of current portion	78,114,000	80,554,000
Other liabilities, net of current portion	0	223,000
Total liabilities	128,016,000	144,993,000
Commitments and contingencies (Note 9)
Stockholders' equity:
Preferred stock, $0.0001 par value; 5,000,000 shares authorized and no shares issued or outstanding at March 31, 2025 and December 31, 2024
Common stock, $0.0001 par value; 150,000,000 shares authorized at March 31, 2025 and December 31, 2024; 67,008,511 and 66,971,977 shares issued and outstanding at March 31, 2025 and December 31, 2024, respectively	7,000	7,000
Additional paid-in capital	791,087,000	789,083,000
Accumulated other comprehensive income	85,000	159,000
Accumulated deficit	(717,847,000)	(703,045,000)
Total stockholders' equity	73,332,000	86,204,000
Total liabilities and stockholders' equity	$ 201,348,000	$ 231,197,000

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Preferred stock, par value per share	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	67,008,511	66,971,977
Common stock, shares outstanding	67,008,511	66,971,977

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues:
Collaboration revenue	$ 8,723	$ 4,059
Operating expenses:
Research and development	15,357	14,335
General and administrative	8,834	10,428
Loss on lease termination	1,138	56,930
Total operating expenses	25,329	81,693
Loss from operations	(16,606)	(77,634)
Other income:
Other income and interest income, net	1,804	3,093
Net loss	$ (14,802)	$ (74,541)
Net loss per share, basic (in dollars per share)	$ (0.22)	$ (1.12)
Net loss per share, diluted (in dollars per share)	$ (0.22)	$ (1.12)
Weighted average common shares outstanding, basic (in shares)	67,002,511	66,433,640
Weighted average common shares outstanding, diluted (in shares)	67,002,511	66,433,640
Comprehensive loss:
Net loss	$ (14,802)	$ (74,541)
Other comprehensive loss:
Unrealized losses on marketable securities	(74)	(471)
Comprehensive loss	$ (14,876)	$ (75,012)

Condensed Consolidated Statements of Stockholders' Equity - USD ($)	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning balance at Dec. 31, 2023	$ 7,000	$ 774,224,000	$ 274,000	$ (571,377,000)	$ 203,128,000
Beginning balance, shares at Dec. 31, 2023	66,205,550
Vesting of restricted common stock		(125,000)			(125,000)
Vesting of restricted common stock, shares	273,550
Stock-based compensation expense		4,000,000			4,000,000
Unrealized losses on marketable securities			(471,000)		(471,000)
Net loss				(74,541,000)	(74,541,000)
Ending balance at Mar. 31, 2024	$ 7,000	778,099,000	(197,000)	(645,918,000)	131,991,000
Ending balance, shares at Mar. 31, 2024	66,479,100
Beginning balance at Dec. 31, 2024	$ 7,000	789,083,000	159,000	(703,045,000)	86,204,000
Beginning balance, shares at Dec. 31, 2024	66,971,977
Vesting of restricted common stock		(7,000)			(7,000)
Vesting of restricted common stock, shares	36,534
Stock-based compensation expense		2,011,000			2,011,000
Unrealized losses on marketable securities			(74,000)		(74,000)
Net loss				(14,802,000)	(14,802,000)
Ending balance at Mar. 31, 2025	$ 7,000	$ 791,087,000	$ 85,000	$ (717,847,000)	$ 73,332,000
Ending balance, shares at Mar. 31, 2025	67,008,511

Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash flows from operating activities:
Net loss	$ (14,802,000)	$ (74,541,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Loss on lease termination	1,138,000	56,930,000
Stock-based compensation expense	2,011,000	4,000,000
Depreciation and amortization expense	1,136,000	1,312,000
Accretion of discount on marketable securities, net	(993,000)	(2,328,000)
Other	2,000	(7,000)
Changes in operating assets and liabilities:
Collaboration receivable	(168,000)	0
Prepaid expenses and other current assets	469,000	(878,000)
Operating lease right-of-use assets	935,000	1,050,000
Other noncurrent assets	269,000	13,000
Accounts payable	643,000	(242,000)
Accrued expenses and other current liabilities	(4,319,000)	(10,032,000)
Deferred revenue	(7,331,000)	(4,059,000)
Operating lease liabilities	(7,127,000)	(2,915,000)
Other noncurrent liabilities	(223,000)	0
Net cash used in operating activities	(28,360,000)	(31,697,000)
Cash flows from investing activities:
Purchases of property and equipment	(246,000)	(1,918,000)
Proceeds from sale of property and equipment	30,000	0
Purchases of marketable securities	(41,827,000)	(86,635,000)
Maturities of marketable securities	45,000,000	88,000,000
Net cash provided by (used in) investing activities	2,957,000	(553,000)
Cash flows from financing activities:
Tax withholding payments related to net share settlements of restricted stock units	(7,000)	(125,000)
Net cash used in financing activities	(7,000)	(125,000)
Net decrease in cash, cash equivalents and restricted cash	(25,410,000)	(32,375,000)
Cash, cash equivalents and restricted cash at beginning of period	78,453,000	72,237,000
Cash, cash equivalents and restricted cash at end of period	53,043,000	39,862,000
Supplemental disclosure of noncash investing and financing information:
Purchases of property and equipment included in accounts payable and accrued expenses	420,000	0
Unrealized losses on marketable securities	(74,000)	(471,000)
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	50,891,000	35,526,000
Restricted cash (included in current assets)	0	2,184,000
Restricted cash (included in non-current assets)	2,152,000	2,152,000
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 53,043,000	$ 39,862,000

Nature of the Business and Basis of Presentation

3 Months Ended

Mar. 31, 2025

Nature of the Business and Basis of Presentation

Nature of the Business and Basis of Presentation

1. Nature of the Business and Basis of Presentation

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2025

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Use of estimates

Unaudited interim financial information

Our significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements included in our 2024 Annual Report.

Recently issued accounting pronouncements

Marketable Securities and Fair Value Measurements

3 Months Ended

Mar. 31, 2025

Marketable securities and fair value measurements

Marketable securities and Fair Value Measurements

3. Marketable Securities and Fair Value Measurements

The following tables present our marketable securities by security type:

As of March 31, 2025

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

106,583

(4)

106,668

As of December 31, 2024

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

108,763

159

—

108,922

Our marketable securities as of March 31, 2025 consisted of investments that mature within one year.


	Fair Value Measurements at March 31, 2025 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	25,616	$	—	$	—	$	25,616
U.S. Treasury securities		—		14,959		—		14,959
Marketable securities:
U.S. Treasury securities		—		106,668		—		106,668
Totals	$	25,616	$	121,627	$	—	$	147,243


	Fair Value Measurements at December 31, 2024 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	46,802	$	—	$	—	$	46,802
Marketable securities:
U.S. Treasury securities		—		108,922		—		108,922
Totals	$	46,802	$	108,922	$	—	$	155,724

Collaboration and License Agreement

3 Months Ended

Mar. 31, 2025

Collaboration and License Agreement

Collaboration and License Agreement

4. Collaboration and License Agreement

Moderna Collaboration and License Agreement

Moderna Agreement Assessment

We initially allocated the transaction price to each unit of account as follows:


Performance Obligations (in thousands)	Standalone Selling Price		Transaction Price Allocated
ctLNP technology and research license	$	52,500	$	42,576
First liver program commercialization option license		7,000		5,677
Second liver program commercialization option license		7,000		5,677
First non-liver program commercialization option license		11,700		9,488
Second non-liver program commercialization option license		11,700		9,488
Third liver or non-liver program commercialization option license		6,150		4,987
Total	$	96,050	$	77,893

The following table provides a summary of the transaction price allocated to each unit of account, in addition to revenue activity during the period:


	Transaction Price Allocated		Revenue Recognized During
	as of		Three Months Ended		Deferred Revenue as of
Performance Obligations (in thousands)	March 31, 2025		March 31, 2025		March 31, 2025
ctLNP technology and research license	$	37,112	$	8,629	$	2,109
First liver program commercialization option license		4,948		—		4,871
Second liver program commercialization option license		4,948		—		4,871
First non-liver program commercialization option license		8,271		—		8,141
Second non-liver program commercialization option license		8,271		—		8,141
Third liver or non-liver program commercialization option license		4,347		—		4,279
Total	$	67,897	$	8,629	$	32,412

The following table presents the balance of our collaboration receivable and contract liabilities related to the Collaboration Agreement:


	Balance at						Balance at
(in thousands)	December 31, 2024		Additions		Deductions		March 31, 2025
Collaboration receivable	$	1,224	$	1,298	$	(1,224)	$	1,298
Contract liabilities:
Deferred revenue	$	39,743	$	1,298	$	(8,629)	$	32,412

Accrued Expenses

3 Months Ended

Mar. 31, 2025

Accrued expenses

Accrued Expenses

5. Accrued Expenses

Accrued expenses and other current liabilities consisted of the following:


	March 31,		December 31,
(in thousands)	2025		2024
Accrued employee compensation and benefits	$	2,345	$	5,975
Accrued external research and development expenses		848		720
Accrued professional fees		950		597
Property and equipment		140		109
Other		1,482		2,658
Total	$	5,765	$	10,059

Leases

3 Months Ended

Mar. 31, 2025

Leases

Leases

6. Leases

Office and Lab Lease

Seyon Lease

For additional information, refer to Note 9 Commitments and Contingencies.

Equity

3 Months Ended

Mar. 31, 2025

Equity

Equity

7. Equity

Stock-Based Compensation

3 Months Ended

Mar. 31, 2025

Stock-based compensation

Stock-based Compensation

8. Stock-Based Compensation

Stock incentive plans

Grant of stock options

Employee stock purchase plan

Stock-based compensation

Stock-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive loss as follows:


	Three Months Ended March 31,
(in thousands)	2025		2024
Research and development expenses	$	714	$	1,521
General and administrative expenses		1,297		2,479
Total	$	2,011	$	4,000

Commitments and Contingencies

3 Months Ended

Mar. 31, 2025

Commitments and contingencies.

Commitments and Contingencies

9. Commitments and Contingencies

401(k) Plan

Indemnification agreements

Legal proceedings

Net Loss per Share

3 Months Ended

Mar. 31, 2025

Net loss per share

Net Loss per Share

10. Net Loss per Share


	March 31,
	2025	2024
Unvested restricted stock units	225,341	497,121
Stock options to purchase common stock	16,041,622	12,514,950
Total	16,266,963	13,012,071

Reduction in Force

3 Months Ended

Mar. 31, 2025

Reduction in Force

Reduction in Force

11. Reduction in Force

Below is a summary of accrued restructuring costs recorded and included in accrued expenses and other current liabilities on our condensed consolidated balance sheets:


(in thousands)	Payroll-Related Costs		Stock-Based Compensation		Total
Balance at December 31, 2024	$	446	$	—	$	446
Restructuring expenses		618		13		631
Cash payments		(690)		—		(690)
Non-cash expenses		—		(13)		(13)
Adjustments		(5)		—		(5)
Balance at March 31, 2025	$	369	$	—	$	369

Reportable Segments

3 Months Ended

Mar. 31, 2025

Segment Reporting [Abstract]

Reportable Segments

12. Reportable Segments

Significant segment revenues and expenses include the following:


	Three Months Ended March 31,
(in thousands)	2025		2024
Revenue:
Collaboration revenue	$	8,723	$	4,059

Operating expenses:
Personnel-related		8,947		6,735
Preclinical and manufacturing		3,489		3,296
Facilities-related		4,753		5,757
Stock-based compensation		2,011		4,000
Lab supplies		803		915
Consulting and professional services		3,234		2,598
Loss on lease termination		1,138		56,930
Other (1)		954		1,462
Total operating expenses		25,329		81,693
Loss from operations		(16,606)		(77,634)
Other income:
Other income and interest income, net		1,804		3,093
Net Loss	$	(14,802)	$	(74,541)

(1)

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Pay vs Performance Disclosure
Net Income (Loss)	$ (14,802)	$ (74,541)

Insider Trading Arrangements

3 Months Ended

Mar. 31, 2025

Trading Arrangements, by Individual

Material Terms of Trading Arrangement


Name	Title	Action taken	Date	Shares to be sold	Expiration Date
Kevin Conway	Chief Financial Officer	Adopted	January 28, 2025	111,397	May 29, 2026

Kevin Conway

Trading Arrangements, by Individual

Name

Kevin Conway

Title

Chief Financial Officer

Rule 10b5-1 Arrangement Adopted

true

Adoption Date

January 28, 2025

Expiration Date

May 29, 2026

Aggregate Available

111,397

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2025
Summary of Significant Accounting Policies
Use of estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the measurement of proportional performance of the combined license and research services performance obligation of our collaboration agreement and to a lesser extent, our accrual of research and development expenses. We base our estimates on historical experience, known trends and other market-specific or other relevant factors that we believe to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates, as there are changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results may differ from those estimates or assumptions.
Unaudited interim financial information	Unaudited interim financial information The condensed consolidated balance sheet as of December 31, 2024 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited financial statements as of March 31, 2025 and for the three months ended March 31, 2025 and 2024 have been prepared by us pursuant to the rules and regulations of the Securities and Exchange Commission, or SEC, for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These financial statements should be read in conjunction with our audited financial statements included in our Annual Report on Form 10-K that was most recently filed with the SEC, or our 2024 Annual Report. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair presentation of our financial position as of March 31, 2025, the results of operations for the three months ended March 31, 2025 and 2024, and cash flows for the three months ended March 31, 2025 and 2024 have been made. The results of operations for the three months ended March 31, 2025 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2025 or any other period. Our significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements included in our 2024 Annual Report.
Recently Adopted and Issued Accounting Pronouncements	Recently issued accounting pronouncements In December 2023, the FASB issued its final standard to improve income tax disclosures. This standard, issued as ASU 2023-09, requires public business entities to annually disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold. This update is effective for us as of and for the year ended December 31, 2025. We are currently evaluating the impact the guidance will have on our consolidated financial statements. In November 2024, the FASB issued its final standard on expense disaggregation disclosures. This standard, issued as ASU 2024-03, requires public business entities to disclose, on an annual and interim basis, disaggregated information about certain income statement line items in a tabular format in the notes to the financial statements. This update is effective for annual periods beginning after December 15, 2026. We are currently evaluating the impact the guidance will have on our consolidated financial statements.

Marketable securities and fair value measurements (Tables)

3 Months Ended

Mar. 31, 2025

Marketable securities and fair value measurements

Summary of marketable securities by security type

As of March 31, 2025

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

106,583

(4)

106,668

As of December 31, 2024

Gross

Amortized

Unrealized

Fair

(in thousands)

Cost

Gains

Losses

Value

U.S. Treasury securities

108,763

159

—

108,922

Summary of assets measured at fair value on a recurring basis


	Fair Value Measurements at March 31, 2025 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	25,616	$	—	$	—	$	25,616
U.S. Treasury securities		—		14,959		—		14,959
Marketable securities:
U.S. Treasury securities		—		106,668		—		106,668
Totals	$	25,616	$	121,627	$	—	$	147,243


	Fair Value Measurements at December 31, 2024 Using:
(in thousands)	Level 1		Level 2		Level 3		Total
Cash equivalents:
Money market funds	$	46,802	$	—	$	—	$	46,802
Marketable securities:
U.S. Treasury securities		—		108,922		—		108,922
Totals	$	46,802	$	108,922	$	—	$	155,724

Collaboration And License Agreement (Tables)

3 Months Ended

Mar. 31, 2025

Collaboration and License Agreement

Summary of allocation of transaction price to each unit of account


Performance Obligations (in thousands)	Standalone Selling Price		Transaction Price Allocated
ctLNP technology and research license	$	52,500	$	42,576
First liver program commercialization option license		7,000		5,677
Second liver program commercialization option license		7,000		5,677
First non-liver program commercialization option license		11,700		9,488
Second non-liver program commercialization option license		11,700		9,488
Third liver or non-liver program commercialization option license		6,150		4,987
Total	$	96,050	$	77,893

Summary of transaction price allocated with revenue activity

The following table provides a summary of the transaction price allocated to each unit of account, in addition to revenue activity during the period:


	Transaction Price Allocated		Revenue Recognized During
	as of		Three Months Ended		Deferred Revenue as of
Performance Obligations (in thousands)	March 31, 2025		March 31, 2025		March 31, 2025
ctLNP technology and research license	$	37,112	$	8,629	$	2,109
First liver program commercialization option license		4,948		—		4,871
Second liver program commercialization option license		4,948		—		4,871
First non-liver program commercialization option license		8,271		—		8,141
Second non-liver program commercialization option license		8,271		—		8,141
Third liver or non-liver program commercialization option license		4,347		—		4,279
Total	$	67,897	$	8,629	$	32,412

Summary of receivables and contract liabilities related to Collaboration Agreement


	Balance at						Balance at
(in thousands)	December 31, 2024		Additions		Deductions		March 31, 2025
Collaboration receivable	$	1,224	$	1,298	$	(1,224)	$	1,298
Contract liabilities:
Deferred revenue	$	39,743	$	1,298	$	(8,629)	$	32,412

Accrued expenses (Tables)

3 Months Ended

Mar. 31, 2025

Accrued expenses

Summary of accrued expenses

Accrued expenses and other current liabilities consisted of the following:


	March 31,		December 31,
(in thousands)	2025		2024
Accrued employee compensation and benefits	$	2,345	$	5,975
Accrued external research and development expenses		848		720
Accrued professional fees		950		597
Property and equipment		140		109
Other		1,482		2,658
Total	$	5,765	$	10,059

Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2025

Stock-based compensation

Summary of stock-based compensation expense was classified in the statements of operations and comprehensive loss


	Three Months Ended March 31,
(in thousands)	2025		2024
Research and development expenses	$	714	$	1,521
General and administrative expenses		1,297		2,479
Total	$	2,011	$	4,000

Net loss per share (Tables)

3 Months Ended

Mar. 31, 2025

Net loss per share

Summary of potential dilutive securities, presented based on amounts outstanding


	March 31,
	2025	2024
Unvested restricted stock units	225,341	497,121
Stock options to purchase common stock	16,041,622	12,514,950
Total	16,266,963	13,012,071

Reduction in Force (Tables)

3 Months Ended

Mar. 31, 2025

Reduction in Force

Summary of accrued restructuring costs recorded and included in accrued expenses and other current liabilities


(in thousands)	Payroll-Related Costs		Stock-Based Compensation		Total
Balance at December 31, 2024	$	446	$	—	$	446
Restructuring expenses		618		13		631
Cash payments		(690)		—		(690)
Non-cash expenses		—		(13)		(13)
Adjustments		(5)		—		(5)
Balance at March 31, 2025	$	369	$	—	$	369

Reportable Segments (Tables)

3 Months Ended

Mar. 31, 2025

Segment Reporting [Abstract]

Schedule of segment profit or loss


	Three Months Ended March 31,
(in thousands)	2025		2024
Revenue:
Collaboration revenue	$	8,723	$	4,059

Operating expenses:
Personnel-related		8,947		6,735
Preclinical and manufacturing		3,489		3,296
Facilities-related		4,753		5,757
Stock-based compensation		2,011		4,000
Lab supplies		803		915
Consulting and professional services		3,234		2,598
Loss on lease termination		1,138		56,930
Other (1)		954		1,462
Total operating expenses		25,329		81,693
Loss from operations		(16,606)		(77,634)
Other income:
Other income and interest income, net		1,804		3,093
Net Loss	$	(14,802)	$	(74,541)

(1)

Nature of the Business and Basis of Presentation - Additional information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Summary of Significant Accounting Policies
Date of incorporation	Oct. 21, 2016
Net loss and net loss attributable to common stockholders	$ 14,802	$ 74,541
Accumulated deficit	$ 717,847		$ 703,045

Marketable securities and fair value measurements - Summary of marketable securities (Detail) - Fair Value, Recurring - U.S. treasury securities - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Marketable Securities [Line Items]
Amortized Cost	$ 106,583	$ 108,763
Gross Unrealized Gains	89	159
Gross Unrealized Losses	(4)	0
Fair Value	$ 106,668	$ 108,922

Marketable securities and fair value measurements - Summary of assets measured at FV on a recurring basis (Detail) - Fair Value, Recurring - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Marketable securities:
Total	$ 147,243	$ 155,724
Level 1
Marketable securities:
Total	25,616	46,802
Level 2
Marketable securities:
Total	121,627	108,922
Level 3
Marketable securities:
Total	0	0
Money Market Funds
Cash equivalents:
Cash equivalents	25,616	46,802
Money Market Funds \| Level 1
Cash equivalents:
Cash equivalents	25,616	46,802
Money Market Funds \| Level 2
Cash equivalents:
Cash equivalents	0	0
Money Market Funds \| Level 3
Cash equivalents:
Cash equivalents	0	0
U.S. treasury securities
Cash equivalents:
Cash equivalents	14,959
Marketable securities:
Marketable securities	106,668	108,922
U.S. treasury securities \| Level 1
Cash equivalents:
Cash equivalents	0
Marketable securities:
Marketable securities	0	0
U.S. treasury securities \| Level 2
Cash equivalents:
Cash equivalents	14,959
Marketable securities:
Marketable securities	106,668	108,922
U.S. treasury securities \| Level 3
Cash equivalents:
Cash equivalents	0
Marketable securities:
Marketable securities	$ 0	$ 0

Collaboration and License Agreement (Details)	1 Months Ended	3 Months Ended
Collaboration and License Agreement (Details)	Mar. 31, 2023 USD ($) product item $ / shares shares	Mar. 31, 2025 USD ($) $ / shares	Mar. 31, 2024 USD ($) $ / shares	Apr. 30, 2023 USD ($)
Quarterly Performance Adjustments
Collaboration revenue		$ 8,723,000	$ 4,059,000
Deferred revenue		$ 7,331,000	$ 4,059,000
Net loss per share, basic (in dollars per share) \| $ / shares		$ 0.22	$ 1.12
Net loss per share, diluted (in dollars per share) \| $ / shares		$ 0.22	$ 1.12
ModernaTX, Inc
Quarterly Performance Adjustments
Revenue Recognized		$ 8,629,000
Collaboration and License Agreement \| ModernaTX, Inc
Collaboration and License Agreement
Upfront payments				$ 40,000,000
Prepaid research services funding				$ 7,500,000
Number of performance obligations \| item	1
Premium paid on common stock	$ 13,300,000
Variable consideration	$ 0
Collaboration and License Agreement \| ModernaTX, Inc \| Maximum
Collaboration and License Agreement
Milestone payments receivable		1,800,000,000
Collaboration and License Agreement \| ModernaTX, Inc \| Minimum
Collaboration and License Agreement
Number of products to be commercialized \| product	1
Royalty payment term	10 years
Collaboration and License Agreement \| Share Purchase Agreement \| Beneficial Owner \| ModernaTX, Inc
Collaboration and License Agreement
Issuance of common stock, shares \| shares	5,859,375
Shares issue price (in dollars per share) \| $ / shares	$ 6.14
Proceeds from issuance/sale of common stock	$ 36,000,000
Collaboration and License Agreement \| Share Purchase Agreement \| Beneficial Owner \| ModernaTX, Inc \| Maximum
Collaboration and License Agreement
Percent of shares to be issued	3.06%
Collaboration and License Agreement \| Share Purchase Agreement \| Beneficial Owner \| ModernaTX, Inc \| Minimum
Collaboration and License Agreement
Equity financing	$ 25,000,000
Collaboration and License Agreement \| Contracts Accounted for under Percentage of Completion \| ModernaTX, Inc
Quarterly Performance Adjustments
Change in Allocated Transaction Price		3,500,000
Collaboration revenue		5,300,000
Deferred revenue		$ 5,300,000
Net loss per share, basic (in dollars per share) \| $ / shares		$ 0.08
Net loss per share, diluted (in dollars per share) \| $ / shares		$ 0.08
Option To Receive Additional Service
Quarterly Performance Adjustments
Revenue Recognized		$ 100,000

Collaboration and License Agreement - Schedule of Allocated Transaction Price and Revenue Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Apr. 30, 2023
Collaboration and License Agreement
Deferred Revenue	$ 32,412	$ 39,743
ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			$ 96,050
Transaction Price Allocated	67,897		77,893
Revenue Recognized	8,629
Deferred Revenue	32,412
ctLNP technology and research license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			52,500
Transaction Price Allocated	37,112		42,576
Revenue Recognized	8,629
Deferred Revenue	2,109
First liver program commercialization option license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			7,000
Transaction Price Allocated	4,948		5,677
Revenue Recognized	0
Deferred Revenue	4,871
Second liver program commercialization option license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			7,000
Transaction Price Allocated	4,948		5,677
Revenue Recognized	0
Deferred Revenue	4,871
First non-liver program commercialization option license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			11,700
Transaction Price Allocated	8,271		9,488
Revenue Recognized	0
Deferred Revenue	8,141
Second non-liver program commercialization option license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			11,700
Transaction Price Allocated	8,271		9,488
Revenue Recognized	0
Deferred Revenue	8,141
Third liver or non-liver program commercialization option license \| ModernaTX, Inc
Collaboration and License Agreement
Standalone Selling Price			6,150
Transaction Price Allocated	4,347		$ 4,987
Revenue Recognized	0
Deferred Revenue	$ 4,279

Collaboration and License Agreement - Schedule of Receivables and Contract Liabilities (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($)
Collaboration and License Agreement
Collaboration Receivable, Beginning Balance	$ 1,224
Collaboration Receivable, Additions	1,298
Collaboration Receivable, Deductions	(1,224)
Collaboration Receivable, Ending Balance	1,298
Deferred Revenue, Beginning Balance	39,743
Deferred Revenue, Additions	1,298
Deferred Revenue, Deductions	(8,629)
Deferred Revenue, Ending Balance	$ 32,412

Accrued expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Accrued expenses
Accrued employee compensation and benefits	$ 2,345	$ 5,975
Accrued external research and development expenses	848	720
Accrued professional fees	950	597
Property and equipment	140	109
Other	1,482	2,658
Total	5,765	10,059
Restructuring Reserve	$ 369	$ 446

Leases - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
Leases - Narrative (Details) - USD ($) $ in Thousands	Jul. 31, 2021	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2021
Lessee, Lease, Description [Line Items]
Operating lease agreement option to renewal term	5 years
Operating lease term					12 years
Total rent payments					$ 104,300
Initial monthly base rent on operating lease	$ 400
Option to extend lease	two
Reduction of security deposit in lieu of monthly payments				$ 3,600
Impairment of right-of-use asset			$ 45,800
Accretion and other lease related expenses		$ 1,100	1,000
Loss on lease termination		1,138	56,930
Current operating lease liability		9,463		13,006
Non-current operating lease liability		78,114		80,554
Seyon Lease
Lessee, Lease, Description [Line Items]
Construction allowance in operating lease	$ 26,000
Operating lease payments		7,100
Operating lease payments for rent from July through December 2024		4,900
Operating Lease, Liability		58,500		63,100
Current operating lease liability		$ 3,400		$ 7,100
Seyon Lease \| Tenant Improvement Allowance
Lessee, Lease, Description [Line Items]
Tenant improvement allowance receivable write-off			3,900
Construction in progress
Lessee, Lease, Description [Line Items]
Impairment charge			$ 6,200
Maximum
Lessee, Lease, Description [Line Items]
Estimated monthly base rent on operating lease	600
Letter of Credit
Lessee, Lease, Description [Line Items]
Security deposit	$ 3,600

Equity - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Aug. 31, 2024 USD ($)	Mar. 31, 2025 security $ / shares shares	Dec. 31, 2024 $ / shares shares
Capital Unit [Line Items]
Common stock, shares authorized \| shares		150,000,000	150,000,000
Common stock, par value per share \| $ / shares		$ 0.0001	$ 0.0001
Preferred stock, shares authorized \| shares		5,000,000	5,000,000
Preferred stock, par value per share \| $ / shares		$ 0.0001	$ 0.0001
Number of vote per common share \| security		1
At the Market Offering \| Maximum
Capital Unit [Line Items]
Aggregate gross offering price \| $	$ 237.0

Stock-based compensation - Stock incentive plans (Detail) - $ / shares		3 Months Ended
	Jun. 11, 2020	Mar. 31, 2025	Jan. 31, 2025	Dec. 31, 2024
Service Based Vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation period of expiry		10 years
Share based compensation by share based payment weighted average period		4 years
Time Based Stock Option \| Certain Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted during the period		3,681,752
Weighted average grant date fair value		$ 0.77
Share based compensation by share based payment weighted average period		4 years
2020 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock reserved for future issuance	2,547,698	700,090
Share based compensation by share based payment arrangement number of shares authorized for issuance			22,141,904	19,462,688
2020 Stock Incentive Plan \| Maximum \| Additional From 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock reserved for future issuance	7,173,014
2020 Stock Incentive Plan \| Maximum \| Annual Increase 2021 To 2030
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of common stock shares additionally reserved for issuance	4.00%
Employee Stock Purchase Plan 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock reserved for future issuance		2,698,529
Share based compensation by share based payment arrangement number of shares authorized for issuance			3,447,778	2,777,974
Employee Stock Purchase Plan 2020 \| Maximum \| Annual Increase 2021 To 2030
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of common stock shares additionally reserved for issuance	1.00%
Number of share instruments newly issued under a share-based compensation plan	1,302,157

Stock-based compensation - Expense Classification (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 2,011	$ 4,000
Research and development expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	714	1,521
General and administrative expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 1,297	$ 2,479

Stock-based compensation - Unrecognized Expense (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	$ 10.3
Share based compensation expected to recognize over a weighted average period one
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	$ 9.4
Unrecognized stock compensation on account of unvested options remaining period over which the compensation is to be recognized	2 years 6 months
Share based compensation expected to recognize over a weighted average period two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Expense	$ 0.9
Unrecognized stock compensation on account of unvested options remaining period over which the compensation is to be recognized	1 year 9 months 18 days

Commitments and contingencies - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2025
Commitments and contingencies.
Defined contribution plan, percentage	4.00%

Net loss per share - Summary of Potential Dilutive Securities (Detail) - shares	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive net loss per share	16,266,963	13,012,071
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive net loss per share	225,341	497,121
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive net loss per share	16,041,622	12,514,950

Reduction in Force (Details) - USD ($) $ in Thousands	3 Months Ended
Reduction in Force (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 631
November 2023 RIF \| General and administrative expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		$ 300
January 2025 RIF
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	600
January 2025 RIF \| Research and development expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	400
January 2025 RIF \| General and administrative expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 200

Reduction in Force - Accrued Restructuring Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($)
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 446
Restructuring expenses	631
Cash payments	(690)
Non-cash expenses	(13)
Adjustments	(5)
Ending Balance	369
Severance and Benefits Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance	446
Restructuring expenses	618
Cash payments	(690)
Non-cash expenses	0
Adjustments	(5)
Ending Balance	369
Stock-Based Compensation
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	13
Non-cash expenses	$ (13)

Reportable Segments (Details)	3 Months Ended
Reportable Segments (Details)	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Number of operating segment \| segment	1
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	srt:ChiefExecutiveOfficerMember
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	Resource allocation decisions are based on the best use of our resources to advance our ctLNP delivery system with the goal of selecting and advancing a drug candidate into clinical development. These decisions are informed by our cash resources, reflected in the balance of cash, cash equivalents and marketable securities on our consolidated balance sheets, forecasted financial results, the actual results included in our consolidated balance sheets, consolidated statements of operations and comprehensive loss, and significant segment expenses included in the table below.
Revenue:
Collaboration revenue	$ 8,723,000	$ 4,059,000
Operating expenses:
Stock-based compensation	2,011,000	4,000,000
Loss on lease termination	1,138,000	56,930,000
Total operating expenses	25,329,000	81,693,000
Loss from operations	(16,606,000)	(77,634,000)
Other income and interest income, net	1,804,000	3,093,000
Net loss	(14,802,000)	(74,541,000)
Depreciation and amortization expense	$ 1,136,000	$ 1,312,000
Single Reportable Segment
Segment Reporting, Disclosure of Entity's Reportable Segments [Abstract]
Segment Reporting, Other Segment Item, Composition, Description	Three Months Ended March 31,	Three Months Ended March 31,
Revenue:
Collaboration revenue	$ 8,723,000	$ 4,059,000
Operating expenses:
Personnel-related	8,947,000	6,735,000
Preclinical and manufacturing	3,489,000	3,296,000
Facilities-related	4,753,000	5,757,000
Stock-based compensation	2,011,000	4,000,000
Lab supplies	803,000	915,000
Consulting and professional services	3,234,000	2,598,000
Loss on lease termination	1,138,000	56,930,000
Other	954,000	1,462,000
Total operating expenses	25,329,000	81,693,000
Loss from operations	(16,606,000)	(77,634,000)
Other income and interest income, net	1,804,000	3,093,000
Net loss	$ (14,802,000)	$ (74,541,000)

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