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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended September 30, 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: 001-38360

Solid Biosciences Inc.

(Exact Name of Registrant as Specified in its Charter)


Delaware		90-0943402
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification No.)

500 Rutherford Avenue, Third Floor Charlestown, MA		02129
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (617) 337-4680

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


Title of each class	Trading Symbol	Name of exchange on which registered
Common Stock, $0.001 par value per share	SLDB	The 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 October 29, 2025, the registrant had 77,910,239 shares of common stock, $0.001 par value per share, outstanding.

SOLID BIOSCIENCES INC.

TABLE OF CONTENTS


		Page
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS AND INDUSTRY DATA		1

PART I.	FINANCIAL INFORMATION	3
Item 1.	Financial Statements (Unaudited)	3
	Condensed Consolidated Balance Sheets at September 30, 2025 and December 31, 2024	3
	Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2025 and 2024	4
	Condensed Consolidated Statements of Comprehensive Loss for the three and nine months ended September 30, 2025 and 2024	5
	Condensed Consolidated Statements of Changes in Stockholders’ Equity for the three and nine months ended September 30, 2025 and 2024	6
	Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2025 and 2024	8
	Notes to the Condensed Consolidated Financial Statements	10
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	20
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	30
Item 4.	Controls and Procedures	30

PART II.	OTHER INFORMATION	32
Item 1.	Legal Proceedings	32
Item 1A.	Risk Factors	32
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	86
Item 5.	Other Information	86
Item 6.	Exhibits	87

SIGNATURES		88

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS AND INDUSTRY DATA

This Quarterly Report on Form 10-Q includes forward-looking statements, which involve risks and uncertainties. These forward-looking statements can be identified by the use of forward-looking terminology, including the terms “believe,” “estimate,” “project,” “anticipate,” “expect,” “seek,” “predict,” “aim,” “continue,” “possible,” “intend,” “may,” “might,” “will,” “could,” “would” or “should” or, in each case, their negative, or other variations or comparable terminology. These forward-looking statements include all matters that are not historical facts. They appear in a number of places throughout this Quarterly Report on Form 10-Q. We derive many of our forward-looking statements from our operating budgets and forecasts, which are based upon many detailed assumptions. While we believe that our assumptions are reasonable, we caution that it is very difficult to predict the impact of known factors, and, of course, it is impossible for us to anticipate all factors that could affect our actual results. All forward-looking statements are based upon information available to us on the date of this Quarterly Report on Form 10-Q.

The forward-looking statements in this Quarterly Report on Form 10-Q include, among other things, statements about:

•

the timing, progress, design and results of ongoing and planned preclinical studies and clinical trials for our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates;

•

our ability to establish or maintain collaborations or strategic relationships;

•

our ability to obtain and maintain U.S. and foreign regulatory approval of our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates, and the timing and scope thereof;

•

the timing and outcomes of regulatory interactions;

•

the size of the patient populations and potential market opportunity for our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates, if approved for commercial use;

•

our manufacturing capabilities and strategy, including capacity constraints and the scalability and commercial viability of our manufacturing methods and processes;

•

our plans to develop and commercialize our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates, if approved;

•

the pricing and reimbursement of our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates we may develop, if approved;

•

the establishment of sales, marketing and distribution capabilities and entry into agreements with third parties to market and sell our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates, if approved;

•

the rate and degree of market acceptance and clinical utility of our neuromuscular (e.g., SGT-003, SGT-212), cardiac (e.g., SGT-401, SGT-501, SGT-601) or other future candidates, if approved;

•

our plans to develop our platform technologies;

•

our expectations related to our use of capital resources;

•

our estimates regarding expenses, ongoing losses, future revenue, capital requirements, and need for and ability to obtain additional financing;

•

our intellectual property position;

•

our competitive and market position;

•

developments relating to our competitors and our industry;

•

our ability to continue as a going concern; and

•

the impact of laws, regulations, and global political and economic developments, including the imposition of tariffs or other trade restrictions, on our business, operations, strategy and goals.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. We caution you that forward-looking statements are not guarantees of future performance and that our actual results of operations, financial condition, business and prospects may differ materially from those made in or suggested by the forward-looking statements contained in this Quarterly Report on Form 10-Q. In addition, even if our results of operations, financial condition, business and prospects are consistent with the forward-looking statements contained in this Quarterly Report on Form 10-Q, those results may not be indicative of results to be expected in subsequent periods.

You should read this Quarterly Report on Form 10-Q and the documents that we have filed as exhibits to this Quarterly Report on Form 10-Q completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements. The forward-looking statements contained in this Quarterly Report on Form 10-Q are made as of the date of this Quarterly Report on Form 10-Q, 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.

This Quarterly Report on Form 10-Q includes statistical and other industry and market data that we obtained from industry publications and research, surveys and studies conducted by third parties as well as our own estimates of potential market opportunities based on our analysis of these data, research, surveys and studies. All of the market data used in this Quarterly Report on Form 10-Q involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such data. Industry publications and third-party research, surveys and studies generally indicate that their information has been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. Our estimates of the potential market opportunities for our candidates include a number of key assumptions based on our industry knowledge, industry publications and third-party research, surveys and studies, which may be based on a small sample size and fail to accurately reflect market opportunities. While we believe that our internal assumptions are reasonable, no independent source has verified such assumptions.

As used in this Quarterly Report on Form 10-Q, the terms “Solid,” “the Company,” “we,” “us” and “our” refer to Solid Biosciences Inc., and its consolidated subsidiaries, unless the context indicates otherwise.

PART I—FINANCIAL INFORMATION

Item 1. Financial Statements (unaudited)

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(Unaudited)

(in thousands, except share and per share data)


	September 30,			December 31,
	2025			2024
Assets
Current assets:
Cash and cash equivalents	$	61,364		$	80,235
Available-for-sale securities		174,778			68,685
Prepaid expenses and other current assets		8,710			8,382
Total current assets		244,852			157,302
Non-current assets:
Operating lease, right-of-use assets		22,535			24,295
Property and equipment, net		4,356			4,747
Other non-current assets		247			366
Restricted cash		1,924			1,952
Total non-current assets		29,062			31,360
Total assets	$	273,914		$	188,662
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	8,429		$	4,237
Accrued expenses and other current liabilities		19,050			19,852
Operating lease liabilities		2,032			1,787
Finance lease liabilities		281			1,231
Derivative liabilities		6,550			3,150
Total current liabilities		36,342			30,257
Non-current liabilities:
Operating lease liabilities, excluding current portion		19,624			21,159
Total non-current liabilities		19,624			21,159
Total liabilities		55,966			51,416
Commitments and contingencies (Note 10)
Stockholders' equity:
Preferred stock, $0.001 par value — 10,000,000 shares authorized; no shares issued or outstanding at September 30, 2025 and December 31, 2024		—			—
Common stock, $0.001 par value — 240,000,000 and 120,000,000 shares authorized at September 30, 2025 and December 31, 2024, respectively; 77,882,685 and 40,468,141 shares issued and outstanding at September 30, 2025 and December 31, 2024, respectively		78			40
Additional paid-in capital		1,125,810			920,609
Accumulated other comprehensive income		48			47
Accumulated deficit		(907,988	)		(783,450	)
Total stockholders’ equity		217,948			137,246
Total liabilities and stockholders’ equity	$	273,914		$	188,662

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

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

(in thousands, except share and per share data)


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Operating expenses:
Research and development	$	38,861		$	27,327		$	102,190		$	65,661
General and administrative		9,197			7,855			27,613			24,171
Total operating expenses		48,058			35,182			129,803			89,832
Loss from operations		(48,058	)		(35,182	)		(129,803	)		(89,832	)
Other income, net:
Interest income		2,586			2,328			7,852			7,544
Interest expense		336			(82	)		208			(265	)
Change in fair value of derivative liabilities		(850	)		—			(3,400	)		—
Other income, net		210			211			605			453
Total other income, net		2,282			2,457			5,265			7,732
Net loss	$	(45,776	)	$	(32,725	)	$	(124,538	)	$	(82,100	)
Net loss per share, basic and diluted	$	(0.48	)	$	(0.79	)	$	(1.46	)	$	(2.04	)
Weighted average shares of common stock outstanding, used to compute basic and diluted net loss per share		94,417,746			41,443,317			85,069,288			40,182,303

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

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(Unaudited)

(in thousands)


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Net loss	$	(45,776	)	$	(32,725	)	$	(124,538	)	$	(82,100	)
Other comprehensive loss:
Unrealized gain on available-for-sale securities		86			131			1			101
Comprehensive loss	$	(45,690	)	$	(32,594	)	$	(124,537	)	$	(81,999	)

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

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY

(Unaudited)

(in thousands, except share data)


	Nine Months Ended September 30, 2025
	Common Stock				Additional Paid-in		Accumulated Other Comprehensive			Accumulated			Total Stockholders'
	Shares		Amount		Capital		Income			Deficit			Equity
Balance at January 1, 2025		40,468,141	$	40	$	920,609	$	47		$	(783,450	)	$	137,246
Issuance of common stock in public offering, net of issuance costs of $8,665		35,739,810		36		135,331		—			—			135,367
Issuance of pre-funded warrants in public offering, net of issuance costs of $3,366		—		—		52,590		—			—			52,590
Issuance of common stock in private placement for payment of developmental milestone consideration		975,496		1		4,999		—			—			5,000
Issuance of common stock in at-the-market public offering, net of sales commissions of $6		61,542		—		246		—			—			246
Vesting of restricted stock units		247,970		—		—		—			—			—
Unrealized loss on available-for-sale securities		—		—		—		(45	)		—			(45	)
Equity-based compensation expense		—		—		3,341		—			—			3,341
Net loss		—		—		—		—			(39,282	)		(39,282	)
Balance at March 31, 2025		77,492,959		77		1,117,116		2			(822,732	)		294,463
Vesting of restricted stock units		32,189		—		—		—			—			—
Issuance of common stock under employee stock purchase plan		74,860		1		196		—			—			197
Exercises of common stock options		2,733		—		6		—			—			6
Unrealized loss on available-for-sale securities		—		—		—		(40	)		—			(40	)
Equity-based compensation expense		—		—		3,145		—			—			3,145
Net loss		—		—		—		—			(39,480	)		(39,480	)
Balance at June 30, 2025		77,602,741		78		1,120,463		(38	)		(862,212	)		258,291
Issuance of common stock in at-the-market public offering, net of sales commissions of $37		236,616		—		1,419		—			—			1,419
Vesting of restricted stock units		43,328		—		—		—			—			—
Unrealized gain on available-for-sale securities		—		—		—		86			—			86
Equity-based compensation expense		—		—		3,928		—			—			3,928
Net loss		—		—		—		—			(45,776	)		(45,776	)
Balance at September 30, 2025		77,882,685	$	78	$	1,125,810	$	48		$	(907,988	)	$	217,948

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

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY

(Unaudited)

(in thousands, except share data)


	Nine Months Ended September 30, 2024
	Common Stock				Additional Paid-in		Accumulated Other Comprehensive			Accumulated			Total Stockholders'
	Shares		Amount		Capital		Income			Deficit			Equity
Balance at January 1, 2024		20,386,606	$	20	$	785,199	$	15		$	(658,753	)	$	126,481
Issuance of common stock in private placement, net of issuance costs of $4,407		16,973,103		17		89,437		—			—			89,454
Issuance of pre-funded warrants in private placement, net of issuance costs of $704		—		—		14,293		—			—			14,293
Issuance of common stock in at-the-market public offering, net of sales commissions of $78		350,664		1		3,055		—			—			3,056
Vesting of restricted stock units		98,677		—		—		—			—			—
Exercises of common stock options		24,639		—		151		—			—			151
Unrealized loss on available-for-sale securities		—		—		—		(19	)		—			(19	)
Equity-based compensation expense		—		—		1,611		—			—			1,611
Net loss		—		—		—		—			(24,303	)		(24,303	)
Balance at March 31, 2024		37,833,689		38		893,746		(4	)		(683,056	)		210,724
Issuance of common stock in at-the-market public offering, net of sales commissions of $138		526,953		1		5,356		—			—			5,357
Vesting of restricted stock units		131,859		—		—		—			—			—
Issuance of common stock under employee stock purchase plan		56,855		—		145		—			—			145
Exercises of common stock options		1,703		—		10		—			—			10
Unrealized loss on available-for-sale securities		—		—		—		(11	)		—			(11	)
Equity-based compensation expense		—		—		2,092		—			—			2,092
Net loss		—		—		—		—			(25,072	)		(25,072	)
Balance at June 30, 2024		38,551,059		39		901,349		(15	)		(708,128	)		193,245
Issuance of common stock in at-the-market public offering, net of sales commissions of $79		330,670		—		3,099		—			—			3,099
Vesting of restricted stock units		6,874		—		—		—			—			—
Exercises of common stock options		41,600		—		277		—			—			277
Unrealized gain on available-for-sale securities		—		—		—		131			—			131
Equity-based compensation expense		—		—		2,995		—			—			2,995
Net loss		—		—		—		—			(32,725	)		(32,725	)
Balance at September 30, 2024		38,930,203	$	39	$	907,720	$	116		$	(740,853	)	$	167,022

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

SOLID BIOSCIENCES INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

(in thousands)


	Nine Months Ended September 30,
	2025			2024
Cash flows from operating activities:
Net loss	$	(124,538	)	$	(82,100	)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of discount on available-for-sale securities		(1,127	)		(2,789	)
Equity-based compensation expense		10,414			6,698
Depreciation and amortization expense		1,169			1,967
Non-cash lease expense		1,760			1,826
Non-cash acquired in-process research and development		—			3,400
Change in fair value of derivative liabilities		3,400			—
Other		(239	)		(90	)
Changes in operating assets and liabilities:
Prepaid expenses and other assets		(344	)		(2,549	)
Accounts payable		4,164			1,390
Operating lease liabilities		(1,291	)		(1,262	)
Accrued expenses and other liabilities		3,898			3,142
Net cash used in operating activities		(102,734	)		(70,367	)
Cash flows from investing activities:
Purchases of property and equipment		(588	)		(450	)
Proceeds from maturities of available-for-sale securities		107,000			134,800
Purchases of available-for-sale securities		(211,965	)		(189,008	)
Other		85			5
Net cash used in investing activities		(105,468	)		(54,653	)
Cash flows from financing activities:
Proceeds from issuance of common stock and pre-funded warrants in public offering, net of underwriting discounts and commissions		189,637			—
Payments of common stock and pre-funded warrants issuance costs in public offering		(1,681	)		—
Proceeds from issuance of common stock and pre-funded warrants in private placement		—			108,858
Payments of common stock and pre-funded warrants issuance costs in private placement		—			(5,111	)
Proceeds from issuance of common stock in at-the-market public offering, net of sales commissions		1,665			11,512
Proceeds from exercises of common stock options		6			438
Employee stock purchase plan purchases		196			145
Payments of principal portion of finance lease obligations		(520	)		(345	)
Net cash provided by financing activities		189,303			115,497
Net decrease in cash, cash equivalents, and restricted cash		(18,899	)		(9,523	)
Cash, cash equivalents, and restricted cash at beginning of period		82,187			75,848
Cash, cash equivalents, and restricted cash at end of period	$	63,288		$	66,325


	Nine Months Ended September 30,
	2025		2024
Supplemental disclosure of cash flow information:
Cash paid for interest	$	87	$	265
Supplemental disclosure of non-cash investing and operating activities:
Common stock issued as payment for developmental milestone consideration	$	5,000	$	—
Right-of-use assets acquired through operating leases	$	—	$	407
Decrease in right-of-use assets due to lease termination	$	—	$	(261	)
Property and equipment purchases included in accounts payable and accrued expenses	$	329	$	36

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

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets to the amounts reported in the condensed consolidated statements of cash flows:


	September 30,
	2025		2024
Cash and cash equivalents	$	61,364	$	64,394
Restricted cash, non-current		1,924		1,931
Total cash, cash equivalents, and restricted cash, as reported in the condensed consolidated statements of cash flows	$	63,288	$	66,325

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

SOLID BIOSCIENCES INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(amounts in thousands, except share and per share data and where otherwise noted)

1. Nature of the Business and Basis of Presentation

Nature of Business

Solid Biosciences Inc. was organized in March 2013 under the name SOLID Ventures Management, LLC and operated as a Delaware limited liability company until immediately prior to the effectiveness of its registration statement on Form S-1 on January 25, 2018, at which time it completed a statutory corporate conversion into a Delaware corporation and changed its name to Solid Biosciences Inc. (the "Company").

The Company is a life sciences company focused on advancing a portfolio of current and future gene therapy candidates (collectively "Candidates"), including SGT-003 for the treatment of Duchenne muscular dystrophy ("Duchenne"), SGT-212 for the treatment of Friedreich’s ataxia ("FA"), SGT-501 for the treatment of catecholaminergic polymorphic ventricular tachycardia ("CPVT"), SGT-601 for the treatment of TNNT2-mediated dilated cardiomyopathy, and additional assets for the treatment of genetic cardiac and neuromuscular diseases, at different stages of development with varying levels of investment. The Company is advancing its diverse pipeline across rare neuromuscular and cardiac diseases, bringing together experts in science, technology, disease management and care. Patient-focused and founded by those directly impacted by Duchenne, the Company’s mission is to improve the daily lives of patients living with these devastating diseases.

The Company is 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 licenses, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need to obtain additional financing to fund operations. Candidates currently under development will require significant additional research and development efforts, including extensive preclinical studies and clinical trials and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting capabilities.

The Company’s Candidates are in development. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from, among others, other pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, partners, and consultants.

Liquidity

Based upon its current operating plan, the Company expects that its cash, cash equivalents and available-for-sale securities of $236.1 million excluding restricted cash of $1.9 million, as of September 30, 2025, will be sufficient to fund its operating expenses and capital expenditure requirements for at least twelve months from the date of issuance of these condensed consolidated financial statements. However, the Company has based this estimate on assumptions that may prove to be wrong, and its operating plan may change as a result of many factors currently unknown to it. As a result, the Company could deplete its capital resources sooner than it currently expects.

Through September 30, 2025, the Company has funded its operations primarily with the proceeds from the sale of redeemable preferred units and member units as well as the sale of common stock and pre-funded warrants to purchase shares of its common stock in private placements (including the January 2024 Private Placement (as defined below)) and the sale of common stock in its initial public offering, follow-on public offerings in March 2021 and February 2025 and under its at-the-market sales agreement.

The Company expects to continue to generate operating losses for the foreseeable future and to finance its future cash needs through a combination of equity offerings, debt financings, collaborations, strategic partnerships and alliances or licensing arrangements. If the Company is unable to obtain funding, the Company would be forced to delay, reduce or eliminate some or all of its research and development programs, preclinical and clinical testing or commercialization efforts, which could adversely affect its business prospects.

Basis of Presentation

These condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") along with the rules and regulations of the Securities and Exchange Commission for interim financial information and include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The year-end condensed consolidated balance sheet data presented for comparative purposes was derived from the Company’s audited financial statements but does not include all disclosures required by GAAP to constitute a complete set of financial statements. These condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for a fair statement of the Company’s financial position at September 30, 2025 and its results of operations, changes in stockholders’ equity, and cash flows for the interim periods ended September 30, 2025 and 2024.

These unaudited condensed consolidated interim financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. The results of operations for the three and nine months ended September 30, 2025 are not necessarily indicative of the operating results to be expected for the year ending December 31, 2025, for any other interim period, or for any other future year.

Significant Judgments and Estimates

The preparation of the Company’s condensed consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated 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, estimates related to the recognition of research and development expenses, equity-based compensation, and derivative liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ materially from the Company’s estimates.

Summary of Significant Accounting Policies

There have been no changes to the significant accounting policies disclosed in the Company's most recent Annual Report on Form 10‑K.

Recently Issued Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This ASU updates income tax disclosure requirements primarily by requiring specific categories and greater disaggregation within the rate reconciliation and disaggregation of income taxes paid by jurisdiction. This ASU is effective for annual periods beginning after December 15, 2024 and is applicable to the Company’s fiscal year beginning January 1, 2025, with early application permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses (Topic 220) requiring that public business entities disclose additional information about specific expense categories in the notes to financial statements at interim and annual reporting periods. The amendments in this ASU are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. The requirements in this ASU may be applied either prospectively to financial statements issued for reporting periods after the effective date or retrospectively to any or all prior periods presented in the financial statements. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

In September 2025, the FASB issued ASU 2025-07, Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606): Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract. This standard adds a new derivative scope exception for certain non-exchange-traded contracts with underlyings based on operations or activities specific to one party, and clarifies that share-based payments received from a customer in a revenue contract should be accounted for under ASC 606 until the entity's right to receive or retain them is unconditional. This standard will be effective for annual periods beginning after December 15, 2026, and for interim periods within those annual reporting

periods. Early adoption of this standard is permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and disclosures.

2. FA212 Asset Acquisition

On September 19, 2024, the Company entered into an asset purchase agreement with FA212 LLC ("FA212") for the purchase of certain intellectual property, including patents and assigned licenses related to a preclinical drug candidate, which the Company now refers to as SGT-212, assigned manufacturing contracts as well as research and development materials such as manufactured materials and samples.

The Company paid FA212 an upfront payment of $1.0 million in the third quarter of 2024. Additionally, the Company agreed to pay FA212 development milestone payments of up to $34.0 million, cumulative sales milestone payments of up to $21.0 million, and tiered royalties on net sales in the low-single-digits. The Company also assumed from FA212 contingent development milestone payments of up to $4.2 million, regulatory milestone payments of up to $13.0 million, cumulative sales milestone payments of up to $27.5 million, and tiered royalties on worldwide net sales in the mid-single digits payable to the University of Pennsylvania.

Certain development milestone payments to FA212 are payable in either cash, equity, or a combination of both, at the Company's discretion. Such contingent payments were determined to be derivative liabilities and were initially recorded at their fair value of $3.4 million.

The Company determined that the FA212 agreement represented an asset acquisition of in-process research and development assets with no alternative future use and recognized the aggregate acquisition cost of $5.1 million as research and development expense in the third quarter of 2024, which included the upfront payment, initial recognition of the derivative liability and $0.7 million in transaction costs.

The Company submitted an investigational new drug application ("IND") for SGT-212 for the treatment of FA to the U.S. Food and Drug Administration ("FDA"), which was cleared in December 2024. Upon clearance of the IND, the first development milestone of $5.0 million became payable to FA212. The $5.0 million milestone payment is included in Accrued expenses and other current liabilities in the accompanying condensed consolidated balance sheet as of December 31, 2024. On February 28, 2025, the Company made the first development milestone payment in the form of 975,496 shares of its common stock. The derivative liabilities for the remaining contingent payments were recorded at a fair value of $6.6 million and $3.2 million as of September 30, 2025 and December 31, 2024, respectively. See Note 4 - Fair Value Measurements.

3. Outlicensing Agreements

From time to time, the Company enters into non-exclusive license and collaboration agreements for the out-licensing of AAV-SLB101, its proprietary, rationally designed capsid technology used in SGT-003, to both companies and academic institutions pursuing treatments for rare diseases. These arrangements may entitle the Company to receive non-refundable upfront payments, contingent obligations for potential development, regulatory and commercial performance milestone payments, cost reimbursement arrangements, product supply and royalty payments as a percentage of worldwide license product sales. At September 30, 2025, potential future milestone payments under these agreements totaled an aggregate of $44.6 million. None of these milestones were assessed to be probable as of September 30, 2025.

4. Fair Value Measurements

The following tables present information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis:


	September 30, 2025
	Level 1		Level 2		Level 3		Total
Financial assets
Cash equivalents:
Money market funds	$	—	$	42,807	$	—	$	42,807
Treasury bills		—		9,970		—		9,970
Total cash equivalents		—		52,777		—		52,777
Available-for-sale securities (Note 5):
Treasury bills		—		57,781		—		57,781
Government bonds		—		116,997		—		116,997
Total available-for-sale securities		—		174,778		—		174,778
Total financial assets	$	—	$	227,555	$	—	$	227,555

Financial liabilities
Derivative liabilities (Note 2):	$	—	$	—	$	6,550	$	6,550
Total financial liabilities	$	—	$	—	$	6,550	$	6,550


	December 31, 2024
	Level 1		Level 2		Level 3		Total
Financial assets
Cash equivalents:
Money market funds	$	—	$	18,088	$	—	$	18,088
Treasury bills		—		17,434		—		17,434
Total cash equivalents		—		35,522		—		35,522
Available-for-sale securities (Note 5):
Treasury bills		—		27,895		—		27,895
Government bonds		—		40,790		—		40,790
Total available-for-sale securities		—		68,685		—		68,685
Total financial assets	$	—	$	104,207	$	—	$	104,207
Financial liabilities
Derivative liabilities (Note 2):	$	—	$	—	$	3,150	$	3,150
Total financial liabilities	$	—	$	—	$	3,150	$	3,150

As of September 30, 2025 and December 31, 2024, the fair values of the Company’s cash equivalents and available-for-sale securities were determined using Level 2 inputs.

The Company estimated the fair value of the derivative liabilities by using a Monte Carlo simulation forecasting the timing and likelihood of certain development milestone events being achieved and discounting the probability of adjusted payments using an appropriate discount rate based on market interest rates. The main assumptions when determining the fair value of the derivative liabilities are the timing and probability of achieving certain milestones, the estimated volatility of the Company’s common stock, and the discount rate. The estimated fair value presented is not necessarily indicative of an amount that could be realized in a current market exchange. The use of alternative inputs and estimation methodologies could have a material effect on these estimates of fair value.

The significant unobservable inputs used in valuing the developmental milestone derivative liabilities at each measurement date are as follows:


	September 30, 2025		December 31, 2024
Unobservable Input	Range	Average	Range	Average
Probability of achieving certain development milestones	28.0% - 70.0%	49.0%	28.0% - 70.0%	49.0%
Volatility	94.0%	94.0%	85.0%	85.0%
Discount rate	3.6% - 4.0%	3.8%	4.2% - 4.3%	4.3%
Timing of achieving certain development milestones	0.3 - 2.9 years	1.6 years	1.0 - 3.7 years	2.3 years

The following table presents a roll forward of activity associated with the Company’s derivative liabilities measured using Level 3 inputs:


	Developmental Milestone Derivative Liabilities
Fair value of derivative liabilities as of January 1, 2025	$	3,150
Change in fair value of derivative liabilities		3,400
Fair value of derivative liabilities as of September 30, 2025	$	6,550

The Company recognized losses of $0.9 million and $3.4 million for the change in fair value of the derivative liabilities during the three and nine months ended September 30, 2025, respectively. No gain or loss was recognized during the three or nine months ended September 30, 2024.

It is the Company's policy to recognize transfers between levels of the fair value hierarchy, if any, at the end of the reporting period. During the nine months ended September 30, 2025, and the year ended December 31, 2024, there were no transfers between Level 1, Level 2, and Level 3.

As of September 30, 2025, and December 31, 2024, the Company's accounts payable, accrued expenses, and other current liabilities approximated their estimated fair values due to the short-term nature of these financial instruments.

5. Available-for-Sale Securities

A summary of the Company's available-for-sale securities is presented below:


	September 30, 2025
Description	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Treasury bills maturing in one year or less	$	57,777	$	6	$	(2	)	$	57,781
Government bonds maturing in one year or less		116,953		45		(1	)	$	116,997
Total available-for-sale securities	$	174,730	$	51	$	(3	)	$	174,778


	December 31, 2024
Description	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Treasury bills maturing in one year or less	$	27,879	$	16	$	—	$	27,895
Government bonds maturing in one year or less		40,759		31		—		40,790
Total available-for sale securities	$	68,638	$	47	$	—	$	68,685

The weighted average contractual maturity of the Company’s available-for-sale securities was approximately 0.6 years and 0.5 years as of September 30, 2025, and December 31, 2024, respectively.

6. Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following:


	September 30, 2025		December 31, 2024
Prepaid research and development expenses	$	5,600	$	6,731
Prepaid other and other current assets		3,110		1,651
Total	$	8,710	$	8,382

7. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following:


	September 30, 2025		December 31, 2024
Accrued research and development expenses	$	10,418	$	7,268
Accrued compensation		7,160		6,221
Accrued milestone payment (Note 2)		—		5,000
Accrued other and other current liabilities		1,472		1,363
Total	$	19,050	$	19,852

8. Stockholders' Equity

On January 11, 2024, the Company issued and sold in a private placement 16,973,103 shares of the Company’s common stock at a price per share of $5.53 and, to one investor in lieu of shares of common stock, pre-funded warrants to purchase 2,712,478 shares of common stock at a price of $5.529 per pre-funded warrant, (the "January 2024 Private Placement"). The Company received $103.7 million of net proceeds from the January 2024 Private Placement after deducting offering costs.

On February 19, 2025, the Company issued and sold 35,739,810 shares of its common stock at a price per share of $4.03 and, to certain investors in lieu of shares of common stock, pre-funded warrants to purchase 13,888,340 shares of common stock at a price of $4.029 per pre-funded warrant (the "February 2025 Offering"). The Company received approximately $188.0 million of net proceeds from the February 2025 Offering after deducting underwriting discounts and commissions and offering costs.

The Company determined the pre-funded warrants met the criteria for equity classification. No warrants were exercised during the nine months ended September 30, 2025.

9. Equity-Based Compensation

Equity-Based Compensation Expense

The Company has classified equity-based compensation expense in its condensed consolidated statements of operations as follows:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	1,342	$	934	$	3,560	$	2,314
General and administrative		2,586		2,061		6,854		4,384
Total	$	3,928	$	2,995	$	10,414	$	6,698

Equity Incentive Plans

As of September 30, 2025, the Company’s approved equity incentive plans include: the 2018 Omnibus Incentive Plan (the "2018 Plan"); Amended and Restated 2020 Equity Incentive Plan, as amended (the "2020 Plan"); the Amended and Restated 2021 Employee Stock Purchase Plan; and the 2024 Inducement Stock Incentive Plan (the "2024 Plan"). These plans are administered by the Board of Directors (the "Board") and permit the granting of stock options, stock appreciation rights, restricted stock, restricted stock units (the "RSUs"), performance awards, and other stock‑based or cash-based awards. Upon the adoption of the 2020 Plan, the Company no longer grants new equity awards under its 2018 Plan.

Amended and Restated 2020 Equity Incentive Plan

On June 12, 2025 and June 11, 2024, the Company's stockholders approved amendments to the 2020 Plan to increase the number of shares of common stock reserved for issuance under the plan by 9,000,000 shares and 2,000,000 shares, respectively. As of September 30, 2025, there were 3,520,813 stock options outstanding, 2,975,050 RSUs outstanding, 2,074,188 performance stock units outstanding, and 7,552,961 shares remained available for future issuance under the 2020 Plan.

2024 Inducement Stock Incentive Plan

In March 2024, the Board approved the 2024 Plan, which provides for the reservation of 1,000,000 shares of common stock for equity granted as an inducement material to the individual’s entering into employment with the Company and in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). As of September 30, 2025, there were 100,000 stock options outstanding, 603,291 RSUs outstanding, and 239,931 shares remained available for future issuance under the 2024 Plan.

Stock Options

The table below summarizes the activity with respect to stock options for the nine months ended September 30, 2025:


	Number of Options			Weighted Average Exercise Price		Remaining Contractual Life (in years)		Aggregate Intrinsic Value
Outstanding at January 1, 2025		2,927,937		$	18.22		8.01	$	193
Granted		1,752,148		$	5.58
Exercised		(2,733	)	$	2.35
Expired		(192,579	)	$	50.81
Forfeitures		(104,817	)	$	6.10
Outstanding at September 30, 2025		4,379,956		$	12.03		8.48	$	1,657
Vested and expected to vest at September 30, 2025		4,379,956		$	12.03		8.48	$	1,657
Exercisable at September 30, 2025		1,759,673		$	20.85		7.44	$	360

The assumptions used in the Black-Scholes option-pricing model for all stock options granted during each period presented are as follows:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2025	2024	2025	2024
Common stock price	$6.17	$8.64	$4.10 - $6.17	$5.76 - $8.64
Expected volatility	111.7%	119.7%	111.7% - 114.2%	119.7% - 128.7%
Expected dividends	0%	0%	0%	0%
Expected term (in years)	6.38	6.08	5.31 - 6.38	5.31 - 6.25
Risk-free rate	4.0%	3.7%	4.0% - 4.4%	3.7% - 4.4%

The weighted average grant date fair values of stock options granted during the three months ended September 30, 2025 and 2024 were $5.31 and $7.56, respectively, and the weighted average grant date fair values of stock options granted during the nine months ended September 30, 2025 and 2024 were $4.77 and $6.96, respectively.

The Company recognized $1.6 million and $1.6 million of equity-based compensation expense in connection with stock options during the three months ended September 30, 2025 and 2024, respectively. During the nine months ended September 30, 2025 and 2024, the Company recognized equity-based compensation expense in connection with stock options of $4.1 million and $3.6 million, respectively. As of September 30, 2025, there was $12.7 million of total unrecognized equity-based compensation expense related to unvested stock options, which is expected to be recognized over a weighted average period of 2.5 years.

Restricted Stock Units

The following table summarizes activity with respect to RSUs during the nine months ended September 30, 2025:


	Units			Weighted- Average Grant Date Fair Value
Nonvested RSUs at January 1, 2025		1,480,272		$	7.50
Granted		2,904,036		$	3.91
Vested		(323,487	)	$	7.75
Forfeitures		(306,201	)	$	4.69
Nonvested RSUs at September 30, 2025		3,754,620		$	4.93

The Company recognized $1.3 million and $0.8 million of equity-based compensation expense in connection with RSUs during the three months ended September 30, 2025 and 2024, respectively. During the nine months ended September 30, 2025 and 2024, the Company recognized equity-based compensation expense in connection with RSUs of $3.4 million and $2.2 million, respectively. As of September 30, 2025, there was $15.5 million of total unrecognized equity-based compensation expense related to nonvested RSUs, which is expected to be recognized over a weighted average period of 3.1 years.

Performance Stock Units

In June 2024, the Board approved a grant of performance-based restricted stock unit awards ("PSUs" or "Performance Awards") to the Company’s executive team. Each PSU represents the contingent right to receive one share of the Company’s common stock. These

Performance Awards provide for the vesting of 25% of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board ("Performance Milestones"), subject to the grantee’s continued service with the Company (the "Approval Conditions").

The Performance Milestones are tied to the achievement of certain business objectives and are non-market and non-financial in nature. The Board will determine that all Approval Conditions have been satisfied and the number of units that will ultimately vest on the 2026 Evaluation Date, which will occur in the first quarter of 2026, and the 2027 Evaluation Date, which will occur in the first quarter of 2027. A maximum of 25% of the target number of RSUs may vest at the 2026 Evaluation Date and the percentage of the target number of RSUs allocable to any Performance Milestone that has not been achieved on or prior to the 2027 Evaluation Date shall be cancelled.

The following table summarizes activity with respect to PSUs during the nine months ended September 30, 2025:


	Units			Weighted- Average Grant Date Fair Value
Nonvested PSUs at January 1, 2025		2,165,325		$	7.51
Granted		—		$	—
Vested		—		$	—
Forfeitures		(91,137	)	$	7.51
Nonvested PSUs at September 30, 2025		2,074,188		$	7.51

The Company recognized $0.9 million and $0.6 million of equity-based compensation expense in connection with PSUs during the three months ended September 30, 2025 and 2024, respectively. During the nine months ended September 30, 2025 and 2024, the Company recognized equity-based compensation expense in connection with PSUs of $2.7 million and $0.6 million, respectively.

As of September 30, 2025, there was $2.9 million of unrecognized equity-based compensation expense related to nonvested PSUs based on the achievement of all Performance Milestones, which is expected to be recognized over a weighted average period of 1.1 years.

10. Commitments and Contingencies

Letter of Credit

The Company had an outstanding letter of credit in the amount of $1.9 million and $2.0 million at September 30, 2025 and December 31, 2024, respectively, which is required as a condition of the Company’s office and laboratory lease.

Indemnification Agreements

In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with its executive officers and members of its Board that require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as executive officers or directors of the Company. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification arrangements.

The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of September 30, 2025 and December 31, 2024.

Legal Proceedings

The Company may periodically become subject to legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which the Company is focused. The Company is not aware of any material legal proceedings or claims as of September 30, 2025.

11. Net Loss Per Share

The following table sets forth the computation of the Company's basic and diluted net loss per share:


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Numerator:
Net loss	$	(45,776	)	$	(32,725	)	$	(124,538	)	$	(82,100	)
Denominator:

Solid Biosciences Inc. 10-Q