Solid Biosciences Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business Updates

– Duchenne (SGT-003): Positive interim Phase 1/2 INSPIRE DUCHENNE data reported at the 2026 MDA Annual Meeting continued to suggest differentiated clinical, safety and tolerability profiles; SGT-003 has been generally well tolerated in the 41 participants dosed as of March 18, 2026 –

– Company anticipates dosing the first participant in the Phase 3 IMPACT DUCHENNE trial in April 2026; additional meetings planned with FDA in H1 2026 for guidance on a potential accelerated approval pathway for SGT-003 –

– Friedreich’s Ataxia (SGT-212): First participant dosed in the Phase 1b FALCON trial; SGT-212 has been well tolerated with no treatment-related adverse events –

– CPVT (SGT-501): Clinical sites activated for Phase 1b ARTEMIS first-in-human clinical trial evaluating SGT-501 for the treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT); first participant dosing expected in Q2 2026 –

– Strong Capital Position: Cash, cash equivalents and available-for-sale securities of $187.9 million at December 31, 2025; in March 2026, the Company completed a $240 million private placement; the Company’s cash runway is anticipated to extend into H1 2028 –

CHARLESTOWN, Mass., March 19, 2026 (GLOBE NEWSWIRE) — Solid Biosciences Inc. (Nasdaq: SLDB) (the “Company” or “Solid”), a life sciences company developing precision genetic medicines for neuromuscular and cardiac diseases, today reported financial results for the fourth quarter and full year ended December 31, 2025, and provided a business update.

Bo Cumbo, President and CEO of Solid Biosciences, commented, “We continue to build momentum across our portfolio, highlighted by updated interim INSPIRE DUCHENNE data presented at MDA, positive feedback from our FDA Type C meeting on the Phase 3 IMPACT DUCHENNE trial design for SGT-003, the dosing of our first participant in the FALCON trial for SGT-212 and the completion of an oversubscribed $240 million private placement. Together, these achievements strengthen our operational and financial foundation and position Solid to deliver on the promise of our science and improve the daily lives of people living with devastating rare diseases.

“Looking to the year ahead, we expect several important milestones, including continued engagement with the FDA to seek guidance on a potential accelerated approval pathway for SGT-003 for the treatment of Duchenne, dosing the first participant in the Phase 3 IMPACT DUCHENNE trial for SGT-003 and the Phase 1b ARTEMIS trial for SGT-501, and further progressing each of our clinical stage programs. With multiple anticipated regulatory and clinical milestones ahead, we believe 2026 will be a transformational year for Solid.”

Company Updates

Neuromuscular Pipeline

SGT-003 Next-Generation Duchenne Muscular Dystrophy (Duchenne) Program

• SGT-003 continued to be generally well tolerated in the 41 participants dosed as of March 18, 2026; SGT-003 is administered using a lower-burden, steroid-only prophylactic immunomodulation regimen.
• As announced on March 11, 2026, the Company reported positive interim data from the ongoing Phase 1/2 INSPIRE DUCHENNE clinical trial.
  • Updated interim data provided continuing evidence suggesting a disease-relevant treatment effect.
  • Observed robust microdystrophin expression and restoration of key components of the dystrophin-associated protein complex (DAPC), including beta-sarcoglycan and neuronal nitric oxide synthase (nNOS).
  • Observed improvements across an extensive panel of muscle integrity biomarkers.
  • Observed stabilization and improvement in cardiac function as measured by left ventricular ejection fraction (LVEF).
  • Participant dosing remains ongoing in the INSPIRE DUCHENNE trial.
• The Company announced on February 9, 2026, that it had reached alignment with the FDA on the overall study design for IMPACT DUCHENNE, Solid’s randomized, double-blind, placebo-controlled Phase 3 clinical trial of SGT-003.
  • Participant screening is underway and the Company anticipates dosing the first participant in the IMPACT DUCHENNE trial in April 2026.
• In the first half of 2026, the Company plans to have additional meetings with the FDA to receive guidance on a potential accelerated approval pathway for SGT-003.

SGT-212 for Friedreich’s ataxia (FA)

• As announced on January 12, 2026, the first participant was dosed in the Phase 1b FALCON clinical trial evaluating SGT-212 for the treatment of FA.
• SGT-212 was well tolerated with no treatment-related adverse events as of March 18, 2026.
• Participant dosing remains ongoing with initial data expected in the second half of 2026, subject to participant enrollment.

Cardiac Pipeline
SGT-501 for Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

• Clinical trial sites have been activated and participant screening is underway for the Phase 1b ARTEMIS trial.
• The first participant is expected to be dosed in the second quarter of 2026, with initial safety data anticipated in the second half of 2026, subject to participant enrollment.

Platform Technologies – Capsids

• In March 2026, AAV-SLB101, the Company’s next-generation, muscle-tropic capsid used in SGT-003, was renamed POLARIS-101™.
• Solid has executed 50+ agreements, including licenses, with corporations, institutions and academic labs for the use of POLARIS-101^™.

Oversubscribed $240 Million Private Placement

• On March 6, 2026, the Company announced that it had entered into a securities purchase agreement with a select group of institutional accredited investors for a private placement of approximately $240 million in gross proceeds.
• Solid expects to use net proceeds from the private placement to fund ongoing pipeline development programs, business development activities, and for working capital and other general corporate purposes.

Fourth Quarter and Full-Year 2025 Financial Highlights

• Cash Position: Solid had $187.9 million in cash, cash equivalents, and available-for-sale securities as of December 31, 2025, compared to $148.9 million as of December 31, 2024. Including the net proceeds from the $240 million private placement, the Company expects that its existing cash, cash equivalents, and available-for-sale securities will be sufficient to fund its operational runway into the first half of 2028.
• Research and Development (R&D) Expenses: R&D expenses for the fourth quarter of 2025 were $38.1 million, compared to $30.8 million for the fourth quarter of 2024. Research and development expenses for the full year ended December 31, 2025, were $140.3 million, compared to $96.4 million for the full year ended December 31, 2024. The increase of $43.9 million in research and development expenses was primarily due to a $43.8 million increase in costs for SGT-003 related to manufacturing and clinical costs, a $10.3 million increase in personnel related expenses, a $5.0 million increase in costs for SGT-601 primarily related to manufacturing and research costs, partially offset by a net decrease of $7.6 million in costs for SGT-501 related to lower manufacturing and study costs partially offset by an increase in clinical, regulatory and licensing fees, and a $6.0 million decrease in costs for other development programs.
• General and Administrative (G&A) Expenses: G&A expenses for the fourth quarter of 2025 were $11.3 million, compared to $9.1 million for the fourth quarter of 2024. General and administrative expenses for the full year ended December 31, 2025, were $38.9 million, compared to $33.3 million for the full year ended December 31, 2024. The increase of $5.6 million was primarily related to a $6.1 million increase in personnel related costs and a $0.6 million increase in information technology support and services, partially offset by a $1.1 million decrease in general legal fees.
• Net Loss: Net loss for the fourth quarter of 2025 was $49.8 million, compared to a net loss of $42.6 million for the fourth quarter of 2024. Net loss for the full year ended December 31, 2025, was $174.3 million, compared to a net loss $124.7 million for the full year ended December 31, 2024.

About SGT-003
SGT-003 is an investigational gene therapy containing a differentiated microdystrophin construct and a proprietary, next-generation capsid, POLARIS-101™ (formerly known as AAV-SLB101), which was rationally designed to target integrin receptors, and has shown enhanced cardiac and skeletal muscle transduction with decreased liver targeting in data from the Phase 1/2 INSPIRE DUCHENNE clinical trial and in nonclinical studies. SGT-003’s microdystrophin construct uniquely includes the R16/17 domains, which localize nNOS to the muscle. Nonclinical studies have shown that nNOS can improve blood flow to the muscle thereby reducing muscle breakdown from ischemia and muscle fatigue. Together, these design features suggest that SGT-003 could be a potential best-in-class investigational gene therapy for the treatment of Duchenne.

About the INSPIRE DUCHENNE Clinical Trial
INSPIRE DUCHENNE is a first-in-human, open-label, single-dose, multicenter Phase 1/2 clinical trial to evaluate the safety, tolerability and efficacy of SGT-003 in pediatric participants with a genetically confirmed Duchenne diagnosis with a documented dystrophin gene mutation. INSPIRE DUCHENNE is a multinational trial designed to enroll participants in the United States, Canada, the United Kingdom and Italy.

About the IMPACT DUCHENNE Clinical Trial
IMPACT DUCHENNE is a Phase 3 randomized, double-blind, placebo-controlled trial to evaluate the efficacy of a single dose of SGT-003 in ambulatory participants aged 7 to less than 12 with a genetically confirmed Duchenne diagnosis. IMPACT DUCHENNE is a multinational trial intended to support potential regulatory authorizations.

About SGT-212
SGT-212 is a recombinant AAV-based gene replacement therapy for Friedreich’s ataxia (FA) designed to deliver full-length human frataxin (FXN) via a dual route of administration: intradentate nucleus (IDN) infusion, using an FDA-approved neurosurgical device in a stereotactic, precision MRI-guided technique, followed by an intravenous (IV) infusion, with the intent to increase therapeutic FXN levels in the cerebellar dentate nuclei, cardiomyocytes and other systemic tissues. Targeted delivery to the dentate nuclei will be confirmed in real time via MRI. Restoration of FXN levels is expected to repair the underlying mitochondrial dysfunction in neurons and cardiomyocytes to address neurologic, cardiac and systemic manifestations of the disease.

About the FALCON Clinical Trial
FALCON is a first-in-human, open-label, multi-center Phase 1b clinical trial designed to evaluate the safety and tolerability of SGT-212 in participants aged 18-40 who have been diagnosed with FA. FALCON is being conducted in the United States.

About Solid Biosciences
Solid Biosciences is a precision genetic medicine company focused on advancing a portfolio of gene therapy candidates targeting rare neuromuscular and cardiac diseases, including SGT-003 for Duchenne muscular dystrophy (Duchenne), SGT-212 for Friedreich’s ataxia (FA), SGT-501 for catecholaminergic polymorphic ventricular tachycardia (CPVT), SGT-601 for TNNT2-mediated dilated cardiomyopathy and additional fatal, genetic cardiac diseases. The Company is also focused on developing innovative libraries of genetic regulators and other enabling technologies with promising potential to significantly impact gene therapy delivery cross-industry. Solid is advancing its diverse pipeline and delivery platform in the pursuit of uniting experts in science, technology, disease management, and care. Patient-focused and founded by those directly impacted by Duchenne, Solid’s mission is to improve the daily lives of patients living with devastating rare diseases. For more information, please visit www.solidbio.com.

Cautionary Note Regarding Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding future expectations, plans and prospects for the company; the ability to successfully achieve and execute on the company’s goals; anticipated benefits of SGT-003, SGT-212, SGT-501and other pre-clinical programs and technologies; strategies and expectations for the company’s SGT-003 program, SGT-212, SGT-501, SGT-601 and other pre-clinical programs and technologies; expectations for planned enrollment, planned regulatory interactions and the potential approval pathways for SGT-003, SGT-212 and SGT-501; the cash runway of the company and the sufficiency of the Company’s cash, cash equivalents, and available-for-sale securities to fund its operations; and other statements containing the words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “would,” “working” and similar expressions. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in, or implied by, such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with the company’s ability to advance SGT-003, SGT-212, SGT-501, SGT-601 and other preclinical programs, capsid libraries and other enabling technologies on the timelines expected or at all; obtain and maintain necessary approvals from the FDA and other regulatory authorities; replicate in clinical trials positive results found in preclinical studies and early-stage clinical trials of the company’s product candidates; manufacture sufficient quantities of our drug product in a timely manner and maintain adequate supply to support our clinical development and potential commercialization; obtain, maintain or protect intellectual property rights related to its product candidates; replicate preliminary or interim data from clinicals trials in the final data of such trials; compete successfully with other companies that are seeking to develop Duchenne, FA, CPVT and other neuromuscular and cardiac treatments and gene therapies; manage expenses; and raise the substantial additional capital needed, on the timeline necessary, to continue development of SGT-003, SGT-212, SGT-501, SGT-601 and other candidates; achieve its other business objectives and continue as a going concern. For a discussion of other risks and uncertainties, and other important factors, any of which could cause the company’s actual results to differ from those contained in the forward-looking statements, see the “Risk Factors” section, as well as discussions of potential risks, uncertainties and other important factors, in the company’s most recent filings with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent the company’s views as of the date hereof and should not be relied upon as representing the company’s views as of any date subsequent to the date hereof. The company anticipates that subsequent events and developments will cause the company’s views to change. However, while the company may elect to update these forward-looking statements at some point in the future, the company specifically disclaims any obligation to do so.

Solid Biosciences Investor Contact:
Nicole Anderson
Senior Director, Investor Relations and Corporate Communications
Solid Biosciences Inc.
investors@solidbio.com

Media Contact:
Glenn Silver
FINN Partners
glenn.silver@finnpartners.com