CHARLESTOWN, Mass. — May 7, 2026 — Leads & Copy — Solid Biosciences Inc. (Nasdaq: SLDB), a life sciences company focused on precision genetic medicines for neuromuscular and cardiac diseases, has announced the dosing of the first participant in its Phase 3 IMPACT DUCHENNE clinical trial.
The multi-country, placebo-controlled, randomized, double-blind trial is investigating SGT-003 for the treatment of Duchenne muscular dystrophy (Duchenne).
IMPACT DUCHENNE and the ongoing Phase 1/2 INSPIRE DUCHENNE clinical trials are designed to evaluate the safety and efficacy of a single intravenous dose of SGT-003 in individuals with Duchenne.
To date, 46 participants have been dosed with SGT-003 in the Phase 1/2 INSPIRE DUCHENNE trial using a steroid-only prophylactic immunomodulation regimen. As of May 4, 2026, SGT-003 has been generally well tolerated.
According to Gabriel Brooks, M.D., Chief Medical Officer of Solid Biosciences, initiating the Phase 3 trial marks a critical moment for both the company and the Duchenne community. Brooks stated the trial reinforces the company’s conviction in SGT-003 and commitment to generating high-quality data to inform potential additional treatment options.
The first participant in the Phase 3 trial was dosed in Australia at The Children’s Hospital at Westmead.
Solid Biosciences has also received a positive opinion from the European Medicines Agency (EMA) on its Pediatric Investigation Plan (PIP) for SGT-003, establishing alignment on a pediatric clinical development framework in Europe. Approval of a PIP is required for a future marketing authorization application. SGT-003 has also received Orphan drug designation from the European Commission.
Additionally, Solid was one of three recipients of the newly relaunched Innovation Passport under the UK’s Innovative Licensing and Access Pathway (ILAP), aimed at expediting patient access to transformative products addressing unmet clinical needs.
SGT-003 is an investigational gene therapy with a novel microdystrophin construct and the POLARIS-101TM capsid, designed to target integrin receptors. Data from the Phase 1/2 INSPIRE DUCHENNE clinical trial and nonclinical studies have shown enhanced cardiac and skeletal muscle transduction with decreased liver targeting. The microdystrophin construct includes the R16/17 domains, which localize nNOS to the muscle, potentially improving blood flow and reducing muscle breakdown.
The INSPIRE DUCHENNE trial is being conducted at clinical sites in the United States, Canada, the United Kingdom and Italy. Clinical trial sites for IMPACT DUCHENNE are currently active in Australia and Canada, with additional sites expected in the UK and US in the second half of 2026, followed by sites in the EU, subject to regulatory clearances.
Duchenne is a genetic muscle-wasting disease primarily affecting boys, with symptoms appearing between three and five years of age. It affects approximately one in every 5,000 live male births and has an estimated prevalence of 10,000 to 15,000 cases in the United States.
Solid Biosciences is focused on advancing a portfolio of gene therapy candidates targeting rare neuromuscular and cardiac diseases.
Solid Biosciences 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.
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.
Source: Solid Biosciences
