Solid Biosciences Aligns with FDA on SGT-003 Trial Design

Solid Biosciences announced a regulatory update from its recent Type C meeting with the U.S. Food and Drug Administration that supports the continued advancement of SGT-003 as a potential treatment for Duchenne muscular dystrophy. Solid reached alignment with the FDA on the overall study design for the Company's randomized, double-blind, placebo-controlled Phase 3 clinical trial, IMPACT DUCHENNE. The FDA agreed that the trial design was reasonable including: the patient population of ambulant participants 7 to less than12 years of age, the primary endpoint of change from baseline in Time to Rise velocity from supine position evaluated at 18 months and other key secondary endpoints. "As outlined at the start of 2026, we have structured our U.S. regulatory strategy around engaging with the FDA regarding a potential accelerated approval pathway for SGT-003, and the successful alignment on the design of our Phase 3 IMPACT DUCHENNE trial marks a critical first step in that plan," said Bo Cumbo, President & CEO of Solid Biosciences. "The IMPACT DUCHENNE trial is currently planned to be conducted at sites in Australia, Canada, the EU and the UK. Due to strong key opinion leader and patient demand, we are also evaluating the potential to open sites in the US. 36 participants have been dosed in the ongoing Phase 1/2 INSPIRE DUCHENNE trial and SGT-003 continues to be generally well tolerated as of a February 9, 2026, cutoff. With dosing of the first participant in the Phase 3 IMPACT DUCHENNE trial expected later this quarter, this regulatory clarity adds further momentum to SGT-003 as we progress toward our second meeting with the FDA where we plan to discuss the confirmatory evidence necessary to support a potential accelerated approval pathway. Our dedication to the Duchenne community remains unwavering: they deserve therapeutic options, and we are committed to collaborating with the FDA to help make that a reality," Mr. Cumbo concluded.