Solid Biosciences Achieves 91% Microdystrophin Expression, 44% eMHC Reduction in Trial
Solid Biosciences dosed 40 Duchenne patients with SGT-003 demonstrating microdystrophin expression of 60% (Day 90) rising to 91% (Day 360), restored 60%–69% beta-sarcoglycan fibers, 35% nNOS activity and 44% reduction in eMHC-positive fibers. SGT-003 was well tolerated with steroid-only immunomodulation and Solid expects FDA guidance on accelerated approval in mid-2026.
1. Interim Efficacy Data
Forty pediatric Duchenne patients received a single 1E14vg/kg SGT-003 infusion, with mean microdystrophin expression rising from 60% at Day 90 to 91% at Day 360 by western blot. Biopsies also showed restoration of 60%–69% beta-sarcoglycan fibers, 35% nNOS activity and a 44% reduction in eMHC-positive fibers, indicating improved muscle integrity and potential interruption of the degeneration–regeneration cycle.
2. Safety and Administration
SGT-003 was administered intravenously under a low-burden, steroid-only prophylactic immunomodulation regimen and was generally well tolerated across all 40 dosed participants. No serious adverse events related to treatment were reported, reinforcing the candidate’s favorable safety profile in ongoing Phase 1/2 evaluation.
3. Regulatory Plans and Next Milestones
Solid Biosciences plans additional meetings with the FDA in the first half of 2026 to discuss an accelerated approval pathway for SGT-003 and expects to provide a more detailed regulatory update by mid-2026. Participant dosing continues across 15 sites in the US, Canada, Italy and the UK, supporting the company’s drive toward potential approval and commercialization.