Sarepta Shows Dose-Dependent Muscle Uptake and Biomarker Effects in FSHD1, DM1 Trials
Phase 1/2 studies of SRP-1001 (FSHD1) and SRP-1003 (DM1) demonstrated dose-dependent muscle siRNA exposure, early biomarker improvements, and proof-of-concept target protein/mRNA knockdown after a single dose. Both programs showed favorable safety profiles with mostly mild-to-moderate adverse events and no dose-limiting toxicities.
1. Positive Phase 1/2 Clinical Data
Sarepta reported first clinical results from its SRP-1001 and SRP-1003 siRNA programs in FSHD1 and DM1, respectively. Data showed clear dose-dependent increases in muscle and plasma drug exposure alongside early reductions in DUX4 protein for FSHD1 and DMPK mRNA for DM1 after a single dose.
2. Favorable Safety Profile
Across both trials, the majority of adverse events were mild to moderate and showed no clear dose dependency. There were no dose-limiting safety signals, supporting continued escalation and confidence in tolerability for chronic administration.
3. αvβ6 Integrin-Targeted Delivery Platform
These investigational treatments leverage an optimized siRNA chemistry coupled with a proprietary αvβ6 integrin-targeted ligand to enhance muscle uptake and penetration. This targeted approach aims to overcome rapid degradation issues and enable higher effective dosing in neuromuscular tissues.
4. Next Steps and Pipeline Outlook
Sarepta will discuss detailed results during an investor call on March 25, 2026. Beyond FSHD1 and DM1, the company’s next-generation siRNA platform also includes programs for idiopathic pulmonary fibrosis, spinocerebellar ataxias, Huntington’s disease and others.