Today, Dyne Therapeutics, a clinical-stage company dedicated to developing life-changing treatments for individuals with genetically driven neuromuscular diseases, announced that DYNE-251 has been designated as an orphan drug by the European Commission (EC) for the treatment of Duchenne muscular dystrophy (DMD). DYNE-251 is being tested in DMD patients who are susceptible to exon 51 skipping in the Phase 1/2 DELIVER global clinical study. (Exon 51 Skipping Therapies)
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Phase 1/2 trial of DYNE-251
At the 2025 Muscular Dystrophy Association (MDA) Clinical & Scientific Conference in March, long-term clinical data from the ongoing DELIVER study of DYNE-251 were presented. These data showed an unparalleled and sustained functional improvement at the chosen registrational dose. Stride Velocity 95th Centile (SV95C), an objective digital outcome recognized as a primary endpoint for DMD clinical studies in Europe, is one of the functional assessments used in the DELIVER trial. (Read more: Phase 1/2 DELIVER Trial of DYNE-251)
What is orphan drug?
The EC grants orphan drug designation to drugs and biologics intended for the treatment, diagnosis or prevention of rare, life-threatening or chronically debilitating diseases or conditions that affect fewer than five in 10,000 people in the European Union (EU). Orphan designation provides companies with certain benefits, including reduced regulatory fees, clinical protocol assistance, research grants and the potential for up to 10 years of market exclusivity in the EU if approved. DYNE-251 was also granted U.S. Food and Drug Administration (FDA) orphan drug and rare pediatric disease designations in March 2023.
Key Milestones for the DELIVER Trial
- Dyne continues to pursue expedited approval pathways globally for DYNE-251 in patients with DMD who are amenable to exon 51 skipping.
- Dyne has fully enrolled the registrational expansion cohort of 32 patients as part of the DELIVER trial. Data from this cohort are planned for late 2025.
- Dyne anticipates filing a Biologics License Application (BLA) submission for US accelerated approval in early 2026.
About DYNE-251
DYNE-251 is an investigational therapeutic being evaluated in the Phase 1/2 global DELIVER clinical trial for people living with DMD who are amenable to exon 51 skipping.
DYNE-251 has been granted fast track, orphan drug and rare pediatric disease designations by the U.S. Food and Drug Administration for the treatment of DMD mutations amenable to exon 51 skipping.
