The European Commission (EC) has granted orphan drug designation to Dyne Therapeutics’ DYNE-251 for treating Duchenne muscular dystrophy (DMD).
This designation is pivotal for developing DYNE-251, which is currently being evaluated in the Phase I/II DELIVER trial for DMD individuals amenable to exon 51 skipping.
The trial’s long-term clinical data showed functional improvement at the chosen registrational dose.
Its functional evaluations include the objective digital outcome, Stride Velocity 95th Centile (SV95C), which is recognised as a primary endpoint for the European DMD studies.
Dyne Therapeutics is committed to pursuing accelerated approval pathways for the therapy worldwide, especially for individuals with DMD who may benefit from exon 51 skipping therapies.
The company has enrolled 32 subjects in the registrational expansion cohort of the DELIVER trial, with data expected by late 2025.
Furthermore, it anticipates submitting a biologics license application for accelerated approval in the US in early 2026.
According to the company, the therapy comprises a phosphorodiamidate morpholino oligomer, which is conjugated to a fragment antibody that attaches to the transferrin receptor 1, facilitating the delivery of targeted muscle tissue.
This therapeutic approach aims to promote exon skipping in the nucleus, potentially halting or reversing the progression of DMD, a rare genetic condition characterised by mutations in the gene that encodes dystrophin protein, required for the normal functioning of muscle cells.
Dyne Therapeutics' chief medical officer Doug Kerr said: “We are pleased that the EC has granted orphan drug designation to DYNE-251, reinforcing our belief that our next-generation exon 51 skipping investigational therapy for DMD may be able to bring clinically meaningful functional improvement to those living with this devastating disease.”
The US Food and Drug Administration has already granted orphan drug, rare paediatric disease, and fast track designations for the DMD therapy.
Beyond DYNE-251, the company is expanding its DMD franchise with preclinical programmes aiming at other exons such as 44, 45, and 53.
