Dyne Therapeutics' DMD therapy receives orphan drug status from EC

The European Commission (EC) has awarded orphan drug status to Dyne Therapeutics' DYNE-251, a promising treatment for Duchenne muscular dystrophy (DMD). This designation marks a significant step in the development of the drug, which is currently in the Phase I/II DELIVER trial. The trial targets DMD patients who can benefit from skipping exon 51, a specific alteration in the genetic makeup of these individuals.

Emerging data from the trial have shown promising improvements in patient functionality when administered the chosen dose. The trial uses the Stride Velocity 95th Centile (SV95C) as a key measure, a recognized primary endpoint for DMD studies in Europe. Dyne Therapeutics aims to use this data to expedite regulatory approval processes worldwide, particularly for patients who might benefit from exon 51 skipping therapies.

The company's efforts have led to the enrollment of 32 participants in the DELIVER trial's expansion cohort. Results from this cohort are anticipated by late 2025. Following this, Dyne Therapeutics plans to submit a biologics license application in the United States to seek accelerated approval by early 2026.

DYNE-251 is based on an innovative therapeutic platform involving a phosphorodiamidate morpholino oligomer. This compound is linked to a fragment antibody that binds specifically to the transferrin receptor 1, allowing precise delivery to muscle tissue. The main objective of this approach is to facilitate exon skipping within the cell nucleus, with the potential to slow or even reverse the progression of DMD. This genetic disorder is marked by mutations in the dystrophin gene, which is crucial for normal muscle cell function.

Doug Kerr, the Chief Medical Officer at Dyne Therapeutics, expressed satisfaction with the EC's decision to grant orphan drug designation to DYNE-251. He emphasized the potential of this next-generation exon 51 skipping therapy to significantly enhance the lives of those affected by DMD. The U.S. Food and Drug Administration (FDA) has already recognized the promise of DYNE-251 by granting it orphan drug, rare pediatric disease, and fast track designations.

In addition to DYNE-251, Dyne Therapeutics is broadening its DMD treatment portfolio with preclinical initiatives focused on other exons such as 44, 45, and 53. These efforts underscore the company's commitment to addressing the diverse needs of the DMD patient population and paving the way for more comprehensive therapeutic options in the future.