Dyne Therapeutics, Inc. (NASDAQ: DYN) has just announced that the U.S. Food and Drug Administration (FDA) has granted breakthrough therapy designation to their drug, Dyne-251, for the treatment of patients with Duchenne Muscular Dystrophy (DMD) who have mutations in the DMD gene that are amenable to exon 51 skipping. This designation was based on data from the ongoing Deliver clinical trial.
The company's Chief Medical Officer, Doug Kerr, M.D., Ph.D., highlighted that Dyne-251 has demonstrated sustained functional improvement through eighteen months, as assessed by key measures such as time to rise and stride velocity 95th centile. Moreover, the drug has shown a significant level of near-full-length dystrophin expression, marking a significant step forward in potentially delivering meaningful benefits to patients.
The company's lead programs, including Dyne-101, have also been granted FDA breakthrough therapy designation. This designation is intended to expedite the development and review of drugs that are designed to treat serious conditions with preliminary clinical evidence indicating substantial improvement over available therapy on one or more clinically significant endpoints.
Dyne-251 has been granted fast track, orphan drug, and rare pediatric disease designations by the FDA, as well as orphan drug designation by the European Medicines Agency (EMA) for the treatment of DMD.
The company has completed enrollment of 32 patients in the registrational expansion cohort of the Deliver trial, with data from this cohort planned for late 2025. They anticipate a potential Biologics License Application (BLA) submission for U.S. accelerated approval in early 2026.
Dyne Therapeutics is also pursuing approval pathways outside of the U.S. for Dyne-251 in patients with DMD who have a confirmed mutation amenable to exon 51 skipping. The Deliver trial is a global, randomized, placebo-controlled, double-blind, phase 1/2 clinical trial evaluating the safety, tolerability, and efficacy of Dyne-251 in individuals with DMD. The registrational expansion cohort of the study has already resulted in the selection of a registrational dose and regimen of 20 mg/kg of Dyne-251 administered every four weeks, with the primary endpoint for this cohort being the change from baseline in dystrophin protein levels as measured by western blot at 6 months. Following these announcements, the company's shares moved 3.48%, and are now trading at a price of $10.3999. For more information, read the company's full 8-K submission here.
