Dyne Therapeutics, Inc. (NASDAQ: DYN) released new clinical data from its phase 1/2 DELIVER trial of Dyne-251, a treatment for Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping. The data showed unprecedented dystrophin expression and functional improvement in multiple cohorts, leading to the initiation of registrational cohorts and a path to registration by the end of 2024.
The assessment of the DELIVER trial showed 6-month biomarker and functional data from 8 male patients in the 20 mg/kg cohort, demonstrating significant results. Dyne-251 achieved the highest level of dystrophin expression reported for an exon 51 skipping therapy, with a mean absolute dystrophin expression of 3.71% of normal (unadjusted for muscle content) in the 20 mg/kg cohort, which is over 10-fold higher than the standard of care, eteplirsen. When adjusted for muscle content, the dyne-251 treated group reached 8.72% mean absolute dystrophin, greater than levels reported by peptide conjugate PMOs in clinical development.
Furthermore, meaningful improvements in multiple functional endpoints were observed in both the 20 mg/kg and 10 mg/kg dyne-251 cohorts, including stride velocity 95th centile (SV95C) and 10-meter walk/run time. The change from baseline observed in both cohorts met the published minimal clinically important difference (MCID) defined by the European Medicines Agency.
In terms of safety and tolerability, Dyne-251 demonstrated a favorable safety profile, with the majority of treatment emergent adverse events being mild or moderate. Notably, no related serious treatment emergent adverse events were identified other than in two participants at the 40 mg/kg dose level, both of whom have recovered.
Based on these compelling data and regulatory interactions, Dyne is initiating registrational cohorts in the DELIVER trial and plans to provide an update on the path to registration by the end of 2024. Additionally, the company is executing its ongoing phase 1/2 ACHIEVE clinical trial of Dyne-101 in myotonic dystrophy type 1, with a favorable safety profile up to the 6.8 mg/kg q8w cohort.
Dyne Therapeutics will host a virtual investor event to discuss the DELIVER data on September 3, 2024, at 8:00 a.m. ET, and a replay will be accessible for 90 days following the presentation.
Dyne-251, the investigational therapeutic being evaluated in the DELIVER trial, 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.
These new clinical data from the DELIVER trial showcase the potential of Dyne-251 in transforming the treatment paradigm for individuals living with DMD and represent significant progress in the field of muscle disease therapeutics. The market has reacted to these announcements by moving the company's shares 1.8% to a price of $46.09. Check out the company's full 8-K submission here.
