Dyne Therapeutics Inc. (DYN) announced encouraging clinical data from its ongoing Phase 1/2 DELIVER trial of DYNE-251 in patients with Duchenne muscular dystrophy (DMD). The trial assessed DYNE-251’s effectiveness in patients amenable to exon 51 skipping, a genetic mutation that causes DMD.
The trial evaluated 8 male patients who received either DYNE-251 or a placebo at a 20 mg/kg dose every four weeks. After six months, the DYNE-251 group showed a mean absolute dystrophin expression of 3.71% of normal, significantly exceeding the 0.3% observed in a reference trial using the standard of care treatment Sarepta Therapeutics Inc.’s (SRPT) EXONDYS 51 (eteplirsen). When adjusted for muscle content, the DYNE-251 group’s mean absolute dystrophin expression increased to 8.72%, surpassing levels typically seen in studies of other investigational DMD treatments.
The trial also included a cohort of 6 patients who received DYNE-251 at a 10 mg/kg dose every four weeks. After six months, this group showed a mean absolute dystrophin expression of 3.22% of normal, and after 12 months, the group continued to demonstrate improvements in all reported measures. These results are consistent with the six-month data released in May for patients treated with the 10 mg/kg dose.
Dyne Therapeutics emphasized that DYNE-251 showed meaningful improvements in multiple functional endpoints in both the 20 mg/kg and 10 mg/kg cohorts. Additionally, the drug demonstrated a favorable safety profile, with most treatment-emergent adverse events being mild or moderate.
Based on these positive results, Dyne Therapeutics is moving forward with initiating registrational cohorts in the DELIVER trial. The company plans to provide an update on the path to registration by the end of 2024.
It’s important to note that DYN stock experienced a significant decline of 31.90% at $31.39 during Tuesday’s trading session.
