Dyne reports new one-year data from ACHIEVE trial of z-basivarsen in DM1

Dyne Therapeutics announced on September 29, 2026 that it had gathered additional one-year efficacy data from the MAD portion of its ongoing Phase 1/2 ACHIEVE clinical trial of zeleciment basivarsen (z-basivarsen, also known as DYNE-101) for DM1, showing functional improvement across multiple measures.¹ The data were shown at the World Muscle Society congress and the AANEM annual meeting, both running through early October 2026 in Hiroshima and Orlando respectively.

The analysis pooled participants (N=25-26) from the 3.4 mg/kg Q4W, 5.4 mg/kg Q8W and 6.8 mg/kg Q8W cohorts of the MAD portion of the ACHIEVE trial, including participants originally assigned to the placebo group, assessed through 12 months of treatment.¹ Dyne cautioned that the pooled group reflects a mixture of dose exposures, since only 8 of 26 participants received the registrational dose for the full 12 months.¹

On myotonia, the pooled group's mean baseline vHOT of 8.2 seconds decreased by 3.2 seconds at 6 months, versus a 0.4 second increase in the ACHIEVE MAD placebo group (N=14), a 3.6 second relative improvement.¹ On function, participants improved on 5xSTS by 1.2 seconds and on 10MWR by 0.3 seconds at 12 months relative to baseline.¹ On strength, participants improved on both QMT total and hand grip by 4.8% predicted relative to baseline.¹ On patient-reported outcomes, MDHI total score improved by 25.2% relative to baseline.¹ Safety data as of April 20, 2026 showed a favorable safety profile, with no related serious treatment emergent adverse events identified.¹

Dyne also disclosed that the mean baseline vHOT of the 71 participants enrolled in the ACHIEVE registrational expansion cohort is 8.3 seconds, with a standard deviation of 6.0 seconds.¹ Those baseline figures remain blinded to treatment assignment.¹ The company said topline data from the ACHIEVE REC, intended to support a potential U.S. Accelerated Approval application, are planned for Q1 2027.¹