An investigational therapy for myotonic dystrophy type 1 (DM1) continues to show signs of durable benefit, according to new data from the phase I/II ACHIEVE trial presented at the American Association of Neuromuscular and Electrodiagnostic Medicine meeting. The analysis focused on a pooled-dose group of 26 patients from the multiple ascending dose portion of the trial, most of whom received lower doses than the selected registrational dose of 6.8 mg/kg every 8 weeks.
At 6 months, the pooled group's mean video hand-opening time fell from 8.2 seconds at baseline by 3.2 seconds, while the placebo group's time worsened by 0.4 seconds. At 12 months, improvements from baseline were sustained in hand myotonia, the 5-times sit-to-stand test, quantitative muscle testing total scores, and patient-reported disease burden. Compared with a natural history cohort, treated patients showed better functional and strength outcomes.
The safety profile remained favorable, with no serious treatment-emergent adverse events linked to the drug. Reported treatment-related adverse events included infusion-related reactions, nasopharyngitis, diarrhea, headache, procedural pain, influenza, and back pain. The drug, also called DYNE-101, is designed to reduce toxic nuclear DMPK RNA and is being tested in the phase III HARMONIA trial and in a registrational expansion cohort of ACHIEVE; topline data from that cohort are expected in the first quarter of 2027.