WALTHAM, Massachusetts — September 8, 2026
Dyne Therapeutics announced plans to present additional one-year clinical data from the Phase 1/2 ACHIEVE trial of zeleciment basivarsen (z-basivarsen, DYNE-101) in patients with myotonic dystrophy type 1 (DM1) at upcoming international neuromuscular meetings. The data will be presented at the 31st Annual International Congress of the World Muscle Society (WMS) and the 2026 Annual Meeting of the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) on September 29–October 3. The presentations will include six- and 12-month data from a pooled dose group of 25–26 ACHIEVE participants, alongside 12-month data from 41–46 propensity-matched participants in the END-DM1 natural history study. Dyne will also provide the average baseline video hand opening time (vHOT) value for the 71-participant registrational expansion cohort (REC), which remains blinded to treatment assignment. The company said topline ACHIEVE REC data remain on track for the first quarter of 2027, marking an important upcoming milestone for the program
ACHIEVE Data Strengthen the Clinical Development Program
The new presentations are designed to provide longer-term clinical context for z-basivarsen and its potential to deliver functional improvement in DM1. The pooled ACHIEVE group includes participants originally enrolled in the multiple ascending dose portion of the study across the 3.4 mg/kg every four weeks, 5.4 mg/kg every eight weeks and 6.8 mg/kg every eight weeks cohorts, including participants initially assigned to placebo. Dyne plans to compare their longitudinal outcomes with a propensity-matched natural history cohort from END-DM1, while also presenting updated safety data. The MAD portion of ACHIEVE previously supported selection of the 6.8 mg/kg every-eight-week regimen as the registrational dose and schedule. The registrational expansion cohort is now fully enrolled and is intended to support potential regulatory submissions, including a potential Accelerated Approval pathway in the United States. The primary REC endpoint is change from baseline in middle-finger myotonia measured by vHOT at six months compared with placebo.
Dyne Advances HARMONIA Phase 3 Development
Dyne is simultaneously advancing z-basivarsen into the global Phase 3 HARMONIA confirmatory study, expanding the clinical development program beyond ACHIEVE. HARMONIA is evaluating the investigational therapy in people living with DM1 and will be highlighted through additional presentations at both WMS and AANEM. The continued clinical program reflects Dyne’s strategy of moving z-basivarsen toward a potential registrational pathway while generating longer-term evidence on functional outcomes and safety. Z-basivarsen is an antisense oligonucleotide (ASO) conjugated to an antigen-binding fragment (Fab) that targets transferrin receptor 1 (TfR1), enabling delivery to muscle and the central nervous system. The therapeutic is designed to reduce toxic nuclear DMPK RNA, release sequestered splicing proteins and restore more normal mRNA processing, addressing an underlying molecular driver of DM1 rather than focusing only on symptoms.
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Z-Basivarsen Builds on Dyne’s Targeted Delivery Platform
The continued development of z-basivarsen reinforces Dyne’s strategy of using targeted delivery technologies to address genetically driven neuromuscular diseases. By combining an ASO with a TfR1-targeting Fab, z-basivarsen is designed to improve delivery of genetic medicines to tissues affected by DM1, including skeletal muscle and the central nervous system. The program has received Breakthrough Therapy, Orphan Drug and Fast Track designations from the FDA, along with Orphan Drug designations from the EMA and Japan’s MHLW. Dyne is also advancing clinical programs for Duchenne muscular dystrophy and preclinical programs targeting facioscapulohumeral muscular dystrophy, Pompe disease and additional DMD mutations. With one-year ACHIEVE data scheduled for presentation, the REC topline readout expected in Q1 2027 and the HARMONIA Phase 3 program progressing, Dyne is positioning z-basivarsen as a central clinical asset in its neuromuscular disease pipeline
Source: Dyne Therapeutics, press release
