Dyne Therapeutics to share one-year ACHIEVE DM1 data at WMS and AANEM
Dyne Therapeutics has announced it will present additional one-year clinical data from the Phase 1/2 ACHIEVE trial of zeleciment basivarsen (z-basivarsen, DYNE-101) in myotonic dystrophy type 1 (DM1) at two neuromuscular disease congresses running concurrently at the end of September: the World Muscle Society (WMS) annual congress in Hiroshima and the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) meeting in Orlando.
The datasets at the centre of both presentations cover a pooled dose group of 25 to 26 participants drawn from the multiple ascending dose (MAD) portion of ACHIEVE, spanning the 3.4 mg/kg Q4W, 5.4 mg/kg Q8W and 6.8 mg/kg Q8W cohorts, including participants originally randomised to placebo. Six- and twelve-month functional data from this group will be compared against a propensity-matched natural history cohort of 41 to 46 participants from the ongoing END-DM1 study. Dyne will also disclose the mean baseline video hand opening time (vHOT) in the 71-patient registrational expansion cohort (REC), which remains blinded to treatment assignment pending topline readout, now expected in the first quarter of 2027.
Mechanism and regulatory designations
Z-basivarsen is an antisense oligonucleotide conjugated to an antigen-binding fragment (Fab) that binds the transferrin receptor 1, a design intended to drive delivery to both muscle and the central nervous system. The drug is engineered to reduce toxic nuclear DMPK RNA, thereby releasing splicing proteins and restoring normal mRNA processing, targeting the molecular root of DM1 rather than its downstream symptoms. The FDA has granted the candidate Breakthrough Therapy, Orphan Drug and Fast Track designations; the EMA and Japan's MHLW have each granted Orphan Drug designation. If the REC data are positive, Dyne is positioned to seek Accelerated Approval in the US, with vHOT at six months versus placebo as the primary endpoint.
The WMS oral presentation, titled "Long-term functional improvement with zeleciment basivarsen in the phase 1/2 ACHIEVE trial," will be delivered by Karlien Mul of Radboud University Medical Centre on 30 September. Both conferences will also feature poster sessions on the HARMONIA Phase 3 design and data from the DELIVER DMD trial of zeleciment rostudirsen.
Market context and competitive landscape
DM1 is the most prevalent adult-onset muscular dystrophy and has long been an unmet-need space with no approved disease-modifying therapy. The natural history comparison methodology Dyne is deploying reflects a broader shift in rare neuromuscular disease development, where regulators have shown increasing willingness to accept matched external controls in the absence of large, fully powered placebo arms. Ionis Pharmaceuticals, which has its own ASO platform, has historically been active in RNA-targeting approaches to neuromuscular diseases, and several academic and early-stage biotechs are exploring splice-switching strategies in DM1. Dyne's combination of the FORCE platform's targeted delivery with Breakthrough Therapy status places it among the more advanced programmes in the indication.
The Q1 2027 topline date for the REC will be closely watched by investors and clinicians alike. A successful vHOT readout would represent the first substantial evidence that targeted ASO delivery can drive measurable functional improvement in DM1 under conditions that could satisfy regulators, and would likely sharpen the competitive pressure on others in the field to accelerate or partner their own programmes.