Announcement • Jun 04
Dyne Therapeutics, Inc. Announces Completion of Enrollment in Registrational Expansion Cohort of ACHIEVE Trial of Z-Basivarsen for Myotonic Dystrophy Type 1 (DM1) Dyne Therapeutics, Inc. announced the completion of enrollment in the registrational expansion cohort (REC) of the Phase 1/2 ACHIEVE trial of zeleciment basivarsen (z-basivarsen, also known as DYNE-101) in individuals with DM1. The registrational expansion cohort enrolled 71 participants. Topline data from the ACHIEVE REC are planned for the First Quarter 2027 to support a potential Biologics License Application (BLA) submission for U.S. Accelerated Approval in the Third Quarter 2027. Dyne intends to use data from the REC and from the already enrolled participants in the multiple ascending dose (MAD) and ongoing long-term extension portions of the ACHIEVE trial to support a potential submission for Accelerated Approval in the U.S. Dyne expects a potential U.S. launch of z-basivarsen in the first half of 2028, assuming FDA grants Priority Review and approval is received on the anticipated timeline. Dyne also continues to pursue approval pathways outside of the U.S. for z-basivarsen in DM1. ACHIEVE is a global, randomized, placebo-controlled, double-blind, Phase 1/2 clinical trial evaluating the safety, tolerability and efficacy of zeleciment basivarsen (z-basivarsen, also known as DYNE-101) in patients with myotonic dystrophy type 1 (DM1). The multiple ascending dose (MAD) portion of the study resulted in the selection of a registrational dose and regimen of 6.8 mg/kg z-basivarsen administered every eight weeks. A registrational expansion cohort to support potential regulatory submissions, including Accelerated Approval in the U.S., is fully enrolled. The primary endpoint for this cohort is the change from baseline in middle finger myotonia as measured by video hand opening time (vHOT) at 6 months, compared to placebo. Z-basivarsen is an investigational therapeutic being evaluated in the fully enrolled global Phase 1/2 ACHIEVE clinical trial and the global confirmatory Phase 3 HARMONIA clinical trial for people living with DM1. Z-basivarsen consists of an antisense oligonucleotide (ASO) conjugated to an antigen-binding fragment (Fab) that binds to the transferrin receptor 1 (TfR1) to enable delivery to muscle and the central nervous system. It is designed to deliver functional improvement in individuals living with DM1 by reducing toxic nuclear DMPK RNA to release splicing proteins and allow normal mRNA processing. Z-basivarsen has been granted Breakthrough Therapy, Orphan Drug and Fast Track designations by the U.S. Food and Drug Administration (FDA), as well as Orphan Drug designation from the European Medicines Agency (EMA) and the Ministry of Health, Labour and Welfare (MHLW) in Japan for the treatment of DM1. Myotonic dystrophy type 1 (DM1) is a rare, progressive, genetic neuromuscular disease with high morbidity and early mortality. DM1 affects approximately 40,000 people in the U.S. and approximately 55,000 people in the EU. The severity of symptoms and rate of progression varies. Symptoms can begin at any point in an affected persons life, depending on the DM1 subtype. Adult-onset DM1 symptoms typically appear between 20 to 40 years of age. DM1 is caused by mutations in the DMPK gene, leading to a widespread disruption of RNA splicing, known as spliceopathy, which drives the multi-system manifestations of the disease. People experience a broad spectrum of symptoms, including: muscle weakness throughout the body, myotonia or difficulty relaxing muscles, excessive daytime sleepiness, fatigue, dysregulated sleep, cognitive impairments, cardiac arrhythmias, respiratory issues and gastrointestinal dysfunction. Although the genetic cause of DM1 is well understood, there are currently no approved disease-modifying treatments for DM1. DYN
Live News • Jun 04
Dyne Therapeutics Reaches Enrollment Milestone in Pivotal DM1 Trial With Data Expected in 2027 Dyne Therapeutics reported completion of enrollment in the registrational expansion cohort of its Phase 1/2 ACHIEVE trial evaluating z-basivarsen in individuals with myotonic dystrophy type 1 (DM1).
The company plans to report topline data from this cohort in the first quarter of 2027, with the goal of supporting a potential Biologics License Application submission for U.S. Accelerated Approval.
Dyne outlined expectations for a potential U.S. launch of z-basivarsen in the first half of 2028, subject to Priority Review and regulatory approval on the anticipated timeline.
The key takeaway is that Dyne has reached an important operational milestone in its DM1 program, and there is now a clearer clinical and regulatory timetable in place around z-basivarsen.
Investors should keep in mind the long lead time to the next major data readout in 2027 and the regulatory uncertainties that accompany any Accelerated Approval path. Announcement • May 26
Dyne Therapeutics Submits Biologics License Application to U.S. FDA For Z-Rostudirsen In Exon 51 Duchenne Muscular Dystrophy Dyne Therapeutics, Inc. announced the submission of a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) for zeleciment rostudirsen (z-rostudirsen, also known as DYNE-251) 20 mg/kg once every 4 weeks for the treatment of individuals with Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping. Submission for Accelerated Approval is based on dystrophin as a surrogate endpoint. In the registrational expansion cohort of the DELIVER trial, treatment with z-rostudirsen resulted in a robust and statistically significant increase in dystrophin production with functional improvement observed across multiple clinical endpoints and a favorable safety profile. Dyne has requested Priority Review for the BLA, which, if granted, would shorten the review process from 10 months to 6 months following the FDA’s 60-day filing review period. Dyne continues to expect a potential U.S. launch of z-rostudirsen in the First Quarter 2027, assuming the FDA grants Priority Review and approval is received on the anticipated timeline. In addition to z-rostudirsen, Dyne is advancing four development candidates (DYNE-253, DYNE-245, DYNE-244 and DYNE-255) for the potential treatment of DMD amenable to skipping of exons 53, 45, 44, and 55, respectively. Z-rostudirsen is an investigational therapeutic for individuals with DMD who have mutations in the DMD gene that are amenable to exon 51 skipping. The registrational expansion cohort of the global Phase 1/2 DELIVER clinical trial of z-rostudirsen met its primary endpoint. Data from the DELIVER trial served as the basis for a Biologics License Application (BLA) for potential U.S. Accelerated Approval. Z-rostudirsen continues to be evaluated in the long-term extension portion of the DELIVER trial and in the global confirmatory Phase 3 FORZETTO clinical trial. Z-rostudirsen consists of a phosphorodiamidate morpholino oligomer (PMO) conjugated to an antigen-binding fragment (Fab) that binds to the transferrin receptor 1 (TfR1). It is designed to enable the production of near-full length dystrophin in muscle and the central nervous system (CNS) to provide functional improvement. Z-rostudirsen has received Breakthrough Therapy, Fast Track and Rare Pediatric Disease designations from the U.S. Food and Drug Administration (FDA), as well as Orphan Drug designation from the FDA, European Medicines Agency (EMA) and the Ministry of Health, Labour and Welfare (MHLW) in Japan for the treatment of individuals with DMD amenable to exon 51 skipping. In addition to z-rostudirsen, Dyne is building a DMD franchise and has preclinical programs targeting other exons, including DYNE-253, DYNE-245, DYNE-244 and DYNE-255. 
