Dyne Therapeutics Secures Orphan Drug Designation in Japan for Zeleciment Basivarsen (DYNE-101) Targeting Myotonic Dystrophy Type 1
WALTHAM, Mass., January 20, 2026 (GLOBE NEWSWIRE) -- Dyne Therapeutics, Inc. (Nasdaq: DYN), a clinical-stage company dedicated to improving outcomes for individuals with genetically driven neuromuscular diseases, has announced that the Ministry of Health, Labour and Welfare (MHLW) in Japan has granted Orphan Drug designation for their investigational drug zeleciment basivarsen (z-basivarsen) for the treatment of myotonic dystrophy type 1 (DM1).
Clinical Advancements in the ACHIEVE Trial
Z-basivarsen is currently being evaluated in the Phase 1/2 ACHIEVE clinical trial where it has shown evidence of sustained functional improvements across multiple clinical metrics. Enrollment in the Registrational Expansion Cohort of this trial is expected to be completed by early Q2 2026.
Insights from Leadership
Doug Kerr, M.D., Ph.D., Chief Medical Officer of Dyne, stated, “By targeting the underlying biology of DM1, z-basivarsen has shown early and sustained improvements in myotonia, muscle strength, and function, with a favorable safety profile. This designation in Japan, alongside those already granted in the U.S. and Europe, underscores the urgent need for new therapies and highlights the potential of z-basivarsen to deliver meaningful functional improvement for people living with DM1.”
Understanding Orphan Drug Designation
The Orphan Drug designation in Japan is specifically aimed at treatments for rare diseases affecting fewer than 50,000 patients and addresses conditions with a high medical demand. Benefits of this designation include:
- Subsidies for drug development costs
- Potential market exclusivity for up to 10 years upon approval
In addition to the Japanese designation, z-basivarsen has received Breakthrough Therapy, Fast Track, and Orphan Drug designations from the U.S. FDA and Orphan Drug designation from the European Medicines Agency (EMA).
The ACHIEVE Clinical Trial Explained
The ACHIEVE clinical trial is a global, randomized, placebo-controlled, double-blind study aimed at evaluating the safety, tolerability, and efficacy of z-basivarsen (previously known as DYNE-101) in patients diagnosed with myotonic dystrophy type 1. The study’s multiple ascending dose (MAD) portion has led to the selection of a registrational dose of 6.8 mg/kg z-basivarsen administered every eight weeks.
The primary endpoint for the registrational expansion cohort is the change from baseline in middle finger myotonia, measured by video hand opening time (vHOT) at six months, compared to a placebo group. Additional details about the ACHIEVE trial can be found at clinicaltrials.gov.
About Zeleciment Basivarsen
Z-basivarsen is an investigational therapeutic featuring an antisense oligonucleotide (ASO) conjugated to an antigen-binding fragment (Fab) that binds to the transferrin receptor 1 (TfR1). This design aims to deliver functional improvement for individuals with DM1 by reducing toxic nuclear DMPK RNA, which is crucial for normal mRNA processing.
Impact of Myotonic Dystrophy Type 1
Myotonic dystrophy type 1 (DM1) is a rare, progressive genetic neuromuscular disease that affects approximately 40,000 individuals in the U.S. and ~55,000 in the EU. Symptoms can start between the ages of 20 and 40 and may include severe muscle weakness, myotonia (difficulty relaxing muscles), cognitive impairments, and other debilitating complications. Currently, there are no approved disease-modifying treatments specifically for DM1.
About Dyne Therapeutics
Dyne Therapeutics is on a mission to provide functional improvements for individuals suffering from genetically driven neuromuscular diseases. In addition to myotonic dystrophy type 1 (DM1), Dyne is advancing clinical programs for Duchenne muscular dystrophy (DMD) and is also pursuing preclinical programs for other related conditions. For more information about Dyne Therapeutics, visit dyne-tx.com.
Forward-Looking Statements
This press release contains forward-looking statements that involve substantial risks and uncertainties. These statements may include projections regarding Dyne’s strategy, potential benefits of z-basivarsen, and the anticipated timelines for clinical trial completion and regulatory submissions. Actual results may differ materially, and readers are cautioned not to place undue reliance on forward-looking statements.