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20 | InTouch WINTER 2025 Dyne Therapeutics, a clinical-stage company focused on delivering functional improvement for people living with genetically driven neuromuscular diseases, announced in June that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to DYNE-101 for the treatment of myotonic dystrophy type 1 (DM1). This means that the FDA will work closely with Dyne Therapeutics to reduce the timeline to when it can make an application for Accelerated Approval of its drug for the treatment of DM1. People living with DM1 typically experience myotonia and progressive weakness of major muscle groups, which can affect mobility, breathing, heart function, speech, digestion and vision. Cognitive dysfunction may manifest as fatigue, excessive daytime sleepiness, an apathic temperament and brain fog. Over 300 New Zealanders are diagnosed with myotonic dystrophy type 1, which is an autosomal dominant condition often affecting multiple family members. DYNE-101 is being assessed in six sites around the world in a trial called ACHIEVE. Here in New Zealand there are currently 15 New Zealanders with DM1 participating in the ACHIEVE clinical trial led by Associate Professor Richard Roxburgh. Dyne Therapeutics Aims for Accelerated Approval for DYNE-101 in Myotonic Dystrophy Groundbreaking research brings hope for those living with myotonic dystrophy Data from the trial has enabled Dyne to identify the dose of 6.8mg/ kg as showing robust and sustained improvement in myotonia as measured by videoed hand opening time (vHOT) as well as sustained improvements across multiple other endpoints. As well as showing efficacy, updated safety and tolerability data from 56 patients enrolled in ACHIEVE continues to show a favourable safety profile, with no related serious treatment emergent adverse events identified. Over 300 New Zealanders are diagnosed with myotonic dystrophy type 1, which is an autosomal dominant condition often affecting multiple family members. Dyne Therapeutics plans to initiate a confirmatory Phase 3 clinical trial in early 2026 and are aiming for an accelerated approval submission to the FDA in late 2026. Recruitment to the ACHIEVE trial is taking place through Pūnaha Io the New Zealand Neurogenetic Registry & Biobank. Email Miriam Rodrigues neurogenetics@adhb.govt.nz for more information. RESEARCH NEWS