On June 17, 2025, Dyne Therapeutics announced that the FDA granted Breakthrough Therapy Designation to their drug DYNE-101 for treating myotonic dystrophy type 1 (DM1), alongside a revised plan for obtaining U.S. Accelerated Approval based on new long-term clinical data. The company reported a positive improvement in clinical endpoints, including a 3.3-second decrease in myotonia and a 20% strength improvement at 12 months for treated patients.