Dyne Therapeutics Announces New Long-Term Clinical Data from Phase 1/2 DELIVER Trial of DYNE-251 in Duchenne Muscular Dystrophy Demonstrating Unprecedented and Sustained Functional Improvement Through 18 Months

Core Insights - Dyne Therapeutics is advancing DYNE-251, a therapeutic for Duchenne muscular dystrophy (DMD), showing significant functional improvements in clinical trials [2][3][4] - The DELIVER trial has fully enrolled its registrational expansion cohort, with data expected in late 2025 and a potential Biologics License Application submission for U.S. accelerated approval anticipated in early 2026 [2][13] Group 1: Clinical Trial Results - The DELIVER trial demonstrated unprecedented and sustained functional improvement at the registrational dose of 20 mg/kg Q4W, with meaningful improvements observed in multiple functional endpoints [2][4] - At the 6-month mark, patients receiving 20 mg/kg of DYNE-251 exhibited a mean absolute dystrophin expression of 8.72% of normal, indicating significant clinical efficacy [4][10] - Safety data as of February 7, 2025, continues to show a favorable profile for DYNE-251, with no new treatment-related serious adverse events reported [13] Group 2: Regulatory Pathway and Future Plans - The company is leveraging dystrophin expression as a surrogate endpoint for regulatory submissions, with the FDA's precedent for using dystrophin as a biomarker for accelerated approval still available [5][13] - Dyne Therapeutics has fully enrolled a registrational expansion cohort of 32 patients in the DELIVER trial, with plans for data release in late 2025 [13] - The potential for rapid adoption of DYNE-251 by physicians and patients is anticipated if the therapy receives approval [3][13] Group 3: Industry Context - DMD is a rare genetic disorder affecting approximately 12,000 to 15,000 individuals in the U.S. and 25,000 in Europe, characterized by progressive muscle degeneration due to lack of dystrophin [14] - Current therapies for DMD provide limited benefits, highlighting the urgent need for effective treatments like DYNE-251 [14][15] - Dyne Therapeutics is building a global DMD franchise, with ongoing preclinical programs targeting other exons beyond exon 51 [11][15]