Safety and Tolerability of Wharton's Jelly-Derived Mesenchymal Stem Cells for Patients With Duchenne Muscular Dystrophy: A Phase 1 Clinical Study

This study was an open-label, dose-escalation, phase 1 clinical trial to determine the safety and dose of EN001 for patients with Duchenne muscular dystrophy (DMD). EN001, developed by ENCell, are allogeneic early-passage Wharton's jelly-derived mesenchymal stem cells that originate at the umbilical cord, with preclinical studies demonstrating their high therapeutic efficacy for DMD. This phase 1 clinical trial explored the safety and tolerability of EN001 as a potential treatment option for patients with DMD. Six pediatric participants with DMD were divided into two subgroups of equal size: low-dose EN001 (5.0×10⁵ cells/kg) and high-dose EN001 (2.5×10⁶ cells/kg). All participants were monitored for 12 weeks after EN001 administration to assess its safety. Dose-limiting toxicity (DLT) was evaluated across 2 weeks post administration. Exploratory efficacy was evaluated by measuring serum creatine kinase levels, and functional evaluations-including spirometry, myometry, the North Star Ambulatory Assessment, and the 6-minute walk test-were conducted at week 12 and compared with the baseline values. No participants experienced serious adverse events related to EN001 injection during the 12-week follow-up period. Mild adverse events included injection-related local erythema, edema, parosmia, and headache, but DLT was not observed. Functional evaluations at week 12 revealed no significant changes from baseline. These results demonstrated that EN001 are safe and well tolerated for patients with DMD, and did not cause serious adverse events. The efficacy of EN001 could be confirmed through larger-scale future studies that incorporate repeated dosing and have a randomized controlled trial design.