The phase 3 EMBARK study assessed the safety and efficacy of delandistrogene moxeparvovec for the treatment of Duchenne muscular dystrophy (DMD). At 1 year after treatment, patients who received delandistrogene moxeparvovec showed stabilization or slowing of disease progression. Meanwhile, patients who received placebo showed disease progression, “demonstrating [delandistrogene moxeparvovec] treatment efficacy,” according to a presentation at the AMCP 2025 Annual Meeting.
This study reported on a prespecified exploratory analysis of muscle health and changes in muscle pathology as assessed by magnetic resonance (MR) in a subgroup of patients from the randomized, placebo-controlled, phase 3 EMBARK study, which assessed delandistrogene moxeparvovec (1.33×1014 vg/kg; n=19) versus placebo (n=20) in ambulatory patients with DMD between the ages of 4 and 8 years.
Patients who received the gene therapy showed less disease progression compared with those who received placebo. In all muscles, as determined by MRI and MR spectroscopy, muscle fat fraction magnitude of changes favored delandistrogene moxeparvovec. The placebo group also showed worsening in transverse relaxation time (all muscles) compared with an improvement seen in delandistrogene moxeparvovec–treated patients (4 of 5 muscles; baseline to week 52 change ranged from −1.05 to 0.05 msec with delandistrogene moxeparvovec and 1.11 to 3.02 msec with placebo). The result of a global statistical test supported overall treatment benefit (P=0.0328).
“Muscle MRI changes were consistent with secondary functional outcomes from EMBARK Part 1,” the authors concluded.
The study was sponsored by Sarepta Therapeutics, Inc.
Reference
Patel B, Vandenborne K, Walter G, et al. Muscle MRI outcomes in patients with Duchenne muscular dystrophy treated with delandistrogene moxeparvovec: findings from EMBARK Part 1. Abstract M8 presented at: AMCP 2025; March 31-April 3, 2025; Houston, TX.
