One year after treatment with the gene therapy delandistrogene moxeparvovec for Duchenne muscular dystrophy (DMD), researchers observed no changes in cardiac function, volume, or mass compared with placebo. The results were presented at the AMCP 2025 Annual Meeting.
Delandistrogene moxeparvovec is a recombinant adeno-associated virus rhesus isolate serotype 74 vector–based gene therapy that is approved in the United States to treat DMD.
A prespecified, exploratory analysis of the phase 3 EMBARK trial assessed outcomes in patients who underwent noncontrast cardiac MRI to evaluate the effect of this treatment on cardiac function, volume, and mass.
The 2-part, multinational, randomized, double-blind, placebo-controlled trial included patients with DMD between the ages of 4 and 8 years who experienced previous stabilization of disease progression after treatment with delandistrogene moxeparvovec.
This report includes outcomes for 19 patients who received delandistrogene moxeparvovec (1.33×1014 vg/kg) and 20 who received placebo (n=20).
At 1 year, an analysis of cardiac MRI left ventricular parameters—including end-diastolic volume, ejection fraction, end-systolic volume, and mass—showed no relevant differences between delandistrogene moxeparvovec and placebo.
Global circumferential strain of the left ventricle and analyses of segmental circumferential strain parameters across different regions of the left ventricle also revealed no relevant differences between delandistrogene moxeparvovec and placebo.
“Results indicated no adverse cardiac effects one year after treatment, supporting the previously demonstrated manageable safety profile of delandistrogene moxeparvovec,” the authors concluded. They will continue to assess long-term cardiac safety and efficacy of this gene therapy.
The study was sponsored by Sarepta Therapeutics, Inc.
Reference
Kennedy S, Walter G, Vandenborne K, et al. Cardiac MRI outcomes in patients with Duchenne muscular dystrophy treated with delandistrogene moxeparvovec: findings from EMBARK Part 1. Abstract M6 presented at: AMCP 2025; March 31-April 3, 2025; Houston, TX.
