This phase 1b, multi-center, non-randomized, open-label, ascending dose escalation, no-intervention-control trial will assess the safety and explore the efficacy of SRD-001 administered as a one-time antegrade epicardial coronary artery infusion for the treatment of participants with cardiomyopathy secondary to DMD. SRD-001 is an AAV1 vector expressing the transgene for SERCA2a. Twelve participants will be assigned to either active treatment with SRD-001 or no-intervention based upon their neutralizing antibody status. The objectives of the trial are (1) to evaluate the safety of a one-time intracoronary administration of SRD-001 in participants with cardiomyopathy due to DMD; and (2) to explore the impact of SRD-001 on heart and skeletal muscle function and quality of life. After screening to determine eligibility, participants will be sequentially assigned to low dose SRD-001, high dose SRD-001 or no-intervention. Participants assigned to active treatment with SRD-001 will under cardiac catheterization and angiography just prior to the intracoronary infusion of SRD-001 and spend overnight int he hospital for observation.
