A Long-term Follow-up Study of Participants Who Received Delandistrogene Moxeparvovec (SRP-9001) in a Previous Clinical Study (EXPEDITION)

A Long-term Follow-up Study of Participants Who Received Delandistrogene Moxeparvovec (SRP-9001) in a Previous Clinical Study

A Phase 3, Multinational, Long-term Follow-up Study to Evaluate Safety and Efficacy in Subjects Who Have Previously Received SRP-9001 in a Clinical Study

The purpose of this study is to provide a single clinical study with a uniform approach to monitoring long-term safety and efficacy in participants who received delandistrogene moxeparvovec in a previous clinical study. No study drug will be administered as part of this study. Pre-infusion baseline will be defined as the timepoint just prior to infusion of delandistrogene moxeparvovec from a previous clinical study. Each participant will be followed for a minimum of 5 years post-infusion of delandistrogene moxeparvovec from a previous clinical study. The duration of participation in this study is dependent on the length of follow-up the participant completed post-infusion of delandistrogene moxeparvovec from a previous clinical study.

No study drug will be administered as part of this study. Eligible participants who received treatment with delandistrogene moxeparvovec during a previous clinical study will be included.

Number of Participants with a Treatment-emergent Adverse Event (TEAE), Serious Adverse Event (SAE), and Adverse Event of Special Interest (AESI)

Change in the North Star Ambulatory Assessment (NSAA) Total Score From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Time to Rise From Floor From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in the Time of 10-meter Walk/Run (10MWR) From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Performance of Upper Limb (PUL) (Version 2.0) Total Scores From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in PUL (Version 2.0) Domain Specific Scores From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Forced Vital Capacity Percent (FVC%) Predicted From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Peak Expiratory Flow Percent (PEF%) Predicted From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Cardiac Magnetic Resonance Imaging (MRI) Findings From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Change in Musculoskeletal MRI Findings From Pre-infusion Baseline to 5 Years Post-infusion of Delandistrogene Moxeparvovec

Inclusion Criteria: Received delandistrogene moxeparvovec for Duchenne muscular dystrophy in a previous clinical study. Has (a) parent(s) or legal caregiver(s) or is ≥18 years of age and able to understand and comply with the study visit schedule and all other protocol requirements. Exclusion Criteria: Participant or family does not want to disclose participation with general practitioner/primary care physician and other medical providers. Other inclusion/exclusion criteria may apply.