A Gene Transfer Therapy Study to Evaluate the Safety and Efficacy of Delandistrogene Moxeparvovec (SRP-9001) in Non-Ambulatory and Ambulatory Participants With Duchenne Muscular Dystrophy (DMD)

Inclusion Criteria:

• Definitive diagnosis of DMD based on documented clinical findings and prior genetictesting.

• Cohort 1 only: Non-ambulatory per protocol-specified criteria.

• Cohort 2 only: Ambulatory per protocol-specified criteria and ≥8 to <18 years of ageat the time of Screening.

• Ability to cooperate with motor assessment testing.

• Stable daily dose of oral corticosteroids for at least 12 weeks prior to Screening,and the dose is expected to remain constant throughout the study (except formodifications to accommodate changes in weight).

• Recombinant Adeno-Associated Virus Serotype rh74 (rAAVrh74) antibody titers are notelevated as per protocol-specified requirements.

• A pathogenic frameshift mutation or premature stop codon in the DMD gene, except forany deletion mutations in exon 8 and/or 9.

Exclusion Criteria:

• Exposure to gene therapy, investigational medication, or any treatment designed toincrease dystrophin expression within protocol specified time limits.

• Abnormality in protocol-specified diagnostic evaluations or laboratory tests.

• Presence of any other clinically significant illness, medical condition, orrequirement for chronic drug treatment that in the opinion of the Investigatorcreates unnecessary risk for gene transfer.

Other inclusion or exclusion criteria could apply.