Study of SRP-4045 (Casimersen) and SRP-4053 (Golodirsen) in Participants With Duchenne Muscular Dystrophy (DMD)

Prior treatment

• Treatment with gene therapy at any time
• Previous treatment with SMT C1100 within 1 week prior to Week 1 and previous treatment with PRO045 (BMN 045), PRO053 (BMN 053), or PRO051 (BMN 051) within 24 weeks prior to Week 1
• Current or previous treatment with any other experimental treatment within 12 weeks prior to Week 1
• Major surgery within 3 months prior to Week 1

Other illness

• Presence of other clinically significant illness

Other

• Other inclusion/exclusion criteria may apply.

• Genotypically confirmed DMD, with genetic deletion amenable to exon 45 or exon 53 skipping
• Stable dose of oral corticosteroids for at least 24 weeks prior to Week 1, and the dose is expected to remain constant throughout the study (except for modifications to accommodate changes in weight).
• Intact right and left biceps brachii muscles or 2 alternative upper arm muscle groups
• Mean 6MWT ≥300 meters and ≤450 meters
• Stable pulmonary function: forced vital capacity (FVC) ≥50% predicted