for males ages 7-13 (full criteria)
at San Diego, California and other locations
study started
estimated completion



The main objective of this study is to evaluate the efficacy of SRP-4045 and SRP-4053 compared to placebo in Duchenne muscular dystrophy (DMD) patients with out-of-frame deletion mutations amenable to skipping exon 45 and exon 53, respectively.

Official Title

A Double-Blind, Placebo-Controlled, Multi-Center Study With an Open-Label Extension to Evaluate the Efficacy and Safety of SRP-4045 and SRP-4053 in Patients With Duchenne Muscular Dystrophy


This is a double-blind, placebo-controlled, multi-center study to evaluate the efficacy and safety of SRP-4045 and SRP-4053. Eligible patients with out-of-frame deletion mutations amenable to exon 45 or 53 skipping will be randomized to receive once weekly intravenous (IV) infusions of 30 mg/kg SRP-4045 or 30 mg/kg SRP-4053 respectively (combined-active group) or placebo for up to 96 weeks (the placebo-controlled period of the trial). This will be followed by an open label extension period in which all patients will receive open-label active treatment for 48 weeks (up to Week 144 of study).

The study will enroll approximately 222 patients, with a planned minimum target of 111 patients amenable to exon 45 skipping and 111 patients amenable to exon 53 skipping.

Approximately 148 patients will be randomized to receive active treatment with either SRP-4045 or SRP-4053 (depending on deletion mutation), and 74 patients will be randomized to receive placebo. Twice as many patients will receive active treatment as will receive placebo (2:1 randomization).

Clinical efficacy will be assessed at regularly scheduled study visits, including functional tests such as the six-minute walk test (6MWT). All patients will undergo a muscle biopsy at baseline and a second muscle biopsy either at Week 48 or Week 96.

Safety will be assessed through the collection of adverse events (AEs), laboratory tests, electrocardiograms (ECGs), echocardiograms (ECHOs), vital signs, and physical examinations throughout the study.

Blood samples will be taken periodically throughout the study to assess the pharmacokinetics of both drugs.


Duchenne Muscular Dystrophy Exon Skipping DMD Exon 53 Exon 45 Ambulatory Pediatric Duchenne Muscular Dystrophies Muscular Dystrophy, Duchenne SRP-4045 SRP-4053


You can join if…

Open to males ages 7-13

  • Genotypically confirmed DMD, with genetic deletion amenable to exon 45 or exon 53 skipping
  • Stable dose of oral corticosteroids for at least 24 weeks
  • Intact right and left biceps or 2 alternative upper muscle groups
  • Mean 6MWT greater than or equal 300 meters and less than or equal to 450 meters
  • Stable pulmonary function: forced vital capacity (FVC) equal to or greater than 50% predicted

You CAN'T join if...

  • Treatment with gene therapy at any time
  • Previous treatment with SMT C1100, 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 (other than deflazacort) within 12 weeks prior to Week 1
  • Major surgery within 3 months prior to Week 1
  • Presence of other clinically significant illness

Other inclusion/exclusion criteria may apply


  • Rady Children's Hospital San Diego/ UCSD in progress, not accepting new patients
    San Diego California 92123 United States
  • David Geffen School of Medicine, UCLA in progress, not accepting new patients
    Los Angeles California 90095 United States


accepting new patients
Start Date
Completion Date
Sarepta Therapeutics, Inc.
Phase 3
Study Type
Last Updated