The ESSENCE study is a double-blind, placebo-controlled, multi-center Phase 3 clinical trial (NCT02500381) with an open-label extension period, evaluating the two drugs’ safety and efficacy in DMD boys between 7 to 13 years of age, with a confirmed deletion amenable to exon 45 or 53 skipping.
Sarepta plans to target at least 45 DMD boys potentially responsive or amenable to exon 45 skipping with SRP-4045, and 45 DMD boys potentially responsive or amenable to exon 53 skipping with SRP-4053. The boys will be randomized to receive once-a-week intravenous infusions of 30 mg/kg SRP-4045 or 30 mg/kg SRP-4053 or placebo, for up to 96 weeks. Then, in the open-label extension phase, all boys will receive open-label active treatment for up to 96 weeks.
After about 75 of the boys have been in the trial for 48 weeks, researchers will review the initial results to determine which patients are eligible to enroll in the open-label extension period.
The study’s primary objective is to test the efficacy of both compounds, which will be assessed at regular study visits, with functional tests such as the six-minute walk test (6MWT). All patients will undergo a muscle biopsy at baseline and a second muscle biopsy at week 48. Sarepta will assess the drugs’ safety through adverse events, laboratory tests, electrocardiograms, echocardiograms, vital signs, and physical examinations. In addition, to assess how both drugs work in the body, researchers will collect blood samples from patients throughout the study.
SRP-4045 and SRP-4053 are designed to address the underlying cause of DMD by enabling the production of a shorter, but functional, form of the dystrophin protein. Neither the U.S. Food and Drug Administration nor any other regulatory agency has approved these drugs to treat DMD.
Sarepta, based in Cambridge, Massachusetts, is conducting the trial at 17 study sites across the United States, as well as sites in Belgium, Canada, France, Germany, Italy, Netherlands, Spain, Sweden and the United Kingdom. More information about how to enroll in this study can be found here.