Phase 2 Study of EDG-5506 in Becker Muscular Dystrophy (GRAND CANYON)

The EDG-5506-201 protocol was amended to include an additional cohort thus consists of two parts. Part 1: CANYON is a double-blind, randomized, placebo-controlled design to investigate the effect of sevasemten on the safety, pharmacokinetics, biomarkers, and functional measures. Approximately 32 adults and 18 adolescents with Becker muscular dystrophy are planned to enroll in this study. This study will have up to a 4-week Screening period, a 12-month Treatment period, followed by a 4-week follow-up period. Approximately 32 adult participants will randomize to Cohort 1 or Cohort 2 in a 1:1 ratio then each cohort will further randomize to sevasemten or placebo in a 3:1 ratio. Approximately 9 adolescent participants will enroll in Cohort 4 and randomize in a 2:1 ratio to sevasemten or placebo. Cohort 5 will randomize an additional 9 participants in a 2:1 ratio to either sevasemten or placebo after Cohort 4. Part 2: GRAND CANYON or Cohort 6 is a double-blind, randomized, placebo-controlled design to investigate the safety and efficacy of sevasemten in adults with Becker muscular dystrophy after 18 months of treatment. Approximately 175 adults with Becker muscular dystrophy are planned to enroll in this study. This study will have up to a 4-week Screening period, an 18-month Treatment period, followed by a 4-week follow-up period. Approximately 175 adult participants will be randomized in Cohort 6 in a 2:1 ratio either to sevasemten or placebo. Enrollment for CANYON and GRAND CANYON has been completed.