Phase 2 Study of EDG-5506 in Children and Adolescents With Duchenne Muscular Dystrophy Previously Treated With Gene Therapy

Phase 2

Active, not recruiting

• Conditions: Duchenne Muscular Dystrophy
• Interventions: Drug: Sevasemten Dose 3; Drug: Sevasemten Dose 1; Drug: Sevasemten Dose 2; Drug: Placebo

• Registration Number: NCT06100887
• Lead Sponsor: Edgewise Therapeutics, Inc.

Brief Summary

The FOX study is a 2-part, multicenter, Phase 2 study of safety, pharmacokinetics, and biomarkers in children and adolescents with Duchenne muscular dystrophy previously treated with gene therapy including a randomized, double-blind, placebo-controlled Part A, followed by an open-label part B.

Detailed Description

FOX is a 2-part, multi-center, Phase 2 study to evaluate the effect of EDG-5506 on safety, pharmacokinetics and biomarkers of muscle damage in approximately 24 children and adolescents with Duchenne muscular dystrophy treated with oral, once-daily EDG-5506.This study will have up to a 4-week Screening period, a 12-week randomized double-blind, placebo-controlled treatment period (Part A), followed by a 40-week open-label extension period (Part B) .

Approximately twenty-four (24) participants aged 6 to 14, inclusive, will be randomized to EDG-5506 or placebo in a 2:1 ratio. Two dose cohorts (Cohort 1 and Cohort 2) of approximately 12 participants each will be enrolled.

Study Timeline

• Study First Submitted: 2023-10-20
• Study First Submitted QC: 2023-10-20
• Study First Posted: 2023-10-25
• Study Start: 2024-03-22
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-14
• Last Update Posted: 2025-05-18
• Primary Completion: 2025-10
• Study Completion: 2025-10

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: Male
• Target Recruitment: 43

Inclusion Criteria

• Aged 6 to 14 with a documented mutation on the DMD gene and phenotype consistent with DMD.
• Prior receipt of an AAV-based gene therapy (≥ 2 years after study drug administration in an open-label study or ≥ 3 years after randomization in a randomized study).
• Able to complete stand from supine in ≤ 8 seconds at the Screening visit and able to perform the 4-stair climb in < 10 seconds at the Screening visit.
• Body weight ≥ 20 kg at the Screening visit.
• Treatment with a stable dose of corticosteroids for a minimum of 6 months prior to the Baseline visit.

Key

Exclusion Criteria

• Medical history or clinically significant physical exam/laboratory result that, in the opinion of the investigator, would render the participant unsuitable for the study. This includes venous access that would be too difficult to facilitate repeated blood sampling.
• Screening visit cardiac echocardiography showing left ventricular ejection fraction (LVEF) < 40%.
• Receipt of an investigational drug (other than the AAV-based gene therapy per Inclusion criteria) within 30 days or 5 half-lives (whichever is longer) of the Screening visit in the present study.
• Receipt of an exon-skipping therapy within 6 months prior to the Screening visit.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SEQUENTIAL

Arm && Interventions

Group	Intervention	Description
Cohort 3	Sevasemten Dose 3	Drug: Sevasemten Drug: Placebo
Cohort 3	Placebo	Drug: Sevasemten Drug: Placebo
Cohort 1	Sevasemten Dose 1	Drug: Sevasemten Drug: Placebo
Cohort 1	Placebo	Drug: Sevasemten Drug: Placebo
Cohort 2	Sevasemten Dose 2	Drug: Sevasemten Drug: Placebo
Cohort 2	Placebo	Drug: Sevasemten Drug: Placebo

Primary Outcome Measures

Name	Time	Method
Number of adverse events during treatment with sevasemten or placebo	12 months	All participants
Severity of adverse events during treatment with sevasemten or placebo	12 months	All participants

Secondary Outcome Measures

Name	Time	Method
Incidence of abnormal coagulation test results	12 months	All participants
Incidence of abnormal urinalysis test results	12 months	All participants
Change from Baseline in fast skeletal muscle troponin I	12 weeks	All participants
Incidence of abnormal clinical chemistry test results	12 months	All participants
Incidence of abnormal hematology test results	12 months	All participants
Change from Baseline in serum creatine kinase	12 weeks	All participants
Pharmacokinetics as measured by steady state plasma concentration	12 months	All participants

Trial Locations

Locations (7)

UCLA Medical Center; 🇺🇸 Los Angeles, California, United States

UC Davis Medical Center; 🇺🇸 Sacramento, California, United States

University of Florida; 🇺🇸 Gainesville, Florida, United States

University of Massachusetts Memorial Medical Center; 🇺🇸 Worcester, Massachusetts, United States

Washington University School of Medicine; 🇺🇸 Saint Louis, Missouri, United States

Rare Disease Research; 🇺🇸 Hillsborough, North Carolina, United States

Nationwide Children's Hospital; 🇺🇸 Columbus, Ohio, United States