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

Study Overview
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Brief Summary
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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
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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.

Official Title
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A Phase 2 Study to Evaluate the Effect of EDG-5506 on Safety, Pharmacokinetics, and Biomarkers in Children and Adolescents With Duchenne Muscular Dystrophy Previously Treated With Gene Therapy

Conditions
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Duchenne Muscular Dystrophy

Intervention / Treatment
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* Drug: EDG-5506 Dose 1
* Drug: EDG-5506 Dose 2
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Key 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.

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 14 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Sequential Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1<br>Drug: EDG-5506 Drug: Placebo | Drug: EDG-5506 Dose 1<br>* EDG-5506 is administered orally once per day<br>Drug: Placebo<br>* Placebo is administered orally once per day<br>|
| Experimental: Cohort 2<br>Drug: EDG-5506 Drug: Placebo | Drug: EDG-5506 Dose 2<br>* EDG-5506 is administered orally once per day<br>Drug: Placebo<br>* Placebo is administered orally once per day<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of adverse events during treatment with EDG-5506 or placebo | All participants | 12 months | 
| Severity of adverse events during treatment with EDG-5506 or placebo | All participants | 12 months | 

Secondary Outcome Measures

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

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Duchenne Muscular Dystrophy