---
title: Phase 2 Study of EDG-5506 in Children and Adolescents With Duchenne Muscular Dystrophy Previously Treated With Gene Therapy
nct_id: NCT06100887
overall_status: ACTIVE_NOT_RECRUITING
phase: PHASE2
sponsor: Edgewise Therapeutics, Inc.
study_type: INTERVENTIONAL
primary_condition: Duchenne Muscular Dystrophy
countries: United States
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT06100887.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT06100887"
ct_last_update_post_date: 2025-11-06
last_seen_at: "2026-05-12T07:26:10.485Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Phase 2 Study of EDG-5506 in Children and Adolescents With Duchenne Muscular Dystrophy Previously Treated With Gene Therapy

**Official Title:** 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

**NCT ID:** [NCT06100887](https://clinicaltrials.gov/study/NCT06100887)

## Key Facts

- **Status:** ACTIVE_NOT_RECRUITING
- **Phase:** PHASE2
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 43
- **Lead Sponsor:** Edgewise Therapeutics, Inc.
- **Conditions:** Duchenne Muscular Dystrophy
- **Start Date:** 2024-03-22
- **Completion Date:** 2027-03
- **CT.gov Last Update:** 2025-11-06

## 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 sevasemten (EDG-5506) on safety, pharmacokinetics and biomarkers of muscle damage in approximately 48 children and adolescents with Duchenne muscular dystrophy treated with oral, once-daily sevasemten. 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 up to a 144-week open-label extension period (Part B).

Approximately forty-eight (48) participants aged 6 to 17, inclusive, will be randomized to sevasemten or placebo in a 2:1 ratio. Three dose cohorts (Cohort 1, Cohort 2 and Cohort 3) of approximately 12 participants each will be enrolled. Approximately 12 additional participants may be added to 1 of these cohorts.

After review of emerging data, the protocol was amended so all dose cohorts receive the same dose in Part B.

## Eligibility

- **Minimum age:** 6 Years
- **Maximum age:** 17 Years
- **Sex:** MALE
- **Healthy Volunteers:** No

```
Key Inclusion Criteria:

* Aged 6 to 17 with a documented mutation on the DMD gene and phenotype consistent with DMD.
* Prior receipt of an AAV-based gene therapy (≥ 2 years after documented receipt of gene therapy administration 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 ≥ 15 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.
```

## Arms

- **Cohort 1** (EXPERIMENTAL) — Drug: Sevasemten Drug: Placebo
- **Cohort 2** (EXPERIMENTAL) — Drug: Sevasemten Drug: Placebo
- **Cohort 3** (EXPERIMENTAL) — Drug: Sevasemten Drug: Placebo

## Interventions

- **Sevasemten Dose 1** (DRUG) — Sevasemten is administered orally once per day
- **Sevasemten Dose 2** (DRUG) — Sevasemten is administered orally once per day
- **Sevasemten Dose 3** (DRUG) — Sevasemten is administered orally once per day
- **Placebo** (DRUG) — Placebo is administered orally once per day

## Primary Outcomes

- **Number of adverse events during treatment with sevasemten or placebo** _(time frame: 36 months)_ — All participants
- **Severity of adverse events during treatment with sevasemten or placebo** _(time frame: 36 months)_ — All participants

## Secondary Outcomes

- **Incidence of laboratory test-related treatment emergent adverse events** _(time frame: 36 months)_
- **Pharmacokinetics as measured by steady state plasma concentration** _(time frame: 36 months)_
- **Change from Baseline in serum creatine kinase** _(time frame: 12 weeks)_
- **Change from Baseline in fast skeletal muscle troponin I** _(time frame: 12 weeks)_

## 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, St Louis, Missouri, United States
- Rare Disease Research, Hillsborough, North Carolina, United States
- Nationwide Children's Hospital, Columbus, Ohio, United States

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.ucla medical center|los angeles|california|united states` — added _(2026-05-12)_
- `locations.uc davis medical center|sacramento|california|united states` — added _(2026-05-12)_
- `locations.university of florida|gainesville|florida|united states` — added _(2026-05-12)_
- `locations.university of massachusetts memorial medical center|worcester|massachusetts|united states` — added _(2026-05-12)_
- `locations.washington university school of medicine|st louis|missouri|united states` — added _(2026-05-12)_
- `locations.rare disease research|hillsborough|north carolina|united states` — added _(2026-05-12)_
- `locations.nationwide children's hospital|columbus|ohio|united states` — added _(2026-05-12)_

---

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*Source data (authoritative): https://clinicaltrials.gov/study/NCT06100887*  
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