A Study of SGT-003 Gene Therapy in Ambulant Males With Duchenne Muscular Dystrophy (IMPACT DUCHENNE)

Solid Biosciences

Status and phase: Enrolling; Phase 3

Conditions: Duchenne Muscular Dystrophy

Treatments: Drug: Placebo; Drug: SGT-003

Study type: Interventional

Funder types: Industry

Identifiers

NCT07160634

2025-522949-22 (EudraCT Number)

1013075 (Other Identifier)

SGT-003-301

Details and patient eligibility

About

This is a Phase 3, double-blind, placebo-controlled study with the primary objective of evaluating the efficacy of a single IV infusion of SGT-003 in pediatric ambulant male participants with DMD. The secondary objectives include the evaluation of additional efficacy and safety outcomes. The study will be divided into 2 parts. Participants will be randomized 1:1 to either SGT-003 in Part 1 followed by placebo in Part 2 or to placebo in Part 1 followed by SGT-003 in Part 2. Participants will continue to be monitored in long term follow up (LTFU) for at least 5 years from their SGT-003 dosing date.

Enrollment: 80 estimated patients

Sex: Male

Ages: 7 to 11 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Participant is ambulatory.
• Established clinical diagnosis of DMD and documented DMD gene mutation predictive of DMD phenotype.
• Negative for antibodies against adeno-associated virus.
• On a stable daily oral regimen of at least 0.5 mg/kg/day prednisone or 0.75 milligrams per kilogram per day (mg/kg/day) deflazacort for at least 6 months prior to entering the study, allowing for weight-based dose modifications in accordance with clinical practice.
• Meet 10-meter walk/run time criteria.
• Meet time to rise from supine criteria.
• Participant has bodyweight ≤50 kg.

Exclusion criteria

• Current or prior treatment with an approved or investigational gene transfer drug or gene editing therapy.
• Exposure to vamorolone, givinostat, approved or investigational dystrophin- or disease-modifying drugs (such as eteplirsen, golodirsen, casimersen, viltolarsen, and ataluren), or another investigational drug for any indication within 6 months or 5 half-lives, whichever is longer, prior to enrollment.
• Established clinical diagnosis of DMD that is associated with any deletion variant or variant predicted not to express exons 1 to 11, exons 42 to 45, or exons 57 to 69, inclusive of the DMD gene as documented by a genetic report.

Other Inclusion/Exclusion criteria to be applied as per protocol.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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80 participants in 2 patient groups

SGT-003 followed by Placebo

Experimental group

Description:

Enrolled participants will receive a single intravenous (IV) infusion of SGT-003 in Part 1 and a single IV infusion of matching Placebo in Part 2.

Treatment:

Drug: SGT-003

Drug: Placebo

Placebo followed by SGT-003

Experimental group

Description:

Enrolled participants will receive a single intravenous (IV) infusion of matching Placebo in Part 1 and a single IV infusion of SGT-003 in Part 2.

Treatment:

Drug: SGT-003

Drug: Placebo