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

Phase 3RecruitingNCT07160634

Solid Biosciences Inc.80 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Duchenne Muscular Dystrophy

Interventions

Eligibility

Sex: MALEMin age: 7 YearsMax age: 11 Years

Medical Language ↔ Plain English

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.

Locations (2)

The Children's Hospital of Westmead

Sydney, New South Wales, Australia

RECRUITING

BC Children's Hospital

Vancouver, British Columbia, Canada

RECRUITING

Outcomes

Primary Outcomes

Change From Baseline in Time to Rise (TTR) from Supine Velocity (rise/s) at Day 540

Time frame: Baseline, Day 540

Secondary Outcomes

Change From Baseline in Stride Velocity 95th Centile (SV95C) (m/s) at Day 540

Time frame: Baseline, Day 540

Change From Baseline in 4-Stair Climb (4SC) Velocity (tasks/s) at Day 540

Time frame: Baseline, Day 540

Change From Baseline in 10-meter Walk/Run (10MWR) Velocity (m/s) at Day 540

Time frame: Baseline, Day 540

Change From Baseline in North Star Ambulatory Assessment (NSAA) total score at Day 540

Time frame: Baseline, Day 540

Cumulative Loss of Function in NSAA Items at Day 540

Time frame: At Day 540

Change From Baseline in Microdystrophin Protein Levels by western blot (% of normal dystrophin) at Day 90

Time frame: Baseline, Day 90

Change From Baseline in Microdystrophin Tissue Distribution by Immunofluorescence (% positive fibers) at Day 90

Time frame: Baseline, Day 90

Change from baseline in Percent Predicted Forced Vital Capacity (FVC) at Day 540

Time frame: Baseline, Day 540

Change from baseline in Percent Predicted Peak Expiratory Flow (PEF) at Day 540

Time frame: Baseline, Day 540

Change from baseline in Percent Predicted Forced Expiratory Volume in 1 second (FEV1) at Day 540

Time frame: Baseline, Day 540

Change from baseline in the Pediatric Outcomes Data Collection Instrument (PODCI) Global score at Day 540

Time frame: Baseline, Day 540

Number of Participants with Treatment Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Adverse Events of special interest (AESIs), and clinically significant changes in Electrocardiogram (ECG) and Echocardiography (ECHO)

Time frame: From first dose up to Day 540

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

Overview

Conditions

Interventions

Eligibility

Locations (2)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts