A Study of SGT-003 Gene Therapy in Duchenne Muscular Dystrophy (INSPIRE DUCHENNE)

Study Overview
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Brief Summary
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This is a multicenter, open-label, non-randomized study to investigate the safety, tolerability, and efficacy of a single IV infusion of SGT-003 in participants with Duchenne muscular dystrophy. There will be 2 cohorts in this study, dosed sequentially. Cohort 1 will include participants 4 to <6 years of age, inclusive. Cohort 2 will only be opened after dosing and monitoring a subset of participants in Cohort 1. Cohort 2 will include participants 6 to <8 years of age, inclusive. All participants will receive SGT-003 and will be enrolled in the study for 5 total years for long-term follow up.

Official Title
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A Phase 1/2, Multicenter, Open-Label Study to Investigate the Safety, Tolerability, and Efficacy of a Single Intravenous Dose of SGT-003 in Ambulant Males With Duchenne Muscular Dystrophy (INSPIRE DUCHENNE)

Conditions
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Duchenne Muscular Dystrophy

Intervention / Treatment
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* Genetic: SGT-003


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Cohort 1: 4 to <6 years of age, inclusive Cohort 2: 6 to <8 years of age, inclusive Ambulatory as defined as being able to walk without the use of an assistive device. Negative for AAV antibodies. On a stable dose of at least 0.5 mg/kg/day of oral daily prednisone or 0.75 mg/kg/day deflazacort for ≥12 weeks prior to entering the study. Cohort 1: <18 kg body weight Cohort 2: <30 kg body weight Exclusion Criteria: Current or prior treatment with approved or investigational dystrophin modifying drugs such as eteplirsen, golodirsen, casimersen, and viltolarsen. Current or prior treatment with an approved or investigational gene transfer drug. Exposure to another investigational drug within 3 months prior to screening or 5 half-lives since last administration, whichever is longer. Established clinical diagnosis of DMD that is associated with any deletion mutation in exons 1 to 11 or 42 to 45, inclusive, in the DMD gene as documented by a genetic report and confirmed by Sponsor genetic testing. Other inclusion or exclusion criteria apply.

Ages Eligible for Study
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Minimum Age: 4 Years
Maximum Age: 7 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: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1: SGT-003<br>All participants will receive a single IV infusion of SGT-003 on Day 1. | Genetic: SGT-003<br>* Adeno-associated virus serotype SLB101 containing the human microdystrophin gene (h-µD5)<br>|
| Experimental: Cohort 2: SGT-003<br>All participants will receive a single IV infusion of SGT-003 on Day 1. | Genetic: SGT-003<br>* Adeno-associated virus serotype SLB101 containing the human microdystrophin gene (h-µD5)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of treatment-emergent adverse events (AEs) |  | Day 360 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in microdystrophin protein levels | Microdystrophin expression evaluation in muscle biopsies | Day 90, Day 360 | 
| Change from baseline in North Star Ambulatory Assessment (NSAA) total score | Assessment of muscle function using a 17-item scale | Day 360 | 
| Change from baseline in stride velocity 95th centile (SV95C) | Assessment of peak ambulatory performance captured by wearable activity monitoring device | Day 360 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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DMD, Gene Therapy