Microdystrophin (GNT0004) Gene Therapy Clinical Trial in Duchenne Muscular Dystrophy: A phase I/II/III study with a dose determination part followed by an efficacy and safety evaluation, quadruple blind placebo-controlled part and then by a long term safety follow up part, in ambulant boys

Actively RecruitingPhase 3Gene Therapy

Study Overview

Age: 6–10 years
Phase: Phase 3
Sponsor: Genethon
Therapeutic Approach: Gene Therapy
Variant Requirement: Being included in the GNT-014-MDYF study Diagnosis of DMD based upon Gene testing positive with detailed genotyping except subjects with any mutations affecting exons 8 and/or 9
Eligible Sex: Male
Ambulation: Ambulatory
Study Start (Actual): 01/10/2020
Primary Completion (Estimated): 01/10/2028
Study Completion (Estimated): 01/10/2028
Enrollment (Estimated): 5
Countries: BelgiumSpainFrance

Steroid Use

Ongoing corticosteroid therapy with prednisolone (or prednisone) according to standard of care (participants receiving deflazacort or vamorolone daily dose can switch to prednisolone (or prednisone) 4 weeks before screening)

Inclusion Criteria

Enrolled in the GNT-014-MDYF study (a natural history study preceding the present gene therapy study)
Able to achieve a score in the NSAA (North Star Ambulatory Assessment) scale 18 and Time to Rise From Floor (RFF) 7 sec at screening visit
Up to date vaccination record including hepatitis A and B, PCV

Exclusion Criteria

DMD patients with any mutations affecting: - exons 1 through 17, (and any mutations affecting other exons as per a country’s requirement which will be applicable to this specific country) for Part 1 participants - affecting exons 8 and/or 9 (and any mutations affecting other exons as per a country’s requirement which will be applicable to this specific country) for Part 2 participants
Presence of neutralizing antibodies against AAV8
Cardiomyopathy based on physical/cardiological examination and echocardiography (or cardiac MRI if available) with Left Ventricular Ejection Fraction (LVEF) below 55% and fractional shortening (SF) below 28%
Any respiratory assistance needed including non-invasive daytime or nocturnal ventilation
Inability to perform the planned respiratory functions tests