Genethon Begins Phase 3 Trials of Gene Therapy for Duchenne Muscular Dystrophy

Genethon Begins Phase 3 Trials of Gene Therapy for Duchenne Muscular Dystrophy

By, Admin 31 July 2025

Genethon has received the green light from both the MHRA (UK) and EMA (EU) to initiate Phase 3 clinical trials for its gene therapy GNT0004.

This pivotal trial targets Duchenne muscular dystrophy (DMD), a rare and devastating genetic disorder affecting muscle strength and function in young boys.

A Major Milestone for Genethon

Genethon CEO Frédéric Revah highlighted this regulatory approval as a decisive turning point for the DMD program, which began in 2021.

He emphasized two major points:

  • The strong results observed in the Phase 1/2 portion of the study
  • The lower dose of GNT0004 chosen for the pivotal trial—lower than doses used in competing DMD gene therapy trials

“We are determined to bring GNT0004 to market for young patients who have been waiting too long for a solution,” said Dr. Revah.

What Makes GNT0004 Stand Out?

Early-phase results from the first patients showed:

  • Good tolerance of GNT0004
  • Strong expression of microdystrophin
  • Reduction in creatine phosphokinase (CPK)—a biomarker for muscle damage
  • Stabilization or improvement of motor function

These outcomes gave regulators confidence in the product’s potential and its safety profile.

Phase 3 Trial Overview

  • Start Date: August–September 2025
  • Trial Sites: France and the UK
  • Enrollment: 64 ambulant boys aged 6–10 with DMD
  • Administration: Single intravenous injection of GNT0004
  • Vector: AAV8 with hMD1 microdystrophin gene (3×10¹³ vg/kg dose)
  • Target Tissues: Muscle and cardiac cells (via Spc5-12 promoter)
  • Protocol: Double-blind, placebo-controlled trial
  • Immunological Prophylaxis: Given to manage any immune response

Understanding Duchenne Muscular Dystrophy

DMD is a progressive genetic disease affecting 1 in 5,000 boys worldwide. It stems from mutations in the gene that encodes dystrophin, a key protein that stabilizes muscle membranes.

Without dystrophin, boys with DMD face:

  • Gradual loss of mobility
  • Severe heart and respiratory decline
  • Death often between ages 20 to 40

About Genethon

Genethon is a non-profit R&D lab founded by the AFM-Telethon. It focuses exclusively on gene therapies for rare diseases.

One of its previous gene therapy contributions has already been approved for spinal muscular atrophy, marking a historic achievement in rare disease treatment.

Optimize Your trial insights with Clival Database.

Are you exhausted from the uncertainty of trial insights pricing? Clival Database ensures the clarity in the midst of the global scenario for clinical trials to you.

Clival Database is one of the best databases that offers an outstanding number of clinical trial data in terms of 50,000+ molecules and from primary regulatory markets as well as new entrants like Indian and Chinese markets.

With Clival, you get accurate positioning of historical sales data, patent database, company profiling, safety & efficacy, and prediction of launch of new innovative molecules helping you to align your research and driving down the cost.

To add value, we further break down our analytics for you so that improving your operational effectiveness; optimizing your clinical trials; and offering you accurate and high-quality data at lowest possible prices becomes possible.

Elevate your trial success rate with the cutting-edge insights from Clival database.

Check it out today and make more informed sourcing decisions! Learn More!