Genethon Presents Promising Results for Gene Therapy in DMD
Genethon, the pioneering gene therapy research laboratory created by AFM-Telethon, today presented positive results from the Phase 1/2 dose escalation part of the trial evaluating its gene therapy, GNT0004, for Duchenne muscular dystrophy (DMD) at the ASGCT Breakthroughs in Muscular Dystrophy conference, Nov. 19 - 20, 2024, in Chicago, IL. Based on these results, Genethon plans to launch a pivotal trial in Europe and the United States in 2025.
GNT0004 gene therapy was developed by Genethon, in partnership with the teams of Prof. Dickson (University of London, Royal Holloway) and the Institut de Myologie (Paris). The trial is being carried out since 2021 in France and the UK, and includes boys aged 6 to 10 with DMD who have retained their ability to walk. GNT0004 is administered by a single intravenous injection.
The Phase 1/2 part of the trial, designed to assess tolerance and initial evidence of efficacy, was completed at the end of October and determined the therapeutic dose of GNT0004 to be used in the pivotal study. Five patients, between ages 6 and 10, were treated at one of two doses; two at the first level and three at a higher level. The safety and pharmacodynamic data showed good tolerance of GNT0004 combined with transient immunological prophylaxis, as well as efficacy data, both in terms of micro-dystrophin expression and functional improvement.
Stabilization of Motor Functions: An Encouraging Advancement
The results showed that one to two years after treatment at the higher of two doses of GNT0004, patients experienced stabilization in the North Star Ambulatory Assessment measuring motor functions compared with a decline in untreated patients in the parallel disease natural history study. For one patient, an improvement was even observed, reaching the maximum score of 34 at 12 months, and confirmed at 18 months post-treatment.
"These results show that gene therapy can provide solutions for one of the most complex genetic diseases," said Frédéric Revah, CEO of Genethon.
Upcoming Expanded Clinical Trials
The success of this first phase allows Genethon to plan the inclusion of more than 60 children for the confirmatory (pivotal) phase as early as the second quarter of 2025. This new step will be crucial to confirm the efficacy of GNT0004 in treating Duchenne Muscular Dystrophy. After review and advice from the independent monitoring committee, these conclusive results enable Genethon to launch the confirmatory part of the trial (pivotal phase) with the inclusion of the first patients in mid-2025. The trial is being carried out in France and the UK and includes boys aged 6 to 10 with DMD who have retained their ability to walk.
You are affected by Duchenne muscular dystrophy and have questions about this trial or other ongoing trials? Feel free to contact us at : questionessai@afm-telethon.fr