ASGCT 2026: Genethon presents results from three gene therapy programs in clinical development
At ASGCT 2026 in Boston, Genethon presented new clinical data from three of its gene therapy programs in Duchenne muscular dystrophy, gamma-sarcoglycanopathy (LGMD-R5), and Crigler-Najjar syndrome. In total, Genethon teams presented 8 oral presentations and 13 posters.
Genethon, the French laboratory dedicated to the research and development of gene therapies for rare diseases created by AFM-Telethon, presented several clinical results at the annual meeting of the American Society of Gene & Cell Therapy (ASGCT), held from May 11 to 15, 2026, in Boston, USA.
Genethon teams presented a total of 8 oral presentations and 13 posters covering several gene therapy programs currently in clinical development.
Duchenne muscular dystrophy: long-term follow-up data for GNT-0004
Genethon presented data from the early phases of the combined Phase 1/2/3 clinical trial evaluating the GNT-0004 gene therapy in Duchenne muscular dystrophy.
Long-term follow-up data from the three patients treated at the effective dose level during the dose-escalation phase confirmed:
- sustained clinical efficacy at two years across several parameters;
- persistence of pharmacodynamic effects;
- safety of the treatment.
These results enabled the launch of the pivotal phase of the trial last September. This phase will include 72 patients.
The data were presented during the “Late Breaking Abstracts II” session by Gerald Perret, Head of Development at Genethon.
Gamma-sarcoglycanopathy: more than 90% of muscle fibers express the therapeutic gene
Dr. Barry Byrne, M.D., Ph.D., from the Powell Gene Therapy Center at the University of Florida, presented safety, pharmacodynamics, and efficacy results for the ATA-200 gene therapy in LGMD-2C/R5 limb-girdle muscular dystrophy associated with γ-sarcoglycan deficiency.
These results concern the first patients treated in the clinical trial conducted by Atamyo Therapeutics, a Genethon spin-off.
ATA-200 restored SGCG protein expression in more than 90% of muscle fibers:
- 90.2% for patient 1;
- 92.1% for patient 2;
six months after treatment.
These results were presented during the “Clinical Trials: In vivo gene transfer and gene-editing therapies” session.
Read also: “ASGCT 2026: Atamyo Therapeutics presents encouraging ATA-200 results in LGMD-R5.”
Crigler-Najjar syndrome: a first patient successfully treated despite pre-existing immunity
Giuseppe Ronzitti, Genethon’s Director of Scientific Strategy and Head of the “Immunology and Liver Disease” laboratory, presented results on the use of imlifidase as a pre-treatment to gene therapy in a patient with a severe form of Crigler-Najjar syndrome.
The patient had pre-existing immunity against the AAV8 vector used for gene therapy and was treated as part of the GNT-018-IDES clinical trial conducted by Genethon in collaboration with Hansa Biopharma.
The results were presented during the “Advancing clinical trials and redosing” session.
About Genethon
A pioneer in the discovery and development of gene therapies for rare diseases, Genethon is a non-profit laboratory created by AFM-Telethon.
Fifteen gene therapy products originating from Genethon’s research, or to which Genethon has contributed, are currently in clinical trials for liver, blood, immune, muscle, and eye diseases.
Learn more about Genethon