Atamyo Therapeutics Reports Promising Early Results for ATA-200 Gene Therapy in Rare Muscular Dystrophy
核心洞察
Atamyo Therapeutics announced encouraging safety and efficacy results for ATA-200 gene therapy in the first four patients with LGMD-R5 (搜索), a severe childhood muscular dystrophy (搜索) that leads to loss of walking ability before adulthood.
The Phase 1b/2 trial showed over 90% of muscle fibers expressing the therapeutic protein in the first two patients at six months, with significant reductions in muscle damage biomarkers and clinical improvements in functional tests at nine months.
No serious adverse events were observed in the four treated patients, demonstrating the safety profile of the single intravenous AAV-based gene therapy targeting gamma-sarcoglycan (搜索) deficiency.
Atamyo Therapeutics announced promising early results from its Phase 1b/2 clinical trial of ATA-200, an adeno-associated virus (AAV) gene therapy for LGMD-R5 (搜索) limb-girdle muscular dystrophy (搜索), at the MDA Conference 2026. The biotechnology company reported encouraging safety and efficacy data from the first four patients treated in the ongoing study targeting this severe childhood muscular dystrophy (搜索).
Strong Biological Response in Early Patients
The trial, conducted at the Powell Gene Therapy Center (搜索) at the University of Florida under principal investigator Dr. Barry Byrne, has demonstrated remarkable biological activity in the first two patients with nine-month follow-up data. Muscle biopsies performed at six months revealed that more than 90% of muscle fibers were expressing the SGCG (搜索) protein, with patient 1 showing 90.2% expression and patient 2 achieving 92.1% expression.
"These initial results are very encouraging and demonstrate the potential of our product with biological data rarely seen in neuromuscular diseases and at such an early stage of the trial," said Angela Columbano, CEO of Atamyo Therapeutics.
The single intravenous injection of ATA-200 at a dose of 1.0E+14 vg/kg delivered a normal copy of the human SGCG (搜索) gene to nearly all muscle fibers, demonstrating successful gene delivery and expression. This level of protein restoration represents a significant achievement in gene therapy for muscular dystrophies.
Sustained Clinical Benefits Observed
Nine months after treatment, patients showed significant and sustained reductions in CPK levels, a key biomarker of muscle damage, along with decreased transaminases. Clinical benefits were also observed in several important parameters in ambulatory patients, particularly in timed functional tests, suggesting meaningful improvements in muscle function.
The therapy targets LGMD-2C (搜索)/R5, a rare genetic disease caused by mutations in the gene producing γ-sarcoglycan, a transmembrane protein essential for connecting muscle fibers to their environment. This severe form of muscular dystrophy (搜索) appears in childhood and causes progressive muscular weakness leading to loss of walking ability before adulthood, with cardiac involvement reported in approximately half of patients.
Safety Profile Supports Continued Development
Importantly, no serious side effects were observed in any of the four patients treated, confirming the safety profile of ATA-200. The Phase 1b/2 clinical trial (NCT05973630) is evaluating safety, pharmacodynamics, efficacy, and immunogenicity in children aged 6 to 13 years.
The gene therapy product was developed by Isabelle Richard, Chief Scientific Officer at Atamyo and Research Director at CNRS, who heads the Progressive Muscular Dystrophies Laboratory at Genethon. In preclinical mouse models, ATA-200 demonstrated tolerability and capability to correct symptoms and biomarkers of the pathology.
Addressing Significant Unmet Medical Need
LGMD-2C (搜索)/R5 affects an estimated 2,000 people in Europe and the US, with no curative treatment currently available. Management remains solely supportive, making ATA-200's potential particularly significant for patients and families facing this devastating disease.
ATA-200 has received Orphan Drug Designation in both the US and Europe, as well as Rare Pediatric Disease Designation from the US FDA, recognizing the significant unmet medical need in this patient population.
The company expects to publish additional results from the ongoing study in the coming months as longer-term follow-up data becomes available. The trial is supported by The Dion Foundation (搜索) for Children with Rare Diseases and CureSCG (搜索), whose financial contributions enabled the launch of this potentially life-changing therapy.