SMA: new gene therapy results

Gene therapy in proximal spinal muscular atrophy type 1 (SMA1) improves long-term motor function.

Following an agreement with Genethon, Avexis laboratory is continuing the development of the AVXS-101 gene therapy product, an AAV9 carrying the SMN1 gene. New gene therapy results were presented at the 70th Congress of the American Academy of Neurology (AAN) held from April 21-27 in Los Angeles, USA.

Long-lasting effects of gene therapy
An initial phase I gene therapy trial was conducted in the United States by Avexis laboratory in 15 infants less than 6 months old with proximal SMA1. The goal was to evaluate the effects of the AVXS-101 gene therapy product over 2 years.

The results presented at AAN showed that after a 2-year follow-up, all participants were still alive and none needed permanent ventilation. Treatment improved CHOP INTEND (Children’s Hospital of Philadelphia’s Infant Test of Neuromuscular Disorders, a motor function test in infants with SMA) and motor development: 92% of children could sit down without help.

An early and rapid improvement
Based on these results, Avexis laboratory is conducting a pivotal (phase III equivalent) study, STR1VE, in 15 infants less than 6 months of age with SMA1.
The first results reported at AAN are for the first 11 participants that have been included in the study so far. They demonstrate, after 3 months of treatment, a good tolerance to treatment and an early and rapid improvement of motor function (on the CHOP INTEND).

Other gene therapy trials underway or in preparation
Further trials are also planned or have started in SMA type 2 in the United States (STRONG trial), SMA type 1 in Europe (STR1VE EU pivotal study), SMA types 1, 2 or 3 presymptomatic (SPRINT trial) and in SMA types 1, 2 or 3 for patients not eligible for other trials (REACH trial).

 

> Consult Avexis press release, April 24th « AveXis Presents Initial Data from Pivotal U.S. Trial for SMA Type 1 and 24-Month Follow-Up Data from Phase 1 Trial of AVXS-101 in SMA Type 1 at the Annual Meeting of the American Academy of Neurology »

> Consult trial details on Clinicaltrials.gov: NCT02122952 and NCT03306277