At the 22nd Annual Meeting of the American Society of Gene and Cell Therapy, promising results for the AT132 genetic therapy for X-linked Myotubular Myopathy ( XLMTM ) were presented.
XLMTM is a rare neuromusclular condition that is caused by mutations in the MTM1 gene. This results in extreme muscle weakness, and a majority of patients require a ventilator to continue breathing, as well as a gastrostomy tube for nutritional support. The average lifespan of a XLMTM patient is approximately 10 years.
AT132 is a genetic therapy that uses an AAV8 vector containing a functional copy of the MTM1 gene, which has the potential to cure the disease in a single intravenous administration.
In the phase 1/2 trial involving 11 patients, a majority of the patients demonstrated progressive attainment of motor developmental milestones, such as head control, sitting unassisted, crawling, standing with support, and initiating stepping movements. Four patients were successfully weaned off of ventilation by the 48-week timepoint, with all other treated patients demonstrating sustained and clinically meaningful reductions in ventilator use.
For more information about AT132, you can see Audentes Therapeutics’ press release here.