Sio Gene Therapies Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to AXO-AAV-GM2, an investigational gene therapy for the treatment of early infantile, late infantile, and juvenile-onset Tay-Sachs and Sandhoff disease. The Fast Track designation is intended to facilitate the development and review of drugs to treat serious conditions and fill an unmet medical need. The current Phase 1/2 study (NCT04669535) is an open-label, two-stage clinical trial designed to evaluate safety and dose-escalation (Stage 1) and safety and efficacy (Stage 2) of surgical delivery of AXO-AAV-GM2 directly to the brain and spinal cord of pediatric participants with both infantile and juvenile GM2 gangliosidosis (also known as Tay-Sachs or Sandhoff disease). GM2 gangliosidosis is a set of rare, monogenic neurodegenerative lysosomal storage disorders caused by mutations in the genes that encode the enzyme ?-Hexosaminidase A. It can be categorized into two distinct diseases, Tay-Sachs disease, which results from a mutation in the gene encoding the alpha subunit of the ?-Hexosaminidase A enzyme (HEXA), and Sandhoff disease, which results from a mutation in the gene encoding the beta subunit of the ?-Hexosaminidase A enzyme (HEXB). Children affected by GM2 gangliosidosis suffer from a progressively debilitating disease course and reduced life expectancy. Currently, there are no FDA-approved treatment options for GM2 gangliosidosis.