PTC Therapeutics completed its previously announced agreement with Sangamo Therapeutics to acquire ST-920, also known as isaralgagene civaparvovec, a one-time administered AAV gene therapy candidate for Fabry disease. The company expects to complete a rolling BLA (Biologics License Application) submission to the FDA (U.S. drug regulator) for accelerated approval in the fourth quarter of 2026. Clinical studies found that ST-920 enabled long-term production of the deficient alpha-galactosidase A enzyme and reduced globotriaosylceramide levels, with durable clinical benefit and a lower burden from chronic enzyme replacement therapy. The FDA has granted the candidate Orphan Drug, Fast Track and RMAT designations, while the European Medicines Agency has granted Orphan Medicinal Product designation and PRIME eligibility; the U.K. Medicines and Healthcare products Regulatory Agency has granted Innovative Licensing and Access Pathway status. Fabry disease is a lysosomal storage disorder caused by mutations in the GLA gene, leading to deficient alpha-galactosidase A activity and the buildup of globotriaosylceramide, which can damage organs including the kidneys, heart, nerves, eyes, gut and skin. PTC said its expectations regarding ST-920, regulatory submissions, potential approval and commercialization remain forward-looking and subject to substantial risks.