Sangamo Therapeutics, Inc. Advances Rolling BLA Submission To U.S. Food And Drug Administration For Investigational Fabry Gene Therapy ST-920

Sangamo Therapeutics, Inc., a genomic medicine company, announced progress on its rolling submission of a Biologics License Application (BLA) to the U.S. Food and Drug Administration seeking accelerated approval of isaralgagene civaparvovec (ST-920). ST-920 is Sangamo’s wholly owned investigational gene therapy being developed for the treatment of adults with Fabry disease.

The rolling submission, which began in December 2025, has now advanced with the company submitting both the preclinical and clinical modules to the FDA for review. This approach enables the agency to evaluate completed portions of the BLA as they become available, rather than waiting for the full application at once. In addition, an antibody assay companion diagnostic—designed to identify eligible patients for treatment with ST-920—has been submitted to and accepted by the FDA’s Center for Devices and Radiological Health for review under a Premarket Approval (PMA) pathway.

Sangamo stated that the data from its registrational STAAR study support the promise of ST-920 as a one-time gene therapy that may offer durable, multi-organ clinical benefits for people living with Fabry disease. The company highlighted that the study showed a positive mean annualized eGFR slope at 52 weeks across all dosed patients—an endpoint the FDA has agreed can support accelerated approval. These results were presented across multiple scientific sessions at a recent medical meeting and are available on the company’s website.

The Phase 1/2 STAAR study is a global, open-label, single-dose, dose-ranging, multicenter clinical trial evaluating isaralgagene civaparvovec in patients with Fabry disease. ST-920 is delivered through a one-time infusion without the need for preconditioning. The therapy has received multiple regulatory designations, including Orphan Drug, Fast Track, and RMAT from the FDA; Orphan Medicinal Product designation and PRIME eligibility from the European Medicines Agency; and entry into the Innovative Licensing and Access Pathway (ILAP) from the U.K. Medicines and Healthcare products Regulatory Agency.

Fabry disease is a lysosomal storage disorder caused by mutations in the GLA gene, which lead to reduced or absent levels of the α-Gal A enzyme. This enzyme is essential for breaking down globotriaosylceramide (Gb3). When Gb3 accumulates in cells, it can damage major organs such as the kidneys, heart, nervous system, eyes, gastrointestinal tract, and skin. Symptoms can include low or absent sweat production, heat intolerance, angiokeratomas, visual problems, kidney disease, heart failure, digestive issues, mood disorders, and episodes of neuropathic pain or tingling in the hands and feet.