Sangamo announces FDA acceptance of BLA rolling submission request for ST-920

Sangamo (SGMO) Therapeutics announced that the U.S. Food and Drug Administration has accepted Sangamo’s request for a rolling submission and review of the Biologics License Application for isaralgagene civaparvovec, or ST-920, a wholly owned investigational gene therapy for the treatment of adults with Fabry disease. This acceptance follows Sangamo’s meeting with the FDA in October 2025 to discuss the proposed efficacy and safety data package for isaralgagene civaparvovec where, in the meeting minutes, among other things, the FDA reiterated its October 2024 agreement to use eGFR slope as an endpoint to support an accelerated approval pathway. Sangamo presented detailed clinical data from the registrational Phase 1/2 STAAR study at the International Congress of Inborn Errors of Metabolism 2025 in September, which demonstrated the potential for isaralgagene civaparvovec as a one-time, durable treatment of underlying pathology of Fabry disease to provide meaningful, multi-organ, clinical benefits above current standards of care. Furthermore, the STAAR study demonstrated a positive mean annualized estimated glomerular filtration rate slope at 52-weeks across all dosed patients in the study, which the FDA has agreed will serve as the primary basis of approval. Isaralgagene civaparvovec has been granted Orphan Drug, Fast Track and RMAT designations from the FDA, Orphan Medicinal Product designation and PRIME eligibility from the European Medicines Agency and Innovative Licensing and Access Pathway from U.K. Medicines and Healthcare products Regulatory Agency. Sangamo plans to initiate rolling submission of the BLA to the FDA under the accelerated approval pathway later in the fourth quarter of 2025.