Sangamo's Fabry Disease Gene Therapy Shows Promising Data, FDA Rolling Submission Initiated — Sangamo Therapeutics, Inc.

Event summary

Sangamo Therapeutics presented detailed data from the Phase 1/2 STAAR study evaluating isaralgagene civaparvovec (ST-920) for Fabry disease at WORLDSymposium™ 2026.
The study demonstrated a positive mean annualized eGFR slope of 1.965 mL/min/1.73m2/year at 52-weeks across all 32 dosed patients, indicating improved renal function.
Rolling submission of the Biologics License Application (BLA) to the FDA has been initiated under the Accelerated Approval pathway.
The study showed stable cardiac function and durable expression of alpha-galactosidase A (α-Gal A) activity for up to 4.5 years in the longest treated patient.

The big picture

Sangamo's data suggests a potential paradigm shift in Fabry disease treatment, moving from enzyme replacement therapy to a one-time gene therapy. The initiation of a rolling BLA submission under the Accelerated Approval pathway indicates confidence in the regulatory path forward. If successful, this could position Sangamo as a leader in gene therapy for rare diseases.

What we're watching

Regulatory Pathway: Whether the FDA will accept the mean annualized eGFR slope at 52 weeks as sufficient evidence for Accelerated Approval.
Clinical Efficacy: The durability of the observed clinical benefits, particularly in renal and cardiac function, over longer follow-up periods.
Market Potential: The pace at which Sangamo can commercialize ST-920 if approved, given the current treatment landscape for Fabry disease.