Sangamo Receives FDA Fast Track Designation for Fabry Disease Gene Therapy Product Candidate

Sangamo Therapeutics, Inc. recently announced the US FDA has granted Fast Track Designation to isaralgagene civaparvovec, or ST-920, a wholly owned gene therapy product candidate for the treatment of Fabry disease.

Fast Track designation aims to facilitate the development and expedite the review of new therapeutics that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs. Companies granted this designation are given the opportunity for more frequent interactions with the FDA. These clinical programs may also be eligible to apply for Accelerated Approval and Priority Review if relevant criteria are met. The FDA has previously granted ST-920 Orphan Drug Designation.

“We are thrilled with the FDA’s decision to grant Fast Track Designation for ST-920. Fabry is a debilitating disease with life-long impact,” said Nathalie Dubois-Stringfellow, PhD, Sangamo’s Senior Vice President, Chief Development Officer. “This decision from the FDA underscores the potential for ST-920 to address a serious unmet need and serve as a meaningful therapeutic option for patients with Fabry disease. We are highly encouraged by this promising development and look forward to our expected meeting with the FDA on Phase 3 trial design in the summer.”

ST-920 is currently being evaluated in the Phase 1/2 STAAR study, with a total of 20 patients dosed to date. In February 2023, Sangamo announced promising results from the STAAR study via an oral presentation at the 19^th Annual WORLD Symposium, showing sustained, elevated expression of alpha-galactosidase A (α-Gal A) activity in the 13 dosed patients as of the data cutoff, 78% globotriaosylceramide (Gb3) substrate clearance at 6-months and 77% reduction in urine podocyte loss in one of the first kidney biopsies, and a clinically meaningful and statistically significant increase in mean general health scores, as measured by the SF-36 General Health survey. A copy of the presentation is available in the Presentations section of the Sangamo website. Sangamo is currently preparing for a potential Phase 3 trial and plans to meet with the FDA on the proposed Phase 3 study design in the summer, with a trial start anticipated by the end of 2023, depending on regulatory interactions.

The Phase 1/2 STAAR study is a global open-label, single-dose, dose-ranging, multicenter clinical study designed to evaluate the safety and tolerability of isaralgagene civaparvovec, or ST-920, a gene therapy product candidate in patients with Fabry disease. Isaralgagene civaparvovec requires a one-time infusion without preconditioning. The STAAR study is enrolling patients who are on ERT, are ERT pseudo-naïve (defined as having been off ERT for six or more months), or who are ERT-naïve. The US FDA has granted Orphan Drug and Fast Track designation to isaralgagene civaparvovec, which has also received Orphan Medicinal Product designation from the European Medicines Agency.

 Fabry disease is a lysosomal storage disorder caused by mutations in the galactosidase alpha gene (GLA), which leads to deficient alpha-galactosidase A (α-Gal A) enzyme activity, which is necessary for metabolizing globotriaosylceramide (Gb3). The buildup of Gb3 in the cells can cause serious damage to vital organs, including the kidney, heart, nerves, eyes, gut and skin. Symptoms of Fabry disease can include decreased or absent sweat production, heat intolerance, angiokeratoma (skin blemishes), vision problems, kidney disease, heart failure, gastrointestinal disturbance, mood disorders, neuropathic pain and tingling in the extremities.

 Sangamo Therapeutics is a clinical-stage biopharmaceutical company with a robust genomic medicines pipeline. Using ground-breaking science, including our proprietary zinc finger genome engineering technology and manufacturing expertise, Sangamo aims to create new genomic medicines for patients suffering from diseases for which existing treatment options are inadequate or currently don’t exist. For more information, visit www.sangamo.com.