US biopharmaceutical company PTC Therapeutics Inc (NASDAQ:PTCT) announced on Wednesday that it was selected as the winning bidder to acquire ST-920, a BLA-stage, one-time administered AAV gene therapy for Fabry disease, from Sangamo Therapeutics in a competitive bankruptcy auction.

The terms include USD111m upfront and up to USD100m in contingent milestone payments based on certain regulatory approvals. A rolling BLA submission to the US FDA for accelerated approval of ST-920 is expected to be completed in Q4 2026. The BLA is based on evidence of meaningful favourable clinical effect on renal function and safety and tolerability profile over 52 weeks in the Phase 1/2 STAAR study.

ST-920 has received Regenerative Medicine Advanced Therapy (RMAT) designation as well as Orphan Drug and Fast Track designations from the FDA.

The Phase 1/2 STAAR study demonstrated positive mean annualised estimated glomerular filtration rate (eGFR) slope at 52 weeks following ST-920 administration, as well as evidence of favourable effect on other aspects of Fabry disease including cardiac function and quality of life. Durability of effect was demonstrated, and ST-920 showed an encouraging safety and tolerability profile with no requirement for routine prophylactic or post-infusion systemic immunosuppressive agents.

PTC also intends to pursue regulatory approval outside of the United States.

The acquisition remains subject to definitive documentation, bankruptcy court approval, antitrust review, and other customary closing conditions. It is expected to close in late Q3 or early Q4 2026.