PTC Therapeutics wins bankruptcy auction for Sangamo's Fabry gene therapy ST-920

PTC Therapeutics announced on August 12, 2026 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.¹ The deal emerged from Sangamo's Chapter 11 bankruptcy proceeding.

Under the deal terms, PTC will pay $111 million upfront, with up to $100 million more in contingent milestones: $80 million tied to accelerated approval and $20 million tied to traditional or full FDA approval.¹ The transaction still needs to clear several hurdles, as it remains subject to finalization of definitive documentation, bankruptcy court approval, antitrust review, and other customary closing conditions.¹ PTC said it anticipates the deal wrapping up late in the third quarter or early in the fourth quarter of 2026.¹

On the regulatory side, PTC plans to complete a rolling BLA submission to FDA for accelerated approval in the fourth quarter of 2026, based on evidence of a meaningful favorable clinical effect on renal function along with a safety and tolerability profile shown over 52 weeks in the Phase 1/2 STAAR study.¹ The BLA relies specifically on the intermediate endpoint of annualized eGFR at Week 52, as aligned with FDA, with 104-week STAAR results expected to serve as confirmatory evidence for traditional approval.¹

The therapy, known chemically as isaralgagene civaparvovec, has already received Regenerative Medicine Advanced Therapy, Orphan Drug, and Fast Track designations from FDA.¹ PTC also said it plans to pursue regulatory approval for ST-920 outside the United States.¹