PTC Expands Rare Disease Portfolio With ST-920 Acquisition
(RTTNews) - PTC Therapeutics, Inc., (PTCT) has agreed to acquire ST-920, a BLA-stage one-time AAV gene therapy for Fabry disease from Sangamo Therapeutics in a $111 million upfront deal plus milestone payments.
Fabry disease is a rare inherited lysosomal storage disorder caused by mutations in the GLA gene, leading to deficiency of the alpha-galactosidase A (a-Gal A) enzyme, leading to organ damage and lifelong treatment needs.
ST-920 is gene therapy designed to deliver a functional copy of the GLA gene using an adeno-associated viral (AAV) vector. By restoring a-Gal A enzyme activity, the therapy aims to provide durable clinical benefit with a single administration. In the Phase 1/2 STAAR study, patients showed sustained enzyme activity for up to 4.5 years, alongside improvements in renal function, cardiac outcomes, and quality of life.
The BLA submission for accelerated approval is based on the intermediate clinical endpoint of annualized eGFR at Week 52, aligned with FDA guidance, with 104-week results planned to provide confirmatory evidence for traditional approval. Nonclinical and clinical modules have already been submitted, with the CMC package expected in Q4 2026, targeting a 2027 launch. PTC will also pursue regulatory filings outside the U.S., leveraging its rare disease infrastructure.
The therapy has FDA RMAT, Orphan Drug and Fast Track designations.
CEO Matthew B. Klein said the acquisition "advances our strategy of leveraging our rare disease commercial infrastructure to accelerate near-term revenue growth," highlighting the opportunity to deliver a transformative therapy without additional development build.
The acquisition is expected to close in Q3 2026, strengthening PTC's pipeline in rare genetic disorders.
PTCT has traded between $45.42 and $90.87 over the past year. The stock closed Wednesday's trading at $72.64, down 1.44%. During after-hours trading the stock is at $74.75, up 3%.
