PTC Therapeutics (PTCT) investor relations material

Transaction and Acquisition Overview

• Announced acquisition of ST-920, a BLA-stage gene therapy for Fabry disease, for $111 million upfront and up to $100 million in regulatory milestones, with no royalties or sales milestones.

• The asset was acquired through a competitive bankruptcy auction, subject to definitive documentation, bankruptcy court approval, antitrust review, and other customary closing conditions, with expected close in late Q3 or early Q4 2026.

• The acquisition leverages existing rare disease commercial and regulatory infrastructure to accelerate revenue growth and expand the rare disease portfolio.

Clinical and Regulatory Highlights

• ST-920 is a one-time AAV6 gene therapy for Fabry disease, showing a differentiated safety and efficacy profile, including no need for immunosuppression and long-term clinical benefits.

• The pivotal STAAR study included 33 adults, demonstrating improved renal and cardiac function, quality of life, a positive eGFR slope at 52 weeks, sustained enzyme activity for up to 4.5 years, and withdrawal from ERT for all treated patients.

• The therapy has received RMAT, Orphan Drug, and Fast Track designations from FDA, and similar designations from European and UK regulators.

• BLA for accelerated approval is planned based on 52-week eGFR data, with confirmatory 104-week data and submission expected to complete in Q4 2026; potential commercial launch in 2027.

Market Opportunity and Commercial Strategy

• Estimated 11,000 Fabry patients in the U.S., with similar prevalence globally; many are concentrated in centers of excellence and covered by newborn screening.

• The therapy is positioned for broad use across Fabry subtypes, treatment histories, and both sexes, with early diagnosis and treatment expected to yield better outcomes.

• Existing global commercial and regulatory infrastructure enables rapid integration and launch without significant new build-out.

• ST-920 aims to reduce the burden of chronic ERT by enabling long-term enzyme production and reducing Gb3 levels.