PTC Therapeutics Soars 10.31% on FDA Approval of Sephience

On July 29, 2025, Ptc Therapeutics' stock surged by 10.31% in pre-market trading, driven by the FDA's approval of Sephience, a groundbreaking treatment for phenylketonuria (PKU).

PTC Therapeutics has received FDA approval for Sephience, a novel treatment for PKU, a rare metabolic disorder. This approval is significant as it includes broad labeling for all disease subtypes in patients aged one month and older, addressing a critical unmet medical need. The approval is based on robust clinical data from the Phase 3 APHENITY trial and its long-term extension study, demonstrating the drug's efficacy and safety.

The approval of Sephience is expected to enhance PTC Therapeutics' market position in the rare disease treatment sector. The drug's unique ability to liberalize diets while maintaining phenylalanine (Phe) control positions it as a potential standard of care for PKU patients. This broad labeling expands the eligible patient base, including children as young as one month, and covers all sepiapterin-responsive PKU subtypes.

PTC Therapeutics is poised to bring Sephience to market quickly, leveraging its expertise in launching rare disease therapies. The company's experienced customer-facing teams are ready to support the rollout of this therapy, which has the potential to significantly improve the quality of life for PKU patients. The approval marks a significant milestone for the PKU community, offering renewed hope and a new treatment option for individuals of all ages and PKU subtypes that respond to this therapy.