PTC Therapeutics Announces Sepiapterin NDA Submission to FDA

Core Viewpoint - PTC Therapeutics has submitted a New Drug Application (NDA) for sepiapterin to the U.S. FDA, aimed at treating both pediatric and adult patients with phenylketonuria (PKU) [1][2]. Group 1: NDA Submission and Clinical Data - The NDA submission is a significant milestone for providing treatment options for PKU patients in the U.S. [2] - The NDA is supported by data from the phase 3 APHENITY trial, which showed a mean reduction in phenylalanine (Phe) levels of 63% in the overall treated population and 69% in subjects with classical PKU [2] - 84% of subjects achieved Phe control under treatment guidelines of <360 µmol/L, and 22% of subjects normalized their Phe levels [2] - The NDA also includes data from the APHENITY open-label extension study, demonstrating the durability of sepiapterin's effects [2] Group 2: Phe Tolerance and Quality of Life - Approximately 60% of subjects in the Phe tolerance sub-study were able to consume protein above the age-adjusted recommended daily allowance while maintaining Phe levels <360 µmol/L [2] - The ability to liberalize diets is expected to enhance patient quality of life and facilitate physician adoption and payer acceptance [2] Group 3: Global Regulatory Status - The European marketing authorization application for sepiapterin is currently under review, with applications for Japan and Brazil expected later in 2024 [3] Group 4: Product Information - Sepiapterin is an oral formulation of synthetic sepiapterin, a precursor to tetrahydrobiopterin, which is essential for the metabolism of various metabolic products [4] - It is considered more bioavailable than exogenously administered synthetic BH4, potentially benefiting a wide range of PKU patients [4] Group 5: Background on PKU - Phenylketonuria (PKU) is a rare inherited metabolic disorder that can lead to severe disabilities if untreated, affecting approximately 58,000 individuals globally [5]