WARREN, N.J. – PTC Therapeutics, Inc. (NASDAQ: PTCT) has reached a pivotal milestone with the FDA's acceptance for filing of the New Drug Application (NDA) for sepiapterin, targeting the treatment of phenylketonuria (PKU) in both pediatric and adult patients. The FDA is expected to provide a Prescription Drug User Fee Act (PDUFA) target action date in the Day 74 Letter.
Clinical Trial Highlights
The NDA submission is supported by the phase 3 APHENITY trial results, showcasing sepiapterin's efficacy in significantly reducing phenylalanine (Phe) levels. Key findings include:
- A mean reduction in Phe levels of 63% in the overall treated population.
- A 69% reduction in the subgroup with classical PKU.
- 84% of subjects achieved Phe control in line with treatment guidelines (<360 µmol/L).
- 22% of subjects showed normalization of Phe levels.
Additionally, the APHENITY open-label extension study and Phe tolerance sub-study further validate sepiapterin's durability and potential to enable diet liberalization while maintaining Phe control.
About Sepiapterin
Sepiapterin, an oral synthetic sepiapterin formulation, operates through a dual mechanism to enhance the phenylalanine hydroxylase (PAH) enzyme activity. It not only serves as a precursor to tetrahydrobiopterin (BH4), a crucial PAH cofactor, but also acts as a chaperone to prevent PAH misfolding, thereby improving enzyme function.
About Phenylketonuria (PKU)
PKU is a rare, inherited metabolic disorder that can lead to severe and irreversible disabilities if untreated. It results from a genetic defect affecting the enzyme needed to metabolize phenylalanine, leading to its harmful accumulation. Early diagnosis through newborn screening is crucial for managing the condition.
This development represents a hopeful advancement for the PKU community, offering a potential new avenue for managing this challenging condition.
