PTC Therapeutics NDA for Treating Phenylketonuria
FDA has accepted for review a PTC Therapeutics NDA for sepiapterin, which the company says is )indicated for treating pediatric and adult patients with phenylketonuria (PKU), including all age groups and the full spectrum of disease subtypes. The agency has a user fee review action target date of 7/29/2025.
The submission is based on data from the Phase 3 APHENITY trial, recently published in The Lancet, which the company says provides evidence of the durability of effect of sepiapterin and the ability of patients to liberalize their diet and still maintain control of phenylalanine (Phe) levels. “The most recent results from the Phe tolerance assessment demonstrate that approximately 60% of subjects achieve protein intake above the age-adjusted recommended daily allowance for an unaffected individual while still maintaining Phe levels < 360 μmol/L,” it adds.
PKU is described as a rare, inherited metabolic disease affecting the brain. “It is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine,” PTC Therapeutics says. “If left untreated or poorly managed, phenylalanine — an essential amino acid found in all proteins and most foods — can build up to harmful levels in the body. This causes severe and irreversible disabilities, such as permanent intellectual disability, seizures, delayed development, memory loss, and behavioral and emotional problems.”