Biopharmaceutical company PTC Therapeutics Inc (NASDAQ: PTCT) announced on Tuesday that it has submitted a New Drug Application (NDA) for sepiapterin to the US Food and Drug Administration (FDA).

This NDA is for the treatment of paediatric and adult patients with phenylketonuria (PKU), a rare but serious inherited disorder, including the full spectrum of ages and disease subtypes.

The company said that the submission is based on the highly statistically significant and clinically meaningful results from the phase 3 APHENITY trial that demonstrated a mean reduction in Phe levels of 63% in the overall treated population, and 69% in the subgroup of patients with classical PKU. The NDA also includes data from the APHENITY open-label extension study providing evidence of sepiapterin's durability of effect and data from the Phe tolerance sub-study.

Matthew B Klein, MD, PTC Therapeutics' chief executive officer, said: "This NDA submission is an important step in bringing this therapy to children and adults living with PKU in the US. The robust sepiapterin clinical trial data, including Phe tolerance results, support the potential of sepiapterin to meet the persistent unmet medical need for the large number of children and adults with PKU."