CHMP Endorses PTC Therapeutics' Sephience™ for PKU Treatment

PTC Therapeutics, Inc. has announced a significant development in the treatment of phenylketonuria (PKU), a rare genetic disorder. The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has given a favorable opinion on the marketing authorization application for Sephience™ (sepiapterin). This medication is intended for both children and adults affected by PKU, covering all ages and levels of disease severity.

Matthew B. Klein, CEO of PTC Therapeutics, expressed optimism about the CHMP's decision, highlighting its importance for the European PKU community, which faces a lack of effective treatment options. The company is preparing for the European launch of Sephience, anticipating its approval by the European Commission. The data supporting Sephience suggest that it not only reduces phenylalanine levels but also allows for a more flexible diet even in patients with severe forms of PKU.

Plans for introducing Sephience to the European market are advancing, focusing initially on Germany and other key regions where named patient access will be immediately available. PTC expects the European Commission to approve Sephience within approximately two months, extending its benefits to all 27 EU member states along with Iceland, Norway, and Liechtenstein.

In parallel, the U.S. Food and Drug Administration (FDA) is reviewing Sephience's New Drug Application, with a decision anticipated by July 2025. Additionally, approval processes are ongoing in countries such as Japan and Brazil.

Sephience is an oral synthetic form of sepiapterin, which operates through a dual mechanism to enhance the activity of the enzyme phenylalanine hydroxylase (PAH). It acts as a precursor, converting into tetrahydrobiopterin (BH4) within cells, a crucial cofactor for PAH. Furthermore, Sephience functions as a pharmacological chaperone, addressing PAH misfolding to improve enzyme function. This dual approach helps significantly lower blood phenylalanine levels, offering the potential to treat a wide spectrum of PKU patients.

Phenylketonuria is a rare inherited disorder impacting brain function. It arises from a genetic defect affecting the enzyme responsible for breaking down phenylalanine (Phe), an essential amino acid present in most proteins. Without proper management, Phe accumulates to toxic levels, leading to severe and irreversible disabilities, including intellectual disability, seizures, developmental delays, memory loss, and behavioral issues. While newborns with PKU typically show no initial symptoms, the condition progressively worsens if untreated, with irreversible damage occurring during the first few years of life. PKU is typically diagnosed through newborn screening programs, and it affects approximately 58,000 individuals globally.

PTC Therapeutics is a global biopharmaceutical company focused on discovering, developing, and commercializing innovative medicines for rare diseases. Its commitment to developing groundbreaking therapies and expanding its product portfolio underscores its dedication to addressing unmet medical needs worldwide.