PTC Therapeutics Announces Health Canada Approval of Sephience™ (sepiapterin) for the Treatment of Children and Adults Living with Phenylketonuria (PKU)

- Broad label includes all age groups and full range of PKU subtypes -

TORONTO, Dec. 10, 2025 /CNW/ - PTC Therapeutics Canada ULC announced that Health Canada has approved Sephience™ (sepiapterin) for the treatment of children and adults living with phenylketonuria (PKU). The approval includes broad labeling for the treatment of hyperphenylalaninemia (HPA) in adult and pediatric patients 1 month old and older with sepiapterin-responsive PKU.

"We're pleased with the Canadian regulatory approval of Sephience and opportunity to provide access to this important therapy to children and adults living with PKU in Canada," said Matthew B. Klein, M.D., Chief Executive Officer, PTC Therapeutics. "There is a significant unmet medical need for new therapies that address a broad spectrum of PKU subtypes."

The Health Canada approval is based on the evidence of significant efficacy and safety from the Phase 3 APHENITY trial as well as durability of treatment effect in the APHENITY long-term extension study.

"There continues to be a significant unmet need for new treatment options in PKU which can support improved dietary flexibility and management, a meaningful goal for those living with PKU in Canada and around the world," said Tanya Chute Nagy, Chief Executive Officer and President, Canadian PKU and Allied Disorders.

Sephience is now commercially available in Canada. Sephience was recently approved by the U.S. Food and Drug Administration and granted marketing authorization by the European Commission.

About Sephience™ (sepiapterin)
Sephience™ (sepiapterin for oral suspension) is indicated for the treatment of hyperphenylalaninemia (HPA) in adult and pediatric patients 1 month old and older with sepiapterin-responsive phenylketonuria (PKU). Sephience is indicated in conjunction with a phenylalanine (Phe)-restricted diet. Please see Sephience product monograph for more information.

Sephience is a natural precursor of the enzymatic co-factor BH4, a critical co-factor for phenylalanine hydroxylase (PAH). Through its mechanism of action, Sephience is able to effectively reduce blood phenylalanine (Phe) levels and has the potential to treat a broad range of PKU patients. Sephience is approved in the European Economic Area, the United States and Canada.

About Phenylketonuria
Phenylketonuria (PKU) is a rare, inherited metabolic disease, characterized by the body's inability to break down an essential amino acid called phenylalanine (Phe) and which can result in neurological and other symptoms. If left untreated or poorly managed, Phe 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. Newborns with PKU initially do not have any symptoms, but symptoms are usually progressive, and damage caused by toxic levels of Phe in the first few years of life is irreversible. Diagnosis of PKU usually takes place during newborn screening programs. There are an estimated 58,000 people living with PKU globally.

About PTC Therapeutics, Inc.
PTC is a global biopharmaceutical company dedicated to the discovery, development and commercialization of clinically differentiated medicines for children and adults living with rare disorders. PTC is advancing a robust and diversified pipeline of transformative medicines as part of its mission to provide access to best-in-class treatments for patients with unmet medical needs. The company's strategy is to leverage its scientific expertise and global commercial infrastructure to optimize value for patients and other stakeholders.

For More Information:

Media:
Jeanine Clemente
+1 (908) 912-9406
jclemente@ptcbio.com

SOURCE PTC Therapeutics, Inc.