New Hope for PKU Patients: Sepiapterin Receives FDA Approval
Phenylketonuria (PKU) is a rare, inherited metabolic disorder that requires lifelong management. Now, you and other individuals living with PKU have a new treatment option. The FDA recently approved sepiapterin (Sephience™) from PTC Therapeutics, offering a novel approach to managing this challenging condition. This approval marks a meaningful step forward, expanding the available tools for PKU treatment.
understanding Sepiapterin’s Unique Mechanism
Traditional PKU management focuses on restricting phenylalanine (Phe) intake thru a specialized diet. sepiapterin works differently. It addresses the underlying cause of PKU in manny patients – a deficiency in the enzyme phenylalanine hydroxylase (PAH).
Specifically, sepiapterin acts as a pharmacological chaperone. It helps correct the misfolding of the PAH enzyme, ultimately boosting its function. This dual action – reducing Phe levels and improving enzyme activity – holds promise for a broader range of PKU patients.
APHENTITY Trial Demonstrates Significant Benefits
The approval is supported by robust data from the Phase 3 APHENITY clinical trial (NCT05099640) and its ongoing open-label extension study.Presented at the 2025 American College of Medical Genetics and Genomics Annual Clinical Genetics Meeting, the results are encouraging.
Here’s what the data revealed:
Dietary Liberalization: Over 97% of participants in the Phe tolerance protocol were able to increase their dietary protein intake while maintaining Phe control.
Increased Protein Intake: participants experienced a mean increase of 126% in protein consumption.
Reaching Recommended Intake: 66% of participants met or exceeded the age-adjusted recommended daily allowance for protein,similar to individuals without PKU.
Genotype Insights: Analysis showed over 70% of patients had a genotype consistent with classical PKU, helping clinicians identify those most likely to benefit from sepiapterin.
These findings suggest sepiapterin can considerably improve quality of life by allowing for a less restrictive diet.
What This Means for You
If you’re living with PKU, talk to your healthcare provider about whether sepiapterin might be a suitable treatment option. It’s vital to remember that PKU management is individualized.
Sepiapterin isn’t a one-size-fits-all solution, but it offers a valuable new avenue for managing Phe levels and potentially improving your overall well-being. The availability of this new therapy provides more choices and the potential for a more manageable PKU journey.
References:
- PTC Therapeutics. PTC Therapeutics Announces FDA Approval of Sephience™ (sepiapterin) for the Treatment of Children and Adults Living with Phenylketonuria (PKU). News Release. July 28, 2025. Accessed July 28, 2025. https://ir.ptcbio.com/news-releases/news-release-details/ptc-therapeutics-announces-fda-approval-sephiencetm-sepiapterin
- PTC therapeutics. PTC Therapeutics Receives Positive CHMP Opinion for Sephience™ (sepiapterin) for the Treatment of Children and Adults Living with Phenylketonuria (PKU). News Release. April 25,2025. Accessed July 28, 2025.https://ir.ptcbio.com/news-releases/news-release-details/ptc-therapeutics-receives-positive-chmp-opinion-sephiencetm
- PTC Therapeutics. PTC Therapeutics Presents New Sepiapterin data from Ongoing Studies. News Release.March
