NCT05166161

A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria

A Phase 3 Open-Label Study of PTC923 (Sepiapterin) in Phenylketonuria

• Status: Active Not Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 200 (estimated)
• Sponsor: PTC Therapeutics · Industry
• Sex: All
• Age: —
• Healthy volunteers: Not accepted

Summary

The main purpose of this study is to evaluate the long-term safety of PTC923 in participants with phenylketonuria, and to evaluate the changes from baseline in dietary phenylalanine (Phe)/protein consumption.

Detailed description

Eligible participants are: Feeder participants: those who have completed a Phase 3 PTC Therapeutics (PTC) sponsored feeder study. Non-feeder controlled participants: those who have not completed a feeder study and have blood Phe levels \<360 μmol/L at study entry. Non-feeder uncontrolled participants: those who have not completed a feeder study and have blood Phe levels ≥360 μmol/L at study entry.

Conditions

• Phenylketonuria

Interventions

Type	Name	Description
DRUG	PTC923	PTC923 powder for oral use will be suspended in water or apple juice prior to administration.

Timeline

• Start date: 2022-02-14
• Primary completion: 2026-06-30
• Completion: 2026-06-30
• First posted: 2021-12-21
• Last updated: 2026-03-23

Locations

45 sites across 19 countries: United States, Australia, Brazil, Canada, Czechia, Denmark, France, Georgia, Germany, Italy, Japan, Mexico, Netherlands, Poland, Portugal, Slovenia, Spain, Turkey (Türkiye), United Kingdom

Regulatory

• FDA-regulated drug study