Phase 3 Phenylketonuria Trial, Recruiting
Who may be able to join
AI generated eligibility summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
Who might be able to join this trial:
- Women who could become pregnant must have a negative pregnancy test at the start of the study and agree to use effective birth control throughout the study and for at least 90 days after the last dose.
- Participants must be willing to stick to their prescribed daily diet for protein and phenylalanine (Phe) during the early parts of the study.
- For participants aged 1 month or older: must have a confirmed diagnosis of PKU with at least 2 recorded blood Phe levels of 600 or above (a measure of the amino acid phenylalanine in the blood).
- For participants aged 1 month or older: must have at least 1 recorded blood Phe level below 480 within the month before the study starts.
- For participants aged 1 month or older: must have 2 blood Phe readings during screening that fall between 120 and 480.
- For newborns under 1 month old at the time of joining: must have had a newborn screening blood Phe level of 600 or above.
- For children aged 30 months up to 10 years old: must have an IQ score of 80 or above on a standard assessment test.
Who may not be able to join:
- Anyone with a known allergy or bad reaction to the ingredients in synthetic BH4 (a compound related to PKU treatment) or sepiapterin.
- Anyone with a serious mental health condition (such as major depression) that is not currently being managed by a doctor, or any other condition that could interfere with taking part in the study or increase health risks.
- Anyone who has used a BH4 supplement (sapropterin/KUVAN®) in the 3 months before the study starts.
- Anyone currently taking part in another clinical trial or who has used an experimental medication within the last 30 days.
- Anyone with a confirmed diagnosis of a specific inherited condition that causes BH4 deficiency due to certain gene mutations (confirm with trial site).
- Anyone with significant abnormal results on lab tests, as judged by the study doctor.
- Anyone with a history of kidney disease or abnormal test results suggesting kidney problems, including a kidney function score below a certain level (confirm with trial site).
- Anyone who has had major surgery within 90 days before the study starts.
- Anyone who has previously been treated with sepiapterin (also called Sephience) for more than 6 weeks.
Important: Always verify eligibility with the trial site directly before applying.
Based on publicly available eligibility criteria from ClinicalTrials.gov. Verify directly with the trial site before acting. This is not medical advice.
Contact this trial
Phone: 1-866-562-4620
Australian sites
Contact details sourced from ClinicalTrials.gov. Verify directly with the trial site before attending.
GP referral letter
Print a one-page summary to share with your doctor.
Trial details
Where this trial is recruiting
2 site(s) in Australia. Confirm current status and contact details directly with the trial site.
Primary endpoints
Mean Change From Baseline in Full-scale Intelligence Quotient (FSIQ) Wechsler Preschool and Primary Scale of Intelligence - Fourth Edition (WPPSI-IV) Score; Mean Change From Baseline in FSIQ Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V) Score
Can't join this trial?
Data last synced from ClinicalTrials.gov: 28 July 2026. Trial status can change. Always verify current status directly with the trial site before making any decision.