A Study of the Long-term Effects on Mental Abilities of 4 to 5 Year-old Children with a Disease Caused by an Enzyme Defect (Phenylketonuria) that Have Been Treated with Kuvan® (a Medicinal Product aimed at Restoring the Defect) for 7 Years.

Recruitment & Eligibility

Status: Not Recruiting

Sex: All

Target Recruitment: 30

Inclusion Criteria

The target population for this trial is children with confirmed diagnosis of PKU.

• Male or female outpatients, 4 to 5 years of age (=4 and <6) at the time of ICF signature by parent(s) or guardian(s).
• Confirmed clinical and biochemical diagnosis of PKU, including at least two separate blood Phe levels =400 µmol/L.
• Defined pre-Kuvan®/-tetrahydrobiopterin (BH4) dietary Phe tolerance consistent with the diagnosis of /PKU.
• Responsive to Kuvan®/BH4:
- For subjects currently treated with Kuvan®/BH4 at Screening: subject is a responder as per Investigator judgment based on documented effect of Kuvan®/BH4 on Phe levels and/or Phe tolerance.
- For subjects not treated with Kuvan®/BH4 at Screening: a response test has been performed during Screening or is available from the patient’s medical records and satisfies the 3 following criteria: a decrease in blood Phe levels of at least 30% was observed after at least 24 hours with a dose of at least 10 mg/kg/day.
• IQ =70, as assessed with the WPPSI™-III 2nd part.
Note: If a subject has undertaken the same test up to 3 months before Screening as part of his/her clinical follow-up, the score can be recorded and the test doesn’t need to be repeated.
• Good adherence with dietary treatment (including prescribed dietary Phe restriction and prescribed amounts of Phe-free protein supplements and low-Phe foods), as assessed by the Investigator.
• Well-controlled Phe levels, as assessed by a minimum of 75% of Phe levels within the target recommended in each centre during the previous 3 months.
• Low Phe diet started within the first 3 weeks of life.
• Parent(s) or guardian(s) willing to comply with all study procedures, maintain strict adherence with the diet, and willing and able to provide written, signed informed consent before any trial-related activities are carried out, as well as ability of child to comply with trial procedures.

Are the trial subjects under 18? yes
Number of subjects for this age range: 30
F.1.2 Adults (18-64 years) no
F.1.2.1 Number of subjects for this age range
F.1.3 Elderly (>=65 years) no
F.1.3.1 Number of subjects for this age range

Exclusion Criteria

• Known hypersensitivity to Kuvan® or its excipients.
• Known hypersensitivity to other approved or non-approved formulations of tetrahydrobiopterin.
• Previous diagnosis of BH4 deficiency.
• Current use of methotrexate, trimethoprim or other dihydrofolate reductase inhibitors.
• Current use of medications that are known to affect nitric oxide synthesis, metabolism or action.
• Current use of experimental or unregistered drugs (other than sapropterin/BH4) that may affect the study outcomes or use of such agents within 30 days prior to Screening.
• Concurrent use of levodopa.
• Concurrent disease or condition that would induce repeatedly catabolic situations, or interfere with the trial participation, diet, or NC development, as assessed by the Investigator.
• Any condition that, in the view of the Investigator, renders the subject at high risk for failure to comply with treatment or to complete the trial.
• Participation in a clinical trial investigating any other agent than Kuvan® within the past 30 days.

Study & Design

Study Type: Interventional clinical trial of medicinal product

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method

Secondary Outcome Measures

Name	Time	Method

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