The Effects of Sapropterin Dihydrochloride Supplementation on in Vivo Redox Status in Patients With Classical PKU

Recruitment & Eligibility

Inclusion Criteria

Sub-study Inclusion criteria same as main study:

≥ 8 years of age
Confirmed diagnosis of PKU
Willing to continue current diet (typical diet for the 3 months prior to study entry)unchanged while participating in the study
Willing and able to provide written, signed informed consent or in the case of subjects under the age of 18, provide written assent (if required) and written informed consent by a legally authorized representative after the nature of the study has been explained, and prior to any research-related procedures
Sexually active subjects must be willing to use an acceptable method of contraception while participating in the study and for at least 30 days following the last dose of sapropterin dihydrochloride
Females of childbearing potential must have a negative pregnancy test at screening and be willing to have additional pregnancy tests during the study. Females considered not of childbearing potential include those who have been in menopause at least 2 years, or had tubal ligation at least 1 year prior to screening, or have had total hysterectomy
Willing and able to comply with all study procedures

Exclusion Criteria

All other sub-study Exclusion criteria same as main study:

Has known hypersensitivity to sapropterin dihydrochloride or its excipients
Subject breastfeeding at screening or planning to become pregnant (subject or partner) at any time during the study
Use of any investigational product or investigational medical device within 30 days prior to screening, or requirement for any investigational agent prior to the completion of all scheduled study assessments
Received sapropterin dihydrochloride within 16 weeks of randomization • Have initiated or adjusted medication for treatment of ADHD, depression, or anxiety ≤ 8 weeks prior to randomization
Taking medication known to inhibit folate synthesis (eg, methotrexate)
Any condition requiring treatment with levodopa or any PDE-5 inhibitor
Concurrent disease or condition that would interfere with study participation, compliance or safety as determined by the Investigator
Any condition that, in the view of the Investigator, places the subject at high risk of poor treatment compliance or not completing the study

Study & Design

Primary Outcome Measures

Name	Time	Method
Determine in vivo redox status in patients with classical phenylketonuria		The primary objective of this study is to determine in vivo redox status in patients with classical phenylketonuria enrolled in PKU-016, compared to historical normal controls, using: * Serial Tc99m-HMPAO SPECT brain imaging (baseline and 26 weeks); and * Blood redox biomarkers, including oxidized and reduced glutathione, tetrahydrobiopterin, ascorbate, alpha-tocotrienol, selenium, etc.

Secondary Outcome Measures

Name	Time	Method
Explore the utility of other blood redox biomarkers		Explore the utility of other blood redox biomarkers (e.g. NAD+/NADH, NADP+/NADPH, protein carbonyls) in determining level of oxidative stress.
Compare redox status with neuropsychological and neuro-cognitive symptoms		Compare redox status as determined by brain imaging and blood redox biomarkers to measures of neuropsychological and neuro-cognitive symptoms (ADHD, anxiety, depression and executive function) and global function using data collected as part of PKU-016

Recruitment & Eligibility