Study of Phenoptin to Increase Phenylalanine Tolerance in Phenylketonuric Children on a Phenylalanine-restricted Diet

Recruitment & Eligibility

Inclusion Criteria

Clinical diagnosis of PKU with hyperphenylalaninemia (HPA) documented by at least one blood Phe measurement >/=360 umol/L (6 mg/dL)
Under dietary control with a Phe-restricted diet as evidenced by:· Estimated daily Phe tolerance </=1000 mg/day
At least 6 months of blood Phe control (mean level of </=480 μmol/L) prior to enrolling in the study
Aged 4 to 12 years inclusive at screening
A blood Phe level </=480 μmol/L at screening
Female subjects of childbearing potential (as determined by the principal investigator) must have a negative blood or urine pregnancy test at entry (prior to the first dose). Note: All female subjects of childbearing potential and sexually mature male subjects must be advised to use a medically accepted method of contraception throughout the study. Female subjects of childbearing potential must be willing to undergo periodic pregnancy tests during the course of the study
Willing and able to comply with all study procedures
Willing to provide written assent (if applicable) and written informed consent by a parent or legal guardian after the nature of the study has been explained and prior to any research-related procedures

Exclusion Criteria

Any condition that, in the view of the PI, renders the subject at high risk from treatment compliance and/or completing the study
Prior history of organ transplantation
Perceived to be unreliable or unavailable for study participation or have parents or legal guardians who are perceived to be unreliable or unavailable
Use of any investigational agent within 30 days prior to screening, or requirement for any investigational agent or vaccine prior to completion of all scheduled study assessments
ALT > 2 times the upper limit of normal (i.e., Grade 1 or higher based on World Health Organization Toxicity Criteria) at screening
Concurrent disease or condition that would interfere with study participation or safety (e.g., seizure disorder, oral steroid-dependent asthma or other condition requiring oral or parenteral corticosteroid administration, or insulin-dependent diabetes)

Study & Design

Arm && Interventions

Group	Intervention	Description
Sapropterin Dihydrochloride	Sapropterin Dihydrochloride	Phenoptin, provided in tablets containing 100 mg of sapropterin dihydrochloride each, was administered orally once daily in the morning as the number of tablets equivalent to a 20mg/kg/day dose dissolved in 4-8 oz (120-240 mL) of water or apple juice for 6 weeks. A follow-up call or visit was made 4 weeks later during this double-blind, placebo-controlled study.
Placebo	Placebo	Placebo, provided as tablets similar to Phenoptin tablets, was administered orally once daily in the morning as the number of tablets equivalent to a 20mg/kg/day dose dissolved in 4 8 oz (120-240 mL) of water or apple juice. for 6 weeks. A follow-up call or visit was made 4 weeks later during this double-blind, placebo-controlled study.

Primary Outcome Measures

Name	Time	Method
Amount of Dietary Supplemented Phenylalanine (Phe)Tolerated in Children With Phenylketonuria	at Week 10

Secondary Outcome Measures

Name	Time	Method
Change in Phenylalanine Levels From Baseline to Week 3	Baseline to Week 3

Recruitment & Eligibility