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

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