Drug: Sapropterin dihydrochloride
20mg/kg/day orally, physicians may adjust the dose within a range of 5-20mg/kg/day as warranted by their clinical judgment.

The sapropterin EAP (SEAP) is an open-label, multi-center program designed to provide access to sapropterin dihydrochloride for patients diagnosed with hyperphenylalaninemia due to PKU. All patients with a confirmed diagnosis of hyperphenylalaninemia due to PKU who are not currently enrolled in a clinical study with sapropterin dihydrochloride and meet the requisite inclusion criteria and do not meet any of the exclusion criteria may be eligible to participate in this program. Eligible patients may receive sapropterin dihydrochloride and participate in the program until commercial drug is available, however, the program will not continue beyond 2 months after the product receives marketing approval from the FDA. During the program, physicians will use their clinical judgment to assess whether a patient is a responder to sapropterin dihydrochloride. Participating physicians will measure blood Phe levels at baseline prior to treatment and then at least once between Day 7 and Day 30 following initiation of treatment to determine if the patient is a responder. A responder is a patient that has a clinically significant reduction in either the absolute or percent decrease in blood phenylalanine level compared to pre-treatment levels. The recommended starting dose of sapropterin dihydrochloride is 20 mg/kg/day. Physicians treating their patients with sapropterin dihydrochloride will be able to adjust the dose within a range of 5 mg/kg/day to 20 mg/kg/day if warranted in their clinical judgment. Adverse event information will be collected in an ongoing fashion through patient reporting AEs to their physician. Physicians will ask patients for information regarding adverse events that have occurred since the last visit. An adverse event report form will be completed in these cases and sent to BioMarin.