SAN RAFAEL, Calif., June 5, 2013 (GLOBE NEWSWIRE) -- BioMarin Pharmaceutical Inc. (Nasdaq:BMRN) announced today that it has initiated the Phase 3 program for PEG-PAL (PEGylated recombinant Phenylalanine Ammonia Lyase) for the treatment of phenylketonuria (PKU). "In the Phase 2 trial, PEG-PAL was shown to dramatically reduce blood Phe levels, and we are hopeful that we will achieve the same outcome with the Phase 3 program," stated Hank Fuchs, M.D., Chief Medical Officer of BioMarin. "Adult patients with PKU and patients on the severe end of the disease spectrum still represent a very high unmet medical need. With PEG-PAL, it may be possible to provide a treatment benefit to this population." The Phase 3 study (165-301) is an open-label, multi-center study to assess the safety and tolerability of an induction, titration and maintenance dose regimen of PEG-PAL self-administered by approximately 90 naïve adult PKU subjects. The primary objective of the 165-301 study is to characterize the safety and tolerability of PEG-PAL during induction, titration, and maintenance dosing. The secondary objective of the study is to evaluate blood Phe levels during induction, titration, and maintenance dosing. After completion of the open label 165-301 study, subjects are expected to enroll in 165-302, a Phase 3 double-blind, placebo-controlled, randomized discontinuation study to evaluate the efficacy and safety of PEG-PAL self-administered by adults with PKU. The study will also enroll approximately 60 subjects from the Phase 2 program who are currently being treated with PEG-PAL. The primary objective of the 165-302 study is to evaluate blood Phe levels. The secondary objective of this study is to evaluate changes in neuropsychiatric assessments as measured by the Inattentive portion of the Attention Deficit and Hyperactivity Disorder Rating Scale (ADHD-RS) and the Profile of Mood States (POMS). These will be administered at baseline, four and eight weeks.