BioMarin Pharmaceutical Inc has initiated treatment of first patient in the phase-2 clinical study of PEG-PAL (PEGylated recombinant phenylalanine ammonia lyase) for phenylketonuria (PKU). Initial top-line results are expected in mid-2010.

"We remain optimistic on this program and believe that, if approved, PEG-PAL may offer a significant benefit for many PKU patients, especially those who do not respond adequately to Kuvan," said Hank Fuchs, chief medical officer of BioMarin. "In our view, the flexible design of the phase-2 protocol provides multiple opportunities to arrive at an optimal dose and dosing frequency that is tolerable in at least in a sub-segment of the PKU population. We are encouraged by the results of the phase-1 study, which showed a substantial blood Phe level reduction across all patients in the fifth cohort at a dose of 0.1mg/kg, no serious adverse events, and reactions as expected with a protein of this nature," Fuchs said.

The phase-2 clinical trial is an open-label, multi-center study to be conducted in up to 35 patients in a series of dose-escalating cohorts from 0.001 mg/kg. The primary treatment period of eight once weekly injections at a fixed dose will be followed by eight weeks of dose and frequency optimization and an extension period where doses can be increased up to 2.0 mg/kg/week.

The primary objective is to evaluate the effect of PEG-PAL on blood Phe concentrations in subjects with PKU. The secondary objectives are to evaluate the safety and tolerability, immune response and steady state pharmacokinetics of subcutaneous injections of multiple dose levels of PEG-PAL.

PEG-PAL (PEGylated recombinant phenylalanine ammonia lyase) is an investigational enzyme substitution therapy for the treatment of PKU.

BioMarin develops and commercializes innovative biopharmaceuticals for serious diseases and medical conditions.