BioMarin Pharmaceutical Inc. has randomized the first patient in its Phase 3 clinical trial of Phenoptin (sapropterin hydrochloride), an investigational oral, small molecule therapeutic for the treatment of the genetic disease phenylketonuria (PKU). The company expects to announce data from this trial in the second half of 2005.

"We are pleased with the rapid pace at which we have been able to advance Phenoptin for PKU into the clinic, moving it from the initiation of our development program into a Phase 3 clinical trial in just over a year," stated Emil Kakkis, senior VP of Business Operations at BioMarin. "During this time, we have also succeeded in forming strategic partnerships with Daiichi Suntory Pharma and Merck Eprova that provided a substantial preclinical and clinical data set and an important intellectual property position surrounding the manufacturing and formulation of sapropterin hydrochloride, the active ingredient in Phenoptin," he added.

The Phase 3, double-blind, placebo-controlled, multi-centre trial is designed to evaluate the safety and efficacy of Phenoptin for the treatment of individuals with PKU. The trial will enroll approximately 100 PKU patients and be conducted at approximately 30 sites worldwide.

Phenoptin is an investigational oral small molecule therapeutic for the treatment of primarily the moderate to mild forms of PKU. The active ingredient in Phenoptin, sapropterin hydrochloride, is the synthetic form of 6R-BH4, a naturally occurring enzyme cofactor. BioMarin received orphan drug designation for Phenoptin to treat PKU from both the US Food and Drug Administration and European Medicines Evaluation Agency. If Phenoptin is the first drug therapy to be approved for the treatment of PKU, BioMarin would receive seven years of market exclusivity in United States and 10 years in the European Union for this indication, the company release says.

PKU, a genetic disorder affecting at least 50,000 diagnosed patients under the age of 40 in the developed world, an estimated half of whom have the moderate to mild form of the disease, is caused by a deficiency of the enzyme, phenylalanine hydroxylase (PAH).