Phenylketonuria drug sapropterin advances to final phase of clinical studies

Sapropterin dihydrochloride (Kuvan), an experimental therapy for neuropsychiatric symptoms in patients suffering from phenylketonuria, or PKU, is currently undergoing late phase human studies.

BioMarin Pharmaceutical, which has developed sapropterin dihydrochloride (Kuvan) announced that the company has started Phase IIIb study of PKU-016 to evaluate the effects of Kuvan, or sapropterin dihydrochloride, on neuropsychiatric symptoms in subjects with phenylketonuria, or PKU.

The safety and therapeutic effects of sapropterin dihydrochloride will be evaluated in the Phase IIIb study. The study is a double-blind, placebo-controlled, randomized 28-week programme on neuropsychiatric symptoms in subjects with PKU.

The study will enroll approximately 200 subjects ages 12 and above at approximately 40 sites in the US and Canada.

The primary efficacy variable for symptoms of attention deficit hyperactivity disorder (ADHD) will be evaluated using the ADHD rating scale in subjects 12 to 17 years of age and the adult ADHD self-report scale in subjects ages 18 and above.

“We hope that this trial will provide quantitative data regarding the neuropsychiatric effects of Kuvan for PKU patients, and if successful, will continue to build its value proposition and to drive the continued expansion of the market,”Jean-Jacques Bienaime, CEO of BioMarin, stated in a press release.

BioMarin is also looking forward to upcoming data from several investigator-sponsored studies on the neurocognitive effects of Kuvan, according to Bienaime.

BioMarin’s product portfolio comprises four approved products and multiple clinical and pre-clinical product candidates. Approved products include Naglazyme (galsulfase) for mucopolysaccharidosis VI (MPS VI), a product wholly developed and commercialized by BioMarin; Aldurazyme (laronidase) for mucopolysaccharidosis I (MPS I), a product which BioMarin developed through a 50/50 joint venture with Genzyme Corporation; Kuvan (sapropterin dihydrochloride) Tablets, for phenylketonuria (PKU), developed in partnership with Merck Serono, a division of Merck KGaA of Darmstadt, Germany; and Firdapse (amifampridine phosphate), which has been approved by the European Commission for the treatment of Lambert Eaton Myasthenic Syndrome (LEMS).

Other product candidates include GALNS (N-acetylgalactosamine 6-sulfatase), which is currently in clinical development for the treatment of MPS IVA and PEG-PAL (PEGylated recombinant phenylalanine ammonia lyase), which is currently in Phase II clinical development for the treatment of PKU.