Drug to treat genetic disorder PKU approved in US

BioMarin Pharmaceutical Inc won U.S. approval for the first prescription drug to treat a serious genetic disorder called phenylketonuria (PKU), the U.S. Food and Drug Administration said on Thursday.

The drug, called Kuvan, was developed with Merck Serono, a division of Merck KGaA .

News of the approval sent BioMarin shares up 6 percent to their highest level since early 2000.

People with PKU are not able to break down phenylalanine, an amino acid found in foods, which can build up in the blood.

High levels of phenylalanine are toxic to the brain and can lead to mental retardation, behavioral abnormalities, seizures, an inability to focus and organize information, and other neurological complications.

FDA said the safety and efficacy of Kuvan was demonstrated in four short-term clinical studies with 579 patients with the disease.

Regulators said Kuvan works by increasing phenylalanine hydroxylase enzyme activity, which helps break down phenylalanine and results in lower levels of phenylalanine in the blood.

Shares in BioMarin were up $1.67 to $29.85 in afternoon Nasdaq trade; they traded as high as $30.49 earlier. Stock in the Novato, California-based company is up around 80 percent so far this year.