UPDATE 2-U.S. approves Shire's drug for Gaucher disease

WASHINGTON, Feb 26 (Reuters) - The U.S. Food and Drug Administration approved Shire Plc's Vpriv drug on Friday to treat children and adults with the most common form of Gaucher disease.

The injectable drug, which treats patients with Type 1 Gaucher disease, will serve as an alternative to Genzyme's Cerezyme, which is in short supply due to manufacturing problems.

'Patients who previously received Cerezyme as an enzyme replacement therapy for their Type 1 Gaucher disease can be safely switched to Vpriv,' Julie Beitz, head of the FDA office that reviewed the drug, said.

On top of the Cerezyme shortage, Shire also hopes to take aim at its rival with plans to sell its drug at a 15 percent discount over Genzyme's drug. At $200,000 on average for a year, Cerezyme is one of the world's most expensive drugs.

Shire has also said it would help patients pay for costs not covered by their insurance.

Analysts have said Vpriv, known generically as velaglucerase, is unlikely to break Genzyme hold on the $1.2 billion Gaucher market, citing difficulty in getting doctors to switch to Shire's newer alternative.

Shire would have to offer even steeper discounts to market share from Genzyme, analysts said.

Other rival products also loom with another Gaucher drug by Protalix Biotherapeutics Inc and Pfizer Inc expected to be approved by the end of the year.

Shire welcomed the FDA approval, adding in a statement that it hopes to launch Vpriv in Europe later this year and in other countries starting in 2011.

Gaucher disease affects people who lack enough of a certain enzyme, according to the agency. Too much fat can build up in the body and prevent organs from working.

According to the U.S. National Institutes of Health, Type 1 Gaucher disease is more prevalent in people of Ashkenazi Jewish ancestry. Overall, the disorder occurs in about 1 in 50,000 to 1 in 100,000 people.

Side effects of Shire's Vpriv include allergic reactions, headache, dizziness, abdominal pain, joint pain, fever and delayed blood clotting, the FDA said.

The company's shares were up less than 1 percent at $65 in after-hours trading after earlier closing at $64.52 on the Nasdaq. Keywords: SHIRE VPRIV/ (Reporting by Susan Heavey; Reuters Messaging: [e-mail], Phone: [phone]) COPYRIGHT Copyright Thomson Reuters 2010. All rights reserved. The copying, republication or redistribution of Reuters News Content, including by framing or similar means, is expressly prohibited without the prior written consent of Thomson Reuters.