* Shire had expected quick approval process
* FDA "disappointed" with Shire's action
March 14 (Reuters) - Shire Plc has pulled its application to the U.S. Food and Drug Administration for approval of its drug to treat Fabry disease, a rare genetic disorder, because the agency likely will require more clinical studies, the company said on Wednesday.
The drug, Replagal, is an enzyme replacement therapy for the disease, which causes fat to build up in the body.
Shire had filed in November for FDA approval for Replagal, "in anticipation of a quick review process," the company said.
Shire has been permitted to supply the drug to the U.S. market after manufacturing problems in 2009 led to short supplies of rival drug Fabrazyme, which is made by Genzyme, now owned by Sanofi SA. Replagal has been on the market in Europe since 2001.
The FDA said Shire has also decided to end that treatment program over the next few months, and the drug will no longer be available to U.S. patients.
The regulatory agency said in a statement it was "disappointed," by Shire's action and is committed to working with Shire and any other company to develop new Fabry treatment options.
Shire said the agency did not express concerns over Replagal's safety. But recent interactions with the FDA have led the company to believe that it will require additional controlled trials for approval, Shire said.
The company said the "likely additional studies would cause a significant delay, and an approval of Replagal for U.S. patients would only be possible in the distant future."
Sanofi said earlier this month that it had begun U.S. deliveries of Fabrazyme from its newly approved manufacturing plant in Framingham, Massachusetts. The French company said a full return to normal supply levels would begin in the second quarter and continue throughout 2012.
The FDA said a March 27 meeting of its Cardiovascular and Renal Drugs Advisory Committee has been canceled because of Shire's withdrawal of the Replagal application.