The FDA said the company is taking the action because of a potential risk of patients developing progressive multifocal leukoencephalopathy -- a rare, serious, progressive neurologic disease caused by a virus that affects the central nervous system.
FDA officials said prescribers are being asked not to initiate new Raptiva (efalizumab) treatment and begin discussions with patients using the medication on how to move to alternative psoriasis therapies.
"The risk that an individual patient taking Raptiva will develop PML is rare and is generally associated with long-term use," the FDA said. "Generally, PML occurs in people whose immune systems have been severely weakened and often leads to an irreversible decline in neurologic function and death. There is no known effective treatment for PML."
Raptiva is a once-weekly injection for adults with moderate to severe plaque psoriasis.
Genentech estimates 2,000 patients in the United States might be receiving Raptiva for chronic plaque psoriasis. The company said that since FDA approval in 2003, approximately 46,000 patients worldwide have been treated with the drug.
More information about the withdrawal of Raptiva is available on the Genentech Web site at http://www.gene.com/gene/news/press-releases/display.do?method=detail&id=12047.