Genentech, Inc. (NYSE: DNA) announced that the company has issued a Dear Healthcare Provider letter to inform potential prescribers of a case of progressive multifocal leukoencephalopathy (PML) in a 70-year old patient who had received Raptiva (efalizumab) for more than four years for treatment of chronic plaque psoriasis. The company will work with the U.S. Food and Drug Administration (FDA) to update the prescribing information for Raptiva and determine if further action is needed.