WASHINGTON, Feb. 21 The U.S. Food and Drug Administration ordered Genentech Inc. to add a boxed warning to its asthmatic drug marketed as Xolair.The FDA said the boxed warning should emphasize Xolair (omalizumab) might cause anaphylaxis, including trouble breathing, chest tightness, dizziness, fainting, itching and hives and swelling of the mouth and throat.In addition, FDA ordered Genentech to revise the Xolair label and provide a medication guide for patients to strengthen the existing warning for anaphylaxis.Xolair was approved in 2003 to treat adults and adolescents suffering moderate to severe persistent asthma and who have tested positive for a perennial aeroallergen and whose symptoms are inadequately controlled with inhaled steroids.Although anaphylaxis was reported in about one-in-1,000 patients during clinical trials, the FDA said continued reports prompted it to issue the Wednesday order.Copyright 2007 by UPI
