The Food and Drug Administration (FDA) has announced that an ongoing clinical trial for the asthma drug omalizimub, commonly known as Xolair, and suggests patients taking the medication may have a stronger risk of blood clots, stroke, heart failure, cardiac arrhythmias and heart enlargement when compared to patients not treated with the drug. The agency said it was assessing the significance of the preliminary data to determine if further regulatory actions are needed to protect patients. In 2007, the FDA required Xolair include a black box warning on its label to warn patients that it may cause potentially fatal anaphylactic reactions.
Xolair is approved as treatment for adults and children over the age of 12 who suffer from moderate to severe asthma complicated by seasonal allergies. The concern regarding the possible side effects arose after a trial compared 5,000 Xolair users and 2,500 asthmatics not taking Xolair over a five-year period. The FDA claims “interim data” provided from the drug’s manufacturer, Genentech, suggested a disproportionate increase in cardiac failure, arrhythmias, pulmonary hypertension and many other disorders among users of Xolair.
The FDA’s announcement acknowledged that no causal link between the drug and the side effects has been determined and has advised patients who are taking the drug not to discontinue its use at this time; the agency called its announcement an “early communication”. Unless the FDA decides to stop the safety trial, it is expected to continue, with final results expected in 2012.