FDA requests label warning on Genentech's Xolair

The US Food and Drug Administration has requested that biotechnology major Genentech add a boxed warning to the product label for the asthma drug Xolair (omalizumab) to emphasize that, when it is used to treat patients with asthma related to allergies, it may cause anaphylaxis. The adverse event may include trouble breathing, chest tightness, dizziness, fainting, itching and hives, as well as swelling of the mouth and throat. In addition, the FDA has asked the firm to revise the Xolair label and provide a Medication Guide for patients to strengthen the existing warning for anaphylaxis.