Anaphylactic reactions associated with omalizumab administration: Analysis of a case-control study

Treatment with omalizumab is associated with a small risk of anaphylaxis (∼0.2%). To clarify the circumstances and risk factors associated with anaphylaxis to omalizumab,1 we conducted a case-control study comparing cases with an adjudicated history of anaphylaxis to omalizumab with controls without a history of anaphylaxis (X-PAND study; ClinicalTrials.gov identifier NCT00813748 March 27, 2009, to April 3, 2014; see Methods and Fig E1 available in this article's Online Repository at www.jacionline.org).