Assessing the association between omalizumab and arteriothrombotic events through spontaneous adverse event reporting

Background: Omalizumab is a monoclonal antibody, indicated for the treatment of severe allergic asthma. In Europe, there have been concerns about the cardiovascular safety of omalizumab. The objective of this study was to analyze the association between omalizumab and arterial thrombotic events in a spontaneous adverse drug reaction reporting database in the US. Methods and materials: Reports of arterial thrombotic events submitted to the US Food and Drug Administration's Adverse Event Reporting System (AERS) between 2004 and 2011 were retrieved and analyzed by the reporting odds ratio data mining algorithm. The reporting odds ratio of arterial thrombotic events for omalizumab was compared with specific asthma medications and all drugs in the AERS. Values =2 were considered significant safety signals. The Medical Dictionary for Regulatory Activities Preferred Terms were used to identify arterial thrombotic events (eg, stroke, myocardial infarction). Results: In total, 293,783 reports of arterial thrombotic events were retrieved (about 2% of all adverse drug reaction reports), corresponding to 2274 asthma drug-arterial thrombotic events pairs (omalizumab, 222; inhaled corticosteroids [ICS], 131; long-acting beta-agonists [LABA], 102; single-device combination ICS-LABA, 506; inhaled short-acting beta-agonists [SABA], 475; oral SABA, 6; inhaled antimuscarinics [AMC], 477; single-device combination AMC-SABA, 127; xanthines, 50; leukotriene modifiers, 174; and mast cell stabilizers, 4). Reporting odds ratio and 95% confidence interval values for omalizumab compared with other asthma drugs and all drugs in AERS were 2.75 (2.39-316) and 1.09 (0.95-1.24), respectively. Omalizumab ranked second after ICS in the risk of arterial thrombotic events, followed by AMC, AMC-SABA, and ICS-LABA. Conclusion: Omalizumab is associated with higher than expected reporting of arterial thrombotic events in asthmatic patients. This hypothesis needs further testing in robust epidemiological studies.