Concomitant Asthma Medication Use in Patients Receiving Omalizumab: Results from Three Large Insurance Claims Databases

Background. Omalizumab (Xolair (R)) is a monoclonal antibody indicated for moderate to severe persistent allergic asthma patients with symptoms that are inadequately controlled with inhaled corticosteroids (ICS). Objective. This study describes concomitant asthma medication use in patients treated with omalizumab. Methods. An analysis of health insurance claims from MarketScan (2002-2009), Medicaid (2002-2009), and the HealthCore Integrated Research Database (HIRD (TM)) (2002-2010) was conducted. Medical charts were also extracted for a subset of HIRD patients. Patients aged >= 12 years and newly initiated on omalizumab with 12 months of continuous insurance coverage prior to the first omalizumab dispensing (baseline period) and >= 2 asthma claims were included. Concomitant asthma medication use was summarized in eight medication classes. Results. A total of 6038 patients were identified (Medicaid: 731; MarketScan: 3521; HIRD: 1786). A high proportion of new omalizumab users had an asthma-related emergency room visit (Medicaid: 34%; MarketScan: 17%; HIRD: 16%) or hospitalization (Medicaid: 36%; MarketScan: 14%; HIRD: 21%) within 12 months prior to initiating omalizumab. Most patients (Medicaid: 96%; MarketScan: 89%; HIRD: 86%) received three concomitant asthma medication classes or more during the baseline period. Concomitant ICS use was observed in 95%, 89%, and 86% of Medicaid, MarketScan, and HIRD patients, respectively. In HIRD patients without evidence of receiving other asthma medication prior to omalizumab, 17 out of 20 patients had a documented baseline history of asthma-related medication use in their medical charts. Conclusions. This large observational study using health insurance claims from three databases and confirming results from medical charts provides evidence that nearly all omalizumab users had received other asthma medications prior to initiating omalizumab.