Methods: Using a large US insurance database, OptumLabsTM Data Warehouse, that includes privately insured and Medicare Advantage patients we identified omalizumab users in 2003-2015. Individuals with diagnostic codes for chronic idiopathic urticaria after 7/1/2013 were excluded from the cohort. New use of omalizumab was calculated for the entire cohort. Persistence of use, defined as the duration of use from initiation to discontinuation, was calculated in users who had pharmaceutical coverage for at least 6 months after stopping omalizumab to limit censoring based on insurance coverage.
Results: We identified 8,545 omalizumab users from 2003-2015 who met our inclusion criteria (64% female, 72% white, 11% Black, 9% Hispanic, 3% Asian, and 5% unknown race/ethnicity). The rate of individuals starting omalizumab for asthma had an initial peak in 2005 at 9.56 new users per 100,000 insured people and declined until 2012 to 5.22 new users per 100,000 insured people. New omalizumab users have increased since 2012, peaking in 2015 with 12.13 new users per 100,000 insured people. The majority of individuals who started omalizumab used it for <1 year (59%); another 14% used for 1-2 years, 7% for 2-3 years, 3% for 3-4 years, 2% for 4-5 years, and 15% for > 5 years.
Conclusions: Since 2012, the rate of new omalizumab users for asthma increased more than two-fold. Fewer than half of those who start omalizumab continue for longer than 1 year.