Methods: A systematic literature review was conducted to identify studies of omalizumab treatment in patients ≥12 years with moderate to severe allergic asthma. A search of MEDLINE and EMBASE databases was conducted for relevant studies published from 2003 to 2014. Included study designs were prospective observational studies and retrospective studies. Outcomes of interest were corticosteroid-sparing effects, including reduction in use of oral corticosteroids (OCS) and inhaled corticosteroids (ICS). Study quality was assessed by the Newcastle-Ottawa Quality Assessment Scale of Cohort Studies (for nonrandomized studies).
Results: A total of 19 studies evaluated OCS usage and 12 studies evaluated ICS usage. The proportion of patients discontinuing maintenance OCS ranged from 20.5% to 74.2%. A reduction in the proportion of maintenance OCS users was reported in 6 studies. A statistically significant reduction in daily dose was reported in 3 studies, ranging from 35% to 95% (7mg to 21mg reduction per day). Statistically significant reductions in ICS usage were reported in 50% of studies (6/12) and the remainder of studies described a reduction with descriptive analyses only. Overall, patients treated with omalizumab reduced their daily use of ICS and a subset of patients discontinued their daily (maintenance) use of ICS therapy.
Conclusions: Patients with moderate to severe allergic asthma utilizing add-on omalizumab therapy are consistently described in the literature as experiencing a reduction in the use of both ICS and OCS.