Efficacy and safety of omalizumab in an Asian population with moderate-to-severe persistent asthma.

Background and objective: The efficacy and safety of the anti-IgE antibody, omalizumab, has been widely studied in patients with asthma. However to date, no large studies have been performed in Asian populations. The aim of this study was to compare the efficacy and safety of omalizumab with placebo, as add-on therapy in Asian patients with moderate-to-severe persistent asthma. Methods: Japanese patients (20-75 years of age) with uncontrolled asthma, despite receiving high-dose inhaled corticosteroids and other standard therapies, were randomized to receive add-on treatment with omalizumab or placebo in a 16-week, double-blind, parallel-group, multicentre study. Results: Altogether, 315 treated patients were included in the efficacy and safety analyses. The change from baseline in morning PEF was 15.45 L/min (least squares mean) with omalizumab versus 2.25 L/min with placebo, a statistically significant difference of 13.19 L/min (P = 0.0004). Clinically significant asthma exacerbations occurred in six patients (4.0%) treated with omalizumab and in 18 patients (11.0%) treated with placebo. The odds ratio for the risk of experiencing an asthma exacerbation was 0.32 in favour of omalizumab (P = 0.0192). Changes in asthma symptom scores, daily life activity scores, sleep scores and rescue medication use were in favour of omalizumab, but group differences did not reach statistical significance. Adverse event rates were similar between omalizumab and placebo, except for injection site reactions, which were more frequently observed in the omalizumab group. Conclusions: Add-on treatment with omalizumab improved asthma control without significant adverse events in Japanese patients with moderate-to-severe persistent asthma.