Background: Previous reports show that addition of omalizumab to standard therapy reduces asthma exacerbations and simultaneously decreases use of inhaled corticosteroids (ICSs) and rescue medication in patients with allergic asthma.
Objective: To determine the effect of omalizumab on long-term disease control in patients with severe allergic asthma.
Methods: The present study concerns the 24-week, double-blind extension phase to a previous 28-week core study in which patients received subcutaneous omalizumab or matching placebo (at least 0.016 mg/kg/IgE [IU/mL] every 4 weeks) for 16 weeks in addition to their existing ICS therapy (beclomethasone dipropionate [BDP]; steroid-stable phase), followed by a 12-week phase in which controlled attempts were made to gradually reduce ICS therapy (steroid-reduction phase). During the extension phase patients were maintained on randomized treatment (omalizumab or placebo) and the lowest sustainable dose of BDP. The use of other asthma medications was permitted during the extension phase. Investigators were also allowed to switch patients from BDP to other ICS medications if considered necessary.
Results: A total of 460 patients (omalizumab, n = 245; placebo, n = 215) entered the extension phase. Overall, omalizumab-treated patients experienced significantly fewer exacerbations vs placebo during the extension phase (0.60 and 0.83 exacerbations per patient, respectively; P = 0.023), despite a sustained significant reduction in their use of ICS (mean BDP equivalent dose: omalizumab, 227 microg/d; placebo, 335 microg/d; P < 0.001). Treatment with omalizumab was well tolerated and the incidence of adverse events was similar in both treatment groups.
Conclusions: These results indicate that omalizumab is effective in the long-term control of severe allergic asthma.