Omalizumab: a review of its use in the treatment of allergic asthma.

Omalizumab, a monoclonal antibody that targets circulating IgE, is approved as add-on therapy for adult and adolescent patients with severe allergic asthma in the EU and moderate to severe allergic asthma in the US. Several randomized, double-blind trials have demonstrated the therapeutic efficacy of subcutaneously administered omalizumab as add-on therapy in patients with allergic asthma. The INNOVATE study included only patients with severe persistent disease, and omalizumab was associated with a statistically significant relative reduction of 26% in the rate of clinically significant asthma exacerbations (primary endpoint) compared with placebo (after adjustment for an imbalance in the exacerbation history at baseline). Results for a number of secondary outcomes also significantly favored omalizumab over placebo. Two large studies in patients with moderate to severe allergic asthma showed that, compared with placebo, omalizumab was associated with statistically significant relative reductions of 41-58% in the mean number of asthma exacerbations (primary endpoint) during the trial. Omalizumab also significantly reduced asthma symptom scores and the use of inhaled corticosteroids and rescue medication. Moreover, all of these trials showed that omalizumab was associated with clinically and statistically significant improvements from baseline in overall asthma-related quality of life. In general, omalizumab was well tolerated in clinical trials. Most adverse events were mild or moderate in severity and occurred at a similar frequency among omalizumab and placebo recipients. Injection-site reactions were the most commonly reported adverse events in clinical trials with omalizumab. Although rare, anaphylactic reactions have occurred following administration of omalizumab, and appropriate precautions should be taken. Results of several large randomized trials, therefore, have established omalizumab as an effective and well tolerated agent for use as add-on therapy in patients with severe persistent allergic asthma (EU labeling) or those with moderate to severe disease (US labeling). In addition, international treatment guidelines acknowledge the importance of omalizumab as a treatment option in these difficult-to-treat patient populations.