Purpose of review: Allergic asthma is a hypersensitivity reaction initiated by immunologic mechanisms mediated by IgE antibodies. IgE plays a central role in the initiation and propagation of the inflammatory cascade and thus the allergic response. Targeting factors involved in the allergic response, such as IgE, is a novel strategy for new therapies. Attenuating allergic disease by specifically inhibiting IgE and the development of the monoclonal anti-IgE antibody, omalizumab, were major breakthroughs in asthma management.
Recent findings: Several studies have shown that omalizumab has significant anti-inflammatory effects and that it may act on multiple components of the inflammatory cascade. Specific binding of IgE by omalizumab reduces both the early allergic response and the late allergic response and symptoms of IgE-mediated allergy. The long-term clinical efficacy of omalizumab has been demonstrated along with improvements in quality of life. As add-on therapy in severe asthma, omalizumab reduces the requirement for inhaled corticosteroids and improves disease control. Clinical studies have shown that the patients who benefit most from omalizumab therapy are those at high risk of exacerbations, those with poorly controlled and/or severe asthma, and those with IgE-mediated comorbidities.
Summary: Omalizumab is a significant addition to current asthma treatments and shows great promise as a therapy for allergic asthma and for patients with concomitant allergic rhinitis. This is particularly true for difficult-to-treat patients with moderate to severe allergic asthma who have poorly controlled disease on conventional therapies, experience severe adverse effects secondary to high-dose or prolonged corticosteroid treatment, have frequent exacerbations, and/or are at high risk of hospitalization. Future studies will continue to investigate the anti-inflammatory mechanisms of anti-IgE therapy. Because many of these mechanisms are common to all IgE-mediated allergic diseases, the efficacy of omalizumab in other allergic diseases should be further explored.