Experiences with monoclonal antibody therapy for allergic asthma

Identification of the central role IgE plays in the pathogenesis of allergic diseases made it a key target for therapy. The first selective anti-IgE therapy, a unique humanized monoclonal anti-IgE antibody (omalizumab), binds with high affinity to the Fc(epsilon)RI receptor binding site on IgE, thereby reducing the amount of free IgE available to bind to Fc(epsilon)RI receptors on mast calls, basophils, and other cells. In addition, administration of omalizumab indirectly reduces Fc(epsilon)RI receptor density on cells involved in allergic responses. In two bronchoprovocation trials involving patients with mild allergic asthma, omalizumab attenuated both early- and late-phase allergic responses. Omalizumab was subsequently evaluated as a treatment for asthma in large, multicenter, randomized, double-blind phase II and III trials involving patients with moderate to severe asthma who required corticosteroid therapy. When added to treatment with oral or inhaled corticosteroids, omalizumab reduced symptoms and exacerbations, improved lung function and quality of life, and reduced the need for rescue medications. These benefits persisted even in the "corticosteroid reduction" phase of these trials, when omalizumab treatment was shown to allow patients to reduce or discontinue their inhaled and/or oral corticosteroids. These effects of omalizu-mab in improving asthma control, as well as its excellent safety profile, may ultimately make this agent a useful addition to the physician's armamentarium of treatments for asthma.