A review of anti-IgE monoclonal antibody (omalizumab) as add on therapy for severe allergic (IgE-mediated) asthma.

Bronchial asthma is recognized as a highly prevalent health problem in the developed and developing world with significant social and economic consequences. Increased asthma severity is not only associated with enhanced recurrent hospitalization and mortality but also with higher social costs. The pathogenetic background of allergic-atopic bronchial asthma is characterized by airway inflammation with infiltration of several cells (mast cells, basophils, eosinophils, monocytes, and T-helper (Th)2 lymphocytes). However, in atopic asthma the trigger factors for acute attacks and chronic worsening of bronchial inflammation are aeroallergens released by pollens, dermatophagoides, and pets, which are able to induce an immune response by interaction with IgE antibodies. Currently anti-inflammatory treatments are effective for most asthma patients, but there are asthmatic subjects whose disease is not completely controlled by inhaled or systemic corticosteroids and who account for a significant portion of the healthcare costs of asthma. A novel therapeutic approach to asthma and other allergic respiratory diseases involves interference in the action of IgE, and this antibody has been viewed as a target for novel immunological drug development in asthma. Omalizumab is a humanized recombinant monoclonal anti-IgE antibody approved for treatment of moderate to severe IgE-mediated (allergic) asthma. This non-anaphylactogenic anti-IgE antibody inhibits IgE functions, blocking free serum IgE and inhibiting their binding to cellular receptors. By reducing serum IgE levels and IgE receptor expression on inflammatory cells in the context of allergic cascade, omalizumab represents a new class of mast cells stabilizing drugs; it is a novel approach to the treatment of atopic asthma. Omalizumab therapy is well tolerated and significantly improves symptoms and disease control, reducing asthma exacerbations and the need to use high dosage of inhaled corticosteroids. Moreover, omalizumab improves quality of life of patients with severe persistent allergic asthma which is inadequately controlled by currently available asthma medications. In conclusion omalizumab may fulfil an important need in patients with moderate to severe asthma.