Omalizumab: a recombinant humanized monoclonal IgE-blocking antibody.

Omalizumab (Xolair) is a recombinant humanized monoclonal antibody that blocks the high-affinity Fc receptor of immunoglobulin E (IgE). It is used to treat patients with moderate-persistent to severe-persistent asthma; patients must be older than 12 years, have a positive skin test to a perennial aeroallergen (e.g., dust mites, cats, dogs, and mold), and be symptomatic with inhaled corticosteroids. Omalizumab has a low incidence of side effects, and it is very expensive. The exact dosage of omalizumab dosage is determined by body weight and pretreatment serum total IgE levels. Omalizumab may have a role in the treatment of atopic dermatitis when IgE plays a causal role.