Omalizumab: a recombinant humanized anti-IgE antibody for allergic asthma

The pharmacology, efficacy, dosage, adverse events, and economics of omalizumab are discussed.

Omalizumab, a recombinant DNA-derived humanized monoclonal antibody, binds to the C epsilon3 domain of immunoglobulin E (IgE) and forms complexes that inhibit the immune system's response to allergens by averting IgE-mediated inflammatory changes. Omalizumab exhibits a similar pharmacokinetic profile in adults, adolescents, and children. Omalizumab is indicated for adults and adolescents with moderate to severe persistent asthma who have a positive skin test or in vitro reactivity to a perennial aeroallergen and whose symptoms are inadequately controlled with inhaled corticosteroids. Because of the limited data regarding the safety and effectiveness of omalizumab in children, the drug is indicated for patients 12 years of age or older. The recommended starting dosage is 150-375 mg s.c. every two or four weeks. Dosages and frequency of dose administration are determined by total serum IgE level, measured before the start of treatment, and body weight. Omalizumab is generally well tolerated in adults and children with allergic asthma. Adverse events most commonly observed are injection-site reaction, viral infection, upper-respiratory-tract infection, sinusitis, headache, and pharyngitis. Three large phase III clinical trials demonstrated that omalizumab is more effective than placebo in controlling moderate to severe allergic asthma in patients who have poor disease control or exacerbations despite recommended therapy. Currently, there are no clinical comparisons of omalizumab with other standard treatments for asthma; therefore, it is difficult to determine its overall place in therapy.

Omalizumab should be considered as a second-line therapy for patients with moderate to severe persistent allergic asthma.