Evaluation of Omalizumab From a Health Plan Perspective

OBJECTIVES: To review the pathophysiology of allergic asthma and information on the pharmacology, clinical efficacy, safety profile, and direct drug costs for omalizumab to provide a basis for a defined role of this agent in allergic asthma therapy in managed care organizations. SUMMARY: Omalizumab is a monoclonal antibody targeting the high-affinity receptor binding site on human immunoglobulin E (IgE). When bound by omalizumab, IgE does not bind to basophils. As a result, degranulation is attenuated and allergic asthma symptoms are reduced. In asthma trials, omalizumab reduced inhaled corticosteroid and rescue medication requirements and improved asthma control and asthma quality of life in moderate-to-severe allergic asthmatics with disease poorly controlled by inhaled corticosteroids. Omalizumab has generally been well tolerated. However, injection site reactions occur in nearly 1 of every 2 patients, a problem that generally becomes less with continued dose administration. Severe injection site reactions are reported in 12% of patients. Other adverse events commonly reported in clinical trials include viral infections (23%), upper respiratory infections (20%), sinusitis (16%), headache (15%), and pharyngitis (11%). Because the acquisition cost of omalizumab is high (generally $15,000 to $44,000 per patient per year, before contractual discounts), its use is cost-prohibitive in all but the most severe, poorly controlled allergic asthmatic patients who are utilizing large amounts of emergency health care resources to manage exacerbations. Experience with use of this drug beyond 52 weeks is lacking. CONCLUSIONS: Although omalizumab has demonstrated efficacy and safety in adults and adolescents with uncontrolled moderate-to-severe allergic asthma, its use should be restricted to a narrowly defined population of allergic asthmatics who utilize large amounts of health care resources. If targeted only toward this population, cost-of-care studies suggest that the high cost of this product in these patients could be offset by savings resulting from the less frequent use of high-intensity medical services for asthma exacerbations. The use of omalizumab beyond 52 weeks needs evaluation.