Omalizumab: a novel therapy for allergic asthma.

OBJECTIVE: To review the pharmacology, efficacy, and safety of omalizumab, focusing on the treatment of allergic asthma.

DATA SOURCES: A MEDLINE search (1966-November 2003) was conducted using the key words omalizumab, Xolair, and Rhu-MAB25, with studies limited to those in humans and published in English. References of identified articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION: Clinical trials evaluating the pharmacology, efficacy, and safety of omalizumab for treatment of allergic asthma in patients aged >or=12 years were selected. Clinical trials examining utility in pediatric patients were also reviewed.

DATA SYNTHESIS: Omalizumab's ability to form complexes with unbound immunoglobulin E (IgE) translates into decreased unbound serum IgE levels and high-affinity IgE receptors on basophils, as well as attenuation of early and late allergic response in patients with allergic asthma. Results of clinical trials demonstrated that omalizumab administered subcutaneously is a safe and effective treatment for moderate to severe allergic asthma. Generally, omalizumab has a mild adverse effect profile. Omalizumab may be particularly useful for treatment of moderate to severe allergic asthma in patients who are poorly controlled on conventional therapy, experience adverse effects secondary to high-dose or prolonged corticosteroid treatment, or who have frequent exacerbations because of poor medication adherence. The high cost associated with omalizumab treatment may be prohibitive for some patients, thereby limiting its utility.

CONCLUSIONS: Omalizumab is a safe and effective therapy for treatment of moderate to severe allergic asthma in difficult-to-treat, high-risk patients.