Anti-immunoglobulin E (omalizumab) therapy in seasonal allergic rhinitis

Anti-immunoglobulin E (anti-IgE) (omalizumab), a humanized monoclonal anti- IgE antibody that binds to circulating IgE, has been studied in several lar ge double-blind, randomized, placebo-controlled clinical trials to determin e its pharmacokinetic characteristics, efficacy, and safety in ragweed- or birch pollen-induced seasonal allergic rhinitis (SAR). The consequences of readministering omalizulab after a lapse of time have also been studied. Th ese studies have confirmed that serum-free IgE declines in a dose-related m anner with such treatment and that omalizumab-induced declines In IgE corre late with symptom improvement. Whether omalizumab is administered intraveno usly or subcutaneously, its pharmacokinetics do not differ. A Phase II dose -ranging study demonstrated that the optimum efficacious dose of omalizumab for the treatment of seasonal allergic rhinitis is 300 mg administered sub cutaneously. The dosing frequency, in terms of whether the antibody is admi nistered every 3 or 4 wk, is based on the patient's baseline IgE level. Wit h adequate dosing, nasal and ocular symptoms are significantly reduced, and quality of life is significantly improved. Omalizumab is safe and well tol erated and can be safely readministered in subsequent pollen seasons.