Omalizumab—Anti-IgE Recombinant Humanized Monoclonal Antibody—for the Treatment of Severe Allergic Asthma

Abstract & Commentary

Synopsis: Omalizumab reduces asthma exacerbation and allows for decreased use of inhaled corticosteroids and rescue medication use in the treatment of asthma.

Source: Busse W, et al. J Allergy Clin Immunol. 2001;108:184-190.

Immunoglobulin E (IgE) plays an important role in the pathogenesis of allergic diseases, such as asthma. Anti-IgE therapy with a recombinant humanized monoclonal antibody (ie, omalizumab) was administered subcutaneously to 525 patients, every 2-4 weeks, depending on the baseline IgE level and body weight, in a double-blind study vs. placebo in allergic asthmatics who are on inhaled steroids. Omalizumab complexes with the free IgE lowers the levels by more than 95%. During the first phase of the study, which lasted 16 weeks, the inhaled corticosteroid doses were kept stable, at which time the active treatment resulted in significantly fewer exacerbations of asthma, compared to the placebo-treated group. During the 12-week beclomethasone dipropionate reduction phase, the active treatment allowed for steroid aerosol reduction and/or discontinuation which was greater than the placebo group and, despite the reduction, there was improved pulmonary function and decreased beta agonist use.

Thus, omalizumab reduces asthma exacerbation and allows for decreased use of inhaled corticosteroids and rescue medication use in the treatment of asthma.

Comment by Sheldon L. Spector, MD, FACP, FAAA, FACA

Omalizumab (RHU M ab-E25) anti-IgE therapy in this study of severe allergic asthmatic subjects was associated with significantly fewer asthmatic exacerbations of shorter duration of action compared to placebo. Moreover, the safety profile was not more significant than that of placebo. The basis of its therapeutic action is thought to be associated with reduction in serum-free IgE levels. However, it might also suppress inflammation in other ways. Its demonstrated beneficial effect in allergic rhinitis1,2 allows not only for the desired effect in hay fever itself, but also for the added improvement in asthma because upper airway disease influences asthmatic symptoms.3-6 Once a novel therapy, such as this, becomes commercially available, it should lend itself to treatment of a panoply of medical problems, such as bronchopulmonary aspergillosis, atopic dermatitis, food allergies, and, even, idiopathic anaphylaxis.

References

1. Casale TB, et al. J Allergy Clin Immunol. 1997;100: 110-121.

2. Adelroth E, et al. J Allergy Clin Immunol. 2000;106: 253-259.

3. Spector S. J Allergy Clin Immunol. 1997;99:S773-S780.

4. Slavin RG. J Allergy Clin Immunol. 1998;101(Suppl 2, Pt 2):S357-S360.

5. Spector S, et al. J Allergy Clin Immunol. 1998; 102(Suppl 6, Pt 2):S107-S144.

6. Spector S. Clin Appl Immunol Reviews. 2001;1:229-234.

Dr. Spector, Clinical Professor, Department of Medicine, UCLA School of Medicine, Los Angeles, is Associate Editor of Internal Medicine Alert.