Purpose of the Study. To demonstrate the clinical benefit and steroid-sparing effect of treatment with anti-immunoglobulin E (IgE) antibody, omalizumab, in patients with moderate-to-severe asthma.
Study Population. A total of 546 allergic asthmatics (aged 12–76 years), symptomatic despite inhaled corticosteroids (500–1200 μg daily of beclomethasone dipropionate) and demonstrating a positive skin prick test to dust mites, dog, or cat and a serum total IgE level of >30 and <700 international units (IU).
Methods. After a run-in period of 4 to 6 weeks, patients were randomized to receive either placebo or omalizumab subcutaneously every 2 to 4 weeks for 7 months. The interval was determined on dosing based on body weight and baseline IgE level. During the run-in period, patients were switched to inhaled beclomethasone using the dose at which they were stable. Dose was maintained during the first 16 weeks of the study. In the next 12 weeks, patients were seen every 2 weeks and inhaled steroid dose was decreased based on clinical symptoms and forced expiratory volume in 1 second (FEV1). Lowest inhaled steroid dose was held for the remaining 4 weeks of the study. IgE levels were determined pre- and poststudy.
Results. There was a reduction in serum-free IgE from baseline by 89% to 99% for those patients on omalizumab. The number of asthma exacerbations per patient were statistically different in favor of omalizumab for both stable steroid and steroid reduction phases (P < .001). Percentage of patients with at least 1 asthma exacerbation was significantly lower in the omalizumab group (P < .001). During the steroid reduction phase, there were 52% fewer exacerbations in the omalizumab group versus the placebo group (P < .001) despite the greater reduction of the beclomethasone dosage on omalizumab (P < .001). There were also statistically significant differences in asthma symptom scores and number of puffs of rescue medication in favor of omalizumab. Incidence of adverse effects were similar in placebo and omalizumab groups.
Conclusion. These results indicate that omalizumab therapy safely improves asthma control in allergic asthmatics who remain symptomatic despite regular use of inhaled corticosteroids and simultaneous reduction in corticosteroid requirement.
Reviewer’s Comments. The role of immunomodulating therapies in the treatment of allergic disease and asthma has become an exciting area of investigation in recent years. This study provides promising results in that anti-IgE therapy may have a role in controlling asthmatics who remain symptomatic despite regular use of inhaled corticosteroids. This therapy also appears to have a steroid-sparing effect, which is desirable. However, I would be interested in seeing more studies comparing anti-IgE with some of the other inhaled steroid compounds, such as fluticasone and budesonide, as long-term follow-up, especially because this therapy would require shots every 2 to 4 weeks indefinitely. Practicality and compliance will be important factors, as well as efficacy and safety, as we continue to study these new therapies.
- Soler M, Matz J, Townley R, et al. Eur Respir J.2001;18 :254– 261
- Copyright © 2002 by the American Academy of Pediatrics