Anti‐IgE: a significant breakthrough in the treatment of airway allergic diseases

Although the introduction of inhaled corticoids in the maintenance treatment has proved to be a major advance in asthma care accounting for a reduction in both morbidity and mortality (1), a substantial part of asthmatics still have incomplete control of their disease despite receiving inhaled corticoids (2). In those patients it has been firmly established that addition of long-acting b2 agonist (LABA) to inhaled corticoids was extremely useful by improving lung function and reducing symptoms and rescue bronchodilator consumption (3). Importantly, when administered in support to inhaled corticoids, LABA have been shown to reduce the rate of exacerbations in moderate to severe asthmatics (4), an outcome that not only contributes to the patient quality of life but also to the economic burden of the disease. Accordingly the most recent Global Initiative for Asthma (GINA) guidelines recommend to add LABA in those patients with persistent asthma despite low dose of inhaled corticoids (5). The recognition that asthma is an airway inflammatory disease has prompted over the last 20 years research in depth in order to unravel the cellular and molecular mechanisms regulating this inflammation. From this intensive research two classes of drug, specifically targeting relevant molecules, have come out so far. The first class of drug is represented by leucotriene receptor antagonists. These agents have been shown to be valuable maintenance treatment in asthma either as first line treatment (6) or as add-on therapy in patients not adequately controlled with inhaled corticoids (7). The second class of drug is represented by omalizumab, a recombinant humanized anti-immunoglobulin (Ig)E antibody (8). This compound, which dramatically reduces the level of circulating free IgE (9) and, thereby, prevents IgE binding to cell-membrane receptor, has proved to be able to attenuate both early and late asthmatic responses after experimental allergen challenge (10). These encouraging results were soon followed by the confirmation that this compound may benefit to atopic asthmatics in longterm clinical studies. Omalizumab has been shown to reduce symptoms (11) and exacerbations (12, 13) as well as to improve quality of life (14, 15) in uncontrolled corticosteroid treated asthmatics. Moreover, in most of these studies, the clinical improvement with anti-IgE was often obtained together with a reduction of the needed dose of corticoids. The spectrum of activity of anti-IgE extends beyond asthma itself as the drug may also improve symptoms and quality of life in seasonal and persistent allergic rhinitis (16, 17). Emphasis has recently been placed on the links between rhinitis and asthma and an initiative in collaboration with WHO, termed Allergic Rhinitis and its Impact on Asthma has been developed (18). In this issue of Allergy two additional large clinical trials add to the evidence of anti-IgE efficacy in airway allergic diseases. Vignola et al. (19) report the effects of anti-IgE on exacerbation rates and quality of life in patients suffering concomitantly from persistent rhinitis and difficult to control allergic asthma. From the presented data it appears that anti-IgE, administered every 2/ 4 weeks for 28 weeks in asthmatics uncontrolled despite moderate to high doses of inhaled corticosteroids combined to LABA for most of them, provided a 33% R. Louis Department of Pneumology, CHU Sart-Tilman, Belgium