Targeting of eosinophils in asthma

Severe asthma continues to be an important source of morbidity despite the availability of bronchodilators and corticosteroids. Although new treatments are needed, better identification of asthma phenotypes may improve treatment effectiveness. One phenotype that has emerged is eosinophilic asthma. Eosinophils in asthma have been studied for many years, and the evidence suggests they play a major role in some forms of asthma. Eosinophilic asthma can be diagnosed using peripheral blood, sputum eosinophil count or exhaled nitric oxide. Depletion of eosinophils can be achieved by corticosteroids, specific anti-interleukin 5 (IL-5) or anti-IL-5-receptor-alpha therapies, or anti-immunoglobulin E approaches. This editorial refers to the approaches that are being taken in eosinophilic asthma with emphasis on the new investigational anti-IL-5-receptor-alpha antibody, benralizumab.