Clinical effects and immune modulation of biologics in asthma

Asthma is considered a syndrome composed of heterogeneous disorders involving complex chronic airway inflammation. Patients with severe asthma, prolonged symptoms, and frequent asthma exacerbations, despite high doses of inhaled corticosteroids, may benefit from treatment with biologics. Four types of biologics are available for severe asthma, including an anti-immunoglobulin E (IgE) antibody (omalizumab), anti-interleukin (IL)-5 antibody (mepolizumab and reslizumab), anti-IL-5 receptor α antibody (benralizumab), and anti-IL-4 receptor α antibody (dupilumab). Biologics for patients with severe asthma demonstrate high therapeutic efficacy and provide significant clinical benefits, including the prevention of asthma exacerbations, alleviation of symptoms, improvement in the quality of life and respiratory function, and reduction in frequencies of hospitalization and emergency outpatient visits. This review provides an overview of the modulation of immunological features by each of the four established biologics in patients with severe allergic asthma. Given the extensive immunomodulatory effects of biologics, further analyses of their precise effects on the human immune system are warranted.