Reslizumab and mepolizumab are recently approved monoclonal antibodies for the treatment of severe (uncontrolled) eosinophilic asthma. Both are effective in neutralizing the function of interleukin-5 (IL-5). Interleukin-5 (IL-5) is the key mediator of eosinophil differentiation, migration, activation and survival, which has led to the development of therapies targeted to IL-5 for the treatment of eosinophilic asthma. Reslizumab and mepolizumab are both humanized monoclonal antibodies that target IL-5.