Reslizumab: Maintenance treatment for eosinophilic asthma inadequately controlled on corticosteroids.

The starting point for this drug was the growing realization that eosinophils appeared to be associated with a severe form of asthma in which patients were subject to exacerbations of their condition that could not be adequately managed using inhaled and/or oral corticosteroids. Studies of the pathophysiology of eosinophils revealed that they produce many bioactive compounds that contribute to the pathophysiology of a number of diseases including asthma. Interleukin-5 (IL-5) in particular is an important factor in some forms of severe asthma. A rat antibody to IL-5 (39D10) was humanized producing the product now know as reslizumab. However, initial studies of this antibody in patients with asthma were unsuccessful. It was only when the importance of the eosinophilic asthma endotype was recognized that reslizumab was found to indeed reduce the severity and exacerbations of asthma in patients who were inadequately treated by inhaled and/ or oral corticosteroids. These studies have determined that reslizumab is a valuable drug for the management of such patients provided that they have an eosinophil count of > 400 cells/mcL. Because a very small percentage of patients receiving reslizumab may experience anaphylaxis, reslizumab must be only given in a facility with adequate facilities and by a health professional trained in the management of anaphylaxis.