Mepolizumab in the treatment of eosinophilic esophagitis

Rana F Ammoury and Sandeep K Gupta

Mepolizumab is a humanized monoclonal antibody that binds specifi cally to and inactivates a protein cell messenger termed IL-5, which plays a major role in the proliferation, maturation, activation and survival of eosinophils. As a result, mepolizumab has been studied in a number of eosinophil-associated diseases, such as asthma, hypereosinophilic syndrome and eosinophilic esophagitis (EE). EE is a clinical entity characterized by eosinophilic infi ltration of the esophagus (≥15 eosinophils/high power fi eld in one or more fi elds) in the absence of gastroesophageal refl ux. EE is on the rise, and this can not be fully accounted for by increased recognition. Currently, available therapies, although successful in many cases, can be disappointing in some patients, whether from lack of response, negative impact on quality of life, or signifi cant toxicity. In order to better defi ne EE therapy, investigators are evaluating novel drugs, including anti-IL-5 agents such as mepolizumab. Mepolizumab has been demonstrated to signifi cantly reduce mean blood and tissue eosinophil count. It is well-tolerated and no drug-related serious adverse events have been described in the published literature to date. Mepolizumab is currently under clinical investigation and is not yet available for general use.