Purpose of review: There is considerable evidence that implicates eosinophils as important effector cells in the inflammation characteristic of eosinophilic asthma. IL-5 is central to eosinophil maturation and release from the bone marrow, their subsequent accumulation, activation and persistence in the tissues. IL-5 therefore represents an attractive target to prevent or blunt eosinophil-mediated inflammation resulting in the development of humanized anti-IL-5 monoclonal antibody such as mepolizumab. This review is an update of the evidence demonstrating the effectiveness of mepolizumab treatment of patients with asthma.
Recent findings: Although early clinical trials with mepolizumab in patients with asthma gave disappointing clinical outcomes, it is becoming apparent that significant clinical effects with this biologic are more likely in carefully selected patient populations that take the eosinophilic asthma phenotype into account. A number of recent studies have reported significant effects by mepolizumab on reductions in exacerbations together with a significant glucocorticoid-sparing effect.
Summary: Mepolizumab is a potentially important and well tolerated therapy in carefully selected populations of patients with asthma.