Mepolizumab, quality of life, and severe eosinophilic asthma.

It is now ten years since the publication of the first clinical trial, eight years since the first key proof of concept studies in a population selected on the basis of inflammatory pattern and two years since approval of Mepolizumab as a treatment for severe eosinophilic asthma. In some countries the treatment has been available to treat patients for over a year. One striking finding of the clinical development programme for this first-in-class anti-IL-5 biological agent has been that evidence for clinical efficacy has become more obvious as we have moved from the first clinical studies to phase 2b and then phase 3 trials. In this issue of the journal Chupp et al8 report the findings of a phase 3b study, which continues this tren