Mepolizumab for severe eosinophilic asthma

Evaluation of: Pavord ID, Korn S, Howarth P et al. Mepolizumab for severe eosinophilic asthma (DREAM): a multicentre, double-blind, placebo-controlled trial. Lancet 380(9842), 651–659 (2012).In this large (616 patients), double-blind, placebo-controlled, dose-ranging study of mepolizumab (a monoclonal antibody that blocks IL-5 binding to its receptor), patients were given placebo, 75-, 250- or 750-mg mepolizumab by intravenous infusion every 4 weeks for 1 year. Exacerbation rates at all doses were 50% less than those in the placebo group. There were no changes in any other asthma measures (symptoms, quality of life or lung function). This may be a useful advance for a subgroup of severe asthma with frequent exacerbations and persistent eosinophilia, which may be about half of severe asthmatics. More information on patient selection and cost–benefit will be required.