Dose Ranging Efficacy And Safety With Mepolizumab in Severe Asthma

The purpose of this study is to show whether mepolizumab given every 4 weeks intravenously (i.v.) can reduce the frequency of asthma exacerbations in subjects with severe asthma despite receiving high doses of standard asthma medications. The study will look at different doses of mepolizumab in comparison to a placebo.

A double-blind, placebo-controlled study to evaluate the efficacy, safety and pharmacodynamics of three doses (75 mg, 250 mg and 750 mg) of mepolizumab intravenous (i.v.) administered every 4 weeks compared with placebo over a 52-week treatment period in subjects with severe uncontrolled refractory asthma. Efficacy will be measured by the frequency of asthma exacerbations. In addition lung function, rescue medication usage, daily symptoms, asthma control score, asthma quality of life score and withdrawals due to asthma exacerbations will be assessed. Safety will be assessed by adverse events, clinical laboratory evaluations, ECGs, immunogenicity and vital signs. Pharmacodynamics will be assessed by eosinophil levels in blood, serum IL-5 and eosinophil levels in induced sputum.