ENCORE: Effect of Mepolizumab in Severe Eosinophilic Asthma Patients Eligible for Omalizumab Treatment
23 February 2017 (online)
In patients with severe eosinophilic asthma (SEA) mepolizumab has demonstrated a reduction in exacerbation frequency. Clinical studies with mepolizumab have shown that ca. half of SEA patients are atopic. Therefore, it is of interest to understand the efficacy of mepolizumab among patients who would have been eligible for omalizumab treatment.
This is a post-hoc analysis of the DREAM (NCT01000506) and MENSA (NCT01691521) studies which enrolled 616 and 576 severe asthma patients ≥12 years of age receiving high-dose inhaled corticosteroids + additional controller(s), with frequent exacerbations and eosinophilic phenotype. Omalizumab was not permitted during the study. Immunoglobulin E (IgE), atopy status and bodyweight were collected, informing on whether each subject would have been eligible for omalizumab based on atopic status and the US label for bodyweight and IgE levels. A subgroup analysis of the rate of exacerbations was performed using the negative binomial model.
Eligibility assessment for omalizumab was possible for 614 and 547 patients. In both studies, 30% of these patients (185/614 and 162/547) were eligible for omalizumab according to the US label. In both studies, mepolizumab showed significant reductions in the rate of exacerbations compared to placebo in patients eligible for omalizumab (Rate ratios DREAM: 0.53, 95% CI [0.35,0.78]; MENSA: 0.54, 95% CI [0.35,0.85]) and in patients not eligible for omalizumab (Rate ratios DREAM: 0.54, 95% CI [0.41,0.71]; MENSA: 0.47, 95% CI [0.34,0.64]).
In patients with SEA, reduction in exacerbations with mepolizumab was consistently shown irrespective of eligibility for omalizumab. The reduction in exacerbation rates seen with mepolizumab in the omalizumab-eligible patients was 46% and 47% suggesting a clinical benefit of mepolizumab in severe asthma patients eligible for treatment with either biologic. (Funded by GSK).
Abstract previously presented at ATS 2016, A6470