This article is part of Pulmonology Advisor‘s coverage of the ACAAI 2019 meeting, taking place in Houston, TX. Our staff will report on medical research related to allergies, asthma, and more conducted by experts in the field. Check back regularly for more news from ACAAI 2019.
HOUSTON — Mepolizumab at licensed doses is associated with reductions in eosinophil levels and asthma exacerbations, as well as improvements in quality of life in patients with uncontrolled severe eosinophilic asthma, according to research presented at the 2019 Annual Meeting of the American College of Asthma, Allergy, and Immunology, held November 7 to 11 in Houston, Texas.
The study was a post-hoc analysis of the MENSA (ClinicalTrials.gov Identifier: NCT01691521) and MUSCA (ClinicalTrials.gov Identifier: NCT02281318) trials, which compared subcutaneous mepolizumab 100 mg or intravenous mepolizumab 75 mg with placebo in patients with severe eosinophilic asthma. Researchers examined 3 baseline blood eosinophil thresholds — ≥500 cells/mL, ≥750 cells/μL, and ≥1000 cells/ μL — in relation to the primary efficacy outcomes.
The efficacy end points were reductions in the yearly rate of asthma exacerbations requiring systemic corticosteroids, asthma exacerbations requiring emergency department visits or hospitalizations, and improvements in asthma control. Quality of life outcomes and prebronchodilator forced expiratory volume in 1 second were also assessed.
In the pooled cohort, 159 patients received mepolizumab and 160 patients received placebo. Patients at the ≥750 cells/mL threshold experienced greater exacerbation reduction compared with patients at the ≥500 cells/μL threshold (85% vs 71%, respectively), which suggests that baseline eosinophil levels could predict the level of improvement in exacerbations. Compared with placebo, there were greater and increasing improvements in quality of life and asthma control with increasing threshold of cells/μL.
In addition, there were lung function improvements of 155 mL, 160 mL, and 92 mL for each blood eosinophil threshold (≥500 cells/μL, ≥750 cells/μL, and ≥1000 cells/μL, respectively) compared with placebo. The investigators observed similar reductions in blood eosinophil values from baseline across the 3 thresholds (≥500 cells/μL, 84%; ≥750 cells/μL, 86%; ≥1000 cells/μL, 88%).
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Silver J, Llanos J, Mayer B, Prazma C, Albers F. Greater efficacy of mepolizumab in severe eosinophilic asthma with high baseline blood eosinophil counts. Presented at: American College of Allergy, Asthma, & Immunology Annual Scientific Meeting 2019; November 7-11, 2019; Houston, TX. Abstract P218.