Impact of Mepolizumab on Exacerbations in the US Medicare Population

Abstract

Asthma is a common chronic respiratory disorder associated with significant disease and economic burden. Mepolizumab is an anti-IL-5 mAb approved for use as an add-on treatment in patients with severe eosinophilic asthma. To assess the impact of mepolizumab initiation on asthma exacerbation frequency, oral corticosteroid (OCS) use, and asthma exacerbation-related costs in a US Medicare population. This was a retrospective cohort study of mepolizumab claims from patients with asthma in the Centers for Medicare and Medicaid Services Medicare database carried out between January 2016 and December 2018. The index date (first claim for mepolizumab) was required to occur between January and December 2017. The baseline and follow-up periods were the 12 months before and 12 months after the index, respectively. Outcomes included changes in the proportion of patients experiencing exacerbations (primary), OCS use (secondary), and asthma exacerbation-related costs during the baseline and follow-up periods. The study identified 1,278 patients (mean age, 67.9 years; 65% female) with one or more prescription or administration claim for mepolizumab who were eligible for study inclusion. There was a significant relative reduction in the proportion of patients with an asthma exacerbation (27%; P < .0001) in the follow-up versus baseline period. Similarly, a lower proportion of patients received OCS for asthma (16% relative reduction; P < .0001), fewer patients were chronic OCS users (5 mg/day or more; 48% relative reduction; P < .0001), and there was a significant decrease in asthma exacerbation-related costs (total reduction, $888; P= .0002) during the follow-up versus the baseline period. Mepolizumab reduced exacerbations, OCS use, and exacerbation-related healthcare costs in a US Medicare population, confirming its benefits in this specific population with severe asthma.