Real-World Effectiveness of Mepolizumab in Patients with Allergic and Non-Allergic Asthma

Purpose: Real-world data on mepolizumab in patients with severe asthma and allergic and non-allergic phenotypes are limited. This study investigated the effectiveness of mepolizumab treatment in patients with severe asthma with allergic and non-allergic phenotypes. Patients and Methods: This retrospective cohort study (GSK ID: 214148) used administrative claims data from the Optum Research Database. Eligible patients were ≥ 6 years of age with asthma and had ≥ 2 mepolizumab claims post-index. Index date was the first mepolizumab claim/administration (January 2016–December 2018). Patients were divided into two cohorts: allergic and non-allergic asthma, based on diagnosis codes, medication use and lab test results. Outcomes included the rate of asthma-related exacerbations and oral corticosteroid (OCS) use during the 12 months before (baseline period) and 12 months after (follow-up period) mepolizumab initiation. Study ended in December 2019. Results: Overall, 240 (44.6%) and 298 (55.4%) patients were included in the allergic and non-allergic asthma cohorts, respectively. Mean (standard deviation SD) counts of asthma-related exacerbations were significantly reduced from baseline to follow-up in both the allergic and non-allergic asthma cohorts (3.2 2.5 to 2.1 2.1, p < 0.001 and 2.5 2.2 to 1.7 1.9, p < 0.001, respectively). The mean number of OCS pharmacy claims was significantly decreased by 33.3% and 41.4% from baseline to follow-up in the allergic and non-allergic cohorts, respectively (p < 0.001); mean daily OCS dose significantly decreased by 30.6% and 45.4%, respectively (p < 0.001) as well as the mean number of OCS bursts, which decreased by 44.9% and 41.8%, respectively (p < 0.001). No significant differences were observed between cohorts in reductions in asthma exacerbations, counts of OCS pharmacy claims or OCS bursts (baseline to follow-up). Conclusion: Mepolizumab significantly reduced asthma exacerbations and OCS use in patients with allergic and non-allergic asthma, suggesting that mepolizumab provides real-world benefit in severe asthma irrespective of whether a patient has an allergic phenotype. Keywords: severe asthma, phenotype, exacerbation, oral corticosteroid