A real-world study of inhaled corticosteroid use in patients with severe eosinophilic asthma treated with mepolizumab

BackgroundMepolizumab is a humanized anti-interleukin-5, monoclonal antibody approved for the treatment of patients with severe eosinophilic asthma (SEA). There is limited evidence that mepolizumab can reduce inhaled corticosteroid (ICS) use in these patients.ObjectiveTo investigate changes in ICS use and clinical outcomes in patients with SEA who initiated mepolizumab treatment.MethodsThis retrospective cohort study (GlaxoSmithKline identification: 212695/HO-20-19951) used administrative claims data from the IBM Watson Health MarketScan Database (identification period: November 2015 to March 2018). Eligible patients had SEA and were receiving high-dose ICS and mepolizumab. Use of ICS, oral corticosteroid (OCS), and short-acting β2-agonist and exacerbation frequency were analyzed quarterly during the 12-month follow-up period after mepolizumab initiation.ResultsIn total, 351 patients were included. The proportion of patients using high-dose ICS decreased in quarters 1 to 4 after mepolizumab initiation (79.8%, 74.6%, 68.9%, 65.5%, respectively); 49.0% of patients reduced or discontinued ICS for one or more quarter. Comparing patients who discontinued ICS vs those who remained on high-dose ICS, a lower proportion had chronic OCS use (3.4%–9.2% vs 13.9%–16.8%) and OCS burst use (15.4%–20.8% vs 19.7%–26.1%) in quarters 1 to 4; similarly in quarters 3 and 4, a lower proportion of patients had exacerbations (16.9% and 20.3% vs 27.2% and 27.7%) and short-acting β2-agonist claims (35.4% and 39.2% vs 43.3% and 49.0%, respectively).ConclusionIn patients with SEA on high-dose ICS, a reduction in both ICS and OCS use was observed after initiating mepolizumab. These findings have important implications for clinical outcomes and follow-up care in this patient population.