Presented at American Thoracic Society Conference 2020
Rationale: Over 25 million people in the U.S. have asthma; 5-10% of whom have severe asthma. Mepolizumab (Nucala®) is an interleukin-5 antagonist monoclonal antibody approved by the FDA in 2015 for add-on maintenance treatment of patients with severe asthma aged ≥12 years with an eosinophilic phenotype. The objective of this study is to describe demographic and clinical characteristics of mepolizumab new users in the U.S.
Methods: We conducted a new-user observational cohort study using data from Aetna, HealthCore, Inc, Harvard Pilgrim Health Care, and IBM MarketScan Research Databases. Curated data in the FDA Sentinel System common data model format and publicly-available Sentinel analytic tools were used to query the databases. From over 92 million individuals, we included subjects who initiated mepolizumab between 2015 and 2018 with a diagnosis of asthma in the 12 months before initiation of mepolizumab based on ICD-9 and ICD-10 codes. Mepolizumab initiation was defined as the first prescription after a 12-month washout period. We excluded subjects with cystic fibrosis. We examined age, sex, co-morbid conditions, asthma medication use, and severe asthma exacerbations (hospitalization, emergency department visits, or need for oral corticosteroids) in the prior 12 months.
Results: In total, 3,191 subjects with mepolizumab use were identified. Subjects without a diagnosis of asthma in the prior 12 months (n=84) and with a diagnosis of cystic fibrosis (n=26) were excluded, leaving 3,075 initiators, including 2,990 adults (mean age 54.1 years) and 85 children (mean age 14.6 years). Of the 2,990 adults, 63.0% were female. In the 12 months before mepolizumab initiation, 69.9% had a diagnosis of allergic rhinitis, 31.0% had chronic obstructive pulmonary disease, 17.5% eosinophilia, 3.4% eosinophilic granulomatosis with polyangiitis. Of adults, 55.6% had an asthma-related ambulatory visit, 72.6% had ≥1 course of oral corticosteroids lasting 3-27 days, 9.9% had an asthma-related emergency department visit, and 22.1% had an asthma-related hospitalization.
Of the 85 children initiating mepolizumab, 45.9% were female, 90.6% had a diagnosis of allergic rhinitis, 25.9% eosinophilia, 18.8% eosinophilic esophagitis, and 3.5% eosinophilic granulomatosis with polyangiitis. Of children, 47.1% had an asthma-related ambulatory visit, 81.2% had ≥1 course of oral corticosteroids, 10.6% had an asthma-related ED visit, and 27.1% had an asthma-related hospitalization in the 12 months prior to initiation of mepolizumab.
Conclusions: Adults and children with asthma are being treated with mepolizumab. Individuals had varying levels of health care utilization and comorbid diagnoses in the 12 months prior to initiating mepolizumab. Funding: GSK (PRJ2757).
