Late Breaking Abstract - International, prospective real-world study of mepolizumab in patients with severe asthma at one year: REALITI-A

Introduction: Mepolizumab improves asthma control in patients (pts) with severe asthma in clinical trials, but real-world data is limited. Aim: To assess real-world clinical outcomes in pts initiating mepolizumab treatment. Methods: REALITI-A is a 2y, international, prospective, single-arm, observational cohort study enrolling pts with severe asthma, newly prescribed mepolizumab 100mg SC. 1y pre-exposure exacerbation data availability was a prerequisite. Primary endpoint: rate of clinically significant exacerbations (CSEs; requiring oral corticosteroids [OCS] and/or emergency room [ER] visit/hospitalisation). Exacerbations requiring ER visit/hospitalisation and maintenance OCS (mOCS) were key secondary endpoints; investigator-determined treatment-related adverse events (TRAEs) were collected. Our interim analysis includes all pts at 1y follow-up (median 366days). Results: 822 treated pts included (mean age, 54.0y; 63% female; geometric mean blood eosinophil count, 353cells/µL; smoker: former/current 40%, never 60%; 39% on mOCS). CSEs reduced from 4.28 (pre-) to 1.23 (post-exposure) events/y (RR: 0.29 [95%CI 0.26,0.32]). Exacerbations requiring hospitalisation/ER visits reduced from 0.95 to 0.23 events/y (RR: 0.24 [0.20,0.29]). mOCS dose data were available for 298 (baseline) and 222 (wk53–56) pts. Median mOCS dose reduced from 10 (baseline) to 2.5mg/day at wk53–56; 43% (95/222) stopped mOCS by wk53–56. 85 (10%) pts had on-treatment TRAEs, 6 (<1%) serious on-treatment TRAEs; 1 fatal (hepatic cancer). Conclusions: This real-world study of mepolizumab in pts with severe asthma shows clinical effectiveness with marked reductions in CSE and mOCS use. Funding: GSK [204710]