Late Breaking Abstract - Effectiveness and safety of mepolizumab in real-world clinical practice: the REALITI-A study

Background: Real-world evidence of mepolizumab use for severe eosinophilic asthma (SEA) in routine clinical practice will aid clinical decision making. Aims: To assess mepolizumab effectiveness in patients (pts) with SEA in the real world. Methods: REALITI-A is a 2y, global, prospective, single-arm, observational cohort study enrolling pts with SEA and newly prescribed mepolizumab 100mg SC at physician’s discretion (no pre-defined eligibility criteria). Data were collected at routine healthcare visits; 1y pre-exposure data were collected retrospectively at enrolment. Primary endpoint was rate of clinically significant exacerbations (CSEs; requiring OCS and/or emergency room [ER] visit/hospitalisation). Exacerbations requiring ER visit/hospitalisation and maintenance OCS use were key secondary endpoints; treatment-related AEs were reported. This interim analysis includes pts with 1y post-exposure data. Results: 368 treated pts were included (mean age, 53y; 62% female; geometric mean blood eosinophil count, 370 cells/µL; smoker: former/current 39%, never 61%; 70% on OCS). The rate ratio (RR) of CSEs was 0.31 (95%CI 0.27,0.35; 4.63 [pre-] reduced to 1.43 [post exposure] events/y); RR of exacerbations requiring hospitalisation/ER visits was 0.23 (0.18,0.30; 1.14 reduced to 0.27 events/y). OCS data were available for 159 (baseline) and 143 (Wk 53–56) pts. Median OCS dose reduced from 10 to 5mg/day at Wk 53–56; 34% (49/143) stopped OCS. 53 (14%) pts had on-treatment AEs and 2 ( Conclusions: This study shows that significant reductions in exacerbations and OCS use with mepolizumab in clinical trials translate to a real-world setting. Funding: GSK [204710]