Effectiveness of mepolizumab in patients switching from prior biologic treatments for severe asthma: a post hoc analysis of the NUCALA Effectiveness Study (NEST)

Introduction Biologic therapy is recommended for patients with severe asthma that remains uncontrolled despite receiving optimal therapy. This post hoc analysis of the Nucala Effectiveness Study (NEST) assessed real-world effectiveness of mepolizumab in biologic-experienced patients with severe asthma.Methods For this post hoc analysis of NEST (a multi-country, bi-directional, observational cohort study in Chile, Colombia, India, Kuwait, Oman, Qatar, Saudi Arabia, Türkiye and United Arab Emirates), data from biologic-experienced patients were included. The primary outcome was comparison of clinically significant exacerbation (CSE) incidence rates 12 months pre and post mepolizumab initiation. Secondary outcomes included changes in oral corticosteroid (OCS) use and Asthma Control Test (ACT) scores.Results Data from 174 patients were included; 94.8% received omalizumab previously and 84.8% had discontinued use due to lack of treatment efficacy. Incidence rate ratio (95% confidence interval) was 0.26 (0.18–0.36; 74.0% reduction in CSEs post initiation). Of 170 patients, OCS use reduced from 60.0% (n = 102) to 23.5% (n = 40); 39/102 (38.2%) patients continued OCS use post mepolizumab initiation. Among OCS users, mean (standard deviation [SD]) OCS dose reduced from 20.8 (17.3) to 6.7 (15.3) mg/day post initiation. Mean (SD) ACT scores improved from 14.0 (5.4; n = 139) to 19.5 (5.2; n = 140) post initiation; of 125 patients, 66.4% achieved a ≥3-point increase in ACT score.Conclusion Mepolizumab treatment led to reduced CSEs and OCS use, and improved ACT scores in biologic-experienced patients with severe asthma. These findings indicate the importance of a patient-centred approach regarding biologic treatment.