Treatment eligibility of mepolizumab-treated severe asthma patients in clinical practice

Background: Clinical trials investigating mepolizumab for eosinophilic severe asthma patients employed strict eligibility criteria. Nonetheless, patients not meeting these criteria are treated with mepolizumab in clinical practice. Aim: To investigate the extent and reasons for trial ineligibility of real-life, mepolizumab-treated severe asthma patients. To compare characteristics of these patients with trial populations. Methods: Trial criteria and patient characteristics of the SIRIUS, DREAM and MENSA trials were extracted. Baseline characteristics from mepolizumab-treated, oral glucocorticoid-dependent severe asthma patients were studied in RAPSODI (the Dutch severe asthma registry). Results: 7 of 70 mepolizumab-treated patients (10%) from RAPSODI fulfil the trial criteria, whereas 34 (48.6%) and 29 (41.4%) patients are ineligible on the basis of exclusion and inclusion criteria, respectively. Predominant deviations from criteria are summarised in table 1. Significant differences exist in age (56.5 vs 50.1 years), gender (41.4% vs 57.1% females) and FEV1 (2.49 vs 1.82 L) between the real-life and MENSA trial populations. Conclusion: Only a small part of mepolizumab-treated patients in clinical practice fulfils trial criteria and significant differences in patient characteristics exist between trial and real-life severe asthma populations, indicating limited representativeness. The RAPSODI registry was financially supported by GSK and Novartis.