Among patients with severe eosinophilic asthma, mepolizumab (Nucala, GSK) reduced exacerbations regardless of baseline maintenance oral corticosteroid (OCS) use, according to data from the MENSA and MUSCA studies presented at CHEST 2019.
In a post-hoc analysis of the previous SIRIUS trial, which assessed mepolizumab among patients with severe asthma receiving maintenance OCS, researchers found that blood eosinophils are inversely correlated with OCS dose. This suggests that OCS use may impact efficacy of mepolizumab.
To test this, the researchers conducted a post-hoc analysis of the MENSA and MUSCA studies, assessing the clinically significant exacerbations, which was defined as requiring administration of systemic glucocorticoids for 3 or more days or an emergency department visit/hospitalization.
Of the 936 patients included in the analysis, 24% (n=227) used maintenance OCS and 796% (n=709) did not. Median dose was 10 mg daily. Use of maintenance OCS was associated with a greater burden of disease, higher SGRQ total score (52.9 vs. 45.2), higher mean ACQ-5 score (2.44 vs. 2.16) and higher number of exacerbations requiring hospitalization (38% vs. 31%).
All patients treated with mepolizumab 100 mg saw a clinically meaningful reduction in exacerbation rate come with placebo.
Patients who did not use maintenance OCS had a numerically higher reduction in exacerbation rates, however the association was not clinically significant (rate ratio using OCS = 0.66; 95% CI, 0.47-0.93; RR not using OCS = 0.37; 95% CI, 0.28-0.48).
“This abstract provides health care professionals with clinically relevant information on the impact of maintenance OCS use on the efficacy of mepolizumab in severe eosinophilic asthma patients,” the authors wrote.