Patient-reported outcome measures after 8 weeks of mepolizumab treatment and long-term outcomes in patients with severe asthma: an observational study.

Background The novel anti-IL-5 drug mepolizumab improves asthma outcomes in the majority but not all patients with severe eosinophilic asthma. Currently it is difficult to predict an individuals' chance of being a responder. Early changes in patient-reported outcome measures may contribute to the prediction of long-term outcomes. Aim To compare early changes in patient-reported outcome measures after 8 weeks and long-term response to mepolizumab treatment. Method 22 severe eosinophilic asthma patients starting mepolizumab therapy in a severe asthma centre in the Netherlands were evaluated on baseline, 8 weeks and 52 weeks, collecting questionnaire scores and asthma-related parameters. Well-controlled asthma was defined as an asthma control questionnaire score ≤ 0.75. Long-term treatment response was defined as continuing mepolizumab therapy at 52 weeks. Results Nine patients (41%) had well-controlled asthma at 8 weeks and all were mepolizumab responders at 52 weeks (positive predictive value = 100%, 95%CI 66-100), versus only 5 responders out of 13 patients with not well-controlled asthma at 8 weeks (negative predictive value = 62%, 95%CI 32-86). Conclusion The results in this study suggest that patients receiving mepolizumab therapy with an ACQ-score ≤ 0.75 at 8 weeks are unlikely to need extensive monitoring, for they are very likely to be long-term responders.