Predictors of response to mepolizumab for severe asthma: a REDES study post hoc analysis.

OBJECTIVE

To identify predictors of treatment response to help target mepolizumab to patients with severe asthma with type 2 inflammation (SA-T2) who are most likely to respond to therapy.

DESIGN AND

SETTING

The REal-worlD Effectiveness and Safety of mepolizumab (REDES), a multicentre, observational cohort study, investigated the effectiveness and safety of mepolizumab in Spanish patients with SA-T2.

PARTICIPANTS

We conducted a post hoc analysis of data from REDES to examine relationships between patient characteristics and response to mepolizumab to identify predictive markers of response. Outcomes included annualised clinically significant exacerbations (primary), lung function (forced expiratory volume in 1 s), maintenance oral corticosteroid (OCS) dose and Asthma Control Test (ACT) score. Outcomes after 12 months' treatment with mepolizumab were assessed and stratified by demographic and clinical characteristics. Analyses were descriptive; changes from baseline were summarised as mean (SD) and prespecified two-tailed unpaired t-tests were applied for comparisons (p<0.05).

PRIMARY AND SECONDARY OUTCOME MEASURES: These were stratified by various demographic and clinical characteristics collected during the study.

RESULTS

In total, 318 patients with SA-T2 were included in the analysis. Mepolizumab was effective in patients with a diverse range of demographic and clinical characteristics. Baseline blood eosinophil count ≥150 or ≥300 cells/µL or fraction of exhaled nitric oxide (FeNO) ≥25 or ≥50 ppb resulted in a 77%-88% reduction in exacerbations compared with 51%-55% in patients with lower baseline levels of these biomarkers (descriptive). Baseline factors of sex, body mass index, smoking status, atopic sensitisation and forced expiratory volume in 1 s had no appreciable effects on exacerbations, maintenance OCS use, lung function or asthma symptoms.

CONCLUSIONS

This post hoc analysis indicates mepolizumab is likely to provide clinical benefit in patients with SA-T2 across a broad range of patient characteristics. Patients with baseline blood eosinophils of ≥150 cells/µL and/or FeNO ≥25 ppb are likely to derive more benefit.

TRIAL REGISTRATION NUMBER: 213172.