Baseline epigenetics as a biomarker of mepolizumab response in severe asthma.

Biologic treatment options have expanded considerably for severe asthma, transforming patient management, but only ~70% of patients respond to the treatment following standard criteria. This preliminary study utilized data collected in the Wessex AsThma CoHort of difficult asthma (WATCH) study. DNAm was measured in n=15 severe asthma patients at baseline, i.e., before mepolizumab (MEPO), an interleukin-5 receptor antagonist, was administered and the response to MEPO was analyzed. We aimed to assess the potential of DNA methylation as a feasible biomarker to predict responses to MEPO among severe asthma patients. Our preliminary findings suggested that pre-biologic DNA methylation as a predictor of a patient's response status may outperform pre-biologic blood eosinophils cell counts.