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.

The authors have declared no competing interest.

NCT03996590

HZ's work was partially supported by R21AI175891 related to study design and analyses of DNA methylation data.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethics Committee of the West Midlands Solihull Research (REC reference: 14/WM/1226) gave ethical approval for this work.

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The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.