LATE-BREAKING ABSTRACT: Blood eosinophils (EOS) are a biomarker of COPD exacerbation reduction with inhaled corticosteroids (ICS): An across-trials model-based approach

Retrospective analyses of COPD trials have demonstrated that blood EOS level at baseline (BL) may predict response to ICS; however, comparisons between published data have limitations due to different study designs/analyses. We examined exacerbation risk according to BL blood EOS absolute count (cells/µL; continuous scale) in studies with similar designs that compared long-acting β2-agonists (LABA) with ICS/LABA. NCT01009463/NCT01017952: vilanterol (VI) vs fluticasone furoate [FF]/VI; NCT00929851: formoterol [FOR] vs beclomethasone dipropionate (BDP)/FOR. Studies covered a 48–52wk period . Moderate/severe exacerbation rate was the primary outcome; patients had COPD and a history of exacerbations in the past year. In NCT00929851, exploratory predictive modelling showed that with increasing BL blood EOS count there was an association with increased exacerbation risk in the absence of ICS; stable rates were seen with ICS/LABA. Using similar methodology, a similar trend was seen in a post-hoc analysis of NCT01009463/NCT01017952. These data from comparable trials strengthen the evidence for blood EOS being a useful biomarker of ICS responsiveness. Sponsors: GSK (NCT01009463/NCT01017952)/Chiesi Farmaceutici S.p.A (NCT00929851).