CXCL8 and chronic obstructive pulmonary disease: Although the majority of these trials have not sought to assess CXCL8 expression levels in related pharmacodynamic biomarker studies, the results from one recent phase II clinical trial assessing the p38 MAPK inhibitor losmapimod (GW856553X) in COPD, reported no significant effects on serum CXCL8 levels [91].