Effects of low- versus high-dose fluticasone propionate/formoterol fumarate combination therapy on AMP challenge in asthmatic patients:A double-blind, randomised clinical trial

Background: The dose-response relationship between two dose levels of fluticasone/formoterol (flutiform (R), 100/10 mu g and 500/20 mu g) was evaluated in asthmatic patients. Non-invasive inflammatory markers were used including adenosine monophosphate (AMP) challenge (primary endpoint), and sputum eosinophils and fractional exhaled nitric oxide (FeNO) (secondary endpoints).Methods: Patients aged >= 18 years with forced expiratory volume in 1 s (FEV1) >= 60% predicted and who required a dose ofResults: Sixty-two patients were randomised and 46 completed the study. Fifteen patients received both high- and low-dose fluticasone/formoterol (post hoc subgroup). The difference in AMP PD20 for the overall population was not statistically significant between high- and low-dose fluticasone/formoterol (LS mean fold difference: 1.3; p = 0.489), although both dose levels were superior to placebo: high-dose vs placebo LS mean fold difference: 4.4, p <0.001; low-dose vs placebo LS mean fold difference: 3.5, p <0.001. In the post hoc subgroup, the difference in AMP PD20 between the doses was statistically significant in favour of the high-dose (LS mean fold difference: 2.4, p = 0.012). Other inflammatory parameters (sputum eosinophil counts and FeNO) showed small differences and statistically nonsignificant changes between high- and low-dose fluticasone/formoterol.Conclusions: A significant dose-response was found between low- and high-dose fluticasone/formoterol in the post hoc subgroup (patients who received both doses), but not in the overall population, with the higher dose demonstrating a greater reduction in airway responsiveness to AMP. (C) 2016 Elsevier Ltd. All rights reserved.