Ethnic sensitivity assessment of fluticasone furoate/vilanterol in East Asian asthma patients from randomized double-blind multicentre Phase IIb/III trials

BACKGROUND Fluticasone furoate (FF)/vilanterol (VI) is a once daily (OD) inhaled corticosteroid/long-acting β2-agonist combination asthma therapy approved in Japan and the EU. FF/VI efficacy and safety data from asthma studies including patients in East Asia were evaluated to assess ethnic sensitivity. METHODS Randomized, double-blind, multicenter Phase IIb/III trials were assessed. Change from baseline relative to placebo or twice-daily fluticasone propionate 500 μg in trough FEV1 was compared between patients from Japan (N = 148) and Not-Japan (N = 3,066; three studies). Adverse events (AEs), laboratory results, and electrocardiograms were compared between patients from Japan + Korea (N = 188) and Not-Japan + Korea (N = 3,840; five studies). RESULTS For trough FEV1, improvements from baseline (least-squares mean difference [95% confidence interval]) were reported for FF/VI 100/25 μg OD versus placebo at Week 12 (Japan: 0.323 L [0.104-0.542]; Not-Japan: 0.168 L [0.095-0.241]). Improvements from baseline (least-squares mean change [standard error]) were reported with FF/VI 200/25 μg OD at Week 24 (Japan: 0.355 L [0.1152]; Not-Japan: 0.396 L [0.0313]). A greater proportion of patients from Japan + Korea versus Not-Japan + Korea reported AEs in all treatment arms including placebo (FF/VI 100/25 μg: 79% versus 57%; FF/VI 200/25 μg: 64% versus 45%; placebo: 41% versus 23%). There were no notable differences in treatment-related or class-related AEs. No clinically significant changes in electrocardiogram assessments or statistically significant differences in 24 h urinary cortisol excretion were observed between the Japan + Korea and Not-Japan + Korea cohorts. CONCLUSIONS Good efficacy and an acceptable safety profile were observed for FF/VI 100/25 μg and 200/25 μg OD in East Asian asthma patients; these globally recommended doses are appropriate for asthma patients in Japan. TRIAL REGISTRATION Clinicaltrials.gov registration numbers: NCT01165138 , NCT01134042 , NCT01086384 , NCT00603278 , NCT00603382 .