Comparison of the efficacy of salmeterol/fluticasone propionate combination in Japanese and Caucasian asthmatics

SummaryIntroductionThe effect of ethnicity on the efficacy of salmeterol (S)+fluticasone propionate (FP) has not been examined in Japanese and Caucasian asthmatics. In this study, the efficacy of combination treatment with S and FP from a single inhaler (SFC) was compared with concurrent treatment with S and FP administration from separate inhalers (S+FP) in Japanese and Caucasian asthmatics.MethodsThis was a randomised, double-blind, crossover study in male and female Japanese (n=18) and Caucasian (n=17) asthmatics (50–100% predicted FEV1; >35% reversibility in sGaw). Subjects received SFC (S 50mcg/FP 250mcgb.i.d.) and S+FP (S 50mcgb.i.d.+FP 250mcgb.i.d.) for 14 days. sGaw and FEV1 were determined 0–12h after the first and last doses.ResultsTreatment with both SFC and S+FP produced marked bronchodilation, which was maintained 0–12h after the first dose. Baseline sGaw and FEV1 increased up to 51% and 180mL, respectively, in Japanese subjects over 2 weeks of treatment, with similar improvements in Caucasian subjects. On Day 14 the 0–12h S+FP:SFC treatment ratios (90% CI) for sGaw AUC and peak were 1.05 (0.98, 1.12) and 1.05 (0.97, 1.14), respectively, in Japanese subjects, and 0.99 (0.92, 1.07) and 0.98 (0.89, 1.07), respectively, in Caucasian subjects, with no difference between the two ethnic groups.ConclusionsThe finding of a similar significant bronchodilator response in Japanese and Caucasian asthmatics following concurrent and combination treatment with salmeterol and FP suggests that the therapeutic response to these agents is comparable and independent of ethnicity in Japanese and Caucasian asthma patients