Clinical trial diversity: An opportunity for improved insight into the determinants of variability in drug response.

Although the number of countries participating in pivotal trials submitted to enable drug registration has nearly doubled over the past 25 years, there has not been a substantial increase in the diversity of clinical trial populations. In parallel, our understanding of factors that influence medicine response and variability has continued to evolve. The notion of intrinsic and extrinsic sources of variability has been embedded into different regulatory guidelines, including the recent guideline on the importance of enhancing the diversity of clinical trial populations. In addition to presenting the clinical and scientific reasons for ensuring that clinical trial populations represent the demographics of patient populations, this overview outlines the efforts of regulatory agencies, patient advocacy groups and clinical researchers to attain this goal through strategies to meet representation in recruitment targets and broaden eligibility criteria. Despite these efforts, challenges to participation in clinical trials remain, and certain groups continue to be underrepresented in development programmes. These challenges are amplified when the representativeness of specific groups may vary across countries and regions in a global clinical programme. Whilst enhanced trial diversity is a critical step towards ensuring that results will be representative of patient populations, a concerted effort is required to characterise further the factors influencing interindividual and regional differences in response for global populations. Quantitative clinical pharmacology principles should be applied to allow extrapolation of data across groups or regions as well as provide insight into the effect of patient-specific characteristics on a medicine's dose rationale and efficacy and safety profiles.

The IMPACT Study - Single Inhaler Triple Therapy (FF/UMEC/VI) Versus FF/VI And UMEC/VI In Patients With COPD: Efficacy And Safety In A Japanese Population.

Purpose: The Informing the Pathway of COPD Treatment (IMPACT) study demonstrated that single-inhaler triple therapy fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) reduces moderate/severe exacerbation rates and improves lung function and health status versus FF/VI or UMEC/VI dual therapy in patients with symptomatic COPD and a history of exacerbations. This analysis evaluated the efficacy and safety of FF/UMEC/VI in patients enrolled in Japan. Patients and methods: IMPACT was a 52-week, randomized, double-blind, multicenter study comparing FF/UMEC/VI 100/62.5/25 µg with FF/VI 100/25 µg or UMEC/VI 62.5/25 µg in patients ≥40 years with symptomatic COPD and ≥1 moderate/severe exacerbation in the previous year. Endpoints included annual rate of on-treatment moderate/severe exacerbations (primary endpoint), time-to-first on-treatment moderate/severe exacerbation and change from baseline at Week 52 in trough FEV1, post-bronchodilator FEV1, St. George's Respiratory Questionnaire, and COPD Assessment Test score. Safety was also assessed. Results: The Japan subgroup accounted for only 4% (378/10,355) of the overall IMPACT intent-to-treat (ITT) population. In the Japan subgroup, FF/UMEC/VI reduced the annual rate of on-treatment moderate/severe exacerbations by 15% (95% CI: -20, 40) versus FF/VI (compared with 15% [10, 20] in the ITT) and 36% (95% CI: 6, 57) versus UMEC/VI (compared with 25% [19, 30] in the ITT). FF/UMEC/VI reduced moderate/severe exacerbation risk (time-to-first), improved lung function and health status at Week 52 versus both dual therapies. These results were in the same direction and of a generally similar magnitude to those seen in the overall ITT population. No new safety signals were identified in the Japan subgroup compared with the ITT population. Pneumonia incidence was higher with FF/UMEC/VI and FF/VI versus UMEC/VI. Conclusion: These results highlight the favorable benefit-risk profile of FF/UMEC/VI single-inhaler triple therapy compared with FF/VI or UMEC/VI dual therapy in patients in Japan with symptomatic COPD and ≥1 exacerbation in the prior year.

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 ß2-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 .