BACKGROUND: The comparative efficacy of inhaled corticosteroid/long-acting muscarinic antagonist/long-acting β-agonist (ICS/LAMA/LABA) triple therapy administered via single or multiple inhalers in patients with chronic obstructive pulmonary disease (COPD) has not been evaluated comprehensively. We conducted two replicate trials comparing single- with multiple-inhaler ICS/LAMA/LABA combination in COPD. METHODS: 207608 and 207609 were Phase IV, 12-week, randomized, double-blind, triple-dummy non-inferiority trials comparing once-daily fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) 100/62.5/25 μg via Ellipta inhaler, with twice-daily budesonide/formoterol (BUD/FOR) 400/12 μg via metered-dose inhaler plus once-daily tiotropium (TIO) 18 μg via HandiHaler. Patients had symptomatic COPD and forced expiratory volume in 1 s (FEV) < 50% predicted, or FEV < 80% predicted and ≥ 2 moderate or 1 severe exacerbations in the prior year. The primary endpoint in both trials was weighted mean change from baseline (wmCFB) in 0-24-h FEV at Week 12. Secondary endpoints included CFB in trough FEV at Day 84 and 85. Other endpoints included serial FEV and health status outcomes at Week 12. Safety was evaluated descriptively. RESULTS: The modified per-protocol population included 720 and 711 patients in studies 207608 and 207609 (intent-to-treat population: 728 and 732). FF/UMEC/VI was non-inferior to BUD/FOR+TIO for wmCFB in 0-24-h FEV at Week 12 (Study 207608 treatment difference [95% confidence interval]: 15 mL [- 13, 43]; Study 207609: 11 mL [- 20, 41]). FF/UMEC/VI improved trough FEV CFB versus BUD/FOR+TIO at Day 84 and 85 (Day 85 treatment difference: Study 207608: 38 mL [10, 66]; Study 207609: 51 mL [21, 82]) and FEV at 12 and 24 h post-morning dose at Week 12 in both studies. No treatment differences were seen in health status outcomes. Safety profiles were similar between treatments; pneumonia occurred in 7 (< 1%) patients with FF/UMEC/VI and 9 (1%) patients with BUD/FOR+TIO, across both studies. CONCLUSIONS: FF/UMEC/VI was non-inferior to BUD/FOR+TIO for wmCFB in 0-24-h FEV at Week 12 in patients with COPD. Greater improvements in trough and serial FEV measurements at Week 12 with FF/UMEC/VI versus BUD/FOR+TIO, together with similar health status improvements and safety outcomes including the incidence of pneumonia, suggest that once-daily single-inhaler FF/UMEC/VI triple therapy is a viable option for patients looking to simplify their treatment regimen. TRIAL REGISTRATION: GSK (207608/207609; NCT03478683/NCT03478696).