KRONOS, a Phase III, multicenter, randomized, double-blind study (NCT02497001) conducted in Canada, China, Japan, and the USA, assessed the efficacy and safety of budesonide/glycopyrrolate/formoterol fumarate metered dose inhaler (BGF MDI), a triple fixed-dose combination therapy, relative to dual therapies in patients with moderate-to-very severe COPD. Here we present findings from the Japanese subgroup of KRONOS.Patients received BGF MDI 320/18/9.6μg, glycopyrrolate/formoterol fumarate (GFF) MDI 18/9.6μg, budesonide/formoterol fumarate (BFF) MDI 320/9.6μg, or budesonide/formoterol fumarate dry powder inhaler (BUD/FORM DPI) 400/12μg twice-daily for 24 weeks. The primary endpoint was the change from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV1) over Weeks 12-24. Symptoms, quality of life, exacerbations, and safety were also assessed.In total, 416 Japanese patients (21.9% of the global KRONOS population) were randomized and treated with BGF MDI (n=139), GFF MDI (n=138), BFF MDI (n=70), or BUD/FORM DPI (n=69). Nominally significant improvements in the change from baseline in morning pre-dose trough FEV1 over Weeks 12-24 were observed for BGF MDI vs GFF MDI (least squares mean [LSM] difference 37 mL, 95% confidence interval [CI] 3, 72; P=0.0337) and BFF MDI (67 mL; 95% CI 25, 109; P=0.0020). Treatment with BGF MDI led to a nominally significant reduction in the rate of moderate/severe exacerbations vs GFF MDI (rate ratio 0.40, 95% CI 0.19, 0.83; P=0.0142). Compared with dual therapies, numerical improvements were observed with BGF MDI for Transition Dyspnea Index focal score and the change from baseline in Evaluating Respiratory Symptoms in COPD total score (P≤0.3899). All treatments were generally well tolerated.BGF MDI nominally significantly improved lung function and numerically improved symptoms vs GFF MDI and BFF MDI. BGF MDI nominally significantly reduced exacerbations vs GFF MDI in Japanese patients with COPD. Efficacy and safety findings were generally comparable to those in the global KRONOS population.