Abstract

Introduction: Limited prospective evidence is available to guide selection of first-line maintenance therapy in patients with COPD. This pre-specified analysis of the EMAX trial explored the efficacy and safety of dual- versus mono-bronchodilator therapy in maintenance-naïve and maintenance-treated patients. Methods: The 24-week EMAX trial evaluated lung function, symptoms (including rescue medication use), exacerbations, and safety with umeclidinium/vilanterol, umeclidinium, and salmeterol in symptomatic patients at low exacerbation risk who were not receiving inhaled corticosteroids. Maintenance-naïve and maintenance-treated subgroups were defined by maintenance bronchodilator use 30 days before screening. Results: The analysis included 749 (31%) maintenance-naïve and 1676 (69%) maintenance-treated patients. For both subgroups, improvements from baseline in trough FEV1 at Week 24 (primary endpoint) were greater with umeclidinium/vilanterol versus umeclidinium (mean difference [95% CI]; maintenance-naïve: 44 mL [1, 87]; maintenance-treated: 77 mL [50, 104]), and salmeterol (maintenance-naïve: 128 mL [85, 171]; maintenance-treated: 145 mL [118, 172]), and in rescue medication inhalations/day over 24 weeks versus umeclidinium (maintenance-naïve: -0.44 [-0.73, -0.16]; maintenance-treated: -0.28 [-0.45, -0.12]) and salmeterol (maintenance-naïve: -0.37 [-0.66, -0.09]; maintenance-treated: -0.25 [-0.41, -0.08]). In maintenance-naïve patients, umeclidinium/vilanterol numerically improved scores at Week 24 for Transition Dyspnea Index versus umeclidinium (0.37 [-0.21, 0.96]) and versus salmeterol (0.47 [-0.10, 1.05]) and Evaluating Respiratory Symptoms-COPD versus umeclidinium (-0.26 [-1.04, 0.53]) and versus salmeterol (-0.58 [-1.36, 0.20]), with similar improvements seen in maintenance-treated patients. All treatments were well tolerated across both subgroups. Conclusion: Similar to maintenance-treated patients, maintenance-naïve patients receiving umeclidinium/vilanterol showed greater improvements in lung function and symptoms compared with patients receiving umeclidinium or salmeterol. These findings provide support for the consideration of dual bronchodilator treatment in symptomatic maintenance-naïve patients with COPD.