Efficacy and Safety of Umeclidinium/Vilanterol in Current and Former Smokers with COPD: A Prespecified Analysis of The EMAX Trial

Introduction: Smoking may reduce the efficacy of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD), but its impact on bronchodilator efficacy is unclear. This analysis of the EMAX trial explored efficacy and safety of dual- versus mono-bronchodilator therapy in current or former smokers with COPD. Methods: The 24-week EMAX trial evaluated lung function, symptoms, health status, exacerbations, clinically important deterioration, and safety with umeclidinium/vilanterol, umeclidinium, and salmeterol in symptomatic patients at low exacerbation risk who were not receiving ICS. Current and former smoker subgroups were defined by smoking status at screening. Results: The analysis included 1203 (50%) current smokers and 1221 (50%) former smokers. Both subgroups demonstrated greater improvements from baseline in trough FEV₁ at week 24 (primary endpoint) with umeclidinium/vilanterol versus umeclidinium (least squares [LS] mean difference, mL [95% CI]; current: 84 [50, 117]; former: 49 [18, 80]) and salmeterol (current: 165 [132, 198]; former: 117 [86, 148]) and larger reductions in rescue medication inhalations/day over 24 weeks versus umeclidinium (LS mean difference [95% CI]; current: − 0.42 [− 0.63, − 0.20]; former: − 0.25 − 0.44, − 0.05]) and salmeterol (current: − 0.28 [− 0.49, − 0.06]; former: − 0.29 [− 0.49, − 0.09]). Umeclidinium/vilanterol increased the odds (odds ratio [95% CI]) of clinically significant improvement at week 24 in Transition Dyspnea Index versus umeclidinium (current: 1.54 [1.16, 2.06]; former: 1.32 [0.99, 1.75]) and salmeterol (current: 1.37 (1.03, 1.82]; former: 1.60 [1.20, 2.13]) and Evaluating Respiratory Symptoms–COPD versus umeclidinium (current: 1.54 [1.13, 2.09]; former: 1.50 [1.11, 2.04]) and salmeterol (current: 1.53 [1.13, 2.08]; former: 1.53 [1.12, 2.08]). All treatments were well tolerated in both subgroups. Conclusions: In current and former smokers, umeclidinium/vilanterol provided greater improvements in lung function and symptoms versus umeclidinium and salmeterol, supporting consideration of dual-bronchodilator therapy in symptomatic patients with COPD regardless of their smoking status.