Applying key learnings from the EMAX trial to clinical practice and future trial design in COPD

Early MAXimisation of bronchodilation for improving COPD stability (EMAX) was a large, multicentre, multi-national, randomised, double-blind, 24-week trial. EMAX evaluated the efficacy and safety of dual bronchodilator therapy with umeclidinium bromide (UMEC)/vilanterol (VI) versus monotherapy with either UMEC or salmeterol (SAL) in symptomatic patients with chronic obstructive pulmonary disease (COPD) at low exacerbation risk who were not taking concomitant inhaled corticosteroid (ICS). EMAX generated evidence covering a wide range of patient-centred endpoints in COPD in addition to measures of lung function, clinical deterioration and safety. In addition, prospective and post hoc secondary analyses have generated clinically valuable information regarding the effects of baseline patient characteristics on treatment outcomes. Importantly, as concomitant ICS use was not permitted in this study, EMAX compared dual long-acting muscarinic antagonist (LAMA)/long-acting β₂-agonist (LABA) therapy with LAMA or LABA monotherapy without potential confounding due to concurrent ICS use or withdrawal. EMAX demonstrated beneficial treatment effects of UMEC/VI over UMEC or SAL monotherapy as maintenance treatment across a range of different patient characteristics, with no forfeit in safety. Thus, the trial provided novel insights into the role of LAMA/LABA versus LABA and LAMA monotherapies as maintenance therapy for patients with symptomatic COPD at low risk of exacerbations. This article will explore the clinical implications of the main findings to date of the EMAX trial and consider the key learnings this trial offers for future trial design in COPD.