LAUSR

Introduction Long-acting muscarinic antagonist/long-acting β2-agonist (LAMA/LABA) combination therapy is more effective than monotherapies for improving lung function, breathlessness and health status, in patients with moderate-to-severe COPD (Oba et al. Thorax 2016:71;15–25). Current Global initiative for chronic Obstructive Lung Disease (GOLD) strategy highlights that first-line maintenance therapy in symptomatic GOLD B patients is LAMA or LABA monotherapy (GOLD 2018 report). The Early MAXimal bronchodilation for improving COPD stability (EMAX) trial aims to compare the efficacy and safety of UMEC/VI (LAMA/LABA), UMEC (LAMA) and salmeterol (SAL [LABA]) in symptomatic, steroid-free GOLD B patients with COPD (study 201749; NCT03034915) to inform the positioning of dual versus monotherapy within treatment guidelines for GOLD B patients. Methods EMAX is a 24 week, multicentre, double-blind, double-dummy, parallel-group study. Patients (n=2,431) were randomised 1:1:1 to UMEC/VI 62.5/25 mcg, UMEC 62.5 mcg or SAL 50 mcg (figure 1). Patients were required to be aged ≥40 years, current/former smokers (≥10 pack-years), with a forced expiratory volume in 1 s (FEV1)/forced vital capacity ratio <0.70, post-salbutamol FEV1 ≥30% to≤80% predicted, COPD Assessment Test (CAT) score ≥10, and ≤1 moderate and no severe exacerbations in the past year. Randomisation was stratified by maintenance bronchodilator use (none or one permitted) at screening. The primary endpoint is trough FEV1 with UMEC/VI versus UMEC at Week 24. Secondary endpoints include comparisons of UMEC/VI with UMEC and SAL for other spirometry measures and patient-reported outcomes (transition dyspnoea index [TDI], Evaluating Respiratory Symptoms-COPD [E-RS], SGRQ, CAT), rescue medication use and COPD stability assessed using time-to-first (TTF) exacerbation and TTF clinically important deterioration (CID). Safety and tolerability are assessed. The study is powered for comparisons of trough FEV1 and TDI. Conclusions EMAX is the largest study to date investigating the efficacy of LAMA/LABA versus monotherapy in inhaled corticosteroid-naïve symptomatic GOLD B patients, and the first prospective study to explore the impact of these regimens in maintenance-naïve patients (a pre-specified subgroup) and assess COPD stability using the CID. The study has completed; upon completion of data analysis, the results should help clarify when, and in which population, LAMA/LABA should be initiated as first-choice maintenance therapy. Funding GSK (study 201749). Please refer to page A268 for declarations of interest related to this abstract.Abstract P247 Figure 1 *Patients were permitted to continue use of inhaled LAMA or LABA and/or study-provided salbutamol (rescue meditation) as needed during the run-in period. BID, twice a day; DPI, dry powder inhaler; QD, once a day; R, randomisation; V, visit