Dose-range Finding Efficacy and Safety Study for QBW251 in COPD Patients

This study used a 6 treatment arm, parallel-group, randomized, double-blind study design. 974 male and female COPD patients were randomized into the trial. The study consisted of four distinct study periods: * Screening (Weeks -3 to -2): Participants underwent a screening period of 1 week where were assessed for eligibility and tapered off disallowed medications. * Run-in (Days -14 to 1): Subsequently, participants entered the run-in period of up to 2 weeks to establish baseline values for symptom assessments, to standardize the COPD background therapy (triple combination LABA/LAMA/ICS), and to complete eligibility assessments. * Treatment (Day 1 to Week 24): Eligible participants moved into the Day 1 visit where they were stratified according to their smoking status (current or ex-smoker) and severity of airflow limitation (FEV1 ≥ 30% to \< 50% and ≥ 50% to \< 80%) and then randomized into 1 of 6 treatment arms with a randomization ratio of 2:2:1:1:1:2 (450 mg b.i.d., 300 mg b.i.d., 150 mg b.i.d., 75 mg b.i.d., 25 mg b.i.d., placebo). The treatment period consisted of 24 weeks, during which the participant returned to the site for regular visits (Day 1 - Week 24). QBW251 450 mg arm was discontinued early based on a pre-defined pharmacokinetic exposure stopping rule. * Follow-up (Weeks 25-28): Upon completion of the treatment period, participants were followed up for safety assessments for 30 days.