Addition of a second bronchodilator from a different pharmacological class may benefit patients with moderate-to-severe chronic obstructive pulmonary disease (COPD) whose symptoms are insufficiently controlled by bronchodilator monotherapy. GLOW6 evaluated the efficacy and safety of once-daily coadministration of the long-acting β2-agonist indacaterol (IND) and the long-acting muscarinic antagonist glycopyrronium (GLY) versus IND alone in patients with moderate-to-severe COPD.