TRONARTO: A Randomized, Placebo-Controlled Study of Tiotropium/Olodaterol Delivered via Soft Mist Inhaler in COPD Patients Stratified by Peak Inspiratory Flow

BACKGROUND: Inhaled bronchodilator therapy is currently the mainstay of treatment for patients with chronic obstructive pulmonary disease (COPD). Some inhalers require patients to achieve certain inhalation efforts either to activate the device or to deliver medication to the site of action. For dry powder inhalers, low peak inspiratory flow (PIF) can result in poor medication delivery but the clinical significance of this is not well understood. METHODS: TRONARTO was a 4-week, randomized, double-blind, placebo-controlled, multicenter, parallel-group study which stratified patients with moderate-to-severe COPD according to their PIF against medium-low resistance at screening. Patients were randomized to receive tiotropium/olodaterol (5 μg/5 μg) or matched placebo delivered via the Respimat(®) Soft Mist™ inhaler (SMI). After 4 weeks of treatment, we assessed change from baseline in forced expiratory volume in 1 second (FEV(1)) area under the curve 0–3 hours (FEV(1) AUC(0–3h)) and trough FEV(1). RESULTS: Overall, 213 patients were randomized, of whom 106 received tiotropium/olodaterol (PIF <60 L/min, 55; PIF ≥60 L/min, 51) and 107 received placebo (PIF <60 L/min, 55; PIF ≥60 L/min, 52). For FEV(1) AUC(0–3h), the adjusted mean change from baseline versus placebo was 336 mL (95% confidence interval [CI] 246–425 mL; P<0.0001) in the PIF <60 L/min group and 321 mL (95% CI 233–409 mL; P<0.0001) in the PIF ≥60 L/min group. For trough FEV(1), the adjusted mean change from baseline versus placebo was 201 mL (95% CI 117–286 mL; P<0.0001) in the PIF <60 L/min group and 217 mL (95% CI 135–299 mL; P<0.0001) in the PIF ≥60 L/min group. CONCLUSION: In the TRONARTO study, which included patients with moderate-to-severe COPD and varying inspiratory flow abilities, treatment with tiotropium/olodaterol resulted in significant lung function improvements versus placebo. This SMI can be used irrespective of the PIF that a patient can generate.