Trial to Assess the Anti-inflammatory Effects of Roflumilast in Chronic Obstructive Pulmonary Disease

This was a multicenter, double-blind, randomized, parallel group, phase 3 study. Patients included had a history of COPD (GOLD stage II-III, in Germany stage II only) with chronic productive cough. There were 2 parallel treatment arms (placebo and roflumilast 500 μg once daily). A 1 to 1 randomization scheme was used, that is, patients were allocated to roflumilast 500 μg or placebo in equal proportions. Randomization was stratified by concomitant LABA use. The total duration of this study was 24 weeks maximum per patient. The study consisted of the following periods: * Single-blind placebo run-in period (6 weeks) with visits at Week -6 (visit 0 \[V0\]), Week -2 (V1), and Week 0 (V2, randomization visit), during which all patients received placebo. * Double-blind treatment period (16 weeks) during which patients received either roflumilast or matching placebo with visits at Week 6 (V4), Week 14 (V5), and Week 16 (V6). An additional visit (V3) within 2 weeks after bronchoscopy/bronchial biopsy was performed purely as a safety visit. The exact timing of this safety visit was to be determined by the investigator. Safety follow-up. All AEs were followed up to 30 days after the double-blind treatment period. An additional safety visit, V7, was scheduled within 2 weeks after the second bronchoscopy. The exact timing of the safety visit was to be determined by the investigator. Patients were required not to take any food or drink overnight for at least 8 hours prior to returning to the study center for each visit. Patients were also asked to avoid strenuous exercise for 8 hours prior to each study visit and to avoid smoking for 4 hours prior to each study visit. For visits where patients did not undergo blood collections or biopsies, the fasting requirement was only mandated if clinically indicated, per investigator judgment.