To demonstrate the additional benefit of roflumilast when added on to fixed-dose combination (FDC) LABA/ICS in the reduction of exacerbations in subjects with severe to very severe COPD.

Inclusion Criteria:

• 1. Male or female patients at least 40 years of age
• 2. History of COPD (according to Global Initiative for Chronic Obstructive Lung Disease [GOLD] 2010) for at least 12 months prior to Screening (Visit 1) associated with chronic productive cough for 3 months in each of 2 consecutive years (with other causes of productive cough excluded). Only patients with chronic bronchitis will be included (concomitant emphysema is permitted)
• 3. Forced expiratory volume after 1 second (FEV1)/forced vital capacity (FVC) ratio (postbronchodilator) < 70% at Screening (Visit 1)
• 4. FEV1 (postbronchodilator) ≤ 50% of predicted at Screening (Visit 1)
• 5. At least two documented moderate or severe COPD exacerbations within 12 months prior to Screening (Visit 1)
• 6. Patients must be on FDC LABA/ICS treatment ≥ 3 months prior to Screening (Visit 1)
• 7. Former smokers (defined as smoking cessation at least 1 year ago) or current smokers (including patients who ceased smoking within the past year) both with a smoking history of at least 20 pack-years

Exclusion Criteria:

• 1. Moderate or severe COPD exacerbation and/or COPD exacerbations treated with antibiotics or systemic glucocorticosteroids within 4 weeks of Screening (Visit 1) (ie, patients must be clinically stable)
• 2. Known alpha-1-antitrypsin deficiency
• 3. Current diagnosis of asthma (either controlled or uncontrolled) (Note: History of childhood asthma is not exclusionary.)
• 4. Body mass index (BMI) ≥ 45 kg/m2
• 5. Patients with a history (within 5 years) or current diagnosis of cancer other than basal or squamous cell skin cancer