Safety and Efficacy of NVA237 as an add-on to Fixed Dose Combination LABA/ICS

Inclusion Criteria: * Current or ex-smokers who have a smoking history of at least 10 pack years (e.g., 10 pack years = 1 pack/day × 10 years, ½ pack/day × 20 years, etc.). * COPD (Chronic Obstructive Pulmonary Disease) patients with moderate to severe airflow limitation (Spirometry classification: GOLD 2 or 3) at Visit 2: * Post-bronchodilator FEV1 (Forced Expiratory Volume in one second) ≥30% and \<60% of the predicted normal, and, * Post-bronchodilator FEV1/forced vital capacity (FVC) \<0.70 * Patients on maintenance treatment with fixed-dose combination of inhaled salmeterol and fluticasone propionate (50/500 µg) b.i.d. delivered via a proprietary MDDPI (multidose dry powder inhaler) device for at least 30 days prior to screening visit (Visit 1). * Patients in category Gold B or D with a CAT (COPD Assessment Test) total score ≥10 at screening (Visit 1) and before randomization (Visit 3). * Patients with a history of at least 1 moderate or severe COPD exacerbation within the previous year. Exclusion Criteria: * Pregnant or nursing (lactating) women * Women of child-bearing potential, unless they are using effective methods of contraception during the study * Patients with a history of long QT syndrome or whose QTc measured at run-in (Visit 2) (Fridericia method) is prolonged (\>450 ms). (These patients cannot be re-screened.) * Patients with evidence (upon visual inspection) of oropharyngeal candidiasis at baseline with or without treatment. * Patients who have not achieved an acceptable spirometry result at run-in (Visit 2) in accordance with American Thoracic Society (ATS)/European Respiratory Society (ERS) criteria for acceptability and repeatability. * Patients who have had a COPD exacerbation that required treatment with antibiotics or oral corticosteroids or hospitalization in the 6 weeks prior to screening (Visit 1). * Patients who have had a respiratory tract infection within 4 weeks prior to screening (Visit 1). * Patients requiring long term oxygen therapy prescribed for \>12 hours per day. * Patients with allergic rhinitis who use an H1 antagonist or intra-nasal corticosteroids intermittently. (Treatment with a stable dose or regimen is permitted.) * Patients with concomitant pulmonary disease (e.g., lung fibrosis, sarcoidosis, interstitial lung disease, or pulmonary hypertension), clinically significant bronchiectasis, or history of pulmonary lobectomy, lung volume reduction surgery, or lung transplantation. * Patients with active pulmonary tuberculosis, unless confirmed by imaging to be no longer active. Other protocol-defined inclusion/exclusion criteria may apply.