A Study to Assess the Efficacy of Fluticasone Furoate/Vilanterol (FF/VI) Inhalation Powder 100/25 mcg Once Daily Compared With Fluticasone Propionate/Salmeterol Inhalation Powder 250/50 mcg Twice Daily in Subjects With Chronic Obstructive Pulmonary Disease (COPD)

Inclusion Criteria: * A male or female \>=40 years of age at Screening (Visit 1). * Capable of giving written informed consent. * Female subjects must be post-menopausal or using a highly effective method for avoidance of pregnancy. * Subjects with a clinical history of COPD in accordance with the following definition by the American Thoracic Society/European Respiratory Society. * Subject with a measured post-albuterol (salbutamol) FEV1/forced vital capacity(FVC) ratio of \<=0.70 at Screening. * Subjects with a measured post-albuterol (salbutamol) FEV1 \<=70% of predicted normal values. * Subjects with a current or prior history of ≥10 pack-years of cigarette smoking at Screening. Exclusion Criteria: * Current diagnosis of asthma. (Subjects with a prior history of asthma are eligible if they have a current diagnosis of COPD). * Other respiratory disorders (alpha1-antitrypsin deficiency as the underlying cause of COPD, active tuberculosis, lung cancer, bronchiectasis, sarcoidosis, pulmonary fibrosis, pulmonary hypertension, interstitial lung diseases, or other active pulmonary diseases). * Lung volume reduction surgery within the 12 months prior to Screening. * Hospitalized due to poorly controlled COPD within 12 weeks of Screening. * Poorly controlled COPD (occurrence of the following in the 6 weeks prior to Screening -Acute worsening of COPD that is managed by the subject with corticosteroids or antibiotics or that requires treatment prescribed by a physician). * Lower respiratory tract infection that required the use of antibiotics within 6 weeks prior to Screening. * Moderate/severe COPD exacerbation/lower respiratory tract infection during Run-In Period. * Abnormal and clinically significant 12-lead ECG at Screening * Historical or current evidence of uncontrolled or clinically significant disease like cardiovascular, hypertension, neurological, psychiatric, renal, hepatic, immunological, endocrine (including uncontrolled diabetes or thyroid disease), peptic ulcer disease, or haematological abnormalities. Significant is defined as any disease that, in the opinion of the investigator, would put the safety of the subject at risk through participation, or which would affect the efficacy or safety analysis if the disease/condition exacerbated during the study. * History of hypersensitivity to any of the study medications or components of the inhalation powder; or history of severe milk protein allergy. * Known or suspected history of alcohol or drug abuse within the last 2 years. * Subjects who are medically unable to withhold their albuterol (salbutamol) and/or their ipratropium for the 4-hour period required prior to spirometry testing at each study visit. * The subject has taken any other investigational drug within 30 days or 5 half-lives of the investigational product (IP) prior to the first dosing day in the current study. * Use of additional medications prior to Screening (list of medications and time intervals are different for different class of medications and are indicated in the protocol) * Subjects receiving treatment with long-term oxygen therapy (LTOT) or nocturnal oxygen therapy required for greater than 12 hours a day. Oxygen prn use (i.e., \<=12 hours per day) is not exclusionary. * Subjects who have participated in the acute phase of a Pulmonary Rehabilitation Program within 4 weeks prior to Screening * Subjects at risk of non-compliance, or unable to comply with study procedures. * Study investigators, sub-investigators, study coordinators, employees of a participating investigator or immediate family members of the aforementioned are excluded from participating in this study. * Women who are pregnant or lactating or are planning on becoming pregnant during the study. * Previously randomized to either the HZC113109 or HZC112352 clinical studies.