Overview To Investigate the Efficacy and Safety of OPC-6535 in Chronic Obstructive Pulmonary Disease (COPD) Patients Status: Completed Trial end date: 2014-04-01 Target enrollment: Participant gender: Summary To investigate the efficacy and safety of OPC-6535 in COPD patients, using the measurement of trough FEV1 over time as the primary endpoint. Phase: Phase 2 Details Lead Sponsor: Otsuka Pharmaceutical Co., Ltd.