Mepolizumab as Add-on Treatment IN participants with COPD characterized by frequentExacerbations and Eosinophil Level

INTERVENTION: Mepolizumab 100 mg compared with placebo is given subcutaneously every 4 weeks as a liquid formulation in a pre‐filled safety syringe injection. The study treatment period will be a minimum of 52 weeks up to a maximum of 104 weeks. CONDITION: COPD PRIMARY OUTCOME: To evaluate the efficacy of mepolizumab 100 mg subcutaneous (SC) compared to placebo, given every 4 weeks in liquid formulation by safety syringe (SS) to COPD participants at high risk of exacerbations despite the use of optimized COPD maintenance therapy. SECONDARY OUTCOME: To evaluate mepolizumab 100 mg SC compared to placebo given every 4 weeks in liquid formulation by SS on additional efficacy assessments, health related quality of life (HRQoL), health care utilization, and symptoms INCLUSION CRITERIA: ‐A peripheral blood eosinophil count of >=300 cells/uL from the hematology sample collected at Screening Visit 0; AND A documented historical blood eosinophil count of >=150/uL in the 12 months prior to Screening Visit 0. Participants with no documented historical blood eosinophil count of >=150 cells/uL must meet this threshold based on the Screening Visit 1 assessment in order to return for Randomization Visit 2. ‐Participants with a clinically documented history of COPD for at least 1 year ‐A measured pre‐ and post‐salbutamol FEV1/FVC ratio of <0.70 at Screening Visit 1 ‐A measured post‐salbutamol FEV1>20% and <=80% of predicted normal values calculated using NHANES III reference equations at Screening Visit 1. ‐Participants must have a well‐documented history in the 12 months prior to Screening Visit 1 of: Two or more moderate COPD exacerbations that were treated with systemic corticosteroids OR At least one severe COPD exacerbation req