PRA-216 COPD Safety and Biomarker Study

Inclusion Criteria: * Age 40-80 * Willing and able to attend all study visits, comply with study requirements. * Able and willing to provide written informed consent * Documented COPD diagnosis prior for at least 12 months prior to screening. * Currently receiving maintenance COPD medications at a stable dose for at least 2 months prior to visit 1 Exclusion Criteria: * Evidence of clinically significant pulmonary condition or disease other than COPD * Any physical or psychological condition that prohibits study completion * Known history of illicit drug use or drug abuse, harmful alcohol use (at the Investigator's discretion), alcoholism within 12 months prior to the first dose of study agent * History of severe allergic reactions or hypersensitivity * Receipt of immunosuppressant therapies for asthma within 3 months of screening * Major surgery occurring within 8 weeks months prior to first dose of investigational product. * Use of any marketed or investigational monoclonal or polyclonal antibody therapy within 4 months or 5 half-lives prior to visit 1.