The purpose of this study is to evaluate the safety and efficacy of inhaled PT005 MDI compared to placebo and Foradil Aerolizer in patients with moderate to severe chronic obstructive pulmonary disease (COPD).

Key Inclusion Criteria:

• Signed written informed consent
• 40 - 80 years of age
• Clinical history of COPD with airflow limitation that is not fully reversible
• Females of non-child bearing potential or females of child bearing potential with negative pregnancy test; and acceptable contraceptive methods
• Current/former smokers with at least a 10 pack-year history of cigarette smoking
• A measured post- bronchodilator FEV1/FVC ratio of < or = 0.70
• A measured post- bronchodilator FEV1 > or = 750ml or 30% predicted and < or = 80% of predicted normal values
• Able to change COPD treatment as required by protocol
• Demonstratead reversibility to short acting beta agonist (Ventolin HFA) (> 12% and >150 mL improvement in baseline FEV1 approximately 30 minutes following administration of 4 puffs of Ventolin HFA or > 200 mL improvement in baseline FEV1 30 minutes following administration of 2 puffs of Ventolin HFA)

Key Exclusion Criteria:

• Women who are pregnant or lactating
• Primary diagnosis of asthma
• Alpha-1 antitrypsin deficiency as the cause of COPD
• Active pulmonary diseases
• Prior lung volume reduction surgery
• Abnormal chest X-ray (or CT scan) not due to the presence of COPD
• Hospitalized due to poorly controlled COPD within 3 months of Screening
• Clinically significant medical conditions that preclude participation in the study (e.g. clinically significant abnormal ECG, uncontrolled hypertension, glaucoma, symptomatic prostatic hypertrophy)
• Cancer that has not been in complete remission for at least 5 years
• Treatment with investigational study drug or participation in another clinical trial or study within the last 30 days or 5 half lives

Other inclusion/exclusion criteria as defined by the protocol