To assess the bronchodilation of three doses of formoterol fumarate (6 μg, 12 μg and 24 μg) twice daily (BID) administered via Pressair® compared to placebo and to open-label nebulized formoterol fumarate (20 μg and 40 μg).

This is a prospective, randomized, double-blind, 5-period incomplete unbalanced crossover, placebo and active comparator (open-label) controlled, multicenter clinical trial to assess the efficacy and safety of three doses of formoterol fumarate (6 μg, 12 μg and 24 μg) BID administered via Pressair® compared to placebo and to open-label formoterol fumarate (20 μg BID and 40 μg single dose) administered as an inhalation solution via a standard jet nebulizer (with a mouthpiece) connected to an air compressor (Perforomist® Inhalation Solution). The drug product is an inhalation powder comprising of micronized aclidinium bromide and micronized formoterol fumarate with α-lactose monohydrate as the carrier, presented in a breathactuated device-metered dry-powder inhaler (DPI). It has been approved under the trademarks of Genuair® and/or Pressair® in some territories.

Inclusion Criteria:

• Adult male or non-pregnant, non-lactating female patients aged ≥40.
• Patients with a diagnosis of COPD (GOLD guidelines, 2016) for a period of at least 6 months prior to Visit 1.
• Patients with moderate to severe stable COPD: post-bronchodilator FEV1 ≥ 30% and <80% of the predicted normal and post-bronchodilator FEV1/FVC < 70% at Visit 1.
• Patients with reversible airway obstruction defined as an increase in FEV1 of at least 12% and 200 mL over the baseline value after four inhalations of albuterol sulfate 108 µg via a pMDI at Visit 1.
• Current or former-smokers, with a smoking history of ≥ 10 pack-years.
• Patients able to perform acceptable and repeatable pulmonary function testing for FEV1 according to the American Thoracic Society (ATS)/European Respiratory Society (ERS) 2005 criteria at Visit 1.
• Patients eligible and able to participate in the study and who had signed an Informed Consent Form prior to initiation of any study-related procedures.

Exclusion Criteria:

• Patients with asthma.
• Any respiratory tract infection (including the upper respiratory tract) or COPD exacerbation (including the mild COPD exacerbation) within 6 weeks prior to Visit 1 or during the run-in period.
• Patients hospitalized for a COPD exacerbation (an emergency room visit for longer than 24 hours is considered a hospitalization) within 3 months prior to Visit 1.
• Clinically significant respiratory conditions other than COPD.
• Patients who in the investigator's opinion may need to start a pulmonary rehabilitation program during the study and/or patients who started/finished it within 3 months prior to Visit 1.
• Use of long-term oxygen therapy (≥ 15 hours/day).
• Patients who do not maintain regular day/night, waking/sleeping cycles including night shift workers.
• Clinically significant cardiovascular conditions.
• Patients with uncontrolled Type I or Type II diabetes, uncontrolled hypo-or hyperthyroidism, hypokalaemia, or hyperadrenergic state, uncontrolled hypertension.
• Patients with history of long QT syndrome or whose QTc (calculated according to Fridericia's Formula QTc=QT/RR1/3) > 470 ms as indicated in the centralized reading report assessed at Visit 1.
• Patients with clinically significant abnormalities in the laboratory tests, ECG parameters (other than QTc) or in the physical examination at Visit 1 that might compromise patient safety.
• Patients with a history of hypersensitivity reaction to an inhaled medication or any component thereof, including paradoxical bronchospasm.
• Patients with known narrow-angle glaucoma, symptomatic bladder neck obstruction, acute urinary retention or symptomatic unstable prostate hypertrophy.
• History of malignancy of any organ system (including lung cancer), treated or untreated, within the past 5 years other than basal or squamous cell skin cancer.
• Patients with any other serious or uncontrolled physical or mental dysfunction.
• Patients with a history (within 2 years prior to screening) of drug and/or alcohol abuse that may prevent study compliance based on the Investigator judgment.
• Patients unlikely to be cooperative or who cannot comply with the study procedures.
• Patients treated with any investigational drug within 30 days (or 6 half-lives, whichever is longer) prior to Visit 1.
• Patients who intended to use any concomitant medication not permitted by this protocol or who had not undergone the required washout period for a particular prohibited medication.
• Patients unable to give consent, or patients of consenting age but under guardianship, or vulnerable patients.
• Any other conditions that, in the investigator's opinion, might render the patient to be unsuitable for the study.
• Involvement in the planning and/or conduct of the study (applies to AstraZeneca staff and/or site staff), or patients employed by or relatives of the employees of the site or sponsor.
• Previous randomization in the present study D6571C00002.