Phase IIa study in COPD patients aimed to evaluate the safety, tolerability ,pharmacodynamics (effect on biological markers of inflammation in induced sputum and in blood, and on pulmonary function) and on pharmacokinetics of CHF 6001 (a PDE4 inhibitor) after 28-days of daily inhaled dosing.

Inclusion Criteria:

1. Written informed consent obtained prior to any study-related procedures.
2. Male or female aged between 40 and 70 years inclusive.
3. Current or past smoker of at least 10 pack/years
4. BMI in the range of 18-35 Kg/m2
5. GOLD Stage 2 and 3 COPD subjects
6. A history of chronic bronchitis defined as chronic cough and sputum production
7. At screening, subjects must be able to produce an adequate induced sputum sample
8. Female subjects: post-menopausal women having at least 12 months of natural (spontaneous) amenorrhea, or women of childbearing potential using two acceptable methods of contraception for the duration of the study and for the following three months

Exclusion criteria:

1. Female subjects: pregnant or lactating women
2. Past or current history of asthma
3. History of clinically significant hypotensive episodes
4. History or symptoms of significant cardiovascular disease
5. History or symptoms of significant neurological disease
6. Unstable concurrent disease
7. An abnormal and clinically significant 12-lead ECG
8. Clinically relevant abnormal laboratory values
9. Use of oral or systemic corticosteroids oral and/or nebulised Beta2 agonists and/or antibiotics within 6 weeks preceding the screening visit
10. Moderate or severe hepatic impairment (Child-Pugh B or C)
11. Intolerance/hypersensitivity or any contraindication to treatment with roflumilast, tiotropium bromide or salbutamol or any of the excipients contained in the formulations used in the study
12. Chronic use of any other medication for treatment of lung disease like xanthines, antileukotrienes, systemic and inhaled corticosteroids, long acting beta2- agonists, roflumilast (other than the study drug) and cromoglycates
13. Long term (at least 12 hours daily) use of oxygen therapy for chronic hypoxemia.
14. Having received an investigational medicinal drug within 30 days prior to study entry
15. Blood draws of 250 mL or more within 45 days prior to enrolment into the study.
16. Known respiratory disorders other than COPD.
17. History of alcohol dependency, or substance abuse
18. Inability to comply with the study Protocol for any other reason.