The purpose of this study is to demonstrate that the CHF 1535 (fixed combination of Beclometasone Dipropionate (BDP) 100 µg / Formoterol Fumarate (FF) 6 µg) delivered via the NEXT Dry Powder Inhaler (DPI) does not show a greater exposure to BDP, Beclometasone-17-Monopropionate(B17MP, active metabolite of BDP) and FF in comparison to a free combination of BDP DPI plus FF DPI licensed products after a morning dose administration of BDP and FF (total dose of BDP 400 µg / FF 24 µg) in adolescent and adult asthmatic patients.

Main Inclusion Criteria:

1. Male and female adolescents (≥ 12 years old) and adults (≥18 and ≤ 65 years old)
2. Written informed consent;
3. Diagnosis of asthma as defined in the GINA guidelines;
4. Patients with stable asthma, according to the Investigator's opinion;
5. Asthmatic patients already treated with ICS or using short-acting inhaled β2-agonists as reliever to control asthma symptoms;
6. Patients with a forced expiratory volume in one second (FEV1) > 70% of predicted values;
7. Patients with a peak inspiratory flow (PIF) > 40 L/min
8. Reversibility test;
9. Non- or ex-smokers;
10. A cooperative attitude and ability to be trained about the proper use of DPI and compliant to study procedures;

Main Exclusion Criteria:

1. Pregnant or lactating female;
2. Having received an investigational drug within 2 months before the screening visit
3. Diagnosis of COPD as defined by the current GOLD guidelines;
4. Significant medical history of and/or treatments for cardiac, renal, neurological, hepatic, endocrine diseases, or any laboratory abnormality;
5. Known hypersensitivity to the active treatments;
6. History of drug addiction or excessive use of alcohol;
7. Treatment with a xanthine derivative (e.g. theophylline) formulation in the 4 weeks prior to screening;
8. Hospitalization due to asthma exacerbation or asthma exacerbation within 1 month prior to the screening visit;
9. Inability to perform the required breathing technique and blood sampling;
10. Lower respiratory tract infection within 1 month prior to the screening visit;
11. Blood donation (450 mL or more) or significant blood loss in the 12 weeks before the screening visit.