A Study Comparing the Pharmacokinetic, Pharmacodynamic and Safety of CHF 1535 (Fixed Combination of Beclomethasone + Formoterol) Administered Via the NEXT DPI, Versus the Free Combination of Licenced Beclomethasone DPI and Formoterol DPI in Asthmatic Adolescent and Adult Patients.

Main Inclusion Criteria:

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

Main Exclusion Criteria:

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