The clinical trial is designed to evaluate the non-inferiority of CHF1535 100/6 µg NEXThaler versus CHF1535 100/6 µg pMDI on the onset of relief from methacholine-induced bronchospasm, in terms of pulmonary function (i.e. change in Forced Expiratory Volume in the 1st second, FEV1, from baseline to 5 min after study drug intake) in asthmatic patients.

Inclusion Criteria:

• Informed consent form obtained
• Minimum required Peak Inspiratory Flow (PIF) to activate NEXThaler
• Pre-bronchodilator FEV1 of at least 65%
• Positive response to methacholine challenge test
• Previous treatment with low-medium doses of Inhaled Corticosteroids (ICS) or ICS/Long-acting beta2-agonist (LABA) as per Global Initiative for Asthma (GINA) 2016 guidelines
• For females: non-pregnant, non-lactacting and using highly effective contraceptive methods.

Exclusion Criteria:

• Clinically relevant and uncontrolled concomitant diseases
• Abnormal clinically relevant ECG
• Presence of aortic aneurism
• Uncontrolled hypertension
• Intake of non-permitted concomitant medications
• Participation in another clinical trials in the previous 8 weeks
• Seasonal variation in asthma
• Recent occurrence of asthma exacerbations
• Hypersensitivity to any product used in the trial, including excipients
• Heavy caffeine drinkers
• History of alcohol/drug abuse
• Smokers