A randomised, double-blind, double-dummy, multi-site, phase III, single dose, 4-way cross-over pharmacodynamic study evaluating the efficacy of Bricanyl Turbuhaler M3 compared to Bricanyl Turbuhaler M2 by studying the protective effect on methacholine induced bronchoconstriction in patients with stable, mild to moderate asthma

The study will include female and male patients, between 18 and 65 years old, with stable, mild to moderate asthma who are on short acting β2-agonist (SABA) alone, on low dose inhaled corticosteroid (ICS) (200-400 µg budesonide or corresponding) or on a combination of low dose ICS and long acting β2-agonists (LABA). Approximately 60 patients will be randomised in order to have 49 completed.

The primary objective is to demonstrate therapeutic equivalence between Bricanyl Turbuhaler M3 and Bricanyl Turbuhaler M2 using bronchoprotective effect. Outcome measure: PC20 (Methacholine provocative concentration causing a 20% drop in FEV1). The safety objective is to compare safety of Bricanyl Turbuhaler M2 and Bricanyl Turbuhaler M3. Outcome measure Adverse Events/Serious.

Study period Q1 2015 - Q1 2016.

Inclusion Criteria: - Female and male aged 18 and 65 years.

• At least 6 months of documented clinical diagnosis of asthma as defined by GINA 2012 or American Thoracic Society (Expert Panel Report 3 2007) prior to visit 1
• Stable asthmatics on SABA alone, on low dose ICS (200-400 µg budesonide corresponding) or on fixed combination of low ICS/LABA
• At the enrolment visit 1a, the visit baseline FEV1 must be ≥80 % of that predicted normal (NHANES III). For LABA patients the visit baseline FEV1 must be ≥80 % of that predicted normal (NHANES III) at both visit 1a and visit 1b. If not, the patient will be withdrawn from the study
• At the enrolment visits 1a or 1b (LABA patients only) and at the end of run-in period, visit 2, eligible patients should demonstrate an airway responsiveness to methacholine PC20 <8 mg/mL. If not, the patient will be withdrawn from the study
• Capable of using Turbuhaler inhalation device as judged by investigator. Exclusion Criteria: Diagnosed with COPD or history of cystic fibrosis, bronchiectasis or other respiratory diseases
• Pregnancy, breast-feeding, lactation, or planned pregnancy during the study. Fertile women not using acceptable contraceptive measures
• Conditions which could alter airway reactivity to methacholine (e.g. pneumonia, upper respiratory tract infection, viral bronchitis and/or sinobronchitis) within past six weeks
• Exacerbation due to asthma or change in asthma medication during the last 3 months prior to enrolment
• Night time awakenings due to asthma symptoms on 2 consecutive nights during the last 4 weeks prior to enrolment
• Smokers 6 months prior to the study start or with a history of smoking of more than 10 pack years (e.g. 20 cigarettes/day for at least 10 years, or 10 cigarettes/day for at least 20 years, or equal).