- Reversibility of disease: Demonstrated presence of reversible airway disease at screening (repeat testing of eligibility can be undertaken following the screening visit up to Day -7) OR The presence of reversible airways disease can have been demonstrated historically within 6 months of the screening visit. Reversible airway disease is defined as increase in FEV1 of >=12% over baseline and an absolute change of >=200 mL within 30 minutes following 4 inhalations of albuterol/salbutamol inhalation aerosol/spacer (or equivalent nebulised treatment with albuterol/salbutamol solution).