- Current asthma therapy: Subjects must be using one of the following three stable asthma therapies for at least 3 months prior to screening: a. Currently using a DPI as an inhaled asthma controller therapy; OR b. Currently using an MDI as an inhaled asthma controller therapy (No fluticasone MDI use in the last 3 months); OR c. Currently using no inhaled asthma controller therapy (this includes patients using a leukotriene modifiers (LTM) and/or short-acting beta2-agonists (SABA) as rescue only). All subjects will be allowed the concomitant use of their currently prescribed asthma treatment(s) throughout the study, including rescue albuterol MDI (SABA) as needed.