- Current asthma therapy: The patient must be on a stable dose of an inhaled corticosteroid (ICS) of at least 440 mcg/day of fluticasone propionate or equivalent for a minimum of 4 weeks before screening visit, or any inhaled corticosteroid/long-acting beta2-agonist (ICS/LABA) combination for a minimum of 4 weeks before the prescreening visit.