Control of Asthma Patients Symptomatic on Inhaled Corticosteroids

This multicenter, randomized, double-blind, placebo-controlled, parallel group study will include subjects with persistent moderate to severe asthma who require inhaled corticosteroids and inhaled short-acting β2-agonists (SABAs). Subjects who pass screening at Visit 1 will enter a 2-3 week baseline period to confirm stable asthma symptoms and collect baseline data. Subjects will continue with ongoing prescribed treatment during this period, or as modified by the investigator based on clinical judgment. Subjects will use the SABA prescribed for them to alleviate asthma symptoms on an as needed basis throughout the study. If eligible, at Visit 2 subjects will be randomized to treatment with either IPL512,602 (20 mg) daily or placebo in a 1:1 ratio. Randomization in each treatment group will be stratified into two subgroups: those receiving low to medium doses of inhaled corticosteroids (≤500 µg per day fluticasone or equivalent) and those receiving high doses of inhaled corticosteroids (\>500 µg per day fluticasone or equivalent). During the 8-week treatment period, subjects will return to the clinic after 1, 2, 4, 6, and 8 weeks of treatment (Visits 3-7). Adverse event data will be collected for 14 days following the last dose administration (Visit 8).