Inhaled Corticosteroid Replacement Study - Efficacy and Safety of Ro 27-2441 (Test Drug) in Moderate Persistent Asthma

Inclusion Criteria: Persistent asthma for more than 1 year Currently receiving treatment with a stable dose of inhaled corticosteroids for more than 3 months In good health as demonstrated by medical history and physical exam Negative urine pregnancy test Commitment to use two forms of effective contraception simultaneously throughout the study duration and for 1 month after discontinuing therapy Exclusion Criteria: Hospitalization for treatment of asthma and/or treatment with oral/injectable corticosteroids within 3 months before the start of the study Undergoing allergy shots unless on a stable maintenance dose for 3 months before the start of the study History of chronic pulmonary diseases other than asthma Treatment of conditions other than asthma with oral corticosteroids within 1 month of the start of the study Current tobacco usage Smoking history of greater than 10 pack-year history of cigarette smoking (number of packs smoked per day times the number of years smoked) History or evidence of drug or alcohol abuse Diagnosis or evidence of an infectious illness within one month of Visit 1 Clinically significant diseases as assessed by the study doctor Participation in another clinical study with an experimental drug within one month of start of the study