The primary objective of the study is to evaluate the anti-inflammatory action and safety of Ro 27-2441 (study drug) in asthmatic patients currently taking inhaled corticosteroids. The research is being conducted at up to 40 clinical research sites in the US. Study participants will have a number of visits to a research site over a 4-month period.

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