The purpose of the study is to evaluate an investigational medication to treat chronic asthma. The research is being conducted at 20 clinical research sites in the US and is open to both men and women ages 18 to 70 years. Participants in the study will have a number of visits to a research site over an 8-month period. All study-related care and medication is provided to qualified participants at no cost. This includes all visits, examinations and laboratory work.

Inclusion Criteria:

• At least a 6-month history of asthma
• No use of inhaled, oral or injectable steroids for at least 1 month prior to enrollment

Exclusion Criteria:

• Patients with > 10 pack years of smoking history or smoking within 12 months of study enrollment
• No significant disease other than asthma