The rationale for conducting this study is to explore potential clinical and peripheral biomarkers in subjects requiring daily medium to high dose inhaled corticosteroids for persistent asthma

Inclusion Criteria:

• Age 18 through 75 at the time of screening
• Written informed consent and any locally required authorization obtained from the subject prior to performing any protocol-related procedures, including screening evaluations
• History of physician-diagnosed asthma for at least 12 months prior to screening
• Stable Medium- to high-dose ICS divided twice daily as outlined by the NHLBI Asthma Guidelines, 2007

Exclusion Criteria:

• Any medical condition that, in the opinion of the investigator or medical monitor, would interfere with interpretation of subject safety or study results
• Concurrent enrollment in another clinical study
• Use of immunosuppressive medication within 3 months prior to screening
• Acute upper or lower respiratory infections requiring antibiotics or antiviral medications with in 30 days prior to screening or during screning period.
• Receipt of immunoglobulin or blood products within 30 days prior to screening or during the screening period
• Receipt of any investigational non-biological drug therapy within 30 days or 5 half-lives prior to screening whichever is longer; or receipt of any marketed or investigational biologic within 6 months or 5 half-lives prior to screening whichever is longer
• Pregnant, lactating, or breastfeeding woman
• Diagnosis of lung disease other than persistent asthma
• History of smoking ≥10 pack years or any smoking within 12 months prior to screening
• History of active, infectious hepatitis A, B, C or human immunodeficiency virus (HIV)

Adults with asthma on stable medium- to high-dose inhaled corticosteroids.