Patient Population Patients eligible for this study will have a diagnosis of moderate asthma defined by the American Thoracic Society criteria for > 1 year. These patients should be taking inhaled steroids at doses equivalent to </= 400µg and </= 2000µg per day beclomethasone diproprionate but not oral steroid medication. Patients taking additional oral steroids are required to stop oral medication at least one month prior to pre-screening.