The aim of this study is to compare the responsiveness of lower airways in adult patients with stable asthma after treatment with ciclesonide and fluticasone propionate. Treatment medication will be administered as follows: ciclesonide will be inhaled once daily at one dose level, fluticasone propionate will be inhaled twice daily at one dose level. The study duration consists of a baseline period (5 weeks) and a treatment period (5 weeks). The study will provide further data on safety and tolerability of ciclesonide.

Main Inclusion Criteria:

• History of bronchial asthma
• FEV1 > 1.20 L
• Positive Skin Prick Test
• Not more than 500 mcg/day fluticasone propionate or equivalent for at least 28 days prior to baseline visit

Main Exclusion Criteria:

• Clinically relevant abnormal laboratory values
• Concomitant severe diseases, diseases expected to interfere with the outcome of the study and diseases which are contra-indications for the use of inhaled steroids
• Chronic obstructive pulmonary disease (COPD) and /or other relevant lung diseases
• One asthma exacerbation within 2 months or more than 3 exacerbations within the last year prior to baseline visit
• Current smokers or ex-smokers with more than 10 pack years, or having smoked within 1 year prior to baseline visit
• Positive response to saline challenge at baseline visits
• Positive bronchial hyperresponsiveness