The aim of the present study is to investigate the efficacy and safety of ciclesonide on lung function and safety. Ciclesonide will be inhaled at one dose level once daily, using an inhaler device with or without spacer. The study duration consists of a baseline period (1 to 3 weeks) and a treatment period (12 weeks).

Main Inclusion Criteria:

• Written informed consent
• History of persistent bronchial asthma for at least 6 months
• Good health with the exception of asthma

Main Exclusion Criteria:

• Concomitant severe diseases or diseases which are contraindications for the use of inhaled steroids
• Smoking history with ≥10 cigarette pack years
• Pregnancy
• Intention to become pregnant
• Breast feeding
• Lack of safe contraception
• Previous enrolment into the current study