The aim of the study is to compare the effect of ciclesonide on quality of life, pulmonary function and time to first exacerbation in patients with moderate persistent asthma. Ciclesonide will be administered once daily in the evening at two dose levels. The study duration consists of a baseline period (2 weeks) and a treatment period (8 weeks).

Main Inclusion Criteria:

• Written informed consent
• Good health with the exception of asthma
• Clinical diagnosis of moderate persistent asthma during the last 6 months prior to visit B0
• Pre-treatment with inhaled corticosteroids dose equivalent to 250 - 500 mcg BDP / day at stable dosing during the last 4 weeks prior to visit B0, concomitant or not to short-acting beta2-agonists treatment as rescue medication
• FEV1 ≥ 70% and ≤ 90% predicted measured at least 4 h after the last use of rescue medication at visit B0
• Reversibility ≥ 12% and ≥ 200 mL in B0, B0 or T0, after inhalation of 400 mcg of salbutamol
• Patients compliant to recommended pre-treatment

Main Exclusion Criteria:

• Concomitant severe diseases or diseases which are contraindications for the use of inhaled steroids
• Chronic obstructive pulmonary disease (COPD)
• Hospitalization within previous four weeks from baseline
• Hospitalization due to asthma within the last twelve months
• Asthma exacerbation within two months previous to baseline
• History of almost fatal asthma at any moment
• Pregnancy, breast feeding, intention to become pregnant during the course of the study or lack of safe contraception in pre-menopausal women
• Exacerbation of asthma within 2 months prior to entry into the baseline period
• Use of systemic steroids up to 2 months (injectable depot steroids 6 months) before entry into the baseline period, or more than 3 times during the last 6 months