BI 671800 ED in Steroid-naive Asthmatic Patients

Inclusion criteria: 1. Signed informed consent consistent with ICH-GCP 2. Three month history of reversible (12% with 200 mL) asthma (according to GINA) with following spirometry at randomization: FEV1 60%-85%. 3. No ICS previous 3 months prior to screening. 4. Diagnosis of asthma prior to 40 years. 5. ACQ at least 1.5 at randomization. 6. Male or female, 18 to 65 years. 7. Non-smokers or ex-smokers ( less than 10 pack year history) with negative cotinine screen. 8. Able to perform PFT Exclusion criteria: 1. Significant diseases other than asthma or allergic rhinitis. 2. Hepatic transaminases or total bilirubin greater than 1.5 ULN. 3. Hospitalizations for asthma or asthma related intubation within 3 months. 4. Uncontrolled asthma. 5. Respiratory tract infection or exacerbation within 4 weeks. 6. FEV1 less than 40%, more than 12 puffs of SABA on more than two consecutive days or asthma exacerbation during the run-in period. 7. Participation in another interventional study. 8. Pregnant or nursing women. 9. Women of child bearing potential nor using appropriate methods of birth control as defined by protocol