A Study to Evaluate Efficacy and Safety of Tiotropium in Children 6 to 11 Years Old With Moderate Asthma

Inclusion criteria: Patients must meet all of the following inclusion criteria to be eligible for enrollment into this study: 1. All patients' parents (or legally accepted caregivers) must sign and date an informed consent prior to any study procedures including medication washout and restrictions. In addition, an informed assent suitable for this age group has to be obtained from patients. 2. Male or female patients between 6 and 11 years of age (up to 1 day prior to their 12th birthday at Visit 1). 3. All patients must have at least a 6-month history of asthma at the time of enrolment into the trial. 4. All patients must have been on maintenance treatment with inhaled corticosteroids at a stable medium dose - a patient is eligible on =200 µg to =400 µg Budesonide DPI or equivalent. 5. All patients must be symptomatic (partly controlled) at Visit 1 (screening) and prior to randomisation at Visit 2 as defined by an ACQ mean score of =1.5. 6. All patients must have a pre-bronchodilator FEV1 =60% and =90% of predicted normal at Visit 1. Variation of absolute FEV1 values of Visit 2 (pre-dose) as compared to values at Visit 2 (pre-bronchodilator) must be within ± 30%. 7. All patients must demonstrate an increase in FEV1 of =12% 15 to 30 min. after 200 µg salbutamol (albuterol) at Visit 1. 8. Patients must be able to inhale from the Respimat® inhaler correctly. 9. Patients must be able to perform all trial related procedures including technically acceptable spirometric manoeuvres according to current ATS/ERS standards and the use of the electronic diary/peak flow meter. Exclusion criteria: Patients with any of the following characteristics will not be eligible for entry into this study: 1. Patients with a significant disease other than asthma. 2. Patients with clinically relevant abnormal screening haematology or blood chemistry will be excluded if the abnormality defines a significant disease as defined in exclusion criterion 1. For participation in PK sampling, a haemoglobin of less than 11.3 g/dL will be regarded as exclusion criterion. 3. Patients with a history of congenital or acquired heart disease, or patients who have been hospitalised for cardiac syncope or failure during the past year. 4. Patients with any unstable or life-threatening cardiac arrhythmia, including cardiac arrhythmia requiring intervention (e.g. pacemaker implantation, catheter ablation etc.) or a change in drug therapy within the past year. 5. Patients with a malignancy for which the patient has undergone resection, radiation therapy or chemotherapy within the last five years. 6. Patients with clinically significant lung diseases other than asthma, such as CF, or bronchopulmonary dysplasia. 7. Patients with known active tuberculosis. 8. Patients who have undergone thoracotomy with pulmonary resection. Patients with a history of thoracotomy for other reasons should be evaluated as per exclusion criterion No. 1. 9. Patients who are currently in a pulmonary rehabilitation program or have completed a pulmonary rehabilitation program in the 6 weeks prior to the screening visit (Visit 1). 10. Patients with known hypersensitivity to anticholinergic drugs, BAC, EDTA or any other components of the tiotropium inhalation solution. 11. Patients with known narrow-angle glaucoma, or any other disease where anticholinergic treatment is contraindicated. 12. Patients with moderate to severe renal impairment, as defined by a creatinine clearance \<50 mL/min./1.73 m2 BSA, as tiotropium is a predominantly renally excreted drug.