Fludarabine/Rituximab Combined With Escalating Doses of Lenalidomide in Untreated CLL

Inclusion Criteria: * Signed written informed consent * Male or female ≥ 18 years of age * CLL (as determined by CD23+, CD5+, CD19+) * Treatment indication as defined by the NCI Workshop criteria (see appendix 6 and reference 10) * ECOG ≤ 2 * No previous treatment of the CLL by chemotherapy, radiotherapy (except localized radiotherapy of 1 lymphatic area) or immunotherapy * Life expectancy \> 6 months (except prognosis due to high risk CLL) Exclusion Criteria: * Active bacterial, viral or fungal infection * Positivity for HIV, Hepatitis B or C * Patients with known history of thromboembolic events * Reduced organ functions and bone marrow dysfunction not due to CLL * Creatinine clearance of below 30 ml/min * Patients with known history of thromboembolic events * Patients with a history of other malignancies within 2 years prior to study entry (except for adequately treated carcinoma in situ of the cervix; basal or squamous cell skin cancer; low grade, early stage localized prostate cancer treated surgically with curative intent; good prognosis DCIS of the breast treated with lumpectomy alone with curative intent) * Patients with medical co-morbid conditions that would require long term use (\> 1 month) of systemic corticosteroids during study treatment * Patients with a history of severe cardiac disease; e.g. NYHA Functional Class III or IV heart failure, myocardial infarction within 6 months, ventricular tachyarrhythmias requiring ongoing treatment, or unstable angina * Other known co-morbidity with the potential to dominate survival * Transformation to aggressive B-cell malignancy (e.g., large B-cell lymphoma, Richter's syndrome, or prolymphocytic leukemia (PLL)) * Hypersensitivity with anaphylactic reaction to humanised monoclonal antibodies or any of the applied drugs * Concurrent chronic systemic immune therapy, chemotherapy, or hormone therapy not indicated in the study protocol * Administration of any investigational agent(s) within 4 weeks prior to entry * Pregnancy or lactation * Medical or psychological condition which in the opinion of the Investigator would not permit the patient to complete the study or sign meaningful informed consent