Eltrombopag in Thrombocytopenic Chronic Lymphocytic Leukemia (CLL) Patients (CLL2S Study of GCLLSG)

Inclusion Criteria: * Confirmed diagnosis of CLL (based immunophenotyping performed at the central reference laboratory of the GCLLSG in Cologne) * Platelet count \<50 000/μl at time of screening (measured and confirmed twice) * Patient is planned to receive alkylating agents and/or fludarabine-based therapy as 2nd or higher-line treatment * ECOG Performance Status of 0-2 * Age \>= 18 years * Signed written informed consent, according to ICH-GCP, and national/local regulation, prior to performing any study-specific procedures * Negative pregnancy test and willingness to use highly effective methods of contraception (per institutional standard) during treatment and for 6 months (male or female) after the end of treatment (adequate: oral contraceptives, intrauterine device or barrier method in conjunction with spermicidal jelly). * Able to understand and comply with protocol requirements and instructions and intend to complete the study as planned. * Adequate renal function (creatinine must not exceed the upper limit of normal (ULN) reference range by more than 50%) at study entry * Adequate liver function: bilirubin £ 1.5 times the upper limit of normal. ALT or AST \<= 3 times the upper limit of normal without liver involvement with CLL and \<= 5 times the upper limit of normal in case of the liver involvement with CLL * Prothrombin time (PT/INR) and activated partial thromboplastin time (aPTT) must be within 80 to 120% of the normal range with no history of hypercoagulable state * Total albumin must not be below the lower limit of normal (LLN) by more than 20%. Exclusion Criteria: * Thrombocytopenia that is primarily caused by ITP * Refractory CLL: defined as treatment failure (failure to achieve a CR or PR) or disease progression within 6 months of last fludarabine and/or bendamustine based therapy. NOTE: Subjects refractory to rituximab monotherapy as last therapy are permitted * No prior therapy for CLL * Active autoimmune hemolytic anemia (AIHA) requiring corticosteroid therapy \>100mg equivalent to hydrocortisone, or chemotherapy * Platelet count \> 50 000/μl at screening * Richter's transformation * CNS involvement of B-CLL * Active infectious disease requiring systemic antibiotics, antifungal, or antiviral treatment * Past or current malignancy other than CLL (with the exception of basal cell carcinoma of the skin or in situ carcinoma of the cervix or breast) unless tumor was successfully treated with curative intent at least 2 years prior to trial entry * Clinically significant cardiac disease including unstable angina, acute myocardial infarction within 6 months, congestive heart failure, etc. * History of significant cerebrovascular disease * Recurring venous thrombosis or pulmonary embolism * Glucocorticoids unless given in doses \<= 100 mg/day hydrocortisone (or equivalent dose of other glucocorticoids) and for exacerbations other than CLL (e.g. asthma) * Known HIV positivity * Active hepatitis B, C * Treatment with an investigational drug within 30 days or five half-lives (whichever is longer) preceding the first dose of eltrombopag. * Subjects known or suspected of not being able to comply with a study protocol * Patients with recent history of arterial or venous thrombosis (stroke, transient ischemic attack, myocardial infarction, deep vein thrombosis or pulmonary embolism) within the preceding 6 months. Patients with recurrent arterial or venous thromboembolic events.