Bendamustine and Rituximab (BR) as Induction and Maintenance in Relapsed and Refractory Chronic Lymphocytic Leukemia

Inclusion Criteria: * Confirmed diagnosis of CD20-positive CLL that meets the iwCLL criteria (Hallek et al, 2008). * Relapsed or refractory status of disease after at least one prior chemotherapy regimen. * ECOG performance status of 0-2 at study entry * Patients have not received prior therapy with bendamustine * Prior therapy with rituximab is permitted, even in the setting of rituximab refractory disease. For inclusion in the research part of maintenance therapy (phase B): * At least a partial response (PR or better; Hallek et al, 2008) must be achieved after induction of BR (phase A) Exclusion Criteria: * Any serious medical condition, laboratory abnormality, or psychiatric illness that would prevent the subject from signing the informed consent document or complying with the protocol treatment. * Pregnant or breast-feeding females. * Known to be positive for human immunodeficiency virus (HIV) or infectious hepatitis (type B or C). * Patients are not eligible if there is a prior history or current evidence of central nervous system or leptomeningeal involvement. * Richter syndrome or chronic prolymphocytic leukemia. * Uncontrolled autoimmune hemolytic anemia or thrombocytopenia. * Concurrent use of other anti-cancer agents or treatments. * Laboratory test results within these ranges: ANC ≤ 1000/μL, Platelet count ≤ 75,000/μL. * Total bilirubin Total bilirubin ≥ 2X upper limit laboratory normal (ULN). Patients with non-clinically significant elevations of bilirubin due to Gilbert's disease are not required to meet these criteria. * Serum transaminases AST (SGOT) and ALT (SGPT) ≥ 3 x ULN, and/or serum alkaline phosphatase ≥ 5 X ULN. * New York Heart Association class 3-4 heart failure.