|Inclusion Criteria:||1) Men and women >/= 18 years of age|
2) Eastern Cooperative Oncology Group (ECOG) performance status of 0-1
3) Life expectancy of greater than 4 months from the first dose of study medication
4) Diagnosis of CLL/SLL that meets published diagnostic criteria: a) Monoclonal B-cells (either kappa or lambda light chain restricted) that are clonally co-expressing at least one B-cell marker (CD19, CD20, or CD23) and CD5; b) The diagnosis of CLL requires a history of lymphocytosis with a B-lymphocyte count >/=5,000/mul while SLL patients are characterized by the same criteria with a circulating B-lymphocyte count <5,000/mul. Prolymphocytes may comprise no more than 55% of blood lymphocytes
5) Active disease meeting at least 1 of the following IWCLL 2008 criteria for requiring treatment: a) Evidence of progressive marrow failure as manifested by the development of, or worsening of, anemia (Hgb < 11 g/dL) and/or thrombocytopenia (platelets < 100,000/L); b) Massive (ie, at least 6 cm below the left costal margin), progressive, or symptomatic splenomegaly; c) Massive nodes (ie, at least 10 cm in the longest diameter), progressive, or symptomatic lymphadenopathy; d) Progressive lymphocytosis with an increase of more than 50% over a 2-month period or a lymphocyte doubling time (LDT) of less than 6 months. LDT may be obtained by linear regression extrapolation of absolute lymphocyte counts (ALC) obtained at intervals of 2 weeks over an observation period of 2 to 3 months.
6) continued from #5: In patients with initial blood lymphocyte counts of less than 30 X 109/L (30,000/muL), LDT should not be used as a single parameter to define indication for treatment. In addition, factors contributing to lymphocytosis or lymphadenopathy other than CLL (eg, infections) should be excluded; e) Autoimmune anemia and/or thrombocytopenia that is poorly responsive to corticosteroids or other standard therapy; f) Constitutional symptoms, defined as one or more of the following disease-related symptoms or signs i) Unintentional weight loss > 10% within the previous 6 months prior to Screening, ii) Significant fatigue (inability to work or perform usual activities), iii) Fevers higher than 100.5° F or 38 .0° C for 2 or more weeks prior to Screening without evidence of infection, or iv) Night sweats for more than 1 month prior to Screening without evidence of infection
7) Must have received at least one prior therapy for CLL/SLL and not be appropriate for treatment or retreatment with purine analog based therapy, defined by at least one of the following criteria: a) Failure to respond (stable disease [SD] or disease progression on treatment), or a progression-free interval of less than 3 years from treatment with a purine analog based therapy and anti-CD20 containing chemoimmunotherapy regimen after at least two cycles. b) Age >/= 70 years, or age >/= 65 and the presence of co-morbidities (Cumulative Illness Rating Scale [CIRS] >/= 6 or CrCl < 70 mL/min) that might place the patient at an unacceptable risk for treatment-related toxicity with purine analog based therapy, provided they have received >1 prior treatment including at least two cycles of an alkylating-agent based (or purine analog based) anti-CD20 antibody containing chemoimmunotherapy regimen. CIRS score can be determined utilizing a web-based tool.
8) Continued from #6: c) History of purine analog-associated autoimmune anemia or autoimmune thrombocytopenia. d) FISH showing 17p del in >/= 20% of cells (either at diagnosis or any time before study entry) either alone or in combination with other cytogenetic abnormalities, provided they have received at least one prior therapy.
9) Measurable nodal disease by computed tomography (CT). Measurable nodal disease is defined as at least one lymph node > 1.5 cm in the longest diameter in a site that has not been previously irradiated. An irradiated lesion may be assessed for measurable disease only if there has been documented progression in that lesion since radiotherapy has ended.
10) Meet the following laboratory parameters: a) Absolute neutrophil count (ANC) >/= 750 cells/muL (0.75 x 109/L), independent of growth factor support within 7 days of the first dose with study drug b) Platelet count >/= 30,000 cells/muL (30 x 109/L) without transfusion support within 7 days of the first dose with study drug. Patients with transfusion-dependent thrombocytopenia are excluded c) Serum aspartate transaminase (AST) or alanine transaminase (ALT) < 2.5 x upper limit of normal (ULN) d) Total bilirubin </= 1.5 x ULN (unless due to Gilbert's syndrome or disease infiltration of the liver) e) Creatinine </= 2 x ULN and estimated Glomerular Filtration Rate (GFR [Cockcroft-Gault]) >/= 30 mL/min
11) Able to provide written informed consent and can understand and comply with the requirements of the study
12) Able to receive all outpatient treatment, all laboratory monitoring, and all radiological evaluations at the institution that administers study drug for the entire study
13) Female patients of childbearing potential must have a negative serum or urine pregnancy test within 3 days of the first dose of study drug and agree to use dual methods of contraception during the study and for 1 month following the last dose with study drug. Post-menopausal females (>45 years old and without menses for >1 year) and surgically sterilized females are exempt from this criterion.
14) Male patients must use an effective barrier method of contraception during the study and for 3 months following the last dose if sexually active with a female of childbearing potential.