Study of ABT-263 When Administered in Combination With Either Fludarabine/Cyclophosphamide/Rituximab or Bendamustine/Rituximab in Relapsed or Refractory Chronic Lymphocytic Leukemia

Inclusion Criteria:

   - Must have relapsed or refractory Chronic Lymphocytic Leukemia (CLL), received no more
   than 5 prior myelosuppressive/chemotherapy regimens and must be a candidate for
   treatment with either Fludarabine/Cyclophosphamide/Rituximab (FCR) or
   Bendamustine/Rituximab (BR);

   - Subject has an Eastern Cooperative Oncology Group (ECOG) performance score of
   - Must have adequate bone marrow independent of growth factor support (with the
   exception of subjects with bone marrow heavily infiltrated with underlying disease
   [80% or more] who may use growth factor support to achieve Absolute Neutrophil Count
   (ANC) eligibility criteria), per local laboratory reference range at Screening as
   follows: ANC >/=1000/mcL, Platelets>/= 100,000/mm3 (entry platelet count must be
   independent of transfusion within 14 days of Screening),Hemoglobin >/= 9.0 g/dL.

Exclusion Criteria:

   - Subject has history or is clinically suspicious for cancer-related Central Nervous
   System disease;

   - Has history of severe allergic or anaphylactic reactions to human, humanized, chimeric
   or murine monoclonal antibodies;

   - Has undergone an allogeneic stem cell transplant; Exhibits evidence of other
   uncontrolled condition(s) including, but not limited to: uncontrolled systemic
   infection, diagnosis of fever and neutropenia within 1 week prior to study drug
   administration;

   - Has underlying, predisposing condition of bleeding or currently exhibits signs of
   bleeding; Has a recent history of non-chemotherapy induced thrombocytopenic associated
   bleeding;

   - Currently receiving or requires anticoagulation therapy;

   - Has active immune thrombocytopenic purpura (ITP) or a history of being refractory to
   platelet transfusions (within 1 year prior to 1st dose of study drug);

   - Has active peptic ulcer disease or other hemorrhagic esophagitis/gastritis.