Inclusion Criteria:

          -  Men and women ≥ 18 years of age.

          -  ECOG performance status of 0 to 2.

          -  Diagnosis of CLL.

          -  Must have ≥ 1 of the following high-risk prognostic factors:

               -  Presence of 17p del by central laboratory.

               -  Presence of 11q del by central laboratory.

          -  Active disease meeting ≥ 1 of the following IWCLL 2008 criteria for requiring
             treatment

          -  Must have received ≥ 1 prior therapies for CLL.

          -  Meet the following laboratory parameters:

               -  ANC ≥ 750 cells/μL or ≥ 500 cells/μL in subjects with documented bone marrow
                  involvement, and independent of growth factor support 7 days before assessment.

               -  Platelet count ≥ 30,000 cells/μL without transfusion support 7 days before
                  assessment. Subjects with transfusion-dependent thrombocytopenia are excluded.

               -  Serum AST/SGOT and ALT/SGPT ≤ 3.0 x ULN.

               -  Total bilirubin ≤ 1.5 x ULN.

               -  Estimated creatinine clearance ≥ 30 mL/min.

        Exclusion Criteria:

          -  Known CNS lymphoma or leukemia.

          -  Known prolymphocytic leukemia or history of, or currently suspected, Richter's
             syndrome.

          -  Uncontrolled autoimmune hemolytic anemia or idiopathic thrombocytopenia purpura.

          -  Prior exposure to ibrutinib or to a BCR inhibitor or a BCL-2 inhibitor.

          -  Received any chemotherapy, external beam radiation therapy, anticancer antibodies, or
             investigational drug within 30 days before first dose of study drug.

          -  Prior radio- or toxin-conjugated antibody therapy.

          -  Prior allogeneic stem cell or autologous transplant.

          -  Major surgery within 4 weeks before first dose of study drug.

          -  Prior malignancy, except for adequately treated lentigo maligna melanoma,
             non-melanomatous skin cancer, in situ cervical carcinoma or other malignancy treated
             with no evidence of active disease > 3 years before Screening and at low risk for
             recurrence.

          -  Significant cardiovascular disease within 6 months of screening.

          -  Known history of infection with HIV.

          -  History of stroke or intracranial hemorrhage within 6 months before randomization.

          -  History of bleeding diathesis.

          -  Requires or receiving anticoagulation with warfarin or equivalent vitamin K
             antagonists within 7 days of first dose of study drug.

          -  Requires treatment with a strong CYP3A inhibitor/inducer.