Sponsor has decided to not proceed with this study.

This is a Phase 2b, open-label, multicenter, global study assessing the safety and efficacy of ABT-263 in subjects with B-cell CLL who have failed at least one prior fludarabine-containing regimen.

Inclusion Criteria:

• >= 18 yrs of age, have B-cell CLL, failed at least 1 prior fludarabine-containing regimen.

• Refractory to 1 fludarabine-containing regimen is defined as failure to achieve at least PR to the last fludarabine-containing regimen received, or disease progression while receiving the last fludarabine-containing regimen, or disease progression in responders (i.e., achieved a PR or CR) within 6 mos of the last cycle of the last fludarabine-containing regimen received (e.g., fludarabine monotherapy, FR, or FC) or in responders (i.e., achieved a PR or CR ) within 24 mos of the last cycle of FCR.

• Intolerant to fludarabine is defined as discontinuation of therapy within 2 cycles due to side effects/toxicity from the last fludarabine-containing regimen.

• ECOG score of <=1.

• Adequate coagulation, renal, & hepatic function at Screening as follows:

  • Serum creatinine <= 2.0 mg/dL or calculated creatinine clearance >= 50 mL/min;
  • AST & ALT <= 3.0 x ULN;
  • Bilirubin <= 1.5 x ULN.

• Gilbert's Syndrome may have a Bilirubin > 1.5 x ULN; aPTT, PT, not to exceed 1.2 x ULN.

• Adequate bone marrow (BM) independent of any growth factor support (with the exception of subjects with BM heavily infiltrated with underlying disease [80% or more] who may use growth factor support to achieve adequate BM) at Screening as follows:

  • ANC >= 1000/µL;
  • Platelets >= 75,000/mm3 (entry platelet count must be independent of transfusion within 14 days of Screening);
  • Hemoglobin >= 9.0 g/dL.

• History of autologous BM transplant must be > 6 mos post transplant (prior to the 1st dose of study drug) & have adequate BM independent of any growth factor support (with the exception of subjects with BM that is heavily infiltrated with underlying disease [80% or more] who may use growth factor support to achieve adequate BM) at Screening as follows:

  • ANC >= 1500/µL;
  • Platelets >= 125,000/mm3;
  • Hemoglobin >= 10.0 g/dL.

• Female subjects must be surgically sterile, postmenopausal (at least 1 year), or have negative results on a pregnancy test.

• All female subjects not surgically sterile or postmenopausal (at least 1 year) & non-vasectomized male subjects must practice birth control.

Exclusion Criteria:

• History/clinically suspicious for cancer-related CNS disease.

• Undergone allogeneic stem cell transplant.

• Undergone autologous stem cell transplant w/i 6 mos prior to 1st dose.

• History/predisposing condition of bleeding or currently exhibits signs of bleeding.

• Recent history of non-chemotherapy induced thrombocytopenic associated bleeding w/i 6 mos prior to 1st dose.

• Active peptic ulcer disease or other hemorrhagic esophagitis/gastritis.

• Active immune thrombocytopenic purpura or history of being refractory to platelet transfusions w/i 1 yr prior to 1st dose.

• Currently receiving/requires anticoagulation therapy or any drugs or herbal supplements that affect platelet function, with the exception of low-dose anticoagulation medications used to maintain the patency of a central IV catheter.

• Significant history of cardiovascular disease, renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, or hepatic disease.

• Positive for HIV, Hepatitis B, or Hepatitis C.

• Previous or current malignancies w/i the last 3 yrs:

  • except adequately treated in situ carcinoma of the cervix uteri;
  • basal or squamous cell carcinoma;
  • in situ carcinoma of the bladder;
  • or previous malignancy confined and surgically resected with curative intent.

• Has Prolymphocytic leukemia or Richter's transformation to an aggressive B-cell malignancy.

• Exhibits evidence of other clinically significant uncontrolled condition(s) including, but not limited to uncontrolled systemic infection or diagnosis of fever and neutropenia w/i 1 week prior to study drug.

• Prior exposure to ABT-263.

• Received antibody therapy w/i 30 days prior to 1st dose.

• Received any anti-cancer therapy including chemotherapy, immunotherapy, radiotherapy, hormonal, or any investigational therapy w/i 14 days prior to the 1st dose, or has not recovered to \