A Phase 1b Study Evaluating the Safety and Tolerability of ABT-199 in Combination With Rituximab in Subjects With Relapsed Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

Inclusion Criteria:

* Subject must be greater then or equal to 18 years of age.
* Subject must have relapsed Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma.
* Subject has an Eastern Cooperative Oncology Group performance score of less than or equal to 1.
* Subject must have adequate bone marrow independent of growth factor support per local laboratory reference range at Screening.
* Subject must have adequate coagulation, renal, and hepatic function, per laboratory reference range at Screening.

Exclusion Criteria:

* Chronic lymphocytic leukemia or Small Lymphocytic Lymphoma subject has undergone an allogeneic or autologous stem cell transplant.
* Subject has uncontrolled autoimmune hemolytic anemia or thrombocytopenia.
* Subject has tested positive for human immunodeficiency virus.
* Seropositivity for hepatitis B surface antigen or hepatitis C virus antibody or ribonucleic acid.
* History of severe allergic or anaphylactic reactions to rituximab.
* Subject has received a live viral vaccine within 6 months prior to the first dose of study drug.
* Subject has received a monoclonal antibody for anti-neoplastic intent within 8 weeks prior to the first dose of study drug.
* Subject has received any of the following within 14 days prior to the first dose of study drug, or has not recovered to less than grade 2 clinically significant adverse effect(s)/toxicity(s) of the previous therapy:

  * Any anti-cancer therapy including chemotherapy, immunotherapy, or radiotherapy;
  * Investigational therapy, including targeted small molecule agents.
* Subject has a cardiovascular disability status of New York Heart Association Class greater then or equal to 2. Class 2 is defined as cardiac disease in which subjects are comfortable at rest but ordinary physical activity results in fatigue, palpitations, dyspnea or anginal pain.
* Subject has a significant history of renal, neurologic, psychiatric, pulmonary, endocrinologic, metabolic, immunologic, cardiovascular, or hepatic disease that in the opinion of the investigator would adversely affect his/her participating in this study.
* Subject has a history of other active malignancies other than CLL/SLL within the past 2 years prior to study entry, with the exception of:

  * Adequately treated in situ carcinoma of the cervix uteri;
  * Basal cell carcinoma of the skin or localized squamous cell carcinoma of the skin;
  * Previous malignancy confined and surgically resected (or treated with other modalities) with curative intent.
* Subject has malabsorption syndrome or other condition that precludes enteral route of administration.
* Subject exhibits evidence of other clinically significant ongoing or recent condition(s) including, but not limited to:

  * Ongoing systemic infection (viral, bacterial, or fungal);
  * Diagnosis of fever and neutropenia within 1 week prior to study drug administration