Inclusion Criteria:  Adult male or female, at least ≥ 65 years old; or 20 to 64 years old and have at least 1 of the following:  Cumulative Illness Rating Scale (CIRS) score > 6. Creatinine clearance (CrCl) estimated < 70 mL/min using Cockcroft-Gault equation. Must have measurable nodal disease (by computed tomography [CT]), defined as at least one lymph node > 1.5 cm in longest diameter. Diagnosed Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL) that requires treatment according to the Modified 2008 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria.  Exclusion Criteria:  Transformation of Chronic Lymphocytic Leukemia (CLL) to aggressive non-Hodgkin lymphoma (NHL; Richter's transformation or pro-lymphocytic leukemia). Previous treatment history for CLL/SLL.