A Study of Venetoclax and Rituximab/Hyaluronidase Human in Relapsed/Refractory CLL

Inclusion Criteria: * Signed Informed Consent Form * Ability and willingness to comply with the requirements of the study protocol * Patient must have diagnosis of CLL that meets published 2008 IWCLL NCI-WG criteria. * Patient must have relapsed/refractory disease with an indication for treatment. * Patient must have an Eastern Cooperative Oncology Group (ECOG) performance score of ≤ 2 * Adequate hematologic function (unless caused by underlying disease, as established by extensive bone marrow involvement or as a result of hypersplenism secondary to the involvement of the spleen by lymphoma per the investigator) defined as follows: * Hemoglobin (\> / =) 9 g/dL * Absolute neutrophil count (\> / =) 1.0 x 109/L * Platelet count (\> / =)75 x 109/L * Adequate renal function, as indicated by: * Calculated creatinine clearance ≥ 30 mL/min using 24-hour Creatinine Clearance or modified Cockcroft-Gault equation (eCCR; with the use of ideal body mass \[IBM\] instead of mass) * Adequate liver function, as indicated by: * AST or ALT (\< / =) 2.5 x ULN * Total bilirubin \< 1.5 x ULN (or (\< / =) 3 x ULN for patients with documented Gilbert syndrome) * Female patients who are not of child-bearing potential and female patients of child-bearing potential who have a negative serum pregnancy test within 3 days prior to Cycle 1, Day 1. * Patients with HIV infection could be included in the study, as long as their disease is under control on anti-retroviral therapy. Precautions s…