Cancer drug aims to mop up remaining leukemia cells after chemo

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Diagnosis of CD20+ chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) treated with chemotherapy or chemoimmunotherapy: Post-frontline therapy, patients must have non-progressing disease and be 4 months to 1 year post treatment. Post-treatment for relapsed CLL, eligible patients must have non-progressing disease and be 3 months to 1 year post treatment. 2. Patients (CR, nPR, or PR at enrollment) must have measurable disease, which may include MRD by 4-color flow cytometry. 3. Adequate renal and hepatic function (creatinine \< 2 mg/dL, bilirubin \< 2 mg/dL). Patients with renal or liver dysfunction due to organ infiltration by lymphocytes may be eligible after discussion with the study chairman. Patients with Gilbert's syndrome are eligible. 4. Age \>/= 18 years. 5. ECOG performance status of 0-2. 6. Provide informed consent indicating patient is aware of the investigational nature of this study according to the policies of the MDACC IRB. 7. Patients of childbearing potential (females who have not been postmenopausal for at least 12 consecutive months or who have not undergone previous surgical sterilization or males who have not been surgically sterilized) must be willing to practice birth control during the study. Exclusion Criteria: 1. Positive serology for Hepatitis B virus (HB) defined as a positive test for HBsAg. In addition, if negative for HBsAg but HBcAb positive (regardless of HBsAb status), a HB DNA test will be performed and if positive the subject will be excluded. 2. Concurrent chemotherapy, radiotherapy, or immunotherapy, including other monoclonal antibodies. Localized radiotherapy to an area not comprising bone marrow function does not apply. 3. Active infection or significant medical illness, including current active hepatic or biliary disease (with exception of patients with asymptomatic gallstones, liver involved with CLL or stable chronic liver disease per investigator assessment). 4. Pregnant and breastfeeding females are excluded.