Alemtuzumab + Rituximab Consolidation in CLL

Inclusion Criteria:

* Patients with CLL, CLL/prolymphocytic leukemia (PLL), or Small Lymphocytic Lymphoma (SLL) who have achieved an National Cancer Institute-Working Group (NCI-WG) nodular partial (nPR) or complete response (CR) with documentation of residual disease by MRD flow cytometry following chemotherapy or chemoimmunotherapy.
* Patients with CLL, CLL/PLL, or SLL who have achieved an NCI-WG partial response (PR) following prior chemotherapy or chemoimmunotherapy.
* Age \>/=18 years.
* ECOG performance status \</=2.
* Serum creatinine \</= 2 mg/dL; serum total bilirubin \</= 2 mg/dL; serum AST or ALT \<4 x ULN.
* Signed informed consent.
* Male and female patients who are fertile agree to use an effective barrier method of birth control (ie, latex condom, diaphragm, cervical cap, etc.) to avoid pregnancy. Female patients of childbearing potential (non-childbearing is defined as \>/= 1 year post-menopausal or surgically sterilized) need a negative serum or urine pregnancy test within 14 days of study enrollment.

Exclusion Criteria:

* Past history of anaphylaxis following exposure to rat or mouse derived complementarity determining region (CDR)-grafted humanized monoclonal antibodies.
* Hormonal therapy within 2 weeks prior to study start. Hormonal replacement therapy is permitted.
* Active Hepatitis B (at least one of the following markers positive: HBsAg, HBeAg, IgM anti-HBc, HBV DNA).
* Previous treatment with alemtuzumab plus rituximab in combination.
* Pregnant or nursing women.
* History of HIV infection.
* Active uncontrolled infection (defined as exhibiting ongoing signs/symptoms related to the infection and without improvement, despite appropriate antibiotics or other treatment).
* Less than 6 months from the completion of prior chemotherapy or chemoimmunotherapy. Completion of prior chemoimmunotherapy is defined as the last day of therapy of the respective treatment regimen.
* Symptomatic CNS disease.