Weekly Subcutaneous Alemtuzumab and Rituximab for Relapsed CLL

Inclusion Criteria:

* Subjects must be diagnosed with B-CLL / SLL (B-chronic lymphocytic leukemia / small lymphocytic lymphoma) based on the standard histologic and immunophenotypic criteria described in the WHO classification of lymphoid malignancies, including immunophenotypic confirmation that the tumor cells co-express B cell antigens CD19 / 20 and CD5. Mantle cell lymphoma should be excluded based on positive staining of the tumor cells for CD23, or the absence of staining of the tumor cells for cyclin D1 or the absence of t(11;14).
* The above diagnosis must be confirmed at Brigham \& Women's Hospital or Dana-Farber Cancer Institute.
* Subjects must have relapsed after at least one prior fludarabine-containing regimen and require treatment based on NCI-WG criteria (Appendix A).
* Subjects must have measurable disease (lymphocytosis \> 5,000 / ml, or palpable lymphadenopathy or CT measurable lymphadenopathy \> 1.5 cm, or bone marrow involvement \>30%).
* Men and women of reproductive potential must agree to use an acceptable method of birth control during treatment and for six months after completion of treatment.
* Age \>= 18
* WHO Performance status \<= 2
* Subject has provided written informed consent.
* Expected survival \> 3 months

Exclusion Criteria:

* History of HIV
* Active infection uncontrolled by appropriate antibacterial, antiviral or antifungal therapy
* Known CNS involvement with CLL
* Pregnant (a negative serum pregnancy test should be performed for all women of childbearing potential within 7 days of treatment) or currently lactating women
* Prior anti-neoplastic therapy within the last three weeks
* Patients will NOT be excluded because they have received prior rituximab or alemtuzumab