 - Disease characteristics: Participants with CLL or SLL are eligible if they have failed 2 or more prior courses of standard chemo andor biologic therapy example, Rituxan and PLL will be eligible if they have failed at least one prior standard chemotherapeutic regimen. Medical indications for treatment include progressive disease-related symptoms, progressive cytopenias due to marrow involvement, progressive or painful splenomegaly or adenopathy, rapidly increasing lymphocytosis, autoimmune hemolytic anemia or thrombocytopenia and increased frequency of infections. 