A Study of the Safety and Pharmacokinetics of Escalating Doses of DCDT2980S in Patients With Relapsed or Refractory B-Cell Non-Hodgkin's Lymphoma and Chronic Lymphocytic Leukemia And DCDT2980S in Combination With Rituximab in Patients With Relapsed or Refractory B-Cell Non Hodgkin's Lymphoma

Inclusion Criteria: * Life expectancy of at least 12 weeks * History of histologically-documented hematologic malignancy for which no effective standard therapy exists: indolent NHL (including Grades 1-3a FL; MZL \[including splenic, nodal, and extra-nodal\]; and SLL), Grade 3b FL, DLBCL, MCL, or CLL * Must have at least one bi-dimensionally measurable lesion Exclusion Criteria: * Prior use of any monoclonal antibody or antibody-drug conjugate within 4 weeks prior to study treatment * Treatment with radiotherapy, any chemotherapeutic agent, or treatment with any other investigational anti-cancer agent within 2 weeks prior to of study treatment * Completion of autologous stem cell transplant within 100 days prior to study treatment * Prior allogeneic stem cell transplant