Phase I Trial of Anti-CD74 (hLL1) Antibody Therapy in B Cell Malignancies

Previous experience with antibody therapy in both NHL and CLL warrants further exploration of new antibody treatments for these diseases. Immunomedics has developed hLL1 (previously designated EPB-1), which is a CDR-grafted, fully humanized monoclonal antibody specifically targeting CD74.38 The human IgG1 backbone for hLL1 is the same as hLL2 (epratuzumab), a monoclonal antibody whose safety has been demonstrated in clinical trials of patients with B-cell malignancies and autoimmune disorders. This is a Phase I, open-label, study conducted in patients with recurrent non-Hodgkin's lymphoma (NHL) or chronic lymphocytic leukemia (CLL) who have progressed after at least one prior standard treatment. All patients will receive hLL1 administered intravenously once daily Monday through Friday of each of 2 consecutive weeks (10 total doses.) Patients will be assigned to a cohort for hLL1 treatment dose assignment (escalating doses of hLL1 per statistical plan) in order to determine the maximum tolerated dose (MTD) for this administration schedule.