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.