Veltuzumab (humanized anti-CD20 monoclonal antibody): characterization, current clinical results, and future prospects

Veltuzumab is a humanized, anti-CD20 monoclonal IgG(1) antibody (MAb), constructed recombinantly on the framework regions of epratuzumab, with complementarity-determining regions (CDRs) identical to rituximab, except for a single amino acid in CDR3 of the variable heavy chain. Veltuzumab showed anti-proliferative, apoptotic, and antibody-dependent cellular cytotoxicity effects in vitro similar to rituximab, but with significantly slower off-rates and increased complement-dependent cytotoxicity in several human lymphoma cell lines. In addition, very low doses of veltuzumab, given either intravenously or subcutaneously, depleted B cells in normal cynomolgus monkeys, and controlled tumor growth in mice bearing human lymphomas. Clinically, veltuzumab has been studied in > 150 patients with lymphomas and autoimmune diseases. In non-Hodgkin lymphoma (NHL), infusions of 80-750 mg/m