Veltuzumab is a humanized second-generation anti-CD20 monoclonal antibody (MAb). It was constructed recombinantly using the some human IgG framework as epratuzumab (anti-CD22 MAb) and provides the advantage of having less acute infusional toxicities compared with rituximab, without demonstrating any apparent impairment of biological activity. Veltuzumab displays similar mechanisms of action as rituximab, including apoptosis, antibody-dependent cellular cytotoxicity (ADCC) and cell-mediated cytotoxicity (CMC). In vivo studies in different lymphoma models have shown promising results and comparative studies have demonstrated improved survival with veltuzumab compared to rituximab. Clinically, veltuzumab is being evaluated in patients with B-cell neoplasms and autoimmune diseases. Four weekly doses of veltuzumab iv. at up to 750 mg/m(2) were well tolerated and objective responses were achieved, including durable complete responses (even at low doses). The only significant toxicity was transient mild to moderate infusion reactions. Clinical results with subcutaneous injections in follicular non-Hodgkin's lymphoma (NHL) are also encouraging (e.g., convenient, well tolerated and clinically active). On the basis of these encouraging findings, veltuzumab is being pursued further. Prospective, randomized clinical trials are needed to delineate the role it will play in the future management of lymphoma.