A bispecific, human monoclonal antibody with potential antineoplastic activity. Anti-CD20/CD3 monoclonal antibody REGN1979 contains two antigen-recognition sites: one for human CD3, a T cell surface antigen, and one for human CD20, a tumor-associated antigen that is exclusively expressed on B-cells during most stages of B-cell development and is often overexpressed in B-cell malignancies. Upon administration, REGN1979 binds to both T-cells and CD20-expressing tumor B-cells, which cross-links the T-cells to tumor cells, and may result in a potent cytotoxic T-lymphocyte (CTL) response against CD20-expressing tumor B-cells.