A humanized, bispecific monoclonal antibody (BsAb) against human CD3, a T-cell surface antigen, and the human cell surface glycoprotein CD38, a tumor-associated antigen (TAA), with potential antineoplastic activity. Upon administration, anti-CD38/anti-CD3 bispecific monoclonal antibody GBR 1342 binds to both CD3 on T-cells and CD38 expressed on certain tumor cells. This results in the cross-linking of T-cells and tumor cells, and induces a potent cytotoxic T-lymphocyte (CTL) response against CD38-expressing tumor cells. CD38, a type II transmembrane glycoprotein, is present on various immune cells and hematologic malignancies; its expression has been correlated with poor prognosis. GBR 1342 uses the proprietary bispecific engagement by antibodies based on the T-cell receptor (BEAT) platform.