A bispecific antibody and T-cell engager (TCE) targeting both the tumor-associated antigen (TAA) human epidermal growth factor receptor (EGFR) and the T-cell surface antigen CD3, with potential immunostimulating and antineoplastic activities. Upon administration, anti-EGFR/CD3 bispecific antibody SMET12 binds to both CD3 expressed on T-cells and EGFR expressed on tumor cells. This crosslinks cytotoxic T-lymphocytes (CTLs) and EGFR-expressing tumor cells, and activates and redirects CTLs to EGFR-expressing tumor cells. This leads to CTL-mediated killing of EGFR-expressing tumor cells. EGFR, a receptor tyrosine kinase mutated in many tumor cell types, plays a key role in tumor cell proliferation and tumor vascularization.