WT1-TCB is a trivalent bispecific antibody containing 2 binding sites for a WT1 peptide presented on HLA-A*02 and a binding site recognizing CD3ε on T cells. The Fc region contains a P329G LALA mutation that increases the half-life but eliminates complement and antibody-dependent cellular cytotoxicity. See Figure 2A in the article by Augsberger et al that begins on page 2655.