Definition

A bispecific monoclonal antibody containing one arm targeting human CD3, a T-cell surface antigen that is part of the T-cell receptor (TCR) complex, and two arms targeting the membrane-proximal domain of the tumor-associated antigen (TAA) human mucin 16 (MUC16, cancer antigen 125; CA125; FLJ14303), with potential antineoplastic activity. Upon administration, anti-MUC16/anti-CD3 bispecific antibody LBL-033 binds to both T-cells and MUC16-expressing tumor cells, which cross-links the T cells to the tumor cells, and may result in a potent cytotoxic T-lymphocyte (CTL) response against the MUC16-expressing tumor cells. MUC16, a member of the mucin family of glycoproteins, is overexpressed on a variety of cancer cell types. BY binding in a 2:1 ratio to MUC16 and CD3, LBL-033 improves aggregation in MUC16-overexpressing tumor cells while reducing the non-specific activation of CD3. This may improve efficacy and minimize potential systemic toxicity, such as cytokine release syndrome (CRS).