This is a chimeric IgG1 antibody using the same sequences as the therapeutic antibody zolbetuximab. It mediates specific killing of Claudin-18.2-positive cells through immune effector mechanisms. Zolbetuximab acts by binding to CLDN18.2 on the cancer cell surface of gastric epithelial cells. In pre-clinical studies, this binding interaction then induces cancer cell death by activating two distinct immune system pathways, including antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC).  Zolbetuximab was approved in combination with chemotherapy for patients with hEGFR2-negative, CLDN18.2-positive, unresectable, advanced or recurrent gastric cancer. CLDN18.2 is a type of transmembrane protein found in normal gastric cells and is a major component of epithelial tight junctions controlling the flow of molecules between cells.