Fig. 5
ADCs follow a defined mechanism of action: Initially, they circulate through the bloodstream to reach tumor tissues (①), where they bind to cell surface antigens. This interaction induces internalization of the ADC-antigen complex via antigen-mediated endocytosis (②), followed by processing within the endo-lysosomal pathway (③), which involves linker cleavage and potential antibody degradation. Once inside the cell, the drug payload is released. Depending on its type (④), such as microtubule-disrupting or DNA-targeting agents, it exerts its effects in distinct cellular compartments. Accumulation of the active drug ultimately triggers cancer cell death. Cytotoxic metabolites released during this process may diffuse to adjacent cells, contributing to bystander killing (⑤). Moreover, the Fc region of the antibody can enhance immune cell activity (⑥), promoting immune-mediated tumor cell destruction.
