Strategies and Criteria for Target Selection in ADC Drug Development
Tuesday, February 9, 2021
ADC drugs are currently mainly used in the field of tumors. Therefore, antigen targets are required to be highly expressed in tumor cells, but low or not expressed in normal tissues, or only expressed in specific tissue types. When selecting a target, it is necessary to integrate other factors, including the type of cell expressing the antigen, the cycle state of the cell (such as the division or quiescent phase), the expression level of the target, and the accessibility of the target. The target antigen should be present on the cell surface so that circulating mAb can bind to the target cell. At the same time, the antigen target should have a certain endocytosis ability to trigger the transport of the ADC-antigen complex into the cell. However, the number of surface antigens on tumor cells is usually limited, and the internalization process of antigen-antibody complexes is usually inefficient. Therefore, the selection of targets is challenging.