Targeted Therapy
Bystander Effect
Also known as: Bystander killing, Neighboring cell effect
Definition
The ability of an ADC's released payload to kill nearby cancer cells that don't express the target antigen.
Detailed Explanation
After an ADC enters a cancer cell and releases its payload, the cytotoxic drug can sometimes diffuse to adjacent cells. This bystander killing is advantageous in tumors with heterogeneous antigen expression. Membrane-permeable payloads like MMAE show stronger bystander effects than non-permeable ones.