ADCs are “smart chemo” drugs that attach a potent cytotoxic payload to a monoclonal antibody via a linker, enabling targeted delivery to antigen expressing tumor cells while limiting damage to normal tissue. They are now a major and rapidly growing modality in oncology, with newer generations using humanized antibodies, optimized linkers, and higher, more controlled drug‑to‑antibody ratios to boost efficacy and reduce off‑target toxicity