Ado-trastuzumab emtansine, commonly known as Kadcyla, is an antibody-drug conjugate specifically designed for targeted cancer therapy. It combines the HER2-targeted action of trastuzumab (Herceptin) with the cytotoxic activity of a chemotherapy drug called emtansine (DM1). This dual-action approach helps in delivering the chemotherapy directly to the cancer cells, thereby minimizing the impact on healthy cells.