) is an antibody-drug conjugate combining the monoclonal antibody trastuzumab with a cytotoxic agent (emtansine) enabling delivery of emtansine directly to HER2-positive cancer cells leading to cell death. It is being investigated in clinical trials for HER2-positive gastric cancer. Pertuzumab (Perjeta) is another monoclonal antibody that targets a different epitope on the HER2 receptor. It is used in combination with trastuzumab and chemotherapy in clinical trials.