Trastuzumab moa

Several mechanisms have been proposed: for example, down regulation of HER2-receptor expression, an induction of antibody-dependent cytotoxicity, or a decrease in angiogenesis due to an effect on vascular endothelial growth factor. Efforts are being directed toward identifying those patients with tumors that are sensitive to the drug.In patients with metastatic breast cancer, overexpression of transmembrane human epidermal growth factor–receptor protein 2 (HER2) is seen in 25 to 30 percent of patients. Trastuzumab a recombinant DNA–produced, humanized monoclonal antibody, specifically targets the extracellular domain of the HER2 growth receptor that has intrinsic tyrosine kinase activity.  Trastuzumab binds to HER2 sites in breast cancer tissue and inhibits the proliferation of cells that overexpress the HER2 protein, thereby decreasing the number of cells in the S phase.