Trastuzumab

HER2 amplification defines the tumours treated with trastuzumab, a monoclonal antibody directed at that receptor in breast and gastric cancer. Binding blocks the growth signals the overexpressed receptor transmits and simultaneously marks the cell for destruction by immune effector mechanisms, so the antibody acts through two routes at once. It is given alone or with chemotherapy. Cardiac assessment precedes treatment because the antibody can reduce ventricular function, an effect distinct from the cardiotoxicity of anthracyclines. An elimination half-life near 28 days reflects the slow clearance of immunoglobulin therapeutics and permits dosing intervals measured in weeks. The product belongs to the antineoplastic and immunomodulating group and has completed the final phase of clinical development.