Recombinant monoclonal antibody to Human ErbB2. Trastuzumab (INN; trade names Herclon, trastuzumab) is a monoclonal antibody that interferes with the HER2/neu receptor. Its main use is to treat certain breast cancers.
The HER receptors are proteins that are embedded in the cell membrane and communicate molecular signals from outside the cell (molecules called EGFs) to inside the cell, and turn genes on and off. The HER proteins stimulate cell proliferation. In some cancers, notably certain types of breast cancer, HER2 is over-expressed, and causes cancer cells to reproduce uncontrollably.