A Closer Look at Herceptin®

Many tumors overproduce proteins necessary for cell growth and division. An example is the overexpression of the HER2 receptor protein, which is found in excessive quantities in some breast and ovarian cancer cases. More information on HER-2/neu. In cancers that do overexpress this receptor, Herceptin® may help to prevent the growth of primary and metastatic tumors.

Herceptin® is a monoclonal antibody specifically engineered to bind to the HER2 protein. It is not known exactly how Herceptin® functions to stop the growth of sensitive tumors, but there is evidence that it may have more than one mechanism of action.⁽¹⁾ It is thought that Herceptin® may prevent tumor growth by inhibiting the binding of extracellular growth signals to receptors on the cell surface. The normal signaling process and activity of Herceptin® are shown in the animation below.

Herceptin® may also be able to induce antibody dependent cellular cytotoxicity (ADCC). Other mechanisms are also possible.^{(2) (3)}