Trastuzumab

A healthcare provider may prescribe trastuzumab to treat certain kinds of breast cancer. In particular, the drug is used to treat breast cancer that has a high concentration of HER2 receptors (a protein on the outside of certain cancer cells). The medication is administered intravenously every seven days at your healthcare provider's office, a hospital, or an infusion center. Trastuzumab is not suitable for everyone and not everyone with breast cancer will benefit from the medication. Prior to taking trastuzumab, be sure to tell your healthcare provider if you have congestive heart failure or if you have any allergies.

 

What Is Trastuzumab?

Trastuzumab (Herceptin®) is a prescription medication used to treat breast cancer.
 
(Click What Is Trastuzumab Used For? for more information on what the drug is used for, including possible off-label uses.)
 

Who Makes Trastuzumab?

Trastuzumab is made by Genentech, Inc.
 

How Does Trastuzumab Work?

Trastuzumab is part of a group of medications called monoclonal antibodies. Monoclonal antibodies are used to treat a wide variety of conditions, including breast cancer. Trastuzumab is a special type of monoclonal antibody that is designed to bind to HER2, a protein on the outside of certain cancer cells. When trastuzumab binds to HER2 receptor proteins, it has several effects. It may interfere with the cancer cells' ability to grow and multiply. By binding to the HER2 receptor, trastuzumab may also serve as a signal to the immune system, which can help destroy the cancer cells.
 
Trastuzumab is not a form of chemotherapy. It is a biologic therapy, also known as biological therapy (see Biological Therapy for Breast Cancer). Trastuzumab is less "toxic" than chemotherapy, as it specifically targets the HER2 receptors. Because trastuzumab is only used to treat cancers that have a high concentration of HER2 receptors, it targets the tumors, having less of an effect on healthy, noncancerous cells.
 
Before trastuzumab can be prescribed for a particular patient, certain tests must be performed to make sure that the tumor "overexpresses" HER2. When a cell makes a certain receptor or protein, it is said to "express" that receptor or protein. Tumor cells that overexpress HER2 have a high concentration of the HER2 receptor. Not all breast cancers overexpress HER2, and not all people with breast cancer will benefit from trastuzumab.
 
(Trastuzumab Continued: Page 2)
Add this article to your Favorites     Email this article     Print
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;