Breast Cancer: Biologic or HER2-targeted Therapy
Who should get HER2-targeted therapy?
About 20 percent to 25 percent of breast cancers depend on HER2 (human epidermal growth factor receptor 2) to grow. These cancer cells have either too many HER2 receptors or several copies of the gene. The HER2 gene makes a protein, or receptor, that is found on the breast cancer cell and helps the tumor cells grow more quickly. These breast cancers are called HER2 positive (HER2+).
Targeted therapies against HER2 may be used for HER2+ breast cancer. If your breast cancer is not HER2+, you will not benefit from targeted HER2 therapy.
HER2-targeted therapies interact with the HER2 receptor to stop the growth of breast cancer cells that are HER2 positive. HER2-directed therapy may be given with chemotherapy to shrink a breast cancer before surgery or to prevent the cancer from coming back after surgery. HER2-directed therapy also can be used to control a breast cancer that has spread to other parts of the body.
Why do I need HER2-targeted therapy?
HER2-targeted therapy is given to:
- prevent cancer from coming back (recurrence)
- slow the growth of cancer
- control symptoms caused by cancer
How will I receive HER2-Targeted Therapy?
- Intravenously (IV) – directly into the vein
In the palliative setting, HER2 therapy may be given as a pill.
Drugs Used to Target HER2
The following drugs are approved for use in the neoadjuvant, adjuvant or palliative setting:
- Trastuzumab (Herceptin) is an IV therapy used with chemotherapy to prevent a breast cancer from returning after surgery. It also may be used alone or with chemotherapy to control the growth of metastatic breast cancer.
- Pertuzumab (Perjeta) is an IV therapy used with trastuzumab and chemotherapy before surgery to shrink a breast cancer. It also is used with trastuzumab and chemotherapy to slow the growth of breast cancer cells that have spread to other parts of the body or have metastasized.
The following drugs are approved for use only in a palliative setting:
- Lapatinib (Tykerb) is an oral therapy that is used for metastatic breast cancer when trastuzuamb and pertuzumab in combination with chemotherapy no longer control the growth of the breast cancer.
- Ado-trastuzumab emtansine (TDM-1 or Kadcyla) is an IV therapy used to treat metastatic breast cancer when trastuzumab and chemotherapy no longer control the cancer. The drug is a combination of trastuzuamb linked to a chemotherapy that is delivered into the breast cancer cell. This minimizes side effects by limiting exposure of chemotherapy to healthy cells.