Targeted therapies are designed to slow or stop cancer growth by targeting specific molecules that help cancer cells grow or spread. They have a different mechanism of action than chemotherapy. Targeted therapies are designed to attack only cancer cells. In contrast, chemotherapy drugs attack all rapidly dividing cells.
The following targeted therapies are approved for treating early-stage and/or metastatic breast cancer. New targeted therapies are being developed and studied in clinical trials. You can learn more about these clinical trials on clinicaltrials.gov and BreastCancerTrials.org.
For ER-Positive, HER2-Negative Metastatic Tumors
There are two targeted therapies currently approved for treating metastatic ER-positive, HER2-negative breast cancer. They are:
- Everolimus (Afinitor), an mTOR (mammalian target of rapamycin) inhibitor approved for the treatment of ER+, HER2- metastatic breast cancers in postmenopausal women who have been treated with the aromatase inhibitor letrozole (Femara) or anastrozole (Arimidex).
- Palbociclib (Ibrance), a kinase inhibitor used along with letrozole (Femara) to treat postmenopausal women with ER+, HER2- metastatic breast cancer.
You can find information about clinical trials using targeted therapies for ER+, HER2-negative metastatic tumors here
For HER2-Positive Tumors
There are four targeted therapies currently approved for treating HER2-positive breast cancer. One is used for both early-stage and metastatic breast cancer; the other three are used only in the metastatic setting. They are:
- Trastuzumab (Herceptin), which is approved for use in early-stage and metastatic HER2+ breast cancer.
- Lapatinib (Tykerb), which is approved for use along with letrozole (Femara) for the initial treatment of metastatic, postmenopausal breast cancer that is both HER2+ and ER+.
- Pertuzumab (Perjeta), which is used along with Herceptin and docetaxel to treat HER2+ metastatic breast cancer.
- T-DM1/trastuzumab emtansine (Kadcyla), which is used to treat HER2+ metastatic breast cancer in patients who have already been treated with Herceptin and a taxane. It is a type of drug called an antibody conjugate. These drugs combine chemotherapy with a targeted therapy to deliver the chemotherapy directly to the cancer cells.
You can find information about clinical trials using targeted therapies for HER2+ breast cancer here.