Targeted Therapy for MBC
Researchers are very interested in finding new targeted therapies for all types of breast cancer. Today, a number of targeted therapies are FDA
approved only for treating metastatic breast cancer. Others may be available to you through clinical trials.
There are many different types of targeted therapy. This section tells you about some of the approved treatments.
Targeted Therapy for HER2-Positive Metastatic Disease
Between 15 and 20 percent of breast cancers make too much of the HER2 protein, also known as human epidermal growth factor receptor 2.
HER2 triggers rapid cell division and growth. With too many receptors, breast cancer cells pick up too many growth signals and start growing too often and too fast. HER2-positive cancers tend to be more aggressive than HER2-negative cancers, but targeting the protein has opened up new treatment options.
You may be familiar with trastuzumab (Herceptin), a common targeted therapy for both metastatic and early-stage breast cancer. A number of other treatments are FDA approved for metastatic HER2-positive disease.
They are:
- Ado-trastuzumab emtansine (Kadcyla), which is approved for treatment of metastatic, HER2-positive breast cancer that has grown despite treatment with trastuzumab and taxane chemotherapy.
- Lapatinib (Tykerb), which is given with the chemotherapy treatment capecitabine (Xeloda) to treat metastatic HER2-positive breast cancers that grow or spread after being treated with trastuzumab and anthracyclines or taxanes.
- Pertuzumab (Perjeta), which is used to treat metastatic HER2-positive breast cancer that has not yet been treated with trastuzumab or chemotherapy.
Targeted Therapy for Hormone-Positive Metastatic Disease
There are also targeted therapies available for metastatic breast cancers that are HER2-negative and hormone receptor-positive. They include:
mTOR (Mammalian Target of Rapamycin) Inhibitors
mTOR inhibitors are a type of targeted therapy that stops cancer cells from dividing. They may also block the growth of new blood vessels that tumors need to grow. There is one FDA approved mTOR inhibitor available
- everolimus (Afinitor) is given with the aromatase inhibitor exemestane (Aromasin) to postmenopausal women with metastatic, hormone receptor-positive, HER2-negative breast cancer that grew after treatment with an aromatase inhibitor.
CDK 4/6 Inhibitors
Cyclin-dependent kinase 4/6 inhibitors target two specific enzymes, called kinases, that help tumor cells grow and divide. There is one FDA approved CDK4/6 inhibitor, and others are being studied
- abemaciclib (Verzenio) is given to treat hormone receptor-positive, HER2-negative metastatic breast cancer. It can be given with the hormonal therapy fulvestrant (Faslodex) if another hormonal therapy stopped working and chemotherapy has not been given for metastatic disease. Or, it can be given alone if the cancer grew during treatment with hormonal therapy and chemotherapy.
- palbociclib (Ibrance) is given with the aromatase inhibitor letrozole (Femara) to treat hormone receptor-positive, HER2-negative breast cancer metastatic in postmenopausal women who have not been treated with hormonal therapy.
- ribociclib (Kisqali) is given with an aromatase inhibitor as an initial, or first-line, treatment for hormone receptor-positive, HER2-negative metastatic breast cancer in postmenopausal women.
Clinical trials play an important role in discovering new medicines. We encourage you to talk with your doctor about open clinical trials that may be available to you. You can also visit our section on Clinical Trials and Research Studies for more information.