This section discusses HER2-targeted therapies for early and locally advanced breast cancer.
Learn about HER2-targeted therapies for metastatic breast cancer (also called advanced or stage IV breast cancer).
Some breast cancers have high amounts of a protein called HER2 on the surface of the cancer cells (called HER2-positive breast cancer). The HER2 protein is an important part of the pathway for cell growth and survival.
HER2-targeted therapies target HER2-positive breast cancers. They are only used to treat HER2-positive breast cancers. They have no role in the treatment of HER2-negative cancers.
The HER2 status of a tumor is determined by testing tissue removed during a biopsy.
All newly diagnosed breast cancers are tested for HER2 status.
About 10-20 percent of newly diagnosed breast cancers are HER2-positive [111-112]. These breast cancers can be treated with HER2-targeted therapies.
Trastuzumab is a specially made antibody that targets HER2-positive cancer cells.
Trastuzumab attaches to the HER2 protein on the surface of HER2-positive cancer cells, which can slow or stop their growth.
For women with HER2-positive early breast cancer, chemotherapy plus trastuzumab cuts the risk of recurrence in half compared to chemotherapy alone [113-115].
Trastuzumab is given by vein (through an IV) or by injection every 3 weeks for 1 year.
Trastuzumab is also used to treat HER2-positive locally advanced and metastatic breast cancers.
Learn about neoadjuvant (before breast surgery) treatment with trastuzumab.
Learn more about treatment for HER2-positive metastatic breast cancers.
For a summary of research studies on trastuzumab and overall survival in early breast cancer, visit the Breast Cancer Research Studies section.
For a summary of research studies on trastuzumab and treatment for metastatic breast cancer, visit the Breast Cancer Research Studies section.
Trastuzumab use is linked to congestive heart failure, a serious heart condition.
In clinical trials, about 2-3 percent of those treated with chemotherapy plus trastuzumab had heart failure, compared to fewer than 1 percent of those treated with chemotherapy alone [113-114,116].
This risk of heart problems is higher with chemotherapy regimens that include an anthracycline drug compared to regimens without an anthracycline drug [6,114].
The risk of heart problems may also be higher for women older than 60 and for those who already have heart problems [6,116].
For most people who develop a heart problem while taking trastuzumab, the condition improves after stopping trastuzumab. For a few people, however, it may be permanent.
Your heart will be checked before and during treatment with trastuzumab to help ensure there are no problems.
Adopting a lifestyle that includes a healthy diet, regular exercise and for those who smoke, quitting smoking may help protect the heart while taking trastuzumab.
To learn more about trastuzumab, visit the National Institutes of Health’s Medline Plus website.
Some drugs are made from biological products (biologics) such as antibodies or proteins. Trastuzumab and pertuzumab (Perjeta) are breast cancer treatment drugs made from biologics (they are made from antibodies).
A biosimilar drug is a “generic like” version of a drug that contains biologics. It’s highly similar to the original drug.
The name of a biosimilar drug includes the name of the original biologic drug. For example, trastuzumab-dkst is a biosimilar form of the drug trastuzumab.
A biosimilar drug may cost less than the original drug.
To be approved by the U.S. Food and Drug Administration (FDA), the biosimilar drug must work the same way as the original drug and it must have the same :
The side effects of the biosimilar drug cannot be different from those of the original drug. Also, the biosimilar drug must be the same form as the original drug. For example, if the original drug is given by vein (through and IV) the biosimilar drug must also be given by vein.
At this time, the FDA-approved biosimilar drugs for breast cancer treatment are all biosimilar forms of trastuzumab. They can be used to treat early and metastatic HER2-positive breast cancers:
Other biosimilar drugs for breast cancer are under study.
There are biosimilar forms of some drugs used to treat side effects of chemotherapy and other breast cancer treatments.
For example, some people get a white blood cell growth factor drug, such as filgrastim (Neupogen) or pegfilgrastim (Neulasta), to help maintain their blood counts during chemotherapy. Tbo-filgrastim (Granix) and pegfilgrastim-jmdb (Fulphila) are the biosimilar forms of these drugs.
Ado-trastuzumab emtansine (Kadcyla, T-DM1, trastuzumab emtansine) is an antibody-drug conjugate drug. These drugs are a combination of an antibody HER2-targeted therapy drug and a chemotherapy drug. The combination allows the targeted delivery of chemotherapy to certain cancer cells.
Ado-trastuzumab emtansine consists of trastuzumab linked to a chemotherapy called DM1 (so it’s sometimes called T-DM1 ). Combining these into one drug allows the targeted delivery of chemotherapy to HER2-positive cancer cells.
Ado-trastuzumab emtansine is used to treat some people with HER2-positive breast cancer who have cancer remaining in their breast or lymph nodes after neoadjuvant (before surgery) chemotherapy .
The use of ado-trastuzumab emtansine can reduce the risk of breast cancer recurrence or breast cancer death by 50 percent compared to treatment with trastuzumab .
Ado-trastuzumab emtansine is given by vein (through an IV) every 3 weeks for 14 cycles. Treatment with ado-trastuzumab emtansine begins after breast surgery.
Possible side effects of ado-trastuzumab emtansine include nausea, fatigue, muscle and joint pain, low platelet counts, headache and constipation [117-118]. It can also cause liver and heart problems .
Ado-trastuzumab emtansine does not usually cause hair loss [117-118].
To learn more about ado-trastuzumab emtansine, visit the National Institutes of Health’s Medline Plus website.
Pertuzumab is an antibody that targets HER2-positive cancer cells, but in a different way than trastuzumab.
Pertuzumab is used in combination with trastuzumab and chemotherapy to treat some people with HER2-positive breast cancer .
Adding pertuzumab to treatment with trastuzumab and chemotherapy can reduce the risk of breast cancer recurrence by about 20 percent .
Pertuzumab is always given in combination with trastuzumab (not on its own). Both drugs are given by vein (through an IV) every 3 weeks for up to 1 year. You will get both drugs at the same time through the same IV (not 2 different IV sessions).
Treatment with pertuzumab and trastuzumab may begin before breast surgery or after surgery.
Learn about neoadjuvant (before breast surgery) treatment with pertuzumab and trastuzumab.
Learn about treatment for HER2-positive metastatic breast cancers.
Possible side effects of pertuzumab include diarrhea and fatigue .
Pertuzumab may increase the risk of heart problems . Your heart will be checked before and during treatment with pertuzumab to help ensure there are no problems.
To learn more about pertuzumab, visit the National Institutes of Health’s Medline Plus website.
Tyrosine-kinase inhibitors, such as neratinib, are a class of drugs that target enzymes important for cell functions (called tyrosine-kinase enzymes).
These drugs can block tyrosine-kinase enzymes at many points along the HER2 cancer growth pathway.
Neratinib is used to treat HER2-positive early breast cancer in women who have completed treatment with trastuzumab.
Treatment with neratinib may reduce the risk of breast cancer recurrence in some people .
Neratinib is a pill. Neratinib pills are taken every day for 1 year.
The most common side effect of neratinib is diarrhea . Your health care provider will recommend medications to help control the diarrhea.
Other side effects include nausea, abdominal pain, fatigue, vomiting and rash . More serious health risks include liver damage .
To learn more about neratinib, visit the National Institutes of Health’s Medline Plus website.
SUSAN G. KOMEN® SUPPORT RESOURCES
Breast Cancer 101:Targeted Therapy
Facts for Life: Targeted Therapies
Facts for Life: Biosimilars
Questions to Ask Your Doctor About Biosimilars
Research Fast Facts: HER2-Positive Breast Cancer
1-877 GO KOMEN(1-877-465-6636)