HER2-Targeted Therapies for Early Breast Cancer
This section discusses HER2-targeted therapies for early and locally advanced breast cancer.
HER2-targeted therapies and HER2-positive breast cancer
Some breast cancers have high amounts of a protein called HER2 on the surface of the cancer cells. These are called HER2-positive breast cancers. 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.
Testing for HER2 status
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 [115-116]. These breast cancers can be treated with HER2-targeted therapies.
How does trastuzumab work?
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. This can slow or stop their growth.
Breast cancer treatment
For women with HER2-positive early breast cancer, chemotherapy plus trastuzumab cuts the risk of recurrence in half compared to chemotherapy alone [117-119].
Trastuzumab is given by vein (through an IV) or by injection every 3 weeks for one year.
Treatment with trastuzumab may begin before breast cancer surgery (neoadjuvant therapy) or after surgery (adjuvant therapy).
Trastuzumab is also used to treat HER2-positive metastatic breast cancers.
Learn about neoadjuvant 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.
Heart problems linked to trastuzumab
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 [117-118,120].
This risk of heart problems is higher with chemotherapy regimens that include an anthracycline drug compared to regimens without an anthracycline drug [6,118].
The risk of heart problems may also be higher for women over 60 and for those who already have heart problems [6,120].
For most people who develop a heart problem while taking trastuzumab, the condition improves after stopping trastuzumab. For a few, it may be permanent.
Avoiding heart problems
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.
A biosimilar drug is a “generic-like” version of a drug that contains biological products (biologics) such as antibodies or proteins. Trastuzumab is a biologic drug.
There are some FDA-approved biosimilar forms of trastuzumab. These biosimilars are safe and effective treatments for early and metastatic HER2-positive breast cancers.
Learn more about biosimilars.
Ado-trastuzumab emtansine (Kadcyla, T-DM1, trastuzumab emtansine)
How does ado-trastuzumab emtansine work?
Ado-trastuzumab emtansine (Kadcyla, T-DM1, trastuzumab emtansine) is an antibody-drug conjugate drug.
Ado-trastuzumab emtansine consists of the antibody HER2-targeted therapy drug trastuzumab (Herceptin) and a chemotherapy called DM1 (so it’s sometimes called T-DM1). The combination of drugs allows the targeted delivery of chemotherapy to HER2-positive cancer cells.
Breast cancer treatment
Ado-trastuzumab emtansine is used to treat some women 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 in these women 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.
Ado-trastuzumab emtansine is under study for use in the neoadjuvant setting .
Side effects of ado-trastuzumab emtansine
Possible side effects of ado-trastuzumab emtansine include nausea, fatigue, muscle and joint pain, low platelet counts, headache and constipation [121,123]. It can also cause liver and heart problems .
Ado-trastuzumab emtansine does not usually cause hair loss [121,123].
Because ado-trastuzumab emtansine contains trastuzumab, it can cause congestive heart failure, a serious heart condition. Learn more about this risk and steps taken to monitor your heart during treatment.
To learn more about ado-trastuzumab emtansine, visit the National Institutes of Health’s Medline Plus website.
How does pertuzumab work?
Pertuzumab is an antibody that targets HER2-positive cancer cells, but in a different way than trastuzumab.
Breast cancer treatment
Pertuzumab is used in combination with trastuzumab and chemotherapy to treat some HER2-positive breast cancers .
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. It’s not given on its own. The combination of drugs is given by vein (through an IV) or injection under the skin every 3 weeks for up to one year.
Treatment with pertuzumab and trastuzumab may begin before breast cancer surgery (neoadjuvant therapy) or after surgery (adjuvant therapy).
Learn about pertuzumab and metastatic breast cancer treatment.
Side effects of pertuzumab
Pertuzumab is always given in combination with trastuzumab. Trastuzumab can cause congestive heart failure, a serious heart condition. Learn more about this risk and steps taken to monitor your heart during treatment.
To learn more about pertuzumab, visit the National Institutes of Health’s Medline Plus website.
How does neratinib work?
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.
Breast cancer treatment
Neratinib is used to treat HER2-positive early breast cancer in some women who have completed treatment with trastuzumab (Herceptin).
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 one year.
Side effects of neratinib
To learn more about neratinib, visit the National Institutes of Health’s Medline Plus website.
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