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Targeted therapy for HER2-positive breast cancer


Targeted treatments for HER2-positive breast cancer work by targeting the HER2 proteins or markers on or within cancer cells that help the cells to grow. They attach to HER2 proteins either on the inside or on the outside of a cancer cell and block signals that tell the cells to multiply too quickly.

In this section, you’ll learn more about the different classes of HER2-targeting medicines and how they work to treat breast cancer.

Monoclonal antibodies

Monoclonal antibodies are large molecules made in a lab that attack a specific protein on the outside of a cell. To your body, these molecules look similar to antibodies it makes to fight germs and infection. But monoclonal antibodies are designed to attach to a specific receptor only found on cancer cells, such as the HER2 receptor in HER2-positive breast cancer.

Medicines in this class are given by vein. Monoclonal antibodies used in breast cancer are:

Tyrosine kinase inhibitors

Tyrosine Kinase Inhibitors, or TKIs, are small molecules made in a lab. TKIs look for proteins called tyrosine kinases that signal cancer cells to grow. These medicines block the tyrosine kinases in HER2-positive breast cancer so the cancer cell cannot grow and divide.

TKIs are given as pills. The FDA-approved medicines in this class for HER2-positive breast cancer are

Antibody drug conjugates

An Antibody Drug Conjugate, or ADC, pairs a powerful chemotherapy medicine with a targeted therapy. The targeted therapy directs the medicine to the cancer cells, so the chemotherapy medicine can be delivered right inside them. This helps limit the side effects of the chemotherapy on healthy cells.

There are many ADCs under study for different types of breast cancer. The FDA has approved these antibody drug conjugates for HER2-positive breast cancer :


Related resources


Reviewed and updated: March 16, 2018

Reviewed by: Kanu Sharan, MD


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