While previously considered to be the more aggressive type of breast cancer, today HER2-positive breast cancer can be treated with biologic targeted therapies, also known as monoclonal antibodies, such as trastuzumab emtansine (Kadcyla), that target the human epidermal growth factor receptor 2 (HER2) protein, that are highly effective, allow for a good prognosis, and have increased survival for this cancer by more than 30%.
However, some women with HER2-positive breast cancer do not respond to the targeted treatments and/or develop resistance to these medications, which has led to the development of new or modified drug combinations. Other medications include pertuzumab (Perjeta), docetaxel (Taxotere), lapatinib ditosylate (Tykerb), neratinib maleate (Nerylynx), and, most recently, fam-trastuzumab (Enhertu). HER2-positive breast cancer can also be treated with standard chemotherapy. Treatment for HER2-positive breast cancer usually includes a combination of biologic targeted therapies and chemotherapy.
Trastuzumab, a biologic targeted therapy, is a monoclonal antibody that works against the HER 2 protein, preventing the growth and spread of cancer cells.
Pertuzumab, a biologic targeted therapy, is a monoclonal antibody that works by blocking the HER2 protein from growing and spreading cancer cells. Pertuzumab can be used in combination with trastuzumab and the chemotherapy drug, docetaxel (Taxotere), in women with HER2-positive metastatic breast cancer and as an adjuvant (added after initial treatment) therapy for early breast cancer that has a high risk of recurrence.
Ado-trastuzumab emtansine is a monoclonal antibody that is combined with the chemotherapy drug, emtansine.
Lapatinib is a kinase inhibitor that is combined with chemotherapy or hormone therapy.
Neratinib is a kinase inhibitor that works by stopping cancer cells ability to grow.
Fam-trastuzumab was recently approved (2019) by the U.S. Food and Drug Administration (FDA) as a new targeted therapy for unresectable or metastatic HER2-postive breast cancer that continues to metastasize (spread) after treatment with two or more targeted treatments.