The use of trastuzumab (Herceptin) has become central in the treatment of her2 positive breast cancers. The discovery of this drug was hailed as a milestone by the oncology community and is believed the have "leveled the playing field" for women with this particular kind of breast cancer.
Here is a review article from the Journal of Clinical Oncology that explains how this drug works. I am including a summary and then a link if you want to read more:
Understanding the Mechanisms Behind Trastuzumab
Therapy for Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer
Neil L. Spector and Kimberly L. Blackwell
See accompanying editorial on page 5671 and articles on pages 5685, 5693, and 5700
Targeted therapy with the humanized monoclonal antibody trastuzumab has become a mainstay for human epidermal growth factor receptor 2 (HER2) -positive breast cancer (BC). The mechanisms of action of trastuzumab have not been fully elucidated, and data available to date are reviewed here. The impact of the mechanisms of action on clinical benefit also is discussed.
An extensive literature review of trastuzumab and propoed mechanisms of action was performed.
At least five potential extracellular and intracellular antitumor mechanisms of trastuzumab have been identified in the preclinical setting. These include activation of antibody-dependent cellular cytotoxicity, inhibition of extracellular domain cleavage, abrogation of intracellular signaling, reduction of angiogenesis, and decreased DNA repair. These effects lead to tumor cell stasis and/or death. Clinical benefit from trastuzumab-based therapy in both early and advanced BC has been demonstrated. The benefit of trastuzumab use beyond progression has also been shown, which indicates the need for continuous suppression of the HER2 pathway. Targeting both HER2, with various approaches, and other pathways may enhance the clinical benefit observed with trastuzumab and overcome potential resistance. Novel combinations include pertuzumab (a HER2 dimerization inhibitor), lapatinib (a HER1/HER2 tyrosine kinase inhibitor), bevacizumab (an antiangiogenic agent), tanespimycin (a heat shock protein inhibitor), antiestrogen therapies, and an antibody-drug conjugate (trastuzumab-DM1).
Trastuzumb is the foundation of care for patients with HER2-positive BC. Emerging data from studies of other targeted agents may provide alternative treatment combinations to maximize the clinical benefit from trastuzumab and prevent or delay resistance. The continued development of trastuzumab highlights promising treatment approaches for the future.
J Clin Oncol 27:5838-5847. © 2009 by American Society of Clinical Oncology
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HUMAN EPIDERMAL GROWTH FACTOR
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