A 60 year old female presented with breast carcinoma and she was prescribed herceptin (trastuzumab). Which of the following statement regarding this drug is TRUE?
High-Yield Explanation
Trastuzumab (HERCEPTIN) is a humanized monoclonal antibody that binds to the external domain of HER2/neu (ErbB2). Trastuzumab was the first monoclonal antibody to be approved for the treatment of a solid tumor. Thiy percent of breast cancers overexpress this receptor due to gene amplification on chromosome 17. Also Know: Trastuzumab exes its antitumor effects through several putative mechanisms of action: inhibition of homo- or heterodimerization of receptor, thereby preventing receptor kinase activation and downstream signaling; initiation of Fc-receptor-mediated antibody-dependent cellular cytotoxicity; and blockade of the angiogenic effects of HER2 signaling. Ref: Chabner B.A., Barnes J., Neal J., Olson E., Mujagic H., Sequist L., Wilson W., Longo D.L., Mitsiades C., Richardson P. (2011). Chapter 62. Targeted Therapies: Tyrosine Kinase Inhibitors, Monoclonal Antibodies, and Cytokines. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.