capecitabine + cyclophosphamide + trastuzumab

This is a combination regimen consisting of three agents—capecitabine, cyclophosphamide, and trastuzumab—used primarily in the treatment of HER2-positive breast cancer. - Capecitabine is an oral prodrug that is converted to 5-fluorouracil (5-FU) in the body, where it inhibits thymidylate synthase and disrupts DNA synthesis in rapidly dividing cells. - Cyclophosphamide is an alkylating agent that crosslinks DNA strands, leading to cell death. - Trastuzumab is a monoclonal antibody targeting the human epidermal growth factor receptor 2 (HER2), inhibiting proliferation of tumor cells that overexpress this protein and mediating antibody-dependent cellular cytotoxicity. The combination leverages complementary mechanisms for enhanced antitumor activity. Capecitabine and cyclophosphamide are both orally administered with preclinical synergy and non-overlapping toxicities[5][7][9]. Trastuzumab specifically targets HER2-positive tumors[3][6][8]. This regimen has been studied in metastatic breast cancer as well as other settings where HER2 overexpression drives disease progression[1].