cyclophosphamide + trastuzumab

Cyclophosphamide + trastuzumab is a combination regimen used primarily in the treatment of HER2-positive breast cancer. Cyclophosphamide is an alkylating agent that interferes with DNA replication and transcription, leading to cell death, while trastuzumab is a recombinant humanized IgG1 monoclonal antibody targeting the HER2 (human epidermal growth factor receptor 2) protein. Trastuzumab binds to the extracellular domain of HER2, inhibiting downstream signaling pathways involved in cell proliferation and survival, inducing antibody-dependent cellular cytotoxicity (ADCC), and promoting cell cycle arrest. The combination has demonstrated synergistic antitumor effects in preclinical models and clinical studies for HER2-overexpressing breast cancers[1][2][3]. This regimen may be used as part of neoadjuvant or adjuvant therapy protocols.