cyclophosphamide + doxorubicin + nab-paclitaxel + pyrotinib

This is a combination chemotherapy regimen that includes three established chemotherapeutic agents (cyclophosphamide, doxorubicin, and nab-paclitaxel) plus pyrotinib, which is a newer targeted therapy. Pyrotinib is an irreversible dual pan-ErbB receptor tyrosine kinase inhibitor that targets EGFR (HER1), HER2, and HER4. It works by covalently binding to ATP binding sites in the intracellular kinases of these receptors, blocking the activation of downstream signaling pathways to inhibit tumor cell growth. The combination appears to be used in the treatment of HER2-positive breast cancer. The specific combination of cyclophosphamide + doxorubicin + nab-paclitaxel + pyrotinib may be under investigation in clinical trials for HER2-positive breast cancer, potentially in the neoadjuvant or adjuvant setting. Pyrotinib alone has received conditional approval in China for use in combination with capecitabine for HER2-positive advanced or metastatic breast cancer.