pertuzumab + trastuzumab + metronomic chemotherapy

Pertuzumab plus trastuzumab with metronomic chemotherapy is a combination regimen used primarily for the treatment of HER2-positive metastatic breast cancer, especially in older or frail patients. Pertuzumab and trastuzumab are monoclonal antibodies that target different epitopes on the human epidermal growth factor receptor 2 (HER2), leading to dual blockade of HER2 signaling pathways. Metronomic chemotherapy refers to the continuous or frequent administration of low-dose chemotherapeutic agents, most commonly oral cyclophosphamide in this context, aiming to minimize toxicity while maintaining anti-tumor efficacy. This combination has been shown to improve progression-free survival compared to dual anti-HER2 therapy alone and may offer a less toxic alternative for patients unable to tolerate standard taxane-based regimens[1][2][3][4].