Sequential neoadjuvant chemotherapy using pegylated liposomal doxorubicin and cyclophosphamide followed by taxanes with complete trastuzumab and pertuzumab treatment for HER2-positive breast cancer: A phase II single-arm study.

Objective: Despite cardiotoxicity overlap, the trastuzumab/pertuzumab and anthracycline combination remains crucial due to significant benefits. Pegylated liposomal doxorubicin (PLD), a less cardiotoxic anthracycline, was evaluated for efficacy and cardiac safety when combined with cyclophosphamide and followed by taxanes with trastuzumab/pertuzumab in human epidermal growth factor receptor-2 (HER2)-positive early breast cancer (BC). Methods: In this multicenter, phase II study, patients with confirmed HER2-positive early BC received four cycles of PLD (30-35 mg/m Results: Between May 27, 2020 and May 11, 2022, 78 patients were treated with surgery, 42 (53.8%) of whom had BCS. After neoadjuvant therapy, 47 [60.3%, 95% confidence interval (95% CI), 48.5%-71.2%] patients achieved tpCR, and 49 (62.8%) achieved bpCR. ORRs were 76.9% (95% CI, 66.0%-85.7%) and 93.6% (95% CI, 85.7%-97.9%) after 4-cycle and 8-cycle neoadjuvant therapy, respectively. Nine (11.5%) patients experienced asymptomatic left ventricular ejection fraction (LVEF) reductions of ≥10% from baseline, all with a minimum value of >55%. No treatment-related abnormal cardiac function changes were observed in mean N-terminal pro-BNP (NT-proBNP), troponin I, or high-sensitivity troponin. Conclusions: This dual HER2-blockade with sequential polychemotherapy showed promising activity with rapid tumor regression in HER2-positive BC. Importantly, this regimen showed an acceptable safety profile, especially a low risk of cardiac events, suggesting it as an attractive treatment approach with a favorable risk-benefit balance.