Efficacy and safety of pyrotinib combined with albumin-bound paclitaxel as first-line treatment for HER2-positive metastatic breast cancer in patients previously treated with adjuvant and/or neoadjuvant trastuzumab therapy: The stage 1 results of a single-arm, phase 2 prospective clinical trial.

OBJECTIVE: It has been observed that the prognosis of patients with HER2-positive metastatic breast cancer has improved significantly with HER2-targeted agents. However, there is still a lack of evidence regarding first-line anti-HER2 treatment options for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, there are no reliable markers that can predict the efficacy of anti-HER2 treatment in these patients. METHODS: Patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer were enrolled. Pyrotinib plus albumin-bound paclitaxel were used as first-line treatment. The primary endpoint was the objective response rate (ORR). The safety profile was also assessed. In order to explore predictive biomarkers using Olink technology, blood samples were collected dynamically. RESULTS: From December 2019 to August 2023, the first stage of the study involved 27 eligible patients. It has not yet reached the median PFS despite the median follow-up being 17.8 months. Efficacy evaluation showed that the ORR was 92.6%, and the DCR was 100%. Adverse events of grade 3 or higher included diarrhoea (29.6%), leukopenia (11.1%), neutropenia (25.9%), oral mucositis (3.7%), and hand-foot syndrome (3.7%). Toll-like receptor 3 (TLR3) and Proto-oncogene tyrosine-protein kinase receptor (RET) were proteins with significant relevance to PFS in these patients. CONCLUSIONS: This study demonstrates that pyrotinib plus albumin-bound paclitaxel as a first-line treatment regimen shows good efficacy and manageable safety for patients who have received adjuvant and/or neoadjuvant trastuzumab for HER2-positive metastatic breast cancer. Besides, a significant association was identified between the expression levels of TLR3 and RET and the PFS in patients.

Effectiveness and Safety of Pyrotinib-Based Therapy in the Treatment of HER2-Positive Breast Cancer Patients with Brain Metastases: A Multicenter Real-World Study.

BACKGROUND: Approximately 30% to 50% of patients with human epidermal growth factor receptor 2-positive metastatic breast cancer develop brain metastasis (BMs). Pyrotinib has shown promising efficacy in these patients. However, real-world evidence supporting its use is scarce. Therefore, we evaluate the efficacy and safety of pyrotinib-based regimens in the real world. MATERIALS AND METHODS: We enrolled patients with BMs from various healthcare facilities in China's Shandong region and used an updated breast-graded prognostic assessment (breast-GPA) to predict survival outcomes. RESULTS: Efficacy and toxicity were assessed in 101 patients. Overall, the median progression-free survival (PFS) was 11.0 months (95% CI, 7.6-14.4 months). PFS was shorter in patients with a breast-GPA of 0 to 2.0 (P< .001). Previous treatment with pertuzumab plus trastuzumab (P = .039) and varying numbers of BMs (P = .028) had a significant positive correlation with PFS. Additionally, radiotherapy (P = .033) for BMs, especially pyrotinib concurrent with radiotherapy (P = .013), significantly prolonged the PFS. In patients with a breast-GPA of 0 to 2.0, a significant difference in PFS was observed depending on whether the brain was the first metastatic site (P< .001). Furthermore, a breast-GPA (0-2.0 vs. 2.5-4.0), and radiotherapy for BMs were found to be independent predictors of PFS. Overall, the objective response rate was 42.6%, while the disease control rate was 88.1%. Diarrhea emerged as the most common adverse event. CONCLUSION: Pyrotinib-based therapy is effective and tolerable in human epidermal growth factor receptor 2-positive metastatic breast cancer with BMs. Patients who underwent radiotherapy for BMs, particularly those who received pyrotinib concurrently with radiotherapy, exhibited a more favorable prognosis.