Pyrotinib Plus Taxanes or Vinorelbine for the Treatment of Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer: Prospective Evaluation of Efficacy and Safety.

Purpose: The clinical benefits of pyrotinib plus taxanes or vinorelbine have not been studied systemically. Consequently, we conducted a prospective evaluation to assess the efficacy and safety of pyrotinib plus taxanes or vinorelbine in patients with human epidermal growth factor 2 (HER2)-positive metastatic breast cancer (MBC).

Methods: Patients with HER2-positive MBC were included to receive pyrotinib combined with taxanes or vinorelbine in Jiangsu Cancer Hospital. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), and adverse effects (AEs).

Results: Between December 22, 2020 and January 11, 2023, a total of 101 patients were assigned to pyrotinib plus taxanes (n = 83) and pyrotinib plus vinorelbine (n = 18) groups. As of May 24, 2023, the median PFS for all patients was 11.5 months (95% confidence interval [CI], 8.8-15.7). The median PFS was significantly longer in pyrotinib plus taxanes group than in pyrotinib plus vinorelbine group (median PFS, 12.2 months [95% CI, 9.2-18.6] vs. 8.4 months [95% CI, 5.5-13.7]; P = .005). All the treatment-related side effects were tolerated. The most frequent grade 3 or 4 side effects included diarrhea (22.8%), leukopenia (19.5%), and neutropenia (18.2%).

Conclusion: Pyrotinib plus taxanes could be an alternative or even the preferred treatment strategy for patients with HER2-positive MBC after trastuzumab and small-molecule tyrosine kinase inhibitors (TKIs). We also suggest that pyrotinib combined with vinorelbine has a therapeutic potential.

Registration: This trial was registered in Chinese Clinical Trial Registry. URL: https://www.chictr.org.cn/showproj.html?proj=65697 (ChiCTR2000041217).