AUTHOR=Xie Yizhao , Li Yi , Ting Luo , Sang Die , Yuan Peng , Li Wei , Li Huihui , Ge Rui , Wang Biyun 

TITLE=Pyrotinib Plus Vinorelbine Versus Lapatinib Plus Capecitabine in Patients With Previously Treated HER2-Positive Metastatic Breast Cancer: A Multicenter, Retrospective Study

JOURNAL=Frontiers in Oncology

VOLUME=Volume 11 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2021.699333

DOI=10.3389/fonc.2021.699333

ISSN=2234-943X

ABSTRACT=Background: 
Pyrotinib is a newly-developed irreversible pan-ErbB receptor oral tyrosine kinase inhibitor (TKI) with promising efficacy in the human epidermal growth factor receptor-2 (HER2) positive breast cancer. The phase III PHOEBE study proved that pyrotinib plus capecitabine exceeded lapatinib plus capecitabine (LX) in PFS (p<0.001). Oral vinorelbine is commonly used in combination with anti-HER2 treatment. However, no evidence was reported in terms of the real-world pattern, safety and efficacy of pyrotinib plus vinorelbine (NP) compared with LX. 
Methods:
We retrospectively evaluated the medical records of all patients with HER2 positive MBC who experienced progression on prior trastuzumab-containing regimens (advanced setting) and a taxane (any setting) and received NP or LX treatment from 2015 to 2021 in 5 institutions.
Results:
A total of 224 patients were available for analysis. 132 (58.9%) patients received LX and 92 (41.1%) patients received NP. The median PFS of NP group was significantly longer than that in LX group (8.3 months vs 5.0 months, HR=0.47 95% CI 0.34-0.65, p<0.001). The advantage of NP over LX was seen both in patients with trastuzumab resistance (p<0.001) and refractoriness (p=0.004). NP group had more diarrhea (23.9%) compared to LX group (8.3%). Discontinuation rates in two groups were similar.
Conclusions:
This trial revealed the clinical practice of NP and LX treatment in HER2+ MBC patients previously treated with trastuzumab and taxane in China. More patients received LX than NP in real-world while the efficacy of NP exceeded LX in terms of PFS, regardless of resistant status of trastuzumab. Although NP group had more diarrhea, toxicities in both groups were acceptable.