Pyrotinib in Combination With Capecitabine in Patients With Trastuzumab-resistant HER2-positive Advanced Breast Cancer

Trastuzumab resistance, which is a common therapeutic challenge in HER2 positive metastatic breast cancer, is not fully understood. Pyrotinib is an oral tyrosine kinase inhibitor targeting EGFR, HER-2 and HER-4 receptors. More general inhibition of ErbB family with pyrotinib could provide additional benefit. This study is designed to evaluate the efficacy and safety of pyrotinib in combination with capecitabine in patients with HER2 positive locally advanced or metastatic breast cancer who had early failure on or after trastuzumab treatment.