Pyrotinib Rechallenge in Her2-positive Metastatic Breast Cancer Pretreated With Pyrotinib and Trastuzumab

Pyrotinib is an oral tyrosine kinase inhibitor targeting both HER-1 and HER-2 receptors. This study is a randomized, open-label, multi-center, parallel design study of the combination of pyrotinib, trastuzumab and chemotherapy versus trastuzumab and chemotherapy in HER2+ MBC patients, who have prior received trastuzumab and pyrotinib. Patients will be randomized in a 2:1 ratio to one of the following treatment arms. Arm A: pyrotinib + trastuzumab + chemotherapy, Arm B: trastuzumab + chemotherapy. Patients will receive either arm of therapy until disease progression, unacceptable toxicity, or withdrawal of consent.