Biomarkers for Apatinib and Bevacizumab in Second-line Therapy for Colorectal Cancer(BABST-C)

Bevacizumab, an antibody against vascular endothelial generated factor (VEGF), combined with the fluorouracil-based chemotherapy regimens has been approved in the 1st and 2nd line treatments for metastatic colorectal cancers(mCRC). Other inhibitors of the VEGF pathway, such as Ramucirumab and Aflibercept are also approved in the 2nd line therapy. Apatinib is a small molecule tyrosine kinase inhibitor (TKI), which can highly selectively bind to and strongly block VEGF receptor 2 (VEGFR - 2), resulting in reduced cell migration, proliferation, and tumor microvascular density mediated by VEGF . In this study, the patients who have progressed following or on the first-line oxaliplatin and fluorouracil（5-FU） combined with bevacizumab are randomised into two arms(FOLFIRI plus apatinib or FOLFIRI plus bevacizumab) in the 2nd line setting. To identify specific biomarkers at the genetic and proteomic levels between two arms is the primary end point.