Study to Identify Biomarkers of Clinical Response to Aflibercept in Patients With Metastatic Colorectal Cancer

Aflibercept (Sanofi and Regeneron) targets the Vascular endothelial growth factor (VEGF) pathway that is a composite decoy receptor based on VEGFR-1 and VEGFR-2 fused to an Fc segment of IgG1. In pre-clinical assessments, aflibercept results in stronger angiogenesis inhibition than bevacizumab, exhibiting at least 100-1000 times higher affinity to the circulating VEGFs. It is postulated that in vivo, the binding of these ligands to aflibercept results in the blockade of tumor angiogenesis along with pruning of existing tumor vascular elements and reduction of VEGF-driven vascular permeability. The expected outcome is reduced growth of primary and metastatic tumors by impeding the density of tumor vasculature and diminishing the abnormal leakiness of tumor vessels that supply matrix components to the cancer.