Background：Bevacizumab is a recombinant human IgG1 monoclonal antibody specific for all human vascular endothelial growth factor-A (VEGF-A) isoforms. The humanized anti-VEGF monoclonal antibody, bevacizumab, has been approved by the FDA as a first-line treatment for metastatic colorectal cancer in combination with chemotherapy. The pharmacokinetic properties of bevacizumab in several species have been previously described and are consistent with a typical humanized monoclonal antibody. It was shown in the literature that the surveillance of circulating concentration during maintenance therapy represents a direct and/or indirect factor for some other side effects. Identification of biomarkers for (non-)response and risk factors for adverse drug reactions that might be related to serum concentrations and maintaining the effective concentration of Bevacizumab in order to potentially avoid some side effects with a reliable method might be beneficial.
