Cetuximab is an epidermal growth factor receptor binding FAB.Cetuximab is composed of the Fv (variable; antigen-binding) regions of the 225 murine EGFr monoclonal antibody specific for the N-terminal portion of human EGFr with human IgG1 heavy and kappa light chain constant (framework) regions.Cetuximab is marketed under the brand Erbitux® by Eli Lilly and Company.In the United States,a regimen of cetuximab costs approximately $30,790 for an eight-week course.Cetuximab binds to the epidermal growth factor receptor (EGFr) on both normal and tumor cells. EGFr is over-expressed in many colorectal cancers.Cetuximab competitively inhibits the binding of epidermal growth factor (EGF) and TGF alpha,thereby reducing their effects on cell growth and metastatic spread.