Regorafenib, With Cetuximab or Panitumumab, for the Treatment of Unresectable, Locally Advanced, or Metastatic Colorectal Cancer

This phase II trial how well regorafenib and anti-EGFR therapy (cetuximab or panitumumab) works for the treatment of patients with colorectal cancer that cannot be removed by surgery (unresectable), has spread to nearby tissue or lymph nodes (locally advanced), or has spread to other places in the body (metastatic). Regorafenib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Monoclonal antibodies, such as cetuximab or panitumumab, may interfere with the ability of cancer cells to grow and spread. Drugs used in chemotherapy, such as irinotecan, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. The purpose of this research study is to compare the effects, good and/or bad, of taking regorafenib follow by cetuximab or panitumumab, to those that receive cetuximab or panitumumab before regorafenib.