Clinical Evaluation - A Phase IIA Proof of Concept Study of Regorafenib (Bayer 73-4506) in Biopsy-amenable Asian Colorectal Cancer Patients

1. Primary Endpoints * Biomarker data suggestive of regorafenib-mediated inhibition of the RAS-RAF- MEK-ERK signal transduction pathway,of various tyrosine kinase receptors and/or of angiogenesis. * Evaluation of potential relationships between biomarker data and clinical activity. * Evaluation of a novel biomarker technology (Prometheus COPIA platform) 2. Secondary Endpoints * Biomarker data suggestive of regorafenib-mediated effects on circulating rare cells. * Comparison of tumor genetic profiles obtained using DNA isolated from plasma, tumor biopsies and circulating tumor cells. * Patient safety data * Pharmacokinetics of regorafenib * Changes in tumor metabolic activity as measured by PET CT scan (optional)