Assessment of Tumor Vascular Effects of Axitinib With Dynamic Ultrasonography in Patients With Metastatic Colorectal Cancer

"Axitinib will be given BID orally. The 3 dose levels tested will be: 1st cycle: 5 mg BID; 2nd cycle: 7 mg BID; 3rd cycle: 10 mg BID.~One cycle is defined as a 14-day period (7 days ON / 7 days OFF). Patients will receive a first cycle of single agent axitinib at the starting dose with DCE-US assessment. If no study treatment-related adverse event (AE) of grade \> 1 is observed during this cycle, intrapatient dose escalation will be performed for the second cycle. The same dose escalation method wil apply between the 2d and 3d cycles."