Additional Study Information: The purpose of this study is to compare the effectiveness of tivozanib in renal cell cancer compared to an approved drug sorafenib which works in a similar way to tivozanib. Tivozanib and sorafenib are both called study medication. This study will also see whether tivozanib is safe and tolerable for patients with advanced renal cell cancer. This study will look at the effects of tivozanib on subjects with refractory advanced renal cell cancer.