Dear Christina,
Avastin has been approved for use on RCC. I also have Stage 4 RCC and am presently taking Avastin by itself. I had initially taken Sutent for 72 weeks until it stopped working the beginning of this year. The tumors I have started growing again and had actually doubled in size in two months. I took my second dose of Avastin on the 2nd of the month but have not had any followup Cat Scans yet. My prayers go out to you and your father. You can read about those of us taking both drugs on this site. I havent experienced any side effects on Avastin other than a bad head ache over a few days during the first dose.
My Oncologist told me that he rated Sutent first and Avastin second and the most successful out of the approved treatments available.
Good Luck!
Terry