Several innovative new ways of fighting cancer are now either available or probably soon will be. That's generating excitement in the oncology community -- and among investors. Two companies that are front and center in the development of new treatments for cancer are Exelixis, Inc. (NASDAQ: EXEL) and Novartis AG (NYSE: NVS).Exelixis is an up-and-coming biotech with a stock that has more than tripled in value over the last 12 months.