Sorafenib and sunitinib.

Sorafenib (Nexavar ; Bayer Pharmaceuticals, West Haven, CT) (Fig. 1A) and sunitinib (Sutent ; Pfizer Inc., New York, NY) (Fig. 1B) are orally bioavailable, small molecule inhibitors of multiple intracellular and receptor protein kinases that are components of signaling pathways that control tumor growth and angiogenesis. These agents have similar drug profiles and overlapping targets, which are summarized in Table 1. Sorafenib and sunitinib are currently approved by the U.S. Food and Drug Administration for advanced renal cell cancer (RCC) in adults [1]. Sorafenib is also approved for unresectable hepatocellular carcinoma (HCC) [2] and sunitinib is approved for gastrointestinal stromal tumor (GIST) after disease progression on or intolerance to imatinib mesylate [3]. These differing clinical indications are likely a result of the different development plans of the respective drug companies, rather than the specific mechanism for each drug. There are currently studies underway for GIST patients with sorafenib and for HCC patients with sunitinib.