Sunitinib.

Sunitinib is a small-molecule inhibitor of several receptor tyrosine kinases relevant to tumor angiogenesis, including the vascular endothelial growth factor (VEGF) receptor. Potent inhibition of this related family of receptors and consequent antiangiogenic effects have been demonstrated in vitro and in murine models. Human studies have established 50 mg daily dosing given on an intermittent schedule as a tolerable dose. Significant antitumor effects have been observed, most notably in advanced renal cell carcinoma (RCC) and imatinib refractory/intolerant gastrointestinal stromal tumor (GIST). Sunitinib has received regulatory approval in these two indications, and is at present being investigated across a broad array of solid tumors. Despite these initial results, several questions remain to optimize the utility of this agent.