KDR and gastrointestinal stromal tumor: More recently, two small molecules blocking the VEGF receptor (VEGFR) have shown promising results in the treatment of renal cell carcinoma and gastrointestinal stromal tumors (GISTs): sorafenib (Nexavar; Bayer Pharmaceuticals Corporation, West Haven, CT), approved by the FDA in 2005 as a second-line treatment for advanced renal cell carcinoma after cytokine failure, and sunitinib (Sutent; Pfizer, Inc., New York), approved in 2006 for patients with GIST previously treated with imatinib and for advanced renal cell carcinoma as a first-line treatment.