Sorafenib (Nexavar, Bayer),'s a drug approved for the treatment of primary kidney cancer (advanced renal cell carcinoma) and advanced primary liver cancer (hepatocellular carcinoma). Pharmacology Sorafenib's a small molecular inhibitor of several protein kinases. (Protein kinases are overactive in many of the molecular pathways that cause cells to become cancerous. These pathways include Raf kinase, PDGF (platelet-derived growth factor), VEGF receptor 2 and 3 kinases and c Kit the receptor for… (More on Sorafenib)