Sorafenib (co-developed and co-marketed by Bayer and Onyx Pharmaceuticals as Nexavar), is a drug approved for the treatment of primary kidney cancer (advanced renal cell carcinoma) and advanced primary liver cancer (hepatocellular carcinoma).
Sorafenib (a bi-aryl urea) is a small molecular inhibitor of several Tyrosine protein kinases (VEGFR and PDGFR) and Raf kinases (more avidly C-Raf than B-Raf).
(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 Stem cell factor. )
Sorafenib is/was unique in targeting the Raf/Mek/Erk pathway (MAP Kinase pathway).Sorafenib inhibits some intracellular serine/threonine kinases (e.g. C-Raf, wild-type B-Raf and mutant B-Raf).