View all references ] Sorafenib (compound 1a) is an oral multikinase inhibitor that blocks tumor cell proliferation and angiogenesis by targeting the serine/threonine kinases Raf-1/B-Raf and the tyrosine kinases (RTKs) of VEGFR -2/-3 and PDGFR-β. [ 2 2. (a) Huether , A. ; Hopfner , M. ; Baradari , V. ; Schuppan , D. ; Scherubl , H. Sorafenib alone or as combination therapy for growth control of cholangiocarcinoma . Biochem. Pharmacol. 2007 , 73 , 1308 – 1317 ; (b) ...