Potent B-Raf inhibitor (Kd = 0.3 nM). Selective for B-Raf against 46 other kinases (Ki app values are 0.16 and 1.72 nM for B-Raf and c-Raf respectively). Decreases anchorage-independent growth of melanoma cell lines. Inhibits ERK phosphorylation and proliferation in tumor cells expressing B-RafV600E.