Erdafitinib (JNJ-42756493) is a potent and selective orally bioavailable, pan fibroblast growth factor receptor (FGFR) inhibitor with potential antineoplastic activity. It was discovered in collaboration with Janssen Pharmaceutica, N.V. from a partnership which commenced in June 2008. Astex’s FGFr inhibitor program originated from a collaboration initiated in 2005 with the Cancer Research UK Drug Discovery Group at the Newcastle Cancer Centre (Newcastle University UK), and Cancer Research Technology Limited. JNJ42756493 is currently being evaluated by Janssen in Phase 2 clinical trials in patients with urothelial cancer, advanced hepatocellular carcinoma, advanced non-small lung cancer, esophageal cancer or cholangiocarcinoma. JNJ-42756493 is a potent, oral pan-FGFR tyrosine kinase inhibitor with half-maximal inhibitory concentration values in the low nanomolar range for all members of the FGFR family (FGFR1 to FGFR4), with minimal activity on vascular endothelial growth factor receptor (VEGFR) kinases compared with FGFR kinases (approximately 20-fold potency difference). In vitro, the proliferation of cells treated with JNJ-42756493 is decreased, associated with increased apoptotic death and decreased cell survival. It is also in phase I trials for the treatment of advanced refractory solid tumors or advanced refractory hematologic cancer.