Vatalanib, Free Base

Cell-permeable. An inhibitor of the VEGFR tyrosine kinases VEGFR-1 (Flt-1, IC₅₀ = 77 nM) and VEGFR-2 (FLK-1/KDR, IC₅₀ = 37 nM), with slightly higher potency against the latter.  At higher concentrations, other tyrosine kinases are also inhibited, including PDGFR-β (IC₅₀ = 580 nM), c-KIT (IC₅₀ = 730 nM), FLT-4 (IC₅₀ = 660 nM) and c-FMS (IC₅₀ = 1.4 µM).  On the other hand, vatalanib is not active against the EGFR, c-SRC, v-ABL, and protein kinase Cα (IC₅₀ > 10 µM).