FIIN-3 is an inhibitor of FGF receptors (FGFRs; IC50s = 13, 21, 31, and 35 nM for recombinant FGFR1-4, respectively). It is selective for FGFRs over a panel of 456 kinases at a concentration of 1 μM, however, it does inhibit EGFR (IC50 = 204 nM). FIIN-3 inhibits growth of Ba/F3 cells that are dependent on the kinase activity of wild-type FGFR1-4 as well as gatekeeper mutant FGFR2 and FGFR3 (EC50s = <1-69 nM) and inhibits FGFR-dependent signaling in a concentration-dependent manner in FGFR2TEL/V564M-dependent Ba/F3 cells. FIIN-3 also inhibits growth in a panel of cancer cell lines (EC50s = 1.4-499 nM).
