<p style=/line-height:25px/>KRN-633 is a cell-permeable, reversible, ATP-competitive VEGFR kinase inhibitor with IC50 of 170 nM, 160 nM, and 125 nM for VEGFR-1, VEGFR-2, VEGFR-3, respectively.<br>IC50 value: 170 nM/160 nM/125 nM (VEGFR1/2/3) [1]<br>Target: VEGFR<br>in vitro: KRN 633, a novel quinazoline urea derivative, strongly inhibits VEGFR1, VEGFR2 and VEGFR3 receptors with IC50 values of 170 nM, 160 nM and 125 nM respectively. It shows lower inhibitory activity towards non-RTKs, such as PDGF receptor (PDGFRα and β, c-Kit, breast tumor kinase, and tunica interna endothelial cell kinase tyrosine kinases (IC50 = 965, 9850, 4330, 9200, and 9900 nM, respectively). KRN 633 potently inhibits ligand VEGF induced phosphorylation of VEGFR2 in HUVECs with an IC50 of 1.16 nM. KRN 633 also inhibits VEGF-dependent, but not bFGF-dependent, phosphorylation of the MAP kinases in endothelial cells, with IC50 values of 3.51 nM and 6.08 nM for ERK1 and ERK2, respectively. KRN633 has also been shown to inhibit the VEGF-driven proliferation of HUVECs with an IC50 of 14.9 nM, but it only suppresses FGF-driven proliferation at 3 μM weakly [1]. KRN 633 inhibits hypoxia-induced transcriptional activation of HIF-1α in a concentration-dependent manner with an IC50 of 3.79 μM, through the inhibition of both Akt and ERK phosphorylation signaling pathways [2].<br>in vivo: Although not cytotoxic to various cancer cells in vitro, KRN633 exhibits excellent antitumor activity in vivo due to its inhibitory effect on tumor vessel formation and vascular permeability. Once-daily administration of KRN633 at 100 mg/kg/d produces significant tumor growth inhibition in A549, LC-6-LCK, HT29, Ls174T, LNCap and Du145 cells while twice-daily administration of KRN633 at 100 mg/kg induces ~90% growth inhibition of HT29 tumors [1]. Treatment of mid-pregnancy mice with KRN 633 (300 mg/kg, p.o.) reduces the blood supply to fetal tissues due to diminished vascularization in both placenta and fetal organs and consequently increases the risk of induction of intrauterine growth restriction (IUGR) [3].</p>
