Kinase experiment:

Compounds (ZM323881) are incubated (20 minutes, room temperature) with enzyme in an N-2-hydroxyethylpiperazine-N'-2-ethanesulphonate (HEPES) (pH 7.5) buffered solution containing 10 mM MnCl2 and 2 μM ATP, in96-well plates coated with a poly(Glu, Ala, Tyr) 6:3:1 random copolymer substrate. Phosphorylated tyrosine is then detected bysequential incubation with mouse IgG anti-phosphotyrosine antibody a horseradish peroxidase(HRP)-linked sheep anti-mouse Ig antibody and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid). IC50 data are interpolated by nonlin-ear regression[1].

Cell experiment:

HUVEC cells isolated from umbilical cords are plated (at passage 2–8) in 96-wellplates (1000 cells/well) and dosed with ZM323881±VEGF-A (3 ng/mL), EGF (3 ng/mL), or basicfibroblast growth factor (bFGF, 0.3 ng/mL). The cultures are then incubated for 4 days. On day 4, the cultures are pulsed with 1 μCi/well of 3H-thymidine and reincubated for 4 hours. The cells are then harvested and assayed for the incorporation of tritium by using a beta-counter. IC50 data are interpolated[1].

ZM323881 inhibits VEGF-A-induced endothelial cell proliferation (IC50 = 8 nM) and VEGF-R2 tyrosine phosphorylation (IC50< 2 nM).

Vascular endothelial growth factor (VEGF) increases vascular permeability and angiogenesis in many pathological conditions, such as cancer, arthritis, and diabetes. VEGF activates VEGF-Receptor 1 (VEGF-R1) and VEGF-Receptor 2 (VEGF-R2) that autophosphorylate to initiate a signaling cascade resulting in angiogenesis and increased microvascular permeability. ZM323881 is a potent and selective inhibitor of VEGF-R2 tyrosine kinase.

In vitro: ZM323881 was found to inhibit VEGF-A-induced endothelial cell proliferation (IC50 = 8 nM) and VEGF-R2 tyrosine phosphorylation in vitro (IC50< 2 nM) [1].

In vivo: VEGF-Amediated increases in vascular permeability in perfused mesenteric microvessels in vivo were reversibly abolished by both ZM323881 and the class III receptor tyrosine kinase inhibitor PTK787/ZK222584, suggesting that VEGF-R2 phosphorylation is necessary for VEGF-A-mediated increases in microvascular permeability in vivo [1].

Clinical trials: There is no clinical data are available currenlty.

Reference:
[1] Whittles CE, Pocock TM, Wedge SR, Kendrew J, Hennequin LF, Harper SJ, Bates DO.   ZM323881, a novel inhibitor of vascular endothelial growth factor-receptor-2 tyrosine kinase activity. Microcirculation. 2002;9(6):513-22.