Sulfatinib (KDR-IN-1) (HMPL-012) is a potent and highly selective tyrosine kinase inhibitor against VEGFR1/2/3, FGFR1 and CSF1R with IC 50 s ranging from 1 to 24 nM.

Sulfatinib抑制VEGFR1、2和3、FGFR1及CSF1R激酶，其IC 50值在1至24 nM范围内。Sulfatinib在HEK293KDR细胞中显著阻断由VEGF诱导的VEGFR2磷酸化，以及在RAW264.7细胞中由CSF1刺激的CSF1R磷酸化，其IC 50分别为2和79 nM。同时，Sulfatinib能够减弱VEGF或FGF刺激的HUVEC细胞增殖，IC 50< 50 nM [1]。此外，它也是一种hERG抑制剂，在CHO细胞中的IC 50为6.8 μM [2]。

通过单次口服给药，Sulfatinib 在动物研究中依赖于暴露量抑制裸鼠肺组织中 VEGF 刺激的 VEGFR2 磷酸化。此外，在服药后 24 小时，血浆中 FGF23 水平的提高表明抑制了 FGFR 信号传导。Sulfatinib 在多个人源异种移植模型中展现出强大的肿瘤生长抑制能力，并显著降低 CD31 表达，表明通过 VEGFR 和 FGFR 信号传导强烈抑制血管生成。在同源小鼠结肠癌模型 CT-26 中，Sulfatinib 经单药治疗展现出适度的肿瘤生长抑制 [1]。口服给药 10 mg/kg 后，在小鼠体内的 AUC 和 C max 分别为 397 ng/mL 和 138ng/mL [1]。

The KDR kinase inhibition activity is tested using the the Z-lyte assay kit. Tyr1 peptide is used to test the KDR kinase inhibitory activity of N-(2-(dimethylamino)-ethyl)-1-(3-((4-((2-methyl-1H-indol-5-yl)oxy)pyrimidin-2-yl)amino)phenyl)methanesulfonamide. The testing system contains 300ng/ml of recombinant human KDR catalytic domain, 10 μM of ATP, 1 μM of substrate peptide, and a test compound at a series of different concentrations in 384-well plate; total volume is 10 μL. The enzyme inhibition proceeds at room temperature (25°C), for 1 hour at room temperature on the shaker. 5ul of stop solution is added to stop the reaction. The KDR Kinase inhibition activity of a test compound is calculated based on the method recommended by the manufacturer. The IC50 values of the KDR kinase inhibition activity are calculated using XLfit software[1].

A CHO cellline stably transfected with hEGR cDNA and expressing hERG channels is used for the study.Whole-cell recording are performed using a 700B. Test compound is prepared as a 10 mM DMSO stock solution in a glass vial and is diluted using External Solution, the dilution is prepared no longer than 30 minutes before use. After achieving whole-cell configuration, the cells are monitored for 90 seconds to assess stability and washed with external solution for 66 sec. External solution containing 0.1% DMSO (vehicle) is applied to the cells to establish the baseline. After allowing the current to stabilize for 3 min, the test compound is applied. The test solution is added in 4 steps and the cells are kept in the test solution until the compound is effect reached a steady state or for a maximum of 6 min. Subsequently, the positive control (10 nM cisapride) is added. Washout with external solution is performed until the recovery of the current reached a steady state[1].

The phamacokinetics of the test componds are studied with male ICR mice (n=6 for each group, weight 20-30 g) after a single intraveneous and oral dosing at 2.5 and 10 mg/kg, respectively. For i.v. dosing formulation, the test compound is dissolved in DMSO (0.25%)-solutol(10%)-ethanol(10%)-physiological saline(79.75%) at the concentration of 0.25 mg/mL. And the p.o. Dosing formulation (1 mg/mL) is prepared with 0.5% CMC-Na. After i.v. Or p.o. Dosing, blood samples are collected via the ophthalmic vein at 0 (pre-close), 5, 15, 30 min and 1, 1.5, 2, 4, 8, 24 h, anti-coagulated with heparin-Na. After centrifugation, plasma samples are seprated and protein precipitated with acetonitrilel containing internal standard.\