Sunitinib

A multi-targeted RTK inhibitor that targets VEGFR2 (Flk-1) and PDGFRβ with Ki of 8 nM and 9 nM respectively; displays >10-fold higher selectivity over FGFR-1, EGFR, Cdk2, Met, IGFR-1, Abl, and Src; also inhibits phosphorylation of wild-type FLT3, FLT3-ITD, and FLT3-Asp835 with IC50 of 250 nM, 50 nM, and 30 nM; regresses FLT3-ITD tumors in the subcutaneous tumor xenograft model.Gastric Cancer Approved (In Vitro) :Sunitinib Malate is also a good inhibitor of KIT and FLT-3. In RS4;11 cells (FLT3-WT), treatment with Sunitinib (SU11248) inhibits FLT3-WT phosphorylation in a dose-dependent manner with IC50 of approximately 250 nM. In MV4;11 cells that express FLT3-ITD, Sunitinib inhibits FLT3-ITD phosphorylation in a dose-dependent manner with an IC50 of 50 nM following a 2-hour treatment.In biochemical assays, Sunitinib (SU11248) exhibits competitive inhibition (with regard to ATP) against Flk-1 and PDGFRβ with Ki values of 9 nM and 8 nM, respectively. Sunitinib is also a competitive, albeit less potent, inhibitor of FGFR1 tyrosine kinase activity, with a Ki value of 0.83 μM. In addition to these three structurally related split kinase domain RTKs, the activity of Sunitinib has also been evaluated against a broad panel of additional tyrosine and serine/threonine kinases. In these biochemical assays, the IC50 values for Sunitinib are generally at least 10-fold higher than those for Flk-1 and PDGFR (e.g., IC50values of: >10 μM for EGFR and Cdk2; 4 μM for Met; 2.4 μM for IGFR-1; 0.8 μM for Abl; and 0.6 μM for Src) . (In Vivo) :Sunitinib Malate has very good oral bioavailability, is highly efficacious in a number of preclinical tumor models, and is well tolerated at efficacious doses. Sunitinib (80 mg/kg/day) inhibits the growth of established SF763T and Colo205 tumor xenografts in athymic mice. Sunitinib (SU11248) treatment effectively inhibits the growth of established tumor xenografts.