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Research Area
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Description
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Cancer |
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Biological Activity
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Description
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Motesanib Diphosphate (AMG-706) is a potent ATP-competitive inhibitor of VEGFR1/2/3, PDGFR, c-Kit and Ret with IC50 of 2 nM/3 nM/6 nM, 84 nM, 8 nM and 59 nM, respectively. |
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Targets
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VEGFR1 |
VEGFR2 |
VEGFR3 |
PDGFR |
c-Kit |
Ret |
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IC50 |
2 nM |
3 nM |
6 nM |
84 nM |
8 nM |
59 nM [1] |
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In Vitro
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Motesanib Diphosphate has broad activity against the human VEGFR family, and displays >1000 selectivity against EGFR, Src, and p38 kinase. Motesanib Diphosphate significantly inhibits VEGF-induced cellular proliferation of HUVECs with an IC50 of 10 nM, while displaying little effect at bFGF-induced proliferation with an IC50 of >3,000 nM. Motesanib Diphosphate also potently inhibits PDGF-induced proliferation and SCF-induced c-kit phosphorylation with IC50 of 207 nM and 37 nM, respectively, but not effective against the EGF-induced EGFR phosphorylation and cell viability of A431 cells. [1] Althouth displaying little antiproliferative activity on cell growth of HUVECs alone, Motesanib Diphosphate treatment significantly sensitizes the cells to fractionated radiation. [2] |
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In Vivo
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Administration of Motesanib Diphosphate at 100 mg/kg significantly inhibits VEGF-induced vascular permeability in a time-dependent manner. Oral administration of Motesanib Diphosphate twice daily or once daily potently inhibits, in a dose-dependent manner, VEGF-induced angiogenesis using the rat corneal model with ED50 of 2.1 mg/kg and 4.9 mg/kg, respectively. Motesanib Diphosphate induces a dose-dependent tumor regression of established A431 xenografts by selectively targeting neovascularization in tumor cells. [1] Administration of Motesanib Diphosphate in combination with radiation displays significant anti-tumor activity in head and neck squamous cell carcinoma (HNSCC) xenograft models. [2] Motesanib Diphosphate treatment also induces significant dose-dependent reductions in tumor growth and blood vessel density of MCF-7, MDA-MB-231, or Cal-51 xenografts, which can be markedly enhanced when combined with docetaxel or tamoxifen. [3] |
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Clinical Trials
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A Phase I study to evaluate the effect of different doses of Motesanib Diphosphate on the gallbladder in advanced solid tumors has been completed. |
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Features
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Protocol
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Kinase Assay
[1]
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| In vitro kinase assays |
Optimal enzyme, ATP, and substrate (gastrin peptide) concentrations are established for each enzyme using homogeneous time-resolved fluorescence (HTRF) assays. Motesanib Diphosphate is tested in a 10-point dose-response curve for each enzyme using an ATP concentration of two-thirds Km for each. Most assays consist of enzyme mixed with kinase reaction buffer [20 mM Tris-HCl (pH 7.5), 10 mM MgCl2, 5 mM MnCl2, 100 mM NaCl, 1.5 mM EGTA]. A final concentration of 1 mM DTT, 0.2 mM NaVO4, and 20 μg/mL BSA is added before each assay. For all assays, 5.75 mg/mL streptavidin-allophycocyanin and 0.1125 nM Eu-PT66 are added immediately before the HTRF reaction. Plates are incubated for 30 minutes at room temperature and read on a Discovery instrument. IC50 values are calculated using the Levenberg-Marquardt algorithm into a four-parameter logistic equation. |
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Cell Assay
[1]
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| Cell Lines |
A431, MO7e, HUVEC and NHDF cells |
| Concentrations |
Dissolved in DMSO, final concentrations ~25 μM |
| Incubation Time |
2 hours |
| Methods |
Cells are preincubated for 2 hours with different concentrations of Motesanib Diphosphate, and exposed with 50 ng/mL VEGF or 20 ng/mL bFGF for an additional 72 hours. Cells are washed twice with DPBS, and plates are frozen at -70 °C for 24 hours. Proliferation is assessed by the addition of CyQuant dye, and plates are read on a Victor 1420 workstation. IC50 data are calculated using the Levenberg-Marquardt algorithm into a four-parameter logistic equation. |
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Animal Study
[1]
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| Animal Models |
Female Sprague-Dawley rats with induced corneal angiogenesis, and female CD-1 nu/nu mice injected s.c. with A431 cells |
| Formulation |
Formulated as a suspension in Ora-Plus vehicle adjusted to pH 2.0 |
| Doses |
~100 mg/kg |
| Administration |
Orally administered twice daily or once daily |
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References |
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[1] Polverino A, et al. Cancer Res, 2006, 66(17), 8715-8721.
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[2] Kruser TJ, et al. Clin Cancer Res, 2010, 16(14), 3639-3647.
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[3] Coxon A, et al. Clin Cancer Res, 2009, 15(1), 110-118.
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