Description

Solid tumours, Gastrointestinal and liver cancer

Description

Brivanib is an ATP-competitive inhibitor against human VEGFR2 and mouse Flk-1 with IC50 of 25 nM and 89 nM, respectively.

Targets

IC₅₀

In Vitro

Brivanib also inhibits VEGFR1 and FGFR-1 with IC50 of 0.38 μM and 0.148 μM. Brivanib is not sensitive to PDGFRβ, EGFR, LCK, PKCα or JAK-3 with IC50 all above 1900 nM. Brivanib could inhibit the proliferation of VEGF-stimulated HUVECs with IC50 of 40 nM, compared to 276 nM in FGF-stimulated HUVECs. On the other hand, Brivanib exhibits low activity to tumor cell lines. ^[1]

In Vivo

Brivanib displays antitumor activities in H3396 xenograft in athymic mice. At a dose of 60 and 90 mg/kg (p.o.), Brivanib completely inhibits the tumor growth, with TGI of 85% and 97%, respectively. ^[1] Moreover, Brivanib significantly suppresses tumor growth in Hepatocellular carcinoma (HCC) xenografts, which due to the decrease in phosphorylation of VEGFR2. The results show that the tumor weights in 06-0606 xenograft mice are 55% and 13%, compared with the controls at a dose of 50 mg/kg and 100 mg/kg. Brivanib is suggested to be efficient in treatment of HCC. ^[2]

Clinical Trials

Combining with best supportive care to placebo, Brivanib is currently in Phase III clinical trial in Asian subjects with advanced hepatocellular carcinoma (HCC) who have failed or are intolerant to sorafenib.

Features

In Vitro Kinase Assays

Recombinant proteins containing tyrosine kinases are expressed as GST fusion proteins using baculovirus expression vector system in Sf9 cells. All enzymes are stored at -80 °C. Brivanib is dissolved in DMSO and diluted by water/10% DMSO. The VEGFR2 kinase solution is composed by 8 ng GST-VEGFR2 enzyme, 75 μg/mL substrate, 1 μM ATP, and 0.04 μCi [γ-³³P]-ATP in 50 μL buffer: 20 mM Tris (pH 7.0), 25 μg/mL BSA, 1.5 mM MnCl₂, 0.5 mM dithiothreitol). Flk-1 kinase solution is composed by 10 ng GST-Flk-1 enzyme, 75 μg/mL substrate, 1 μM ATP, and 0.04 μCi [γ-³³P]-ATP in 50 μL buffer: 20 mM Tris, pH 7.0, 25 μg/mL BSA, 4 mM MnCl₂, 0.5 mM dithiothreitol). The reactions are incubated for 1 hour at 27 °C and terminated with cold trichloroacetic acid (TCA) to a final concentration of 15%. These TCA precipitates are collected onto unifilter plates and quantitated by liquid scintillation counter.

Cell Lines

VEGF or FGF stimulated HUVECs

Concentrations

~ 10 μM

Incubation Time

48 hours

Methods

The cells are stimulated by VEGF or FGF at a concentration of 8 or 80 ng/mL. These cells are seeded in 96 well plates at a density of 2 × 10³ and incubated for 24 hours. Brivanib at various dilutions are added to the cells for another 48 hours. Then 0.5 μCi of [³H] thymidine is added for 24 hours. After that the incorporated tritium is quantified using a β-counter.

Animal Models

H3396 xenografts in athymic mice

Formulation

Dissolved in PEG400: Tween80 (75:25) (orally) or PEG400: water (3:2) (intravenously)

Doses

60 mg/kg (orally) or 10 mg/kg (intravenously)

Administration

Administered via oral or i.v.