Encorafenib (LGX818) is an orally available mutated BRaf V600E inhibitor(IC50=0.3 nM) with potential antineoplastic activity.

B-Raf (V600E):0.3 nM

The Raf kinase activity reaction is started by the addition of 10 μL per well of 2×ATP diluted in assay buffer. After 3 hours (bRaf(V600E)) or 1 hour (c-Raf), the reactions are stopped with the addition of 10 μL of stop reagent (60 mM EDTA). Phosphorylated product is measured using a rabbit anti-p-MEK antibody and the Alpha Screen IgG (ProteinA) detection Kit, by the addition of 30 μL to the well of a mixture of the antibody (1:2000 dilution) and detection beads (1:2000 dilution of both beads) in bead buffer (50 mM Tris, pH 7.5, 0.01% Tween20). The additions are carried out under dark conditions to protect the detection beads from light. A lid is placed on top of the plate and incubated for 1 hour at room temperature, then the luminescence is read on a PerkinElmer Envision instrument. The concentration of each compound for 50% inhibition (IC50) is calculated by non-linear regression using XL Fit data analysis software

LGX818 is dissolved in DMSO. A375 is a melanoma cell line that harbors the B-Raf V600E mutation. A375-luc cells engineered to express luciferase is plated to 384-well white clear bottom plates as 1,500 cells/50 μL/well in DMEM containing 10% FBS. Test compounds, dissolved in 100% DMSO at appropriate concentrations, are transferred to the cells by a robotic Pin Tool (100 mL). The cells are incubated for 2 days at 25°C, then 25 μL of BrightGloTM is added to each well and the plates are read by luminescence. The concentration of each compound for 50% inhibition (IC50) is calculated by non-linear regression using XL Fit data analysis software. wild type and V600E B-Raf.