Cell experiment:

Melanoma, colon, breast, and lung cancer cells are left to attach for 16 hours and then treated with a 10-point dilution series in duplicate. CellTiter-Glo reagent is added in each well. Mixture is mixed on an orbital shaker for 2 minutes to allow cell lysing, followed by 10 minutes incubation at room temperature to allow development and stabilization of luminescent signal. Luminescent signal is measured using PHERAstar FS reader. EC50 values for cell viability are determined[1].

Animal experiment:

Mice: When the average tumor size reaches 110 to 200 mm3, mice are randomized to treatment groups and treated twice per day or once daily by oral gavage (p.o.) with vehicle alone or 2.5 to 30 mg/kg of BGB-283. As control, mice are treated with erlotinib (100 mg/kg qd) or cetuximab (40 mg/kg twice weekly). Lifirafenib (BGB-283) and erlotinib are formulated at the desired concentration as a homogenous suspension in 0.5% (w/v) methylcellulose in purified water. Cetuximab is formulated by diluting the injection solution with saline before dosing[1].

BGB-283 is a novel and potent Raf Kinase and EGFR inhibitor with IC50 values of 23 and 29 nM for recombinant BRafV600E and EGFR, respectively.

BGB-283 potently inhibits BRafV600E-activated ERK phosphorylation and cell proliferation. It demonstrates selective cytotoxicity and preferentially inhibits proliferation of cancer cells harboring BRafV600E and EGFR mutation/amplification. In BRafV600E colorectal cancer cell lines, BGB-283 effectively inhibits the reactivation of EGFR and EGFR-mediated cell proliferation[1].

BGB-283 treatment leads to dose-dependent tumor growth inhibition accompanied by partial and complete tumor regressions in both cell line-derived and primary human colorectal tumor xenografts bearing BRafV600E mutation[1].

References:
[1]. Tang Z, et al. BGB-283, a Novel RAF Kinase and EGFR Inhibitor, Displays Potent Antitumor Activity in BRAF-Mutated Colorectal Cancers. Mol Cancer Ther. 2015 Oct;14(10):2187-97.