BI-3406

BI-3406, a selective SOS1 inhibitor, enhanced the AMG 510-induced growth suppression in MIA PaCa-2 cells. Treatment with 5 µM BI-3406 following the excision of endogenous mutant KRAS abolishes both ERK and AKT activation, consistent with the inhibition of WT RAS signaling.^[1]

MIA PaCa-2 cells were seeded at 2,000 cells per well and treated 24 h after seeding with 5 μM BI-3406 or DMSO control and AMG 510 (from 5 μM to 0.1 nM). Cell viability was measured after 4 d with CellTiter-Glo. mT42 cells were seeded at 1,000 cells per well and treated with 4-OHT or DMSO control and BI-3406 in a dose–response manner (from 20 μM to 2 nM). Cell viability was measured using CellTiter-Glo Luminescence assay at day 4. FPC cell line mT42 cells were treated with 5 μM BI-3406, 20 nM trametinib, or DMSO vehicle control in the presence or absence of mutant KRAS by treatment with DMSO vehicle control or 4-OHT, respectively. Immunoblotting was performed for RAS pathways by phospho-ERK and phospho-AKT and the RSK1 substrate phospho-S6.

BI-3406, a potent and selective SOS1-KRAS Interaction Inhibitor, is effective in KRAS-driven cancers through combined MEK inhibition.^[2]