RMC-0331 (RM-023) is a potent, selective and orally bioavailable SOS1 inhibitor. RMC-0331 is an in vivo tool compound that blocks RAS activation via disruption of the RAS-SOS1 interaction.In Vitro: RMC-0331 has an IC50 of 71 nM measuring by the rate of GDP/GTP exchange in vitro.In Vivo: RMC-0331 (100-250 mg/kg; p.o.; qd; immunocompetent mice) shows single agent anti-tumor activity in SHP2-mutant models.