Following a single oral dose or 5 consecutive daily doses, ARS-1620 yields average peak tumor concentrations of 1.5 μM (50 mg/kg) and 5.5 μM (200 mg/kg), respectively, that enables significant KRASG12C target occupancy (>=70% G12C-TE at 200 mg/kg) for >24 hr. In MIAPaCa2 xenografts (p.G12C), ARS-1620 significantly inhibits tumor growth (p<0.001) in a dose-dependent manner with marked regression at a dose of 200 mg/kg, given once daily. Across all tumor models employed, ARS-1620 is well tolerated over the entire 3-week treatment period. Moreover, there are no observed clinical signs or toxicity of ARS-1620 in CD-1 mice even at oral doses up to 1,000 mg/kg administered daily over a 7-day period.
