SCH772984 HCl is a selective inhibitor of ERK1/2 that displays behaviors of both type I and type II kinase inhibitors, with IC50s of 4 and 1 nM, respectively. SCH772984 HCl has nanomolar cellular potency in tumor cells with mutations in BRAF, NRAS, or KRA

ERK1:4 nM, ERK2:1 nM

In LOX BRAFV600E melanoma cells, SCH772984 HCl (3, 10, 30, 100, 300 nM; 24 hours) inhibited ERK and RSK phosphorylation. SCH772984 HCl showed EC50 values less than 500 nM in approximately 88% and 49% of BRAF-mutant (n=25) or RAS-mutant (n=35) tumor lines, respectively. In SCH772984 HCl-sensitive melanoma cells, SCH772984 HCl (300 nM; 24-48hours) resulted in a G1 arrest[1].

In female nude mice bearing human LOX BRAFV600E tumors, SCH772984 HCl (12.5, 25, 50 mg/kg; i.p. twice daily for 14 days) lead to 98% tumor regression at all doses. Dose-dependent antitumor activity is also observed in the KRAS-mutant pancreatic MiaPaCa model, with 36% regression at 50 mg/kg twice daily. Importantly, tumor regression is accompanied by robust inhibition of ERK phosphorylation in tumor tissue[1].