KO947 is an ERK inhibitor (IC50 = <50 nM for ERK2).1,2 It is greater than 50-fold selective for ERK over a panel of 450 kinases.1 KO947 reduces phosphorylation of the ERK target p90 ribosomal S6 kinase (RSK) in A375 cancer cells containing constitutively active B-RAFV600E with an IC50 value of less than 250 nM.2 It inhibits proliferation of A375 cells, as well as mutant K-Ras-expressing HCT116 and H358 cancer cell lines (IC50s = 50-250 nM for all).
1.Burrows, F., Kessler, L., Chen, J., et al.Abstract 5168: KO-947, a potent ERK inhibitor with robust preclinical single agent activity in MAPK pathway dysregulated tumorsCancer Res.77(13 Suppl.)5168-5168(2017) 2.Li, L., Wu, T., Feng, J., et al.Inhibitors of ERK and methods of use(2015)