AGI-5198, potently inhibits mutant IDH1 (R132H-IDH1 and R132C-IDH1), but not wildtype IDH1 (IC50 > 100 μM) or any of IDH2 isoforms (R140Q, R172K, wildtype) (IC50 > 100 μM). AGI-5198, has been shown to have anti-tumor efficacy in the TS603 glioma cell line and to block R-2HG production in a dose-dependent manner. Under conditions of near-complete R-2HG inhibition, AGI-5198 induced demethylation of histone H3K9me3 and expression of genes associated with gliogenic differentiation. Blockade of mIDH1 impaired the growth of IDH1-mutant—but not IDH1–wild-type—glioma cells without appreciable changes in genome-wide DNA methylation.
In vivo
In R132H-IDH1 glioma xenografts, AGI-5198 (450 mg/kg/day) causes 50-60% growth inhibition over a treatment period of three weeks with no affect in the growth of IDH1 wild-type glioma xenografts. Tumors from AGI-5198-treated mice shows reduced staining with an antibody against the Ki-67 protein. But cleaved caspase-3 shows no differences between tumors from vehicle and AGI-5198–treated mice.