AGI-6780 potently reduce (R)-2-hydroxyglutarate (2HG) levels in cell lines ectopically overexpressing IDH2/R140Q with EC50 of 20 nM, with excellent selectivity against other dehydrogenases. AGI-6780 reverses the IDH2/R140Q-induced differentiation block in TF-1 cells, and induces blast differentiation in primary human IDH2/R140Q AML patient samples.