AGI-6780 is a potent and selective inhibitor of IDH2 R140Q mutant.

IDH2 (R140Q):23 nM

AGI-6780 reverses differentiation blockage induced by IDH2/R140Q in TF-1 cells and induces rapid differentiation in primary samples from patients with IDH2/R140Q AML. It effectively reduces the levels of (R)-2-hydroxyglutarate (2-HG) in cell lines overexpressing ectopic IDH2/R140Q, with an EC50 of 20 nM, demonstrating excellent selectivity compared to other dehydrogenases.

AGI-6780 is prepared as 10 mM stock in DMSO and diluted to 50X final concentration in DMSO, for a 50 μL reaction mixture. IDH enzyme activity converting alpha-ketoglutarate to 2-hydroxyglutarate is measured using a NADPH depletion assay. In the assay the remaining cofactor is measured at the end of the reaction with the addition of a catalytic excess of diaphorase and resazurin, to generate a fluorescent signal in proportion to the amount of NADPH remaining. IDH enzyme activity in the direction of isocitrate to alpha-ketoglutarate conversion is measured by direct coupling of the NADPH production to conversion of resazurin to resorufin by diaphorase. In both cases, resorufin is measured fluorometrically at Ex544 Em590[1].

AGI-6780 is dissolved in DMSO and stored, and then diluted with appropriate media before use[1]. Cells are sorted from fresh or frozen bone marrow aspirates and blood samples after labelling with PE-CD34, APC-CD38, PE-CD14, FITC-CD3 (clone HIT3a) and PECy7-CD19 (clone SJ25C1) antibodies using a MoFlow cell sorter. Unfractionated nucleated blood or bone marrow cells are plated in Methocult H4434 methylcellulose medium at 104 cells/dish, in duplicate dishes per condition. AGI-6780 (5 mM) is directly added to the medium. Dishes are incubated in a humidified incubator at 37°C and colonies containing at least 30 cells are counted after 13 days[1].