IDH2R140Q-IN-2 is an orally active and potent IDH2R140Q inhibitor with an IC50 of 29 nM.IDH2R140Q-IN-2 possesses potential antitumour activity, reducing D2HG production in TF-1 cell lines carrying the IDH2R140Q mutation (IC50 of 10 nM) and inhibiting tumour tissue D2HG levels.IDH2R140Q-IN-2 is suitable for the study of acute myeloid leukaemia (AML).