The mutant IDH 1 and IDH2 inhibitor AG-881, which is able to pass the blood–brain barrier, is currently used as a standalone drug in clinical trials to treat IDH-mutated glioma patients (NCT02481154, NCT04164901, NCT03343197), and was used in a Phase I study in patients with hematological malignancies (AML, myelodysplastic syndrome) already completed (NCT02492737). Here, IDH2 is linked to myelodysplastic syndrome.