A multicenter, open-label, dose-escalation, phase 1 study evaluated the IDH1 inhibitor DS-1001 (safusidenib, AB-218) in patients with recurrent IDH-mutant gliomas of any grade.6 Of the 45 patients, 4 had grade 2 oligodendroglioma, 11 had grade 3 oligodendroglioma, 12 had grade 2 astrocytoma, 11 had grade 3 astrocytoma, and 7 had grade 4 astrocytoma. Here, IDH2 is linked to glioma.