Previously, acute myeloid leukemia (AML) treatment options have been confined to chemotherapy, so development of additional treatment options is a priority in combating AML. Recently, based on a phase I/II, open-label, single arm AG221-C-001 trial recruiting 199 relapsed or refractory AML, the US FDA has now approved the first IDH2 inhibitor, enasidenib, for treatment in AML patients with IDH2 mutations. The trial results showed that 19% of patients achieved complete remission (CR) and the medium duration of response was 8.2 months. Moreover, 4% of patients experienced complete remission with partial hematologic recovery and medium duration of response was 9.6 months. Enasidenib hence shown prominence as a new treatment option for relapsed or refractory AML patients with specific IDH2 genetic mutations.