Enasidenib (AG-221) Maintenance Post Allogeneic HCT in Patients With IDH2 Mutation

PRIMARY OBJECTIVES: 1\. Evaluate the efficacy of enasidenib as post-HCT maintenance therapy in patients with mIDH2 AML, at 2-years post-HCT. SECONDARY OBJECTIVES: 1. Assess overall (OS) and leukemia-free survival (LFS) at 1 and 2 years post-HCT; 2. Estimate the cumulative incidence of chronic GVHD at 1 and 2 years post-HCT; 3. Estimate the cumulative incidence of relapse, non-relapse mortality (NRM), GVHD and relapse free survival (GRFS) at 1 and 2 years post-HCT. EXPLORATORY OBJECTIVES: 1. Monitor disease status among subset of patients with MRD positive disease when start to receive Enasidenib by multiparameter flow cytometry post allogeneic HCT on patients BM on days +100 and +365; 2. Investigate clearance of IDH2 mutation post HCT by NGS-PCR testing on the bone marrow specimens on days +100 and +365 and in peripheral blood every 3 months till 2 year follow up; and OUTLINE: Patients receive enasidenib orally (PO) once daily (QD) on days 1-28. Treatment repeats every 28 days for up to 24 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days and periodically thereafter up to 2 years.