Testing the Addition of an IDH2 Inhibitor, Enasidenib, to Usual Treatment (Cedazuridine-Decitabine) for Higher-Risk Myelodysplastic Syndrome (MDS) With IDH2 Mutation (A MyeloMATCH Treatment Trial)

Inclusion Criteria: * GENERAL MYLEOMATCH REGISTRATION CRITERIA: * Patients must be registered to the Master Screening and Reassessment Protocol (MSRP) and assigned to this protocol by the MATCHBox Treatment Verification Team. * Participants must not have received prior anti-cancer therapy for AML or MDS. * Note: Hydroxyurea to control the white blood cell count (WBC) is allowed. * Note: Prior erythroid stimulating agent (ESA) is not considered prior therapy for the purposes of eligibility. * Participants must not be currently receiving any cytarabine-containing therapy other than up to 1 g/m\^2 of cytarabine, which is allowed for urgent cytoreduction. The use of prior hydroxyurea, all-trans retinoic acid (ATRA), BCR-ABL directed tyrosine kinase inhibitor, erythropoiesis-stimulating agent, thrombopoietin receptor agonist and lenalidomide is allowed * REGISTRATION ELIGIBILITY CRITERIA (STEP 1): Patients must have a morphologically-confirmed diagnosis of MDS with a Revised International Prognostic Scoring System (IPSS-R) score ≥ 4. * REGISTRATION ELIGIBILITY CRITERIA (STEP 1): Patients must have a detectable pathogenic IDH2 mutation based on the National Cancer Institute (NCI) Myeloid Panel. * REGISTRATION ELIGIBILITY CRITERIA (STEP 1): No prior treatment with deoxyribonucleic acid (DNA) methyltransferase inhibitors (ASTX727, azacitidine, or decitabine). * REGISTRATION ELIGIBILITY CRITERIA (STEP 1): Prior treatment with growth factors (ESA, granulocyte colony-st…