Inclusion Criteria:

          -  Eastern Cooperative Oncology Group (ECOG) performance status of =< 2

          -  IDH1-R132 mutated disease status as assessed by local laboratory. 2HG-producing IDH1
             variants outside of R132 (i.e. R100) may be eligible after discussion with the
             principal investigator (PI)

          -  Treatment naive or relapsed/refractory AML who are eligible for intensive
             chemotherapy. Patients with high-risk MDS or MPN (defined as >= 10% bone marrow
             blasts, or intermediate or high risk by International Prognostic Scoring System
             [IPSS], revised [R]-IPSS or dynamic [D]-IPSS) may also be eligible after discussion
             with the PI

          -  Direct bilirubin =< 2 x upper limit of normal (ULN) unless deemed to be related to
             underlying leukemia

          -  Alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) =< 3 x ULN
             unless deemed to be related to underlying leukemia

          -  Creatinine clearance >= 30 ml/min based on the Cockcroft-Gault equation

          -  Willing and able to provide informed consent

          -  In the absence of rapidly proliferative disease, the interval from prior treatment to
             time of initiation will be at least 7 days for cytotoxic or non-cytotoxic
             (immunotherapy) agents

          -  Male subjects must agree to refrain from unprotected sex and sperm donation from
             initial study drug administration until 90 days after the last dose of study drug

        Exclusion Criteria:

          -  Patients who have previously received either ivosidenib or CPX-351

          -  Patients with any concurrent uncontrolled clinically significant medical condition
             including infection, laboratory abnormality, or psychiatric illness, which could place
             the patient at unacceptable risk of study treatment

          -  The use of other chemotherapeutic agents or anti-leukemic agents is not permitted
             during study with the following exceptions (1) intrathecal chemotherapy for
             prophylactic use or for controlled central nervous system (CNS) leukemia. (2) use of
             hydroxyurea, and/or cytarabine (1 or 2 doses; up to 2 g/m^2) for patients with rapidly
             proliferative disease is allowed before the start of study therapy

          -  Patients with active graft-versus-host-disease (GVHD) status post stem cell transplant
             (patients without active GVHD on chronic suppressive immunosuppression and/or
             phototherapy for chronic skin GVHD are permitted after discussion with the PI)

          -  Patients with any severe gastrointestinal or metabolic condition which could interfere
             with the absorption of oral study medications

          -  Patients with symptomatic congestive heart failure (New York Heart Association [NYHA]
             class III or IV), unstable angina, or an ejection fraction < 45%

          -  Patients with prior anthracycline exposure of > 360 mg/m^2 daunorubicin (or
             equivalent) or > 210 mg/m^2 daunorubicin (or equivalent) in patients with prior
             mediastinal radiation

          -  Corrected QT (QTc) interval using Fridericia's formula (QTcF) >= 470 msec. A prolonged
             QTc interval in the setting of right bundle branch block is permitted after discussion
             with the PI

          -  Nursing women, women of childbearing potential (WOCBP) with positive urine or serum
             pregnancy test, or women of childbearing potential who are not willing to maintain
             adequate contraception

               -  Appropriate highly effective method(s) of contraception include oral or
                  injectable hormonal birth control, intrauterine device (IUD), and double barrier
                  methods (for example a condom in combination with a spermicide)

          -  Subjects with a known medical history of progressive multifocal leukoencephalopathy
             (PML)

          -  Subjects taking strong CYP3A4 inducers are excluded from the study unless they can be
             transferred to other medications within >= 5 half lives prior to dosing

          -  Patients with a diagnosis of acute promyelocytic leukemia (APL)

          -  Unresolved toxicities > grade 1 from prior treatment including chemotherapy, targeted
             therapy, immunotherapy, experimental agents, radiation, or surgery