Key Inclusion Criteria:

        Subjects are eligible for enrollment into this study if they meet any of the following
        criteria (NOTE: This is not an exhaustive list):

          -  Subjects aged ≥18 years.

          -  ECOG performance status 0 or 1

          -  Subjects must have a documented IDH mutation per immunohistochemistry (IHC),
             polymerase chain reaction (PCR), or next generation sequencing (NGS) testing of tumor
             tissue.

          -  Subjects must have histologically or cytologically documented, advanced or metastatic
             solid malignancy of any type that has recurred or progressed on available standard
             treatment and for which no curative therapy exists.

        Key Exclusion Criteria:

        Subjects are not eligible for enrollment into this study if they meet any of the following
        criteria (NOTE: This is not an exhaustive list):

          -  Subjects who received an investigational agent <14 days prior to their first day of
             study drug administration

          -  Subjects who are pregnant or breastfeeding

          -  Subjects with an active severe infection, some treated infections and with an expected
             or with an unexplained fever >38.3°C during screening visits or on their first day of
             study drug administration.

          -  Subjects with some current or prior heart conditions

          -  Subjects taking medications that are known to prolong the QT interval may not be
             eligible

          -  Subjects with immediately life-threatening, severe complications of leukemia such as
             uncontrolled bleeding, pneumonia with hypoxia or shock, and/or disseminated
             intravascular coagulation

          -  Some subjects with some current or prior gastrointestinal or liver diseases

          -  Subjects with inadequate organ function as defined by the protocol