Inclusion Criteria:

          -  Age >= 18 years;

          -  Informed consent;

          -  Low- and intermediate-risk MDS that has failed to achieve any hematologic improvement
             after at least 4 cycles of induction therapy or has relapsed after any duration of any
             hematologic response. Prior therapy with azanucleosides (i.e., azacitidine,
             decitabine), biologic therapies (i.e., lenalidomide, rigosertib) and hematopoietic
             cell transplant are permissible;

          -  Performance status must be Eastern Cooperative Oncology Group (ECOG) 0, 1, or 2;

          -  Women of child-bearing potential (i.e., women who are pre-menopausal or not surgically
             sterile) may participate, provided they meet the following conditions:

               -  Must agree to use physician-approved contraceptive methods throughout the study
                  and for three months following the last dose of omacetaxine and

               -  Must have a negative serum or urine pregnancy test within 7 days prior to
                  beginning treatment on this trial;

          -  Males with female partners of child-bearing potential must agree to use
             physician-approved contraceptive methods throughout the study and should avoid
             conceiving a child for 6 months following the last dose of omacetaxine.

        Exclusion Criteria:

          -  Subjects who are eligible for hematopoietic stem cell transplant;

          -  History of atrial fibrillation related to azanucleoside therapy in the past;

          -  Active, uncontrolled, clinically significant infection;

          -  Pregnant and nursing patients are excluded because the effects of omacetaxine on a
             fetus or nursing child are unknown;

          -  Treatment with any anticancer therapy (standard or investigational) within the
             previous 14 days prior to the first dose of study drug or less than full recovery from
             the clinically significant toxic effects of that treatment.