I. Determine the efficacy and safety profile of the use of CPX-351 in older patients (age 60 and older) with: higher risk of myelodysplastic syndrome (MDS) who are refractory/relapsed after prior hypomethylating (HMA) therapy; subjects greater than 75 years old with higher risk MDS who are HMA relapsed/refractory who have progressed to acute myeloid leukemia (AML)); AML with refractory/relapsed disease after prior HMA therapy for AML.