Unrelated Umbilical Cord Blood Stem Cell Combined With Azacitidine Based Treatment for Advanced MDS,CMML-2 and sAML

This study is testing a treatment combining donated umbilical cord blood stem cells with azacitidine-based chemotherapy for people with advanced myelodysplastic syndrome (MDS), a pre-leukemia bone marrow disease, a related condition called CMML-2, or secondary acute myeloid leukemia (AML) — in patients who cannot receive a standard bone marrow transplant. **You may be eligible if...** - You have been diagnosed with high-risk MDS, CMML-2, or AML that developed from a previous blood condition - You are not eligible for a standard allogeneic stem cell transplant (due to age, health, or other factors) - Your disease meets specific criteria based on bone marrow testing **You may NOT be eligible if...** - You are eligible for and can receive a standard stem cell transplant - You have serious organ damage or other conditions that make this treatment too risky - Other exclusion criteria as determined by your doctor Talk to your doctor to see if this trial is right for you.