Treosulfan Recruiting Phase 2 Trials for Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Myelodysplastic Syndrome / Childhood Acute Lymphoblastic Leukemia in Remission / Myelodysplastic Syndrome With Excess Blasts-2 / Blasts Under 5 Percent of Bone Marrow Nucleated Cells / Adult Acute Myeloid Leukemia in Remission / Acute myeloid leukaemia (in remission) / Refractory Anemia With Excess Blasts / Adult Acute Lymphoblastic Leukemia in Remission / Childhood Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Childhood Myelodysplastic Syndrome / Acute Lymphoblastic Leukemia in Remission / RAEB-2 / Childhood Acute Myeloid Leukemia in Remission / Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Adult Myelodysplastic Syndrome / Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Acute Biphenotypic Leukemia (ABL) Treatment