Prophylactic DLI for the Prevention of Relapse Post HSCT in Patients With High Risk Myeloid Malignancy

Patient Inclusion Criteria 1. Haematological cancer which can be one of the following 1. Acute Myeloid Leukaemia (AML) if Intermediate or High risk in CR1 2. AML if favourable risk in CR2 3. Patients with AML or MDS with residual cytogenetic or molecular disease pre-HSCT 4. CMML 5. Myelodysplastic Syndrome (MDS) defined by an IPSS category int-1 or higher with \<5% blasts at the time of randomisation following cyto-reduction if necessary 6. Secondary MDS or AML; defined as arising from antecedent haematological disease or secondary to prior chemotherapy. 2. Patients with sibling or 9/10 or 10/10 HLA matched unrelated donor 3. Patients receiving alemtuzumab based reduced intensity conditioned HSCT 4. Age \>/=18 years 5. Able to comprehend and give informed consent Patient Exclusion Criteria 1. Patients with \>5% blasts at time of HSCT 2. Patients eligible for myeloablative (Bu/Cy of Cy/TBI) HSCT protocols 3. Patients with myelofibrosis 4. Patients with hypersensitivity to alemtuzumab, melphalan, fludarabine or busulphan 5. ECOG performance status \> 2 6. Patients who are pregnant or lactating