GRanulocyte Augmented Cord Blood Transplantation for Poor Risk leukaEmia

INCLUSION CRITERIA: 1. Availability of a suitable cord blood unit 2. Age between 16 and 55 years 3. Primary diagnosis of Acute Myeloid Leukaemia (AML) or MDS/AML (as defined by ICC 2022) fitting one or more of the following criteria: * TP53 mutation (single- or multi-hit) * Presence of inv(3) (q21.3q26.2) or t(3;3)(q21.3;q26.2) * Adverse risk (as per ICC 2022) and \>0.1% MRD by flow cytometry after 2 cycles of induction * AML (any risk) with partial remission (\<10% blasts) after 2 cycles induction * Early relapse (\<6 months) after chemotherapy alone (excluding t(16;16), inv(16) or t(8;21)) 4. Bone marrow performed within 28 days of starting conditioning chemotherapy demonstrates either: * \<10% blasts * \>10% blasts with a hypocellular background (must be discussed with the trial team) 5. Suitable fitness and organ function as per the following criteria: * Glomerular filtration rate \>50 mL/min/1.73m2 * Ejection fraction \>50% * FEV1 \>65% without dyspnoea on mild activity * AST/ALT \<3 x ULN * Bilirubin \<1.5 x ULN (excluding Gilbert's syndrome) * Performance Status (ECOG) of 0 or 1 6. Females of and male patients of reproductive potential (i.e., not post-menopausal or surgically sterilised) must agree to use appropriate, highly effective, contraception from the point of commencing therapy until 12 months after transplant EXCLUSION CRITERIA: 1. AML Secondary to a myeloproliferative neoplasm 2. Active CNS disease 3. Prior allogeneic stem cell transplant 4. Participation in another clinical trial that would alter any aspect of the transplant protocol or that aims to reduce the subsequent risk of relapse (discuss with trial team if unsure) 5. History of cardiac arrhythmia 6. Ischaemic heart disease, valvular heart disease or congestive cardiac failure 7. Transient ischaemic attack or cerebrovascular accident 8. Rheumatologic disease (SLE, RA, polymyositis, mixed CTD or polymyalgia rheumatica) 9. Ulcerative colitis or Crohn's disease 10. Liver cirrhosis 11. Presence of an active second malignancy 12. Uncontrolled infection, including viral reactivation (CMV, EBV) 13. HIV positive 14. Hepatitis B/C active infection with measurable viral load (patients with chronic hepatitis B or C infection require clear documentation of absence of cirrhosis by either fibroscan or biopsy, regardless of viral load) 15. Pregnancy, breastfeeding, unwilling to use contraception 16. Contraindications to administration of pooled granulocytes 17. Previous history of sensitivity to granulocytes 18. Inability of patient to give informed consent 19. Any other organ dysfunction or co-morbidity that precludes transplant in the opinion of the investigator 20. Any concern by PI