90Yttrium-labelled Anti-CD66 Monoclonal Antibody as Part of a Reduced Intensity Conditioning Regimen Prior to Allogeneic Haematopoietic Stem Cell Transplantation: an Open Label, Dose Escalating Phase I Study in Children and Adolescents With Relapsed/Refractory Leukaemia

The radio-labeled anti-CD66 monoclonal antibody (with 111In for dosimetry and 90Y for therapy) will be administered in the T11 North room, UCLH, while the reduced intensity conditioning regimen and the allogeneic hematopoietic stem cell transplant will be performed in 2 centers, according to the age of the patient: A) patients aged < 13 years will be transplanted at the Bone Marrow Transplantation Department, Great Ormond Street Hospital (GOSH), and B) patients aged 13-18 years will be transplanted at the Bone Marrow Transplantation Department, University College London Hospitals (UCLH).