Intra Bone Marrow Injection Of Unrelated Cord Blood Cells

Overview

Compared to other stemcell sources cord blood (CB) is easier and safer to procure, has no donor attrition, a limitless supply, reduced viral transmission, less acute \& chronic GVHD, is rich in hematopoietic progenitor cells, and immaturity of T-cell-mediated immunity. CB has delayed neutrophil and platelet engraftment, a prolonged immune reconstitution, uncertain graft-vs-tumor activity, and cell doses from single CB units (U) are a limiting factor for larger recipients Using the intravenous route (IV), a close match between the patient (pts) and the donor or CBU can improve a pts outcome after transplant. Even though a closely matched CBU is preferred, the studies suggest the match may not have to be as close as is needed for marrow or peripheral blood transplants If one has an uncommon tissue type, the doctor may not find a closely matched adult donor and a CBU may be an option, are stored and ready to use. GVHD is a complication after an allogeneic transplant. Studies founded that after a CBtransplant, fewer pts get GVHD than after marrow or peripheral blood transplants. Pts in the studies who did get GVHD after CBtransplant tended to get less severe cases We hypothesized that direct intrabone transplant of CBcells could improve haematologic recovery due to a better stem cell homing, based on the following observations: stem cells recirculate in animals irradiated with limb shielding; a limited fraction (10-15%) of cells injected iv to the haematopoietic sites, possibly because the large majority is lost in other organs; in a mousemodel, HSC directly injected ib repopulated the marrow of lethally irradiated mice 10times more efficiently than HSC cells injected iv; delayed engraftment after CB transplant is possibly not caused by insufficient stem cell numbers; indeed, children grafted with CB cells have superior stem cell reservoir 1year posttransplant when compared to marrow transplant recipients Based on these data, we set-up a phase I-II study to evaluate whether ib injection could be safely performed and whether this procedure could ensure engraftment and shorten the time of complete hematopoietic recovery in adults with high risk haematopoietic malignancies compared to the published data. Neutrophil recovery \>80% at day60 and Platelets recovery \>80% at days100 were defined as success. 1° endpoint was the probability of neutrophils and platelets recovery after ib CB transplant, 2° included incidence of acute GVHD, relapse, overall survival

Study Design Phase I-II study. Neutrophil recovery \> 80% at day 60 and Platelets recovery \> 80% at days 100 are defined as success. The limit of 60 days for neutrophil recovery was chosen because it represents the time at which rescue with a second transplant is decided in case of failure to engraft; the day 100 for platelets recovery is taken corresponds to first form reported after transplant to the European Blood and Marrow Transplant Registry. HLA-A and -B antigens will be identified by low resolution DNA typing, whereas HLA-DRB1 type was determined by high resolution DNA typing techniques. HLA-A, HLA-B, and HLA-DRB1 typing was used to select the most closely matched donor unit-recipient pair, with preference given to HLA-DRB1-matched unit