A Prospective, Multicenter Randomized Study Comparing Single Versus Double Umbilical Cord Blood Transplantation in Children and Young Adults (<35 Years) With Acute Leukemia Remission

Unrelated cord blood transplantation (UCBT) has been used for several years when there is no HLA identical sibling or unrelated donor.Since the recent publication of encouraging results after transplantation of two UCB units, the number of these double-transplantations increases in a very significant way.However, there is currently no prospective study comparing in a reliable way the double-transplantation to single-transplantation results.The investigators propose a prospective and randomized study comparing the results of single versus double unit UCBT in children and young adults (< 35 yrs) with acute leukemia in remission. This is an open, multicenter study carried out in the allogeneic transplant centers from the French society for hematopoietic stem cell transplantation and cell therapy. The primary objective is to compare the incidence of transplantation failure in the two treatment arms. Transplantation failure, the primary endpoint of the study, is defined by the occurrence of one of the following events : transplant-related death, second allogeneic transplantation or autologous backup infusion for primary engraftment failure, autologous recovery. The financial impact of these double-transplantations being to date unknown, the project also includes a cost-effectiveness study, the effectiveness criterion being a decrease in transplantation failure incidence. The secondary clinical endpoints are: overall survival and disease-free survival, relapse incidence, transplant-related mortality, incidence of severe infections and GvHD. The secondary biological endpoints are: hematological and immunological recovery, post transplant chimerism.