Anti-leukaemic activity of a novel haploidentical-transplantation approach employing unmanipulated bone marrow followed by CD6-depleted peripheral blood stem cells in children with refractory/relapsed acute leukaemia

The treatment outcome of children with refractory acute leukaemia or relapse post-stem cell transplantation is dismal. We report 10 children (non-remission n = 7) who underwent a new haploidentical transplant approach utilizing unmanipulated bone marrow followed by CD6-depleted peripheral blood stem cells. Nine patients had successful engraftment and no evidence of leukaemia. Acute and chronic graft-versus-host-disease was observed in five and three patients, respectively; two patients died of treatment-related toxicity. Seven patients relapsed after 7 (range 3-34) months, however two patients are alive at 6·5 and 7·0 years. This approach provides anti-leukaemic activity even in heavily pre-treated children but long-term disease control requires further intervention.