Results of a prospective multicentre myeloablative double‐unit cord blood transplantation trial in adult patients with acute leukaemia and myelodysplasia

Summary Double‐unit cord blood ( CB ) grafts may improve engraftment and relapse risk in adults with haematological malignancies. We performed a prospective high‐dose myeloablative double‐unit CB transplantation ( CBT ) trial in adults with high‐risk acute leukaemia or myelodysplasia ( MDS ) between 2007 and 2011. The primary aim was to establish the 1‐year overall survival in a multi‐centre setting. Fifty‐six patients (31 acute myeloid leukaemia, 19 acute lymphoblastic leukaemia, 4 other acute leukaemias, 2 myelodysplastic syndrome [ MDS ]) were transplanted at 10 centres. The median infused total nucleated cell doses were 2·62 (larger unit) and 2·02 (smaller unit) x 10 7 /kg. The cumulative incidence of day 100 neutrophil engraftment was 89% (95% confidence interval [ CI ]: 80–96). Day 180 grade II ‐ IV acute graft‐ versus ‐host disease ( GVHD ) incidence was 64% (95% CI : 51–76) and 36% (95% CI : 24–49) of patients had chronic GVHD by 3‐years. At 3‐years post‐transplant, the transplant‐related mortality ( TRM ) was 39% (95% CI : 26–52), and the 3‐year relapse incidence was 11% (95% CI : 4–21). With a median 37‐month (range 23–71) follow‐up of survivors, the 3‐year disease‐free survival was 50% (95% CI : 37–63). Double‐unit CBT is a viable alternative therapy for high‐risk acute leukaemia/ MDS in patients lacking a matched unrelated donor. This is especially important for minority patients. The relapse incidence was low but strategies to ameliorate TRM are needed.