Haploidentical transplantation compared with matched sibling and unrelated donor transplantation for adults with standard-risk acute lymphoblastic leukaemia in first complete remission

We retrospectively investigated outcomes of haploidentical donor (HID) transplant for adults with standard-risk acute lymphoblastic leukaemia (ALL) in first complete remission (CR1) compared with human leucocyte antigen (HLA)-matched sibling donor (MSD) and HLA-matched unrelated donor (MUD) transplants. A total of 348 adult patients were enrolled, including 127 HID, 144 MSD and 77 MUD recipients. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 39.5%, 24.0% and 40.3% for HID, MSD and MUD, respectively (P = 0.020). However, there was no difference in grade III-IV aGVHD (11.4%, 7.7%, 13.5%, respectively, P = 0.468). The 5-year cumulative transplant-related mortality was 16.4%, 11.6% and 19.6% (P = 0.162), the 5-year relapse rate post-transplantation was 14.8%, 21.1% and 16.7% (P = 0.231), the 5-year overall survival was 70.1%, 73.7% and 69.8% (P = 0.525), and the 5-year disease-free survival was 68.7%, 67.3% and 63.7%, respectively (P = 0.606). Furthermore, the 3-year GVHD-free, relapse-free survival was not different (50.8%, 54.9% and 52.2%, respectively, P = 0.847). Our results indicate that the outcomes of HID transplants are equivalent to those of MSD and MUD, and that HID transplantation is a valid alternative for standard-risk adults with ALL in CR1 who lack matched donors.