Research paperHaploidentical allogeneic hematopoietic stem cell transplantation compared to matched unrelated transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia

- Efficacy of Haplo-HCT is not significantly different from that of MUD-HCT for Ph+ ALL.
- Haplo-HCT was not related with higher incidences of sever acute GvHD or extend chronic GvHD as compared to MUD-HCT.
- Haplo-HCT could serve as an alternative for Ph + ALL patients without HLA-matched donors.

To investigate the effect of haploidentical allogeneic hematopoietic stem cell transplantation (Haplo-HCT) in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), the outcome of 58 patients with Ph+ ALL who received Haplo-HCT (n = 42) or matched unrelated donor transplantation (MUD-HCT) (n = 16) during the same period were analyzed retrospectively. All patients received a tyrosine kinase inhibitor (TKI)-based regimen before transplantation, and TKI was resumed primarily after transplantation. At the 3-year follow-up, the overall survival (OS), leukemia-free survival (LFS), the cumulative incidence of relapse (CIR), and non-relapse mortality (NRM) rates in Haplo-HCT group were 69.1, 64.3, 19.0, and 14.3%, respectively, without significant differences from that of MUD-HCT. Haplo-HCT was not related to higher incidences of severe acute graft-versus-host disease (GvHD) (17.6 ± 5.2% vs. 20.0 ± 10.0%, P = 0.603) or chronic GvHD (19.5 ± 7.1% vs. 13.3 ± 8.6%, P = 0.637) as compared to MUD-HCT. Multivariate analysis showed that chronic GvHD was associated with lower relapse rate in Haplo-HCT group. Haplo-HCT is a promising choice for improving the long-term survival in Ph+ ALL patients.