Post-Transplantation Cyclophosphamide-Based Graft-versus-Host Disease Prophylaxis in HLA-Matched and Haploidentical Donor Transplantation for Patients with Hodgkin Lymphoma: A Comparative Study of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation

Post-transplantation cyclophosphamide (PTCy) has emerged as a promising approach for preventing graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, there is a lack of studies examining the impact of this GVHD prophylaxis when different donor types are used in patients with Hodgkin lymphoma (HL). This study compared the outcomes of patients with HL undergoing HSCT from HLA-matched donors, including matched sibling donors (MSDs) and matched unrelated donors (MUDs), and haploidentical donors, using PTCy as the GVHD prophylaxis approach in all cohorts. We retrospectively compared outcomes of allo-HSCT from 166 HLA-matched donors (96 sibling and 70 unrelated donors) and 694 haploidentical donors using PTCy-based GVHD prophylaxis in patients with HL registered in the European Society for Blood and Marrow Transplantation database from 2010 to 2020. Compared to HLA-matched HSCT, haploidentical donor HSCT was associated with a significantly lower rate of platelet engraftment (86% versus 94%; P < .001) and a higher rate of grade II-IV acute GVHD (34% versus 24%; P = .01). The 2-year cumulative incidence of nonrelapse mortality (NRM) was significantly lower in the HLA-matched cohort compared to the haploidentical cohort (10% versus 18%; P = .02), resulting in a higher overall survival (OS) rate (82% versus 70%; P = .002). There were no significant differences between the 2 cohorts in terms of relapse, progression-free survival, or GVHD-free relapse-free survival. In multivariable analysis, haploidentical HSCT was associated with an increased risk of grade II-IV acute GVHD and NRM and worse OS compared to HLA-matched HSCT. Our findings suggest that in the context of PTCy-based GVHD prophylaxis, transplantation from HLA-matched donors appears to be a more favorable option compared to haploidentical HSCT.