Patients who received an allogeneic hematopoietic stem cell transplant (HSCT) from matched related donors (MRD) or matched unrelated donors (MUD) had a significantly lower incidence of chronic graft-versus-host disease (cGVHD) after post-transplant cyclophosphamide than patients with haploidentical donors. The research was presented at the 2022 American Society of Clinical Oncology Annual Meeting.
The study comprised 62 patients with similar baseline characteristics who received allogeneic HSCT from MRD or MUD (n = 45) or haploidentical donors (n = 17). Half of the patients had a diagnosis of acute myeloid leukemia, 48% of patients had a high/very high disease risk index, and 55% received reduced intensity conditioning.
Median follow-up was 342 days post-transplant. The cumulative incidence of cGVHD was significantly lower in the MRD/MUD group (6%) than in the haploidentical group (27%) (P=.045). The overall cumulative incidence of cGVHD was 11% (95% CI, 5.8-21.3).
Despite the lower cumulative incidence of GVHD in the MRD/MUD group, the 2-year overall survival (OS) rate was significantly higher for the haploidentical group (61%) than the MRD/MUD group (53%; P=.043). The 2-year OS rate was 55% overall (95% CI, 39.1-68.7).
The cumulative relapse incidence was not significantly different between the MRD/MUD group (34%) and the haploidentical group (13%; P=.09). The cumulative relapse incidence was 28% overall (95% CI, 18-42).
“Although cumulative incidence of relapse was not statistically different between groups, OS was worse in the MRD/MUD allogeneic HSCT group after post-transplant cyclophosphamide, and most deaths were due to relapse,” the authors found.
Hitt MM, Yimer W, Milner CP, et al. Incidence of chronic graft versus host disease using post-transplant cyclophosphamide in HLA-matched versus haploidentical donors. Abstract #e19044. Presented at the 2022 American Society of Clinical Oncology Annual Meeting; June 3-7, 2022; Chicago, IL.