GVHD Outcomes Better with Post-Transplant Cyclophosphamide than Conventional Prophylaxis

Patients with haploidentical donors who received post-transplant cyclophosphamide had less severe graft-versus-host disease (GVHD) outcomes than those with matched unrelated donors who received conventional GVHD prophylaxis.

Rima M. Saliba, PhD, of The University of Texas MD Anderson Cancer Center and colleagues conducted the study because post-transplant cyclophosphamide has “been shown to effectively control [GVHD] in haploidentical transplantations.”

Dr. Saliba and colleagues evaluated outcomes in patients with GVHD that occurred after haploidentical transplantation with post-transplant cyclophosphamide or after matched unrelated donor transplantation with conventional prophylaxis.

They evaluated two cohorts of patients, one of which included patients with grade 2 to 4 acute GVHD and one of which included patients with any grade of chronic GVHD. In the cohort of patients with acute GVHD, 264 were haploidentical donor recipients, while 1,163 were matched unrelated donor recipients. In the patients with chronic GVHD, 206 were haploidentical donor recipients and 1,018 were matched unrelated donor recipients.

Grade 3 to 4 acute GVHD was less common in patients who received haploidentical transplantation with post-transplant cyclophosphamide than in patients with matched unrelated donors who received conventional prophylaxis plus or minus anti-thymocyte globulin (28% and 39%, respectively; P=.001). Stage 3 to 4 lower gastrointestinal tract acute GVHD was also less common in patients who received haploidentical transplantation (14%) than in patients with matched unrelated donors (21%; P=.01), as was chronic gastrointestinal GVHD (21% and 31%, respectively; P=.006).

Of the patients who had grade 2 to 4 acute GVHD, the rate of chronic GVHD was lower in patients who received haploidentical transplantation with post-transplant cyclophosphamide than in patients with matched unrelated donors who received conventional prophylaxis without anti-thymocyte globulin in a nonmyeloablative conditioning setting (P<.001).

The non-relapse mortality rate was significantly lower after haploidentical transplantation with post-transplant cyclophosphamide, irrespective of anti-thymocyte globulin use, except in the cases of transplants from a female donor to a male recipient.

In patients with chronic GVHD, haploidentical transplantation with post-transplant cyclophosphamide led to significantly lower non-relapse mortality rates (P=.04), irrespective of anti-thymocyte globulin use. The mortality rate was significantly higher during the first six months of a patient’s chronic GVHD diagnosis (P=.03) but was not significantly higher after the first six months (P=.6).

“Our results suggest that [post-transplant cyclophosphamide]-based GVHD prophylaxis mitigates the development of [gastrointestinal] GVHD and may translate into lower GVHD-related non-relapse mortality rate,” Dr. Saliba and colleagues concluded.

Reference

Saliba RM, Alousi AM, Pidala J, et al. Characteristics of graft-versus-host disease (GvHD) after post-transplantation cyclophosphamide versus conventional GvHD prophylaxis. Transplant Cell Ther. 2022;28(10):681-693. doi:10.1016/j.jtct.2022.07.013