At the beginning of the COVID-19 pandemic, the National Marrow Donor Program began requiring cryopreservation (cryo) of all unrelated donor grafts, and many institutions have adopted similar practices for all types of allogeneic hematopoietic stem cells. With donor supply limited due to post-pandemic procurement issues, cryo grafts have been used at higher rates.
To determine whether there was any difference between outcomes of fresh and cryo haploidentical (haplo) graft transplants, one institution reviewed the records of all patients who underwent allogeneic hematopoietic cell transplant (HCT) with graft-versus-host disease (GVHD) prophylaxis using posttransplant cyclophosphamide (PTCy) between January 2015 and December 2021.
The Northside Hospital Cancer Institute, Atlanta, Georgia, performed 179 grafts using fresh cells and 115 using cryopreserved cells during the study period (N=294). Conditioning intensity was similar between the 2 groups. Time to platelet engraftment was half a day longer in the cryo group (27.5 versus 27 days), and time to engraftment was a day longer (17 versus 16 days).
After March 2020, the institution performed only 8 transplants from fresh grafts but 73 from cryo cells.
“We found no difference in overall survival (OS), disease free survival (DFS), non-relapse mortality (NRM) and relapse rates between fresh and cryo haplo HCT,” the authors stated. They also found no difference in all-grade chronic GVHD, moderate-severe chronic GVHD, or grade III-IV acute GVHD.
However, when comparing fresh and cryo haplo HCT, the authors noted a statistically significant increase of grade II-IV acute GVHD with cryo grafts.
“Contrary to other reports, we did not see differences in graft failure or rates of cGVHD between fresh and cryo Haplo HCT,” concluded the authors, adding, “The use of cryopreserved HSC grafts for Haplo HCT with PTCy results in favorable outcomes in an outpatient transplant setting.”
Bachier L, Zhang X, Jackson K, et al. Outcomes of Cryopreserved Vs Fresh Haploidentical Allogeneic Donor Grafts Using Post-Transplant Cyclophosphamide (PTCy) for Gvhd Prophylaxis. Abstract #318. Presented at the 2023 Tandem Meetings of ASTCT and CIBMTR; February 15-19, 2023; Orlando, FL.