In an analysis reported in the Journal of Clinical Oncology, Shaffer et al found that use of post–allogeneic hematopoietic cell transplantation (HCT) cyclophosphamide (PTCy)-based graft-vs-host disease (GVHD) prophylaxis resulted in comparable overall survival and GVHD-free, relapse-free survival (GRFS) with either an HLA-matched unrelated donor (MUD) or mismatched unrelated donor (MMUD) vs calcineurin inhibitor (CNI)-based prophylaxis in patients with hematologic malignancies.
Study Details
In the study, 3-year overall survival and 3-year GRFS were ascertained among adult patients undergoing initial MUD or single–HLA locus MMUD HCT with either PTCy- or CNI-based prophylaxis who were reported to the Center for International Blood and Marrow Transplant Research between 2017 and 2021.
Key Findings
The study population consisted of 10,025 HCT recipients—including 7,272 recipients of MUD with CNI; 1,681 MUD with PTCy; 613 MMUD with CNI; and 459 MMUD with PTCy—who underwent HCT for acute leukemia (70.9%) or myelodysplastic syndromes (29.2%). The median patient age was 60.7 years.
Median follow-up was 36.6 months (range = 3.0–77.8 months). Compared with patients with MUD HCT with PTCy, no significant differences in 3-year overall survival were observed among patients with MMUD HCT with PTCy (hazard ratio [HR] = 0.96, 95% confidence interval [CI] = 0.82–1.11, P = .60) or 3-year GRFS (HR = 0.90, 95% CI = 0.79–1.02, P = .1).
Compared with patients with MUD HCT with CNI, patients with MUD HCT with PTCy had significantly better 3-year overall survival (HR = 0.88, 95% CI = 0.80–0.96, P = .004), and 3-year GRFS was improved with PTCy after either MUD HCT (HR = 0.61, 95% CI = 0.57–0.66, P < .0001) or MMUD HCT (HR = 0.68, 0.60–0.76, P < .0001).
Benefit from PTCy was found to be independent of patient ancestry. Global registry level analysis demonstrated that inclusion of MMUD increased donor availability, regardless of recipient ancestry.
The investigators concluded, “Use of PTCy results in comparable overall survival and GRFS using either MUD or MMUD HCT, expanding access to HCT for patients from all racial and ethnic ancestry groups.”
Steven M. Devine, MD, of the Center for International Blood and Marrow Transplant Research, Minneapolis, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Cancer Institute; the National Heart, Lung, and Blood Institute; the National Institute of Allergy and Infectious Diseases; and others. For full disclosures of the study authors, visit ascopubs.org.
