Post-transplant cyclophosphamide (PTCy) has significantly increased the successful use of haploidentical donors with a relatively low incidence of graft-versus-host disease (GVHD). Given its increasing use, we sought to determine risk factors for GVHD after haploidentical hematopoietic cell transplantation (haplo-HCT) using PTCy. Data from the Center for International Blood and Marrow Transplant Research on adult patients with acute myeloid leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome, or chronic myeloid leukemia who underwent PTCy-based haplo-HCT (2013 to 2016) were analyzed and categorized into 4 groups based on myeloablative (MA) or reduced-intensity conditioning (RIC) and bone marrow (BM) or peripheral blood (PB) graft source. In total, 646 patients were identified (MA-BM = 79, MA-PB = 183, RIC-BM = 192, RIC-PB = 192). The incidence of grade 2 to 4 acute GVHD at 6 months was highest in MA-PB (44%), followed by RIC-PB (36%), MA-BM (36%), and RIC-BM (30%) (P =.002). The incidence of chronic GVHD at 1 year was 40%, 34%, 24%, and 20%, respectively (P <.001). In multivariable analysis, there was no impact of stem cell source or conditioning regimen on grade 2 to 4 acute GVHD; however, older donor age (30 to 49 versus <29 years) was significantly associated with higher rates of grade 2 to 4 acute GVHD (hazard ratio [HR], 1.53; 95% confidence interval [CI], 1.11 to 2.12; P =.01). In contrast, PB compared to BM as a stem cell source was a significant risk factor for the development of chronic GVHD (HR, 1.70; 95% CI, 1.11 to 2.62; P =.01) in the RIC setting. There were no differences in relapse or overall survival between groups. Donor age and graft source are risk factors for acute and chronic GVHD, respectively, after PTCy-based haplo-HCT. Our results indicate that in RIC haplo-HCT, the risk of chronic GVHD is higher with PB stem cells, without any difference in relapse or overall survival.
Bibliographical noteFunding Information:
The CIBMTR is supported primarily by Public Health Service grant/cooperative agreement U24CA076518 with the National Cancer Institute (NCI), the National Heart, Lung, and Blood Institute (NHLBI), and the National Institute of Allergy and Infectious Diseases (NIAID); grant/cooperative agreement U24HL138660 with NHLBI and NCI; grant U24CA233032 from the NCI; grants OT3HL147741, R21HL140314, and U01HL128568 from the NHLBI; contract HHSH250201700006C with Health Resources and Services Administration (HRSA); grants N00014-18-1-2888 and N00014-17-1-2850 from the Office of Naval Research; subaward from prime contract award SC1MC31881-01-00 with HRSA; subawards from prime grant awards R01HL131731 and R01HL126589 from NHLBI; subawards from prime grant awards 5P01CA111412, 5R01HL129472, R01CA152108, 1R01HL131731, 1U01AI126612, and 1R01CA231141 from the National Institutes of Health; and commercial funds from Actinium Pharmaceuticals, Inc.; Adaptive Biotechnologies; Allovir, Inc.; Amgen, Inc.; anonymous donation to the Medical College of Wisconsin; Anthem, Inc.; Astellas Pharma US; Atara Biotherapeutics, Inc.; BARDA; Be the Match Foundation; bluebird bio, Inc.; Boston Children's Hospital; Bristol Myers Squibb Co.; Celgene Corp.; Children's Hospital of Los Angeles; Chimerix, Inc.; City of Hope Medical Center; CSL Behring; CytoSen Therapeutics, Inc.; Daiichi Sankyo Co., Ltd.; Dana Farber Cancer Institute; Enterprise Science and Computing, Inc.; Fred Hutchinson Cancer Research Center; Gamida-Cell, Ltd.; Genzyme; Gilead Sciences, Inc.; GlaxoSmithKline (GSK); HistoGenetics, Inc.; Immucor; Incyte Corporation; Janssen Biotech, Inc.; Janssen Pharmaceuticals, Inc.; Janssen Research & Development, LLC; Janssen Scientific Affairs, LLC; Japan Hematopoietic Cell Transplantation Data Center; Jazz Pharmaceuticals, Inc.; Karius, Inc.; Karyopharm Therapeutics, Inc.; Kite, a Gilead Company; Kyowa Kirin; Magenta Therapeutics; Mayo Clinic and Foundation Rochester; Medac GmbH; Mediware; Memorial Sloan Kettering Cancer Center; Merck & Company, Inc.; Mesoblast; MesoScale Diagnostics, Inc.; Millennium, the Takeda Oncology Co.; Miltenyi Biotec, Inc.; Mundipharma EDO; National Marrow Donor Program; Novartis Oncology; Novartis Pharmaceuticals Corporation; Omeros Corporation; Oncoimmune, Inc.; OptumHealth; Orca Biosystems, Inc.; PCORI; Pfizer, Inc.; Phamacyclics, LLC; PIRCHE AG; Regeneron Pharmaceuticals, Inc.; REGiMMUNE Corp.; Sanofi Genzyme; Seattle Genetics; Shire; Sobi, Inc.; Spectrum Pharmaceuticals, Inc.; St. Baldrick's Foundation; Swedish Orphan Biovitrum, Inc.; Takeda Oncology; The Medical College of Wisconsin; University of Minnesota; University of Pittsburgh; University of Texas-MD Anderson; University of Wisconsin, Madison; Viracor Eurofins; and Xenikos BV. The views expressed in this article do not reflect the official policy or position of the National Institutes of Health, the Department of the Navy, the Department of Defense, HRSA, or any other agency of the US government.