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4938 Impact of Post-Transplant Cyclophosphamide (PTCY)-Based Prophylaxis in Matched Sibling Donor Allo-HCT for Patients with Myelodysplastic Syndrome: A Study on Behalf of the Chronic Malignancies Working Party of the EBMT

Program: Oral and Poster Abstracts
Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD, Immune Reconstitution: Poster III
Hematology Disease Topics & Pathways:
Research, MDS, adult, Clinical Practice (Health Services and Quality), Clinical Research, Chronic Myeloid Malignancies, Diseases, Therapies, registries, Adverse Events, survivorship, Myeloid Malignancies, Study Population, Human
Monday, December 11, 2023, 6:00 PM-8:00 PM

Maria Queralt Salas1*, Dirk-Jan Eikema Sr.2*, Linda Koster3*, Johan Maertens4*, Jakob Passweg Sr.5*, Jürgen Finke, MD6, Annoek E.C. Broers7*, Yener Koc8*, Nicolaus Kröger, MD9*, Zubeyde Nur Ozkurt10*, Maria Jesús Pascual11*, Uwe Platzbecker, MD12, Gwendolyn Van Gorkom13*, Thomas Schroeder14*, Jose Luiz Lopez Lorenzo15*, Massimo Martino, MD16*, Simona Sica17*, Martin Kaufmann, MD18, Francesco Onida, MD19*, Carmelo Gurnari, MD20, Christof Scheid21*, Joanna Drozd-Sokolowska, MD, PhD22*, Kavita Raj, MD, PhD23, Marie Robin, MD, PhD24* and Donal P McLornan, MD, PhD23*

1Hematopoietic Cell Transplantation Unit, Hospital Clínic de Barcelona, ICHMO, Barcelona, Spain
2EBMT Statistical Unit, Leiden, Netherlands
3EBMT Leiden Study Unit, Leiden, Netherlands
4University Hospital Gasthuisberg, Leuven, Belgium
5University Hospital | Basel, Basel, Switzerland
6Department of Hematology, Oncology and Stem Cell Transplantation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
7Department of Hematology, Erasmus MC Cancer Institute, Rotterdam, Netherlands
8Medicana International Hospital Istanbul, Istanbul, TUR
9University Medical Center Hamburg, Hamburg, Germany
10Gazi University Faculty of Medicine, Ankara, Turkey
11Hematology Department, Hospital Regional Universitario de Málaga, Málaga, Spain
12Department of Hematology, Cell Hematology and Hemostaseology, Leipzig University Hospital, Leipzig, Germany
13University Hospital Maastricht, Maastricht, Netherlands
14Department of Hematology and Stem Cell Transplantation, University Hospital Essen, Essen, Germany
15Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
16Centro Unico Trapianti A, Grande Ospedale Metropolitano Bianchi Melacrino Morelli, Reggio Calabria, Italy
17Sezione di Ematologia, Dipartimento di Scienze Radiologiche ed Ematologiche, Università Cattolica del Sacro Cuore, Rome, Italy
18Department of Hematology, Oncology and Palliative Care, Robert Bosch Hospital, Stuttgart, Germany
19Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico - University of, Milan, Italy
20Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH
21University of Cologne, Cologne, Germany
22Central Clinical Hospital, The Medical University of Warsaw, Warsaw, Poland
23University College London Hospitals NHS Trust, London, United Kingdom
24Hopital Saint Louis, Paris, France


Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only potentially curative treatment option for patients with myelodysplastic syndrome (MDS). The use of PTCY for GVHD prevention is becoming increasingly prevalent across donor types/transplant platforms. However, limited studies have evaluated the efficacy and safety of using PTCY in patients with MDS undergoing matched sibling donor (MSD) allo-HCT. We hereby compare the outcomes of PTCY-based versus (vs.) conventional GVHD prophylaxis in a contemporaneous cohort of MDS patients undergoing MSD allo-HCT from the EBMT registry.


A total of 404 MDS patients undergoing first MSD peripheral blood allo-HCT between 2014 and 2020 in 52 participating centers, receiving either PTCY or other GvHD prophylaxis, were included. Primary outcomes were overall survival (OS), progression free survival (PFS), GVHD-free/RFS (GRFS), competing risks analyses for relapse (CIR), non-relapse mortality (NRM), and GVHD. The main comparison was PTCY vs. other types of GvHD prevention. Cox regression analyses with predefined covariates were used to obtain adjusted effect estimates of PTCY in post-transplant results.-


The median age at allo-HCT was 57 years (IQR 49-62), 66 patients (16.3%) received PTCY, 338 (83.7%) received other prophylaxis. As reported in Figure 1, patient characteristics, disease risk, and pre-transplant status were balanced between the two cohorts. The majority of transplant characteristics were also analogous except for the proportion of adults receiving myeloablative regimens, which was higher in the PTCY group (52.3% vs. 38.2%, P=0.047).

PTCY was combined with two additional immunosuppressant agents in 66.7% of the cases, with one additional immunosuppressive drug (generally calcineurin inhibitors (CNI)) in 31.8%, and administered as a single agent in only 1 (1.5%) case. Other prophylaxis mainly combined CNI with either mycophenolate mofetil or methotrexate, and in 162 (47.9%) of the cases, anti-thymocyte globulin was also administered.

Post-transplant complications and outcomes are shown in Figure 1. Incidences of Day +28 neutrophil (68% vs. 97%, P=0.011) and platelet (71% vs. 92%, P<0.001) engraftment were lower in patients who received PTCY. The day +100 cumulative incidences (CI) of grade II-IV and III-IV aGVHD, and 5-year CI of extensive cGVHD were 32% (21-43%), 18% (9-27%) and 18% (9-28%) for patients who received PTCY, and 25% (20-30%; p=0.3), 13% (10-17%; p=0.4), 31% (26-36%; p=0.09) for those who did not. The 5-year CIs of cardiac and pulmonary toxicities were similar in both groups (23% (6-40%) vs. 19% (12-25%) (p=0.6) and 23% (8-38%) vs. 27% (21-34%) (p=0.6) in PTCY vs others, respectively). At 5-years after allo-HCT, the estimated OS (51% (39-64%) vs. 52% (46-58%), p=0.6), PFS (48% (36-61%) vs. 46% (40-52%), p=0.9), and GRFS (33% (21-45%) vs. 25% (20-30%), p=0.6), were similar between the two study groups. Nevertheless, patients who received PTCY tended to have lower CIR (20% (10-29%) vs. 33% (28-38%) (p=0.06)), but higher NRM rates (32% (20-43%) vs. 21% (16-25%), p=0.09) than the rest.

Next, we performed a multivariable analysis (MVA) of OS, PFS, NRM and CIR (Figure 1). The results observed in the MVA confirmed that using PTCY in patients with MDS undergoing MSD allo-HCT resulted in comparable OS (HR 1.23 (0.77-1.97), p=0.4) and RFS (HR 1.13 (0.73-1.77), p=0.6) to conventional prophylaxis. Furthermore, the diagnosis of a high or very high-risk MDS (according to IPSS-R), and the presence of TP53 mutation at diagnosis were independent predictors of worse post-transplant outcomes. In addition, PTCY-based prophylaxis was associated with a higher NRM (HR 1.79 (1.07-2.98), p=0.03) when adjusted by variables known to be clinically relevant for NRM.


The use of PTCY in adults undergoing MSD allo-HCT for MDS resulted in comparable OS and RFS rates to conventional GVHD prophylaxis. Allo-HCT performed with PTCY was associated with a longer time to engraftment and comparable incidences of clinically relevant aGVHD. Of note, utilization of PTCY was associated with a non-significant trend to a lower incidence of extensive cGVHD. Furthermore, although a non-significant trend to lower rates of relapse were observed in allo-HCTs performed using PTCY, it use was associated with a higher risk for NRM. Further evaluation of PTCY in the MSD setting for MDS is required.

Disclosures: Finke: Gilead Sciences: Current holder of stock options in a privately-held company; Riemser: Honoraria, Research Funding, Speakers Bureau; Neovii: Honoraria, Research Funding, Speakers Bureau; AbbVie: Current holder of stock options in a privately-held company; Roche: Current holder of stock options in a privately-held company; Medac: Honoraria, Research Funding. Platzbecker: MDS Foundation: Membership on an entity's Board of Directors or advisory committees; Curis: Consultancy, Research Funding; Geron: Consultancy, Research Funding; Roche: Research Funding; Servier: Consultancy, Honoraria, Research Funding; Silence Therapeutics: Consultancy, Honoraria, Research Funding; Syros: Consultancy, Honoraria, Research Funding; Celgene: Honoraria; BeiGene: Research Funding; AbbVie: Consultancy; Jazz: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Fibrogen: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel support; medical writing support, Research Funding; Janssen Biotech: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; BMS: Research Funding. McLornan: UK ALL RIC TRIAL - DSM board: Other: participation on a data safety monitoring board or advisory board; Novartis: Honoraria; EBMT Scientific Council Member: Other: Chair of EBMT CMWP; Jazz Pharma: Honoraria; Abbvie: Honoraria; Imago Biosciences: Research Funding.

*signifies non-member of ASH