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3558 ATG or Post-Transplant Cyclophosphamide to Prevent Gvhd in Matched Unrelated Stem Cell Transplantation? – a Registry Analysis By the EBMT Transplant Complications Working Party

Program: Oral and Poster Abstracts
Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD, Immune Reconstitution: Poster II
Hematology Disease Topics & Pathways:
adult, Clinical Practice (Health Services and Quality), Adverse Events, Study Population, Human
Sunday, December 10, 2023, 6:00 PM-8:00 PM

Olaf Penack, MD1*, Mouad Abouqateb2*, Christophe Peczynski3*, William Boreland3*, Nicolaus Kröger, MD4*, Matthias Stelljes, MD5, Tobias Gedde-Dahl, MD6*, Igor Wolfgang Blau, MD, PhD7*, Thomas Schroeder8*, Urpu Salmenniemi9*, Aleksandr Kulagin Sr.10*, Regis Peffault De Latour11*, Stephan Mielke, MD12, Jürgen Finke, MD13, Ivan Sergeevich Moiseev, MD14*, Helene Schoemans15*, Christian Koenecke, MD16 and Zinaida Peric, MD PhD17*

1Department of Hematology, Oncology, and Cancer Immunology, Charité Universitätsmedizin Berlin, Campus Virchow Klinik, Berlin, Germany
2EBMT Office, Paris, France
3EBMT Paris Study Unit, Paris, France
4University Medical Center Hamburg, Hamburg, Germany
5Universitaetsklinikum Muenster, Muenster, DEU
6Oslo University Hospital, Rikshospitalet, Clinic for Cancer Medicine, Hematology Department, Section for Stem Cell Transplantation, Oslo, Norway
7Medizinische Klinik m. S. Hämatologie, Onkologie und Tumorimmunologie, Berlin, Germany
8Department of Hematology and Stem Cell Transplantation, University Hospital Essen, Essen, Germany
9Dept of Hematology, Helsinki University Hospital Comprehensive Cancer Center and University of Helsinki, Helsinki, Finland
10b. First State Pavlov Medical University of St. Petersburg, Raisa Gorbacheva Memorial Research Institute for Paediatric Oncology, Hematology, and Transplantation, St-Petersburg, Russia, St. Petersburg, RUS
11Hôpital Saint-Louis,, Paris, France
12Department of Cellular Therapy and Allogeneic Stem Cell Transplantation, Karolinska Institute & University Hospital, Stockholm, Stockholms Laen, Sweden
13Department of Hematology, Oncology and Stem Cell Transplantation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
14RM Gorbacheva Research Institute, Pavlov University, Saint-Petersburg, Russian Federation
15University Hospitals Leuven and KU Leuven, Leuven, Belgium
16Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, NDS, Germany
17University of Zagreb, Zagreb, Croatia


There is a considerable risk of GVHD and non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) when matched unrelated donors (MUD) are used. Prophylaxis with either rabbit anti-thymocyte globulin (rATG, also termed anti-T-lymphocyte globulin) or post-transplantation Cyclophosphamide (PTCy) is in standard clinical use. The unresolved question is whether to prefer PTCy or rATG in this setting. So far, two randomized trials, several retrospective studies and a meta-analysis comparing PTCy to rATG in MUD alloSCT gave contradictory results. Current data from large registry cohorts has not been published.

To improve the evidence base, we analyzed outcomes of rATG vs. PTCy prophylaxis in adult patients with hematologic malignancies undergoing peripheral blood alloSCT from 10/10 antigen MUD between Jan 2018 and June 2021 in the EBMT database. We performed multivariate analyses using Cox cause-specific hazard models, adjusting for known risk factors, and variables that showed significant difference between the two comparison groups.

Overall 8764 patients were included, treatment- and patient characteristics are shown in Table 1. Patients receiving PTCy (n=1039) were younger, had undergone alloSCT more recently, and had a lower disease risk compared to patients receiving rATG (n=7725). Median follow up was 2.1 years in both groups. Outcomes graphs are shown in figure 1. All outcomes are given starting from alloSCT (with 95% CI): NRM (fig 1A) was higher in the rATG arm (2-years NRM: PTCy 12.4% [10.2 - 14.7] vs. rATG 16.1% [15.3 – 17]; HR 0.72, p=0.016), same for Relapse incidence, (2-years RI: PTCy 22.8% [19.9 - 25.8] vs. rATG 26.6% [25.5 - 27.7]; HR 0.87, p=0.046), Overall survival (fig 1B) was better in the PTCy arm (2-years OS: PTCy 73.1% [70 – 76] vs. rATG 65.9% [64.7 - 67.1]; HR 0.82, p=0.001), same for Progression free survival (fig 1C) (2-years PFS: PTCy 64.9% [61.4 - 68.1] vs. rATG 57.2% [56 - 58.5]; HR 0.83, p<0.001), Chronic GVHD was lower in the PTCy arm (2-years cGVHD: PTCy 28.4% [25.2 - 31.7] vs. rATG 31.4% [30.3 - 32.6]; HR 0.77, p=0.012), whereas acute GVHD grades II-IV was not significantly different between the two arms (100-day aGVHD: PTCy 24.1% [21.3 - 27] vs. rATG 26.5% [25.5 - 27.6]; HR 0.85, p=0.11)

In conclusion, we found a lower NRM, lower incidence of chronic GVHD as well as higher survival outcomes in adult recipients of peripheral blood alloSCTs from MUD receiving PTCy compared to rATG. The current analysis improves the evidence basis for decision making on GVHD prophylaxis in MUD alloSCT.

Disclosures: Penack: Gilead, Jazz, MSD, Novartis, Pfizer and Therakos: Honoraria, Other: Travel support; Incyte and Priothera: Research Funding; Equillium Bio, Jazz, Gilead, Novartis, MSD, Omeros, Priothera, Sanofi, Shionogi and SOBI: Membership on an entity's Board of Directors or advisory committees. Salmenniemi: Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Immedia Pharma AB: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Viatris: Consultancy. Peffault De Latour: Jazz Pharmaceuticals: Honoraria. Mielke: Immunicum/Mendes, Miltenyi: Other: Participation on a Data Safety Monitoring Board or Advisory Board; SWECARNET: Other: Founder/Leadership (via my institution) ; ScientifyResearch: Other: Founder (spouse) ; Celgene/BMS, Novartis, Janssen, Gilead/KITE, JSMO, Pfizer: Speakers Bureau. Finke: Gilead Sciences: Current holder of stock options in a privately-held company; AbbVie: Current holder of stock options in a privately-held company; Roche: Current holder of stock options in a privately-held company; Riemser: Honoraria, Research Funding, Speakers Bureau; Neovii: Honoraria, Research Funding, Speakers Bureau; Medac: Honoraria, Research Funding. Schoemans: Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; BHS: Honoraria; Sanofi: Consultancy, Honoraria. Koenecke: Sanofi-Aventis: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Medigene: Consultancy; Miltenyi Biotec: Consultancy; Novartis: Consultancy, Speakers Bureau; Pierre Fabre: Consultancy; Kite/Gilead: Consultancy; BMS: Consultancy; Glaxo Smith Kline: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Roche: Consultancy, Speakers Bureau. Peric: Sanofi: Honoraria.

*signifies non-member of ASH