PTCy versus ATG as graft-versus-host disease prophylaxis in mismatched unrelated stem cell transplantation

• Published in: Blood cancer journal (New York) 2024-03, Vol.14 (1), p.45-8, Article 45
• Main Authors: Penack, Olaf, Abouqateb, Mouad, Peczynski, Christophe, Boreland, William, Gülbas, Zafer, Gedde-Dahl, Tobias, Castilla-Llorente, Cristina, Kröger, Nicolaus, Eder, Mathias, Rambaldi, Alessandro, Bonifazi, Francesca, Blau, Igor Wolfgang, Stelljes, Matthias, Dreger, Peter, Moiseev, Ivan, Schoemans, Hélène, Koenecke, Christian, Peric, Zinaida
• Format: Article
• Language: English
• Subjects: 692/308/2171; 692/308/575; 692/699/249/1529; Adult; Antilymphocyte Serum - therapeutic use; Biomedical and Life Sciences; Biomedicine; Cancer Research; Cyclophosphamide - therapeutic use; Disease prevention; Graft versus host disease; Graft vs Host Disease - etiology; Graft vs Host Disease - prevention & control; Hematology; Hematopoietic Stem Cell Transplantation - adverse effects; Hematopoietic Stem Cell Transplantation - methods; Humans; Neoplasm Recurrence, Local - drug therapy; Oncology; Retrospective Studies; Stem cells; Unrelated Donors
• ISSN: 2044-5385; 2044-5385
• DOI: 10.1038/s41408-024-01032-8

There is an increased risk of GVHD and of non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) when mismatched unrelated donors (MMUD) are used. In Europe, it is standard practice to use rabbit anti-thymocyte globulin (rATG) to reduce the high NRM and GVHD risks after MMUD alloSCT. As an alternative to rATG, post-transplantation Cyclophosphamide (PTCy) is in increasing clinical use. It is currently impossible to give general recommendations regarding preference for one method over another since comparative evidence from larger data sets is lacking. To improve the evidence base, we analyzed the outcome of rATG vs. PTCy prophylaxis in adult patients with hematologic malignancies undergoing first peripheral blood alloSCT from MMUD (9/10 antigen match) between Jan 2018 and June 2021 in the database of the European Society for Blood and Marrow Transplantation (EBMT). We performed multivariate analyses using the Cox proportional-hazards regression model. We included 2123 patients in the final analyses (PTCy, n  = 583; rATG, n  = 1540). p values and hazard ratios (HR) presented here are multivariate outcomes. Two years after alloSCT we found a lower NRM in the PTCy group of 18% vs. 24.9% in the rATG group; p  = 0.028, HR 0.74. Overall survival in the PTCy cohort was higher with 65.7% vs. 55.7% in the rATG cohort; p