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4932 Score to Guide Donor Choice in Haploidentical Stem Cell Transplant Using Post-Transplant Cyclophosphamide for Patients with Acute Myeloid Leukemia: A Study from the Acute Leukemia 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:
Acute Myeloid Malignancies, AML, Diseases, Myeloid Malignancies
Monday, December 11, 2023, 6:00 PM-8:00 PM

Jaime Sanz1*, Myriam Labopin2*, Didier Blaise3*, Anna Maria Raiola4*, Alessandro Busca, MD5*, Jan Vydra6*, Johanna Tischer, MD7*, Patrice Chevallier, MD8, Stefania Bramanti9*, Renato Fanin, MD10*, Gerard Socié11, Edouard Forcade, MD, PhD12*, Nicolaus Kröger, MD13*, Yener Koc, MD14, Maija Itäla-remes, MD, PhD15*, Marco Zecca, MD16*, Arnon Nagler, MD17, Eolia Brissot18*, Alexandros Spyridonidis19*, Ali Bazarbachi, MD, PhD20, Sebastian Giebel21*, Simona Piemontese22*, Mohamad Mohty, MD, PhD23 and Fabio Ciceri24*

1Hematology Department, Hospital Universitari i Politècnic La Fe, VALENCIA, ESP
2EBMT Statistical Unit, Sorbonne University, Saint-Antoine Hospital, AP-HP, INSERM UMRs 938, Paris, France
3Programme de Transplantation & Thérapie Cellulaire, Centre de Recherche en Cancérologie de Marseille, Marseille, France
4IRCCS Ospedale Policlinico San Martino, Genova, Italy
5S.S.C.V.D Trapianto di Cellule Staminali, Torino, Italy, ITA
6Institute of Hematology and Blood Transfusion, Prague, Czech Republic
7LMU University Hospital of Munich -grosshadern, Munich, -, DEU
8Service d'hématologie, CHU de Nantes, Nantes, France
9Humanitas Clinical and Research Center, IRCCS, Rozzano, Italy
10Hematology, Azienda Sanitaria Universitaria Integrata di Udine, Udine, Italy
11Hopital St. Louis, Department of Hematology - BMT, Paris, France
12Service d'Hématologie Clinique et Thérapie Cellulaire, CHU Bordeaux, Pessac, France
13University Hospital Eppendorf, Bone Marrow Transplantation Centre, Hamburg, Germany
14MEDICAL PARK HOSPITALS, Beylikduzu, Istanbul, TUR
15Department of Clinical Haematology and Stem Cell Transplant Unit, University Hospital Turku, Turku, Finland
16Pediatric Hematology-Oncology,, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
17Division of Hematology and Bone Marrow Transplantation, Chaim Sheba Medical Center, Tel Hashomer, Israel
18Sorbonne Université Service d' Hématologie Clinique et Thérapie Cellulaire, Hospital Saint-Antoine, Centre de Recherche Saint-Antoine (CRSA), Paris, France
19Department of Internal Medicine, Bone Marrow Transplantation Unit, University Hospital of Patras, Patras, Greece
20American University of Beirut Dept. of Medicine, Beirut, Lebanon
21Department of Bone Marrow Transplantation and Onco-Hematology, Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice Branch, Gliwice, Poland
22San Raffaele Hospital, Milano, Milano, ITA
23Department of Haematology, Saint Antoine Hospital, Paris, France
24Unit of Hematology and Stem Cell Transplantation, Ospedale San Raffaele, University Vita-Salute San Raffaele, Milan, Italy

Introduction: There is paucity of information to guide selection of the most appropriate stem cell donor for haploidentical (Haplo) hematopoietic stem cell transplant (HSCT).

Patients and Methods: We retrospectively analyzed the characteristics of haploidentical family donors that may affect transplant outcomes in patients with acute myeloid leukemia (AML) who received graft-versus-host disease (GVHD) prophylaxis with postransplant cyclophosphamide (PTCy) registered in the EBMT database. The primary endpoint was GVHD and relapse-free survival (GRFS).

Results: Overall, 2200 patients were included with a median age of 56 years (range, 18-75); 1742 (79%) were in complete remission and 1246 (56.6) received reduced intensity conditioning. Regarding donors, the median age was 37 years (range, 8-71), 820 (37%) were females of which 458 (21%) were used for male recipients, 1252 (57%) had positive CMV serostatus, 1631 (74%) donated peripheral blood (PB) and 1638 (75%) had ≥ 4/8 HLA mismatch with the recipient. 100-day acute GVHD grade II-IV and III-IV and 2-year chronic and chronic extensive GVHD were 28% (95% CI 26-30), 11% (95% CI 10-12), 33% (95% CI 31-35) and 14% (95% CI 12-15), respectively. After median follow-up of 24 months, the cumulative incidence of relapse and non-relapse mortality (NRM) and the probability of leukemia-free survival (LFS), overall survival (OS) and GRFS were 26% (95% CI 24-28), 22% (95% CI 20-24), 52% (95% CI 50-55), 57% (95% CI 55-60) and 41% (95% CI 39-43), respectively. In multivariable analysis, donor-related risk factors with a negative impact on GRFS were older age (HR 1.1; 95% CI 1.04-1.15), use of PB (HR 1.19; 95% CI 1.04-1.37), and female donors to male recipients (HR 1.25; 95% CI 1.09-1.43). We further developed a score that distinguished 4 groups with 0 (241), 1 (913), 2 (863) or 3 (183) donor-related risk factors. GRFS was 57% (95% CI 50-63), 43% (95% CI 39-46), 37% (95% CI 33-40), and 30% (95% CI 23-38), respectively (P < 0.001) (Figure 1). The score was also able to stratify risk groups for acute and chronic GVHD, NRM, LFS and OS.

Conclusion: Donor variables have an important impact on AML patient's outcome after Haplo-HSCT using PTCy. With three simple donor characteristics, age, gender and stem cell source, we were able to generate a score that may help to select the most appropriate donor in clinical practice.

Disclosures: Blaise: Jazz Pharmaceuticals: Honoraria. Chevallier: Sanofi: Honoraria; Mallinckrodt Pharmaceuticals: Honoraria; Incyte: Honoraria, Research Funding; Takeda: Honoraria; Immedica Pharma: Honoraria; Servier: Honoraria. Forcade: Novartis: Consultancy, Other: Travel support, Speakers Bureau; Alexion: Other: Travel support, Speakers Bureau; Gilead Sciences: Other: Travel support, Speakers Bureau; GSK: Speakers Bureau; Astellas: Speakers Bureau; Sanofi: Speakers Bureau; MSD: Other: Travel support. Kröger: Neovii Biotech: Honoraria, Research Funding; Takeda: Consultancy; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Riemser: Honoraria, Research Funding; Pfizer: Honoraria; MSD: Honoraria; Jazz: Honoraria; Kite/Gilead: Honoraria; Sanofi: Honoraria. Giebel: Roche: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Abbvie: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Zentiva: Consultancy, Honoraria; BMS: Honoraria, Speakers Bureau; Angelini: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Servier: Honoraria, Speakers Bureau; Swixx: Honoraria, Speakers Bureau. Mohty: JAZZ PHARMACEUTICALS: Honoraria, Research Funding. Ciceri: ExCellThera: Other: Scientific Advisory Board .

*signifies non-member of ASH