Outcome of Human Umbilical Cord Blood Stem Cell Transplantation (CBT) for Acute Myeloid Leukemia in Patients Achieving First Complete Remission after One Versus Two Induction Courses: A Study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.3964-3964
• Main Authors: Nagler, Arnon, Labopin, Myriam, Cornelissen, Jan J., Forcade, Edouard, Chevallier, Patrice, Fegueux, Nathalie, Sierra, Jorge, Labussière-Wallet, Hélène, Byrne, Jennifer, Cluzeau, Thomas, Blaise, Didier, Baron, Frédéric, Ruggeri, Annalisa, Mohty, Mohamad, Desmier, Deborah
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-144827

Background: Achieving a first complete remission (CR1) is an important prognostic factor for transplantation outcome. However, there are no data in the setting of cord blood transplantation (CBT) indicating whether the number of induction courses (1 or 2) needed to achieve CR1, is of prognostic significance. As CBT is advantageous for acute myelogenous leukemia (AML) patients (pts) with positive pre transplant measurable residual disease (MRD) (Milano F, NEJM 2016), it is conceivable that in the CBT setting, no difference in transplantation outcome will be observed between pts achieving CR1 after 1 or 2 inductions. Methods: Using the European Society for Blood and Marrow Transplantation (EBMT)/Acute Leukemia Working Party (ALWP) registry, we compared transplantation outcomes of adult pts aged ≥18 years with AML that underwent CBT in 2005-2020 in CR1, achieved following 1 versus (vs) 2 induction courses. Multivariate analysis (MVA) adjusting for differences between the induction groups was performed using a Cox's proportional-hazards regression model for main outcomes. Results: Three hundred and twenty-five pts were included comprising 243 (75%) with 1 and 82 (25%) with 2 induction chemotherapy courses. Median (range) follow-up was 65.4 (57.4-73.5) and 51.0 (34.8-61.5) months, respectively (p=0.6). Median age was 49.4 (19.0-70.9) and 52.1 (19.2-71.5) years (p=0.8), respectively. For patients with 1 and 2 induction courses, respectively, 49.4% and 57.3% were male, 225 (92.6%) and 78 (95.1%) pts had de novo AML, and 18 (7.4%) and 4 (4.9%) had secondary AML (p=0.6). Pts with 1 and 2 induction courses, respectively, were classified by cytogenetic risk as follows: intermediate, 62.0% and 79.2%, adverse, 33.2% and 19.5%, and favorable, 4.8% and 1.3% (p=0.02) (missing data~25%). The FLT3-ITD mutation was harbored by 33.7% and 32.3% of the pts (p=0.8), respectively (missing data ~6%). Conditioning was myeloablative (MAC) in 43.0% and 36.6% and reduced intensity (RIC) in 57.0% and 63.4%, respectively (p=0.31). Karnofsky performance score (KPS) was > 90 in 74.7% and 71% of the pts, respectively (p=0.5). The most frequent anti-graft-versus-host disease (GVHD) prophylaxis was cyclosporin A (CSA) and mycophenolate mofetil (MMF) in 75.6% and 82.5 %, or CSA with or without steroids in 16.1 % and 11.2%, respectively. Anti-thymocyte globulin (ATG) was administered to 32.9% and 25.6% of the CBT recipients, respectively (p=0.2). Engraftment rates were lower for pts achieving