FLT3 and NPM1 Are Powerful Determinants of Outcome in Acute Myeloid Leukemia Patients Treated with Autologous Stem Cell Transplantation: An Analysis By the Acute Leukemia Working Party of the EBMT

• Published in: Blood 2018-11, Vol.132 (Supplement 1), p.609-609
• Main Authors: Shouval, Roni, Labopin, Myriam, Bomze, David, Baerlocher, Gabriela M, Foà, Robin, Blaise, Didier, Haenel, Mathias, Forcade, Edouard, Huynh, Anne, Saccardi, Riccardo, Milone, Giuseppe, Zuckerman, Tsila, Reményi, Péter, Esteve, Jordi, Gorin, Norbert Claude, Mohty, Mohamad, Nagler, Arnon
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-111614

Background: While intensive consolidation therapy with autologous stem cell transplantation (ASCT) can secure a remission in selected Acute Myeloid Leukemia (AML) patients with intermediate-risk cytogenetics, a substantial proportion will ultimately relapse. Knowledge of the mutational status of FMS like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) and nucleophosmin (NPM) 1 and their possible combinations could further refine a subset of intermediate cytogenetic risk patients who may benefit from ASCT. However, data are limited. We, therefore, set out to evaluate the impact of FLT3-ITD and NPM1 in a large cohort of patients undergoing ASCT. Methods: This was a retrospective analysis of the Acute Leukemia Working Parity of the European Society for Blood and Marrow Transplantation (EBMT) registry. We included 405 de-novo AML patients, from 51 European centers, with intermediate-risk cytogenetics (Grimwade et al., Blood 2010) and complete data on FLT3-ITD and NPM1 status, receiving an ASCT at first complete remission (CR1), between 2000-2014. Leukemia free survival (LFS) was the primary outcome. Secondary outcomes were overall survival (OS), transplantation-related mortality (TRM), and relapse incidence (RI). The latter two were considered as competing events. Univariate and multivariable Cox regression models, adjusted for recipient sex, age, Karnofsky performance status, FLT3/NPM1 combinations, days from diagnosis to transplantation, stem cell source -bone marrow or peripheral blood (PB), and use of total-body irradiation-based conditioning. Results: Patients included had a median age of 52 years and received an autograft at median of 5 months from diagnosis. PB-based autograft and non-TBI conditioning were used in the majority of patients (93% and 90%, respectively). FLT3-/NPM1- was the leading molecular combination (50%), followed by FLT3-/NPM1+ (30%), FLT3+/NPM1+ (11%), and FLT3+/NPM1- (9%). Age, time from diagnosis to transplantation, graft source, and use of TBI were similar between the molecular subgroups. The median year of transplantation was earlier in NPM1- patients (FLT3+/NPM1- 2008, FLT3-/NPM1- 2009, FLT3-/NPM1+ 2010, FLT3+/NPM1+ 2011, p