Allogeneic stem cell transplantation benefits for patients >= 60 years with acute myeloid leukemia and FLT3 internal tandem duplication : a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Intermediate-risk cytogenetic acute myeloid leukemia with an internal tandem duplication of FLT3 (FLT3-ITD) is associated with a high risk of relapse, and is now a standard indication for allogeneic stem cell transplantation. Nevertheless, most studies supporting this strategy have been performed in young patients. To address the benefit of allogeneic transplantation in the elderly, we made a selection from the European Society for Blood and Marrow Transplantation registry of de novo intermediate-risk cytogenetic acute myeloid leukemia harboring FLT3-ITD in patients aged 60 or over and transplanted from a related or unrelated donor between January 2000 and December 2015. Two hundred and ninety-one patients were identified. Most patients received a reduced-intensity conditioning (82%), while donors consisted of an unrelated donor in 161 (55%) patients. Two hundred and twelve patients received their transplantation in first remission, 37 in second remission and 42 in a more advanced stage of the disease. The 2-year leukemia-free survival rate was 56% in patients in first remission, 22% in those in second remission and 10% in patients with active disease, respectively (P= 60 with FLT3-ITD acute myeloid leukemia in first remission, similarly to current treatment recommendations for younger patients.Peer reviewe

Adult Low-Hypodiploid Acute Lymphoblastic Leukemia Emerges from Preleukemic TP53-Mutant Clonal Hematopoiesis

UNLABELLED Low hypodiploidy defines a rare subtype of B-cell acute lymphoblastic leukemia (B-ALL) with a dismal outcome. To investigate the genomic basis of low-hypodiploid ALL (LH-ALL) in adults, we analyzed copy-number aberrations, loss of heterozygosity, mutations, and cytogenetics data in a prospective cohort of Philadelphia (Ph)-negative B-ALL patients (n = 591, ages 18-84 years), allowing us to identify 80 LH-ALL cases (14%). Genomic analysis was critical for evidencing low hypodiploidy in many cases missed by cytogenetics. The proportion of LH-ALL within Ph-negative B-ALL dramatically increased with age, from 3% in the youngest patients (under 40 years old) to 32% in the oldest (over 55 years old). Somatic TP53 biallelic inactivation was the hallmark of adult LH-ALL, present in virtually all cases (98%). Strikingly, we detected TP53 mutations in posttreatment remission samples in 34% of patients. Single-cell proteogenomics of diagnosis and remission bone marrow samples evidenced a preleukemic, multilineage, TP53-mutant clone, reminiscent of age-related clonal hematopoiesis. SIGNIFICANCE We show that low-hypodiploid ALL is a frequent entity within B-ALL in older adults, relying on somatic TP53 biallelic alteration. Our study unveils a link between aging and low-hypodiploid ALL, with TP53-mutant clonal hematopoiesis representing a preleukemic reservoir that can give rise to aneuploidy and B-ALL. See related commentary by Saiki and Ogawa, p. 102. This article is highlighted in the In This Issue feature, p. 101

High tumor burden before blinatumomab has a negative impact on the outcome of adult patients with B-cell precursor acute lymphoblastic leukemia. A real-world study by the GRAALL

Blinatumomab is a bispecific T-cell engager approved for B-cell precursor acute lymphoblastic leukemia (B-ALL) with persistent minimal residual disease (MRD) or in relapse. The prognostic impact of tumor load has been suggested before other immunotherapies but remains poorly explored before blinatumomab. We retrospectively analyzed the outcome of 73 patients who received blinatumomab either in first complete remission (CR) with MRD (n=35) or at relapse (n=38). Among MRD patients, 91% had MRD >0.01% before blinatumomab, and 89% achieved complete MRD response after blinatumomab. High pre-blinatumomab MRD levels were associated with shorter relapse-free survival (P=0.049) and overall survival (OS) (P=0.011). At 3 years, OS was 33%, 58% and 86% for pre-blinatumomab MRD >1%, between MRD 0.1- 1% and <0.1% respectively. Among relapsed patients, 23 received blinatumomab with overt relapse and 15 were in complete response (CR) after bridging chemotherapy. At 3 years, overall CR rate was 68% and complete MRD response rate was 84%. Patients who directly received blinatumomab had shorter relapse-free survival (P=0.033) and OS (P=0.003) than patients bridged to blinatumomab. Three-year OS was 66% in the latter group compared to 16% in the former group. Our observations suggest that pre-blinatumomab tumor burden should help to design more tailored strategies including tumor load reduction in relapsed patients

Diagnosis, prognostic factors and assessment of ALL in adults: 2023 ELN recommendations from a European Expert Panel

Working groups of the European Leukemia Net (ELN) have published several important consensus guidelines. Acute lymphoblastic leukemia (ALL) has many different clinical and biological subgroups and the knowledge on disease biology and therapeutic options is increasing exponentially. The European Working Group for Adult ALL has therefore summarized the current state of the art and provided comprehensive consensus recommendations for diagnostic approaches, biologic and clinical characterization, prognostic factors and risk stratification as well as definitions of endpoints and outcomes. Aspects of treatment, management of subgroups and specific situations, aftercare and supportive care are covered in a separate publication. The present recommendation intends to provide guidance for the initial management of adult ALL patients and to define principles as a basis for future collaborative research

Impact of central nervous system involvement in adult patients with Philadelphia-negative acute lymphoblastic leukemia: a GRAALL-2005 study

Whereas the prognosis of adult patients with Philadelphia-negative acute lymphoblastic leukemia (ALL) has greatly improved since the advent of pediatric-inspired regimens, the impact of initial central nervous system (CNS) involvement has not been formerly re-evaluated. We report here the outcome of patients with initial CNS involvement included in the pediatric-inspired prospective randomized GRAALL-2005 study. Between 2006 and 2014, 784 adult patients (aged 18-59 years) with newly diagnosed Philadelphia-negative ALL were included, of whom 55 (7%) had CNS involvement. In CNSpositive patients, overall survival was shorter (median 1.9 years vs. not reached, HR=1.8 [1.3-2.6], P<0.001). While there was no statistical difference in cumulative incidence of relapse between CNS+ and CNS- patients (HR=1.5 [0.9-2.5], P=0.11), non-relapse mortality was significantly higher in those with initial CNS disease (HR=2.1 [1.2-3.5], P=0.01). This increase in toxicity was mostly observed in patients randomized to the high-dose cyclophosphamide arm and in those who received allogeneic stem cell transplantation. Exploratory landmark analyses did not show any association between either cranial irradiation or allogeneic stem cell transplantation and outcome. Despite improved outcome in young adult ALL patients with pediatric-inspired protocols, CNS involvement is associated with a worse outcome mainly due to excess toxicity, without improved outcome with allogeneic SCT

Absence de valeur diagnostique ou pronostique de l'expression du CD36, du nombre de plaquettes réticulées ou de microparticules plaquettaires évalués par cytométrie de flux au cours des thrombocytémies essentielles et des thrombocytoses réactionnelles

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Different Roles of Two Autotaxin Isoforms in Proliferation, Migration and Adhesion in the Non-Mutational Tyrosine Kinase Inhibitor Resistant Acute Lymphoblastic Leukemia Cell Line SupB15.

Abstract The Bcr-Abl oncogene is present in 30–40% of adult patients with acute lymphoblastic leukemia (ALL). The Abl kinase inhibitor imatinib-based therapy has become standard for this subset ALL. Acquired resistance to imatinib occurs frequently and is associated with mutations in the tyrosine kinase domain (TKD) approximately in about 80% of patients. In contrast, TKD mutations are uncommon in primary imatinib resistance which appears to be multifactorial, although the underlying mechanisms have been incompletely elucidated. We have established a Ph+ cell line for the analysis of non-mutational resistance mechanisms of imatinib resistance: SupB15RT, a Bcr-Abl expressing lymphoblastic cell line derived from SupB15WT cell line by gradually increasing the exposure to imatinib. SupB15RT shows cross-resistance to the second generation Abl kinase inhibitors Nilotinib and Dasatinib. We have shown that several commonly implicated mechanisms of imatinib resistance do not play a role in conferring the imatinib resistance in SupB15RT cells. By comparative gene expression analysis of SupB15WT vs. SupB15RT cells using Affymetrix- Microarrays, we identified 29 differentially regulated genes. Autotaxin (ATX) is one of the most highly up-regulated genes in imatinib resistant SupB15RT cells, and suggested a contribution to imatinib resistance. ATX is an exo-enzyme (pyrophosphophatase/phosphodiesterase). It plays a role in tumor progression and migration as a tumor cell autocrine motilty factor in various solid tumor cell types. ATX is involved in the synthesis of the signaling molecule, lysophosphatidic acid (LPA) which promotes survival and motility. It was the aim of this study to determine whereas ATX plays a functional role for imatinib resistance in Ph+ ALL. Using RT-PCR we demonstrated that 2 isoforms of ATX are expressed in SupB15RT cells: ATXshort and ATXlong. ATXlong (863 aa) contains highly basic insertion in the catalytic domain (52 residues). We retroviraly transfected BaF3 cells with p185 and/or ATXshort or ATXlong to analyze its influence on growth, adhesion and migration in mouse cell model. In comparison to wild type BaF3 cells the proliferation of BaF3 cells expressing ATXshort is enhanced (1,5-fold), whereas ATXlong expressing BaF3 cells showed no difference in proliferation in comparison to Mock infected cells. The proliferation of p185 expressing BaF3 cells co-expressing ATXshort or ATXlong is not inhibited by the treatment with 1μM imatinib after 3 days in contrast to p185 expressing BaF3 cells. In adhesion experiments, BaF3 cells expressing ATXshort showed a higher attachment independent of p185 expression. We also performed migration experiments using transwell assays. These assays showed more migration with cells co-expressing p185 and ATXlong compared to p185 alone. This is in agreement with our results for SupB15RT vs. SupB15WT with a 3-fold migration increase of SupB15RT. Application of 10% fetal calf serum (FCS) in migration experiments resulted in a 1,5-fold higher migration of the ATXlong expressing BaF3 cells compared to culture without FCS. One explanation for this finding may be that FCS contains lysophosphatidic choline (LPC) which is converted to LPA by ATX. Although expression of both 2 isoforms of ATX is important for the increased proliferation, it seems that the 2 isoforms have different cellular functions in Ph+ lymphoblastic cells. ATXshort seems to enhance adhesion whereas ATXlong plays an important role in motility. Taken together our results indicate a role for ATX in TK- inhibitor resistant SupB15RT cells through LPA signaling via LPA receptors. The ratio between ATXshort and ATXlong probably is important for the intracellular signaling and has to be explored.</jats:p