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The negative prognostic impact of internal tandem duplication of FLT3(FLT3-ITD) in patients with acute myeloid leukemia with mutated NPM1(AML-NPM1) is restricted to those with a higher FLT3-ITD allelic ratio (FLT3high; ≥0.5) and considered negligible in those with a wild-type (FLT3WT)/low ITD ratio (FLT3low). Because the comutation of DNMT3A(DNMT3Amut) has been suggested to negatively influence prognosis in AML-NPM1, we analyzed the impact of DNMT3Amutin FLT3-ITD subsets (absent, low, and high ratios). A total of 164 patients diagnosed with AML-NPM1included in 2 consecutive CETLAM protocols and with DNMT3Aand FLT3status available were studied. Overall, DNMT3Amutstatus did not have a prognostic impact, with comparable overall survival (P= .2). Prognostic stratification established by FLT3-ITD (FLT3WT= FLT3low>FLT3high) was independent of DNMT3Amutstatus. Measurable residual disease (MRD) based on NPM1quantitative polymerase chain reaction was available for 94 patients. DNMT3Amutwas associated with a higher number of mutated NPM1transcripts after induction (P= .012) and first consolidation (C1; P< .001). All DNMT3Amutpatients were MRD+after C1 (P< .001) and exhibited significant MRD persistence after C2 and C3 (MRD+vs MRD−; P= .027 and P= .001, respectively). Finally, DNMT3Amutpatients exhibited a trend toward greater risk of molecular relapse (P= .054). In conclusion, DNMT3Amutdid not modify the overall prognosis exerted by FLT3-ITD in AML-NPM1despite delayed MRD clearance, possibly because of MRD-driven preemptive intervention.

The negative prognostic impact of internal tandem duplication of FLT3 (FLT3-ITD) in patients with acute myeloid leukemia with mutated NPM1 (AML-NPM1) is restricted to those with a higher FLT3-ITD allelic ratio (FLT3high; ≥0.5) and considered negligible in those with a wild-type (FLT3WT)/low ITD ratio (FLT3low). Because the comutation of DNMT3A (DNMT3Amut) has been suggested to negatively influence prognosis in AML-NPM1, we analyzed the impact of DNMT3Amut in FLT3-ITD subsets (absent, low, and high ratios). A total of 164 patients diagnosed with AML-NPM1 included in 2 consecutive CETLAM protocols and with DNMT3A and FLT3 status available were studied. Overall, DNMT3Amut status did not have a prognostic impact, with comparable overall survival (P = .2). Prognostic stratification established by FLT3-ITD (FLT3WT = FLT3low > FLT3high) was independent of DNMT3Amut status. Measurable residual disease (MRD) based on NPM1 quantitative polymerase chain reaction was available for 94 patients. DNMT3Amut was associated with a higher number of mutated NPM1 transcripts after induction (P = .012) and first consolidation (C1; P < .001). All DNMT3Amut patients were MRD+ after C1 (P < .001) and exhibited significant MRD persistence after C2 and C3 (MRD+ vs MRD−; P = .027 and P = .001, respectively). Finally, DNMT3Amut patients exhibited a trend toward greater risk of molecular relapse (P = .054). In conclusion, DNMT3Amut did not modify the overall prognosis exerted by FLT3-ITD in AML-NPM1 despite delayed MRD clearance, possibly because of MRD-driven preemptive intervention.

Risk associated to FLT3internal tandem duplication (FLT3-ITD) in patients with acute myeloid leukemia (AML) may depend on mutational burden and its interaction with other mutations. We analyzed the effect of FLT3-ITD/FLT3wild-type (FLT3wt) ratio depending on NPM1 mutation (NPM1mut) in 303 patients with intermediate-risk cytogenetics AML treated with intensive chemotherapy. Among NPM1mut patients, FLT3wt and low ratio (<0.5) subgroups showed similar overall survival, relapse risk, and leukemia-free survival, whereas high ratio (≥0.5) patients had a worse outcome. In NPM1wt AML, FLT3-ITD subgroups showed a comparable outcome, with higher risk of relapse and shortened overall survival than FLT3wt patients. Allogeneic stem cell transplantation in CR1 was associated with a reduced relapse risk in all molecular subgroups with the exception of NPM1mut AML with absent or low ratio FLT3-ITD. In conclusion, effect of FLT3burden is modulated by NPM1mutation, especially in patients with a low ratio.

Risk associated to FLT3 internal tandem duplication (FLT3-ITD) in patients with acute myeloid leukemia (AML) may depend on mutational burden and its interaction with other mutations. We analyzed the effect of FLT3-ITD/FLT3 wild-type (FLT3wt) ratio depending on NPM1 mutation (NPM1mut) in 303 patients with intermediate-risk cytogenetics AML treated with intensive chemotherapy. Among NPM1mut patients, FLT3wt and low ratio (<0.5) subgroups showed similar overall survival, relapse risk, and leukemia-free survival, whereas high ratio (≥0.5) patients had a worse outcome. In NPM1wt AML, FLT3-ITD subgroups showed a comparable outcome, with higher risk of relapse and shortened overall survival than FLT3wt patients. Allogeneic stem cell transplantation in CR1 was associated with a reduced relapse risk in all molecular subgroups with the exception of NPM1mut AML with absent or low ratio FLT3-ITD. In conclusion, effect of FLT3 burden is modulated by NPM1 mutation, especially in patients with a low ratio.

CTLA-4 is an inhibitory molecule that down-regulates T-cell activation. Although polymorphisms at CTLA-4 have been correlated with autoimmune diseases their association with clinical outcome after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has yet to be explored. A total of 5 CTLA-4 single-nucleotide polymorphisms were genotyped on 536 HLA-identical sibling donors of allo-HSC transplants. Genotypes were tested for an association with patients' posttransplantation outcomes. The effect of the polymorphisms on cytotoxic T-lymphocyte antigen 4 (CTLA-4) mRNA and protein production were determined in 60 healthy control participants. We observed a reduction in the mRNA expression of the soluble CTLA-4 isoform in the presence of a G allele at CT60 and +49. Patients receiving stem cells from a donor with at least 1 G allele in position CT60 had worse overall survival (56.2% vs 69.8% at 5 years; P = .001; hazard ratio [HR], 3.80; 95% confidence interval [CI], 1.75-8.22), due to a higher risk of relapse (P = .049; HR, 1.71; 95% CI, 1.00-2.93). Acute graft-versus-host disease (aGVHD) was more frequent in patients receiving CT60 AA stem cells (P = .033; HR, 1.54; 95% CI, 1.03-2.29). This is the first study to report an association between polymorphisms at CTLA-4 and clinical outcome after allo-HSCT. The CT60 genotype influences relapse and aGVHD, probably due to its action on CTLA-4 alternative splicing.

CTLA-4 is an inhibitory molecule that down-regulates T-cell activation. Although polymorphisms at CTLA-4have been correlated with autoimmune diseases their association with clinical outcome after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has yet to be explored. A total of 5 CTLA-4single-nucleotide polymorphisms were genotyped on 536 HLA-identical sibling donors of allo-HSC transplants. Genotypes were tested for an association with patients' posttransplantation outcomes. The effect of the polymorphisms on cytotoxic T-lymphocyte antigen 4 (CTLA-4) mRNA and protein production were determined in 60 healthy control participants. We observed a reduction in the mRNA expression of the soluble CTLA-4 isoform in the presence of a G allele at CT60 and +49. Patients receiving stem cells from a donor with at least 1 G allele in position CT60 had worse overall survival (56.2% vs 69.8% at 5 years; P= .001; hazard ratio [HR], 3.80; 95% confidence interval [CI], 1.75-8.22), due to a higher risk of relapse (P= .049; HR, 1.71; 95% CI, 1.00-2.93). Acute graft-versus-host disease (aGVHD) was more frequent in patients receiving CT60 AA stem cells (P= .033; HR, 1.54; 95% CI, 1.03-2.29). This is the first study to report an association between polymorphisms at CTLA-4and clinical outcome after allo-HSCT. The CT60 genotype influences relapse and aGVHD, probably due to its action on CTLA-4alternative splicing.

Tormo: MSD: Honoraria; Janssen: Honoraria; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Honoraria; Servier: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees. Salamero:Pfizer: Consultancy; Jazz Pharmaceuticals: Consultancy, Honoraria; Daichii Sankyo: Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Sierra:Jazz Pharmaceuticals: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead-Kite: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Salamero: Pfizer: Consultancy; Jazz Pharmaceuticals: Consultancy, Honoraria; Daichii Sankyo: Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Moraleda:Takeda: Consultancy, Other: Travel Expenses; Sandoz: Consultancy, Other: Travel Expenses; Novartis: Consultancy, Other: Travel Expenses; Gilead: Consultancy, Other: Travel Expenses; Jazz Pharmaceuticals: Consultancy, Research Funding. Tormo:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; MSD: Honoraria; Daiichi Sankyo: Honoraria; Servier: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees. Ribera:Pfizer, Amgen: Research Funding; Pfizer, Amgen, Ariad, Novartis: Consultancy, Speakers Bureau. Sureda Balari:Roche: Honoraria; Incyte: Consultancy; Janssen: Consultancy, Honoraria; Gilead/Kite: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Merck Sharpe and Dohme: Consultancy, Honoraria, Speakers Bureau; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Speakers Bureau; Celgene: Consultancy, Honoraria. Sierra:Jazz Pharmaceuticals: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astellas: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead-Kite: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

The progress in the understanding of pathophysiology of AML has allowed the identification of genetic and immune abnormalities with prognostic impact on outcome and suitable as therapeutic targets. The genetic abnormalities are essential for risk allocation and risk-adapted treatment included the indication of hematopoietic cell transplantation. In the last decade, several studies have shown that persistence of measurable residual disease (MRD) after chemotherapy increases relapse incidence and the probability of leukemia recurrence and survival. Therefore, MRD has been progressively incorporated in prognosis estimation. In the last 25 years the CETLAM cooperative group has promoted 4 consecutive trials for AML patients fit for intensive chemotherapy and eventually HCT. Post-remission treatment was based on genetics of the disease and more recently on MRD. The aim of this study has been to investigate if the survival of patients has improved and, if so, to identify the factors that have influenced on the better outcome.

Salamero: Pfizer:Consultancy;Jazz Pharmaceuticals:Consultancy, Honoraria;Daichii Sankyo:Honoraria;Novartis:Consultancy, Honoraria;Celgene:Consultancy, Honoraria.Olivera:BAYER:Consultancy;Pfizer:Consultancy, Speakers Bureau;Daiichi Sankyo:Consultancy, Speakers Bureau;Boehringer Ingelheim:Consultancy, Speakers Bureau.Sureda Balari:Celgene:Consultancy, Honoraria;Merck Sharpe and Dohme:Consultancy, Honoraria, Speakers Bureau;Sanofi:Consultancy, Honoraria;Novartis:Consultancy, Honoraria;Gilead/Kite:Consultancy, Honoraria;Janssen:Consultancy, Honoraria;Incyte:Consultancy;Roche:Honoraria;BMS:Speakers Bureau;Celgene/Bristol-Myers Squibb:Consultancy, Honoraria;Takeda:Consultancy, Honoraria, Speakers Bureau.Ribera:Pfizer, Amgen:Research Funding;Pfizer, Amgen, Ariad, Novartis:Consultancy, Speakers Bureau.Sierra:Jazz Pharmaceuticals:Research Funding;Pfizer:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Daiichi Sankyo:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Abbvie:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Astellas:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Roche:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Gilead-Kite:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Introduction:Acute myeloid leukemia (AML) real-world incidence has been investigated in a limited number of European countries such as Sweden, Denmark and a few others. These prospective population-based analyses give a more precise idea of AML as a health problem than registry data from cooperative groups or other sources, that usually include selected cases as part of research studies and/or therapy trials. In October 2016, the Autonomous Government of Catalonia funded a project (PERIS SLT002/16/00433) to prospectively collect all AML cases from our territory.

Introduction

Sierra: Astellas: Honoraria; Pfizer: Honoraria; Daiichi-Sankyo: Honoraria, Speakers Bureau; Abbvie: Honoraria, Speakers Bureau; Roche: Honoraria; Jazz Pharmaceuticals: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau. Salamero:Daichii Sankyo: Honoraria; Pfizer: Honoraria; Celgene: Honoraria; Novartis: Honoraria. Esteve:Jazz Pharmaceuticals: Consultancy; Celgene: Consultancy, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau; Amgen: Consultancy; Daiichi Sankyo: Consultancy; Roche: Consultancy; Astellas: Consultancy, Speakers Bureau; Pfizer: Consultancy.

BACKGROUND:AML risk classification is based on genetics (cytogenetics and molecular features) and more recently also on minimal residual disease (MRD) after chemotherapy. These two aspects allow predicting relapse and supporting or not the most anti-leukemia treatment that remains allogeneic hematopoietic cell transplantation (HCT). We prospectively investigated the combined use of the two predictive markers to allocate post-remission therapy with or without HCT. Objectives of the study were testing: a) if this approach was feasible in a multicenter setting; b) the proportion of patients who were allocated to an allogeneic HCT and finally received the procedure; c) the final distribution into the risk categories and their outcome; d) to analyze the outcome of patients with favorable or intermediate genetics moved to the high risk category because of positive MRD.

BACKGROUND:Current AML risk stratification relies on genetic data (cytogenetics and molecular characteristics) and minimal residual disease (MRD) assessment. This approach allows optimizing the post-remission allocation to chemotherapy only or hematopoietic cell transplantation (HCT). We investigated the feasibility and results of a prospective risk-adapted phase II trial of intensive chemotherapy followed or not by autologous or allogeneic HCT based on these criteria.

No relevant conflicts of interest to declare.

No relevant conflicts of interest to declare.

Background

Introduction

No relevant conflicts of interest to declare.

Prognosis of acute myeloid leukemia (AML) is mainly determined by presenting cyto- and molecular genetics, as systematized in the recent European LeukemiaNet (ELN) risk classification. Moreover, mutational profiling is currently used to assign post-remission therapy, especially in the category of intermediate-risk cytogenetics (IR-AML), given the observed benefit of allogeneic hematopoietic stem-cell transplantation (alloHSCT) in first complete response in patients harboring high-risk molecular features such as FLT3-ITD and the lack of benefit in patients with a favorable genotype (i.e., mutated NPM1and CEBPAbiallelic mutation). Nonetheless, the prognosis for patients with an IR-AML lacking mutations of these three genes (“triple negative” AML) is uncertain, and optimal post-remission strategy for these bona fideintermediate-risk patients is mostly unknown.

Patients with intermediate-risk cytogenetic AML (IR-AML) have a heterogeneous prognosis, and are currently further stratified based on determined gene mutations. However, the optimal post-remission therapy, especially in younger patients, is unclear. Recently, miR-3151, a novel microRNA (miRNA) located in intron 1 of the BAALC gene, has been identified. High miR-3151 expression –either alone or in combination with high BAALClevels– independently correlates with poor prognosis in patients ≥ 60 years with normal cytogenetics AML (CN-AML) (Eisfeld AK, et al. Blood 2012). However, the prognostic value of miR-3151 in younger patients (≤60 years) with IR-AML has not been examined. We hypothesized that miR-3151 expression could also be a prognostic marker in younger patients.To analyze whether miR-3151 expression – either alone or in combination with BAALC– improved prognostic assessment in younger patients (up to 60 years) with IR-AML and to characterize in this subset of patients the miRNA signature associated with high miR-3151 expression.Samples were available from two separate cohorts of patients with IR-AML who had received intensive therapy: a training set of 76 patients from a single institution and a validation set of 108 patients from several centers who had been treated within the CETLAM AML-2003 protocol. Information on NPM1, FLT3-ITD and CEBPA was available for both patient cohorts. The expression levels of 670 miRNAs had previously been analyzed in the 76 patients in the training set. In the present study, the expression of miR-3151 and BAALC was analyzed using TaqMan® MicroRNA Assay and TaqMan® Gene Expression Assay (Applied Biosystems), respectively. Expression levels of miR-3151 and BAALC –both alone and in combination – were correlated with patient outcome. Statistical analyses were performed with SPSS v.15.0.1, R software v.2.9.0 and TIGR MultiExperiment Viewerv4.0.In the training set, higher expression of miR-3151(dichotomized by its median value of normalized expression) correlated with a shorter 5-year overall survival (OS) (32%±17% vs. 61±17%, p=0.029) and 5-year leukemia-free survival (LFS) (29%±17% vs. 58±17%, p=0.036) in patients ≤ 60 yrs. When the analysis was restricted to patients with CN-AML, miR-3151 expression retained its prognostic significance (p= 0.016). In addition, increased BAALCexpression was associated with shorter OS (28%±20% vs. 58±14%, p=0.054) and LFS (17%±18% vs. 55±14%, p=0.039).In the multivariate analysis for OS and LFS, including age, WBC, NPM1mut, FLT3-ITD, BAALC and miR-3151 expression levels as covariates, miR-3151 showed independent prognostic significance for OS (p=0.016; HR=2.52, 95% CI: 1.2-5.4),and a statistical trend for LFS (p=0.09).Patients with low expression of both miR-3151 and BAALC had better prognosis (OS: 66%±18% vs. 34±16%, p=0.027; LFS: 67%±20% vs. 27±16%, p=0.009).Interestingly, the combination of both miR-3151 and BAALC retained a significant prognostic value for LFS within the favorable molecular subgroup/ ELN favorable subgroup (patients harboring NPM1mut without FLT3-ITD or biallelic CEBPAmut; LFS: 44%±30% vs. 100%, p=0.017) and showed a trend in the unfavorable molecular subgroup/ELN Intermediate I&II subgroups (patients lacking both NPM1 and CEBPA mutations and/or harboring FLT3-ITD; OS: p=0.064 and LFS: p=0.072).In the validation set, miR-3151 overexpression confirmed its prognostic impact in patients in the univariate analysis for OS (45%±12% vs. 26±19%, p=0.039) and LFS (51%±14% vs. 30±24%, p=0.034) and in the multivariate analysis for OS (OS: p=0.038; HR 1.88, IC 95%: 1.06-3.34) and LFS (p= 0.014; HR 2.411 (1.198-4.855)Finally, a supervised analysis revealed that samples exhibiting high levels of miR-3151 expression had a distinctive miRNA signature including miR-509, miR-135a, miR-100*, miR-186*, let-7a* and miR-501.miR-3151 is an independent prognostic marker in patients with IR-AML. The study of miR-3151 refines the molecular prognostic stratification of these patients and hence could be of help to guide therapy.Marina Díaz-Beyá is supported by Fundación Española de Hematologia y Hemoterapia. This research is supported by Sociedad Española de Hematologia y Hemoterapia and by grants from Fondo de Investigaciones Sanitarias FIS-PI080158.No relevant conflicts of interest to declare.

Quantitation of WT1 mRNA levels may be used in minimal residual disease studies in AML cases lacking a suitable molecular target. The normal thresholds of bone marrow WT1 levels at different time–points have not been clearly stated. Difficulties arise as a consequence of the relatively high WT1 expression in normal bone marrow and the unknown influence of chemotherapy.To establish the reference range value of bone marrow WT1 levels in treated CBF-AML and APL in complete remission.Patients with bone marrow samples obtained  from ≥2 years (2-11 y) after initial diagnosis of CBF-AML (AML1-ETO n:21 patients CBFb-MYH11 n:21 patients) or APL(n:22 patients) were included in the study (120 samples). Ages at diagnosis ranged from 1 to 76 years. Mean age was: AML1-ETO 36.8(2-76y),CBFb-MYH11 32.4(1-55y), PML-RARa 47.3(21-76y). Peripheral blood, reticulocyte count and a bone marrow aspirate were also available in 86 cases. WT1 was analyzed following the primers and conditions of the ELN group. Specific chimeric real time PCR was simultaneously performed in each sample in accordance with the BIOMED protocol. Each WT1 or chimeric PCR was analyzed in triplicate whereas the control gene (abl) was analyzed  in duplicate.All patients with an available BM study were in morphologic complete remission. Two samples corresponded to an anemic patient (2/86). Six cases had a reticulocyte count above  2%. Platelet counts were below 120x109/l in 3 cases (3/86). Leukocyte counts below 3.5x109/l were observed in 6 samples (6/86). The calculated mean WT1 copy number from the 120 bone marrow samples was 47.23 (AML1-ETO:61.33, CBFb-MYH11:43.51, PML-RARa:36.4 p:ns). The mean chimeric copy number was 0.75 (AML1-ETO:0.82, CBFb-MYH11:0.72, PML-RARa:0.69 p:ns).  Only 5 samples had a specific copy number of chimeric transcripts above 5 (3 AML1-ETO,1 CBFb-MYH11 and one PMAL-RARa patient who had a molecular relapse one month later and was succesfully treated). In 6 samples, the specific chimeric copy number  was between 1 and 5 copies ( 4 AML1-ETO and 2 CBFb-MYH11). In the remaining 109 BM samples, the specific copy number was <1.  In 9 BM samples, the WT1 levels were in the range of 100-300 copies (7 AML1-ETO and 2 CBFb-MYH11). All these 9 samples had specific chimeric gene number  below 1.5 copies. In three samples (1 AML1-ETO, 1 CBFb-MYH11 and 1 PML-RARa) peaks of WT1 levels of ≥300 copies were detected. In these three samples the specific chimeric gene was undetectable (<0.01).Bone marrow WT1 copy number in treated CBF-AML and APL was 47.23. In ten percent of cases, the WT1 copy number was greater than 100 copies. Occasionally, WT1 peaks (≥300 ) were detected. The meaning of the differential bone marrow WT1 transcriptional activity in long-term survivors of AML remains to be investigated.No relevant conflicts of interest to declare.

The improvements in genetic characterization of AML allowed the ELN to propose a prognostic classification into 4 categories: Favorable, Intermediate I, Intermediate II and Adverse. Several groups have tested the outcome of AML patients based on these genetic subgroups in registries and databases from prospective trials. Since ALLOSCT recommendations are being established based on the ELN risk categories, we considered of interest to investigate whether these also have an impact on the results of allogeneic transplants. This could be helpful to identify the patients that may benefit the most from ALLOHCT in the first complete remission (CR1).To investigate whether the ELN genetic groups of AML have any impact on the results of ALLOHCT performed in CR1. To identify the patients who are best candidates for transplantation, based on the ELN categories as well as in other characteristics.Patients were transplanted between 1990 and 2012. In all cases, treatment prior to transplant had consisted of anthracycline based induction and intermediate-dose cytarabine consolidation according to the CETLAM AML-88, AML-94, AML-99 and AML-03 trials. Upper age limit for transplantation was 60 years until 2002 and 70 years thereafter. Most patients above 50 years received either CD34 selected grafts or reduced intensity conditioning. GVHD prophylaxis after transplant was usually based on cyclosporine and prednisone or methotrexate. The main characteristics of patients and transplants were included in the exploratory analysis of variables influencing survival; those with a p- value up to 0.1 were incorporated as covariates to the multivariable model.One hundred ninety two patients in CR1 received an ALLOHCT from HLA-identical siblings (n=140), adult unrelated donors (n=26) or umbilical cord blood (n= 26). Age distribution of the patients was as follows: 16-35 years-old (y-o) n=65 (34%), 36-50 y-o n= 55 (29%), 51-60 y-o n= 54 (28%), >60 y-o n=18 (9%). Twenty-three patients (12%) were classified as in the favorable ELN category, 54 (28%) in the intermediate I, 41 (21%) in the intermediate II and 74 (39%) in the adverse. One-hundred fifty-seven patients (82%) had achieved CR1 after a single course of chemotherapy. Conditioning was myeloablative (MA) in 139 (72%) patients and reduced-intensity (RIC) in 53 (28%). In 76 cases of the MA regimens total body irradiation was included.Thirty-eight patients (20%) died due to transplant complications other than relapse and 47 (24%) experienced a leukemia recurrence. Overall survival (OS) and leukemia-free survivals at 8-years were 55±4% and 53±4%, respectively. Multivariate analysis of factors influencing OS included as covariates age at diagnosis of AML, ELN categories, courses to CR1 and conditioning regimen (MA versus RIC), since they had a p-value <0.1 in the univariate comparisons. The variables with independent on OS impact were age (p=0.01), courses to CR (p=001) and ELN classification (p=0.01). OS at 8 years in the favorable, intermediate I, intermediate II and adverse categories were 69±10%, 53±8%, 69±7% and 42±6%, respectively. In patients from the adverse ELN category, independent factors influencing OS in the multivariate analysis of this subgroup were age (16-60 y-o vs>60, p=0.01) and courses to CR (1 vs more, p=0.03).The ELN genetic categories have impact on OS of AML patients who receive an ALLOHCT in CR1. The results were very good in the favorable category and, most important, in intermediate II patients. Even patients in the adverse category had a substantial probability of long-term survival. This is remarkable, since the outcome of patients with adverse genetic features when treated with CT only is very poor.No relevant conflicts of interest to declare.

Quantitation of WT1 mRNA levels may be used in minimal residual disease studies in AML cases lacking a suitable molecular target. The normal thresholds of bone marrow WT1 levels at different time–points have not been clearly stated. Difficulties arise as a consequence of the relatively high WT1 expression in normal bone marrow and the unknown influence of chemotherapy.

The improvements in genetic characterization of AML allowed the ELN to propose a prognostic classification into 4 categories: Favorable, Intermediate I, Intermediate II and Adverse. Several groups have tested the outcome of AML patients based on these genetic subgroups in registries and databases from prospective trials. Since ALLOSCT recommendations are being established based on the ELN risk categories, we considered of interest to investigate whether these also have an impact on the results of allogeneic transplants. This could be helpful to identify the patients that may benefit the most from ALLOHCT in the first complete remission (CR1).

Patients with intermediate-risk cytogenetic AML (IR-AML) have a heterogeneous prognosis, and are currently further stratified based on determined gene mutations. However, the optimal post-remission therapy, especially in younger patients, is unclear. Recently, miR-3151, a novel microRNA (miRNA) located in intron 1 of the BAALCgene, has been identified. High miR-3151 expression –either alone or in combination with high BAALClevels– independently correlates with poor prognosis in patients ≥ 60 years with normal cytogenetics AML (CN-AML) (Eisfeld AK, et al. Blood 2012). However, the prognostic value of miR-3151 in younger patients (≤60 years) with IR-AML has not been examined. We hypothesized that miR-3151 expression could also be a prognostic marker in younger patients.

No relevant conflicts of interest to declare.

Acute myeloid leukemia (AML) is a heterogeneous group of neoplastic disorders characterized by the presence of acquired genetic alterations in hematopoietic progenitor and stem cells. The prognostic impact of immunophenotypic markers has long been controversial. Despite this, only a very limited number of studies have investigated the prognostic impact of the levels of cell surface membrane (Sm) proteins commonly expressed on AML blasts. In this study we analyzed the prognostic impact of the levels of expression of several markers associated with AML blasts and normal hematopoietic precursors, as asessed by Multiparameter Flow Cytometry (MFC) in de novo AML patients (pts).Overall, 122 adult de novo AML pts diagnosed between 12/2003 and 08/2011 were studied, after excluding acute promyelocytic leukemia. All cases were diagnosed and classified according to the WHO criteria and they were immunophenotyped using an extensive 4-color panel of monoclonal antibodies by MFC, as previously described. Patients were treated according to the multicenter CETLAM AML-03 trial. Blast cells were gated after excluding all other cell populations, as well-delineated clusters of SSC low/int/CD45dimevents (“blast gate”) using the merge function of the Infinicyt software (Cytognos SL, Salamanca, Spain). For each case, the reactivity for the following markers was evaluated in terms of mean fluorescence intensity (MFI; arbitrary units) in bone marrow samples: CD123, CD117, CD34 and CD7. Normal residual bone marrow lymphocytes were used as reference for internal quality control purposes. Cytogenetic and molecular risk stratifications were based on the European LeukemiaNet (ELN) recommendations and the molecular lesions were investigated using well established protocols. Overall survival (OS), disease-free survival (DFS) and relapse rate (RR) were measured by the Kaplan–Meier method and curves were compared with the log-rank test. Multivariate analysis was performed using the Cox regression model. P-values ≤0.05 were considered to be statistically significant.Median AML patient age was of 54 years (range: 20–70 y) with a M/F ratio of 63/59. Twelve pts (10%) had good cytogenetic/molecular risk, 83 (68%) intermediate, 17 (14%) high risk and 10 (8%) pts were unknown. Fifteen cases (12%) had NPM1mut, 33 (27%) showed FLT3-ITDmut, 5 (4%) pts carried CEBPAmut, 41 (33.6%) pts with no mutations and 28 (23%) pts were unknown. The median follow-up of pts alive was 19 months (range 0–97 months) and the 5-year OS of all pts was 42±5%. Univariate analysis of prognostic factors showed an association between higher CD45 (MFI >232; p=.01), CD117 (MFI>259; p=.008), CD34 (MFI >242; p=.007) and CD7 (MFI> 19; p=.03) expression and both a shorter OS and DFS. In addition, high CD123 expression (MFI >248; p=.04) was associated with a shorter DFS. In multivariate analysis only a high CD45 (p=.03) and a high CD34 (p=.03) expression were identified as independent predictors for a shorter OS. In turn, higher levels of CD123 (p=.03) and of CD34 (p=.02) were independent predictors for DFS and relapse, even when age, gender and WBC were taken in account.In this study, we show that higher levels of expression of immunophenotypic markers associate with immature myeloid precursors (CD45, CD117, CD34 and CD7) as assessed by MFC, have a significantly adverse prognostic impact in AML, both as regards OS and DFS. Accordingly, higher levels of CD45 and CD34 were independent predictors for both a shorter OS whereas, greater CD123 and CD34 values were associated with an increased risk of relapse and a shorter DFS, supporting the adverse prognostic impact of a more immature blast cell phenotype in de novo AML.No relevant conflicts of interest to declare.

Abstract 1452This icon denotes a clinically relevant abstract

Abstract 2524This icon denotes a clinically relevant abstract

From 2007 to 2011, 15 patients (11 males, 4 females) received 5-aza as last treatment prior to an allogeneic SCT (n=13) or as rescue after an early post-transplant relapse (n=2) at our centre. Diagnosis was MDS in 3 cases (median age 62; range 58–63) and AML in 12 cases (median age 58; range 37–67). Patients with MDS received a median of 6 courses of 5-aza (range 3–8) as the only treatment from diagnosis, except for one patient who had received panobinostat prior to 5-aza. Amongst patients with AML, 12 patients received 5-aza either as treatment for AML (2/12) or after remission (8/12) because of the high relapse risk while awaiting for a suitable donor to be found. Two patients with AML received 5-aza as treatment for early post-SCT relapse. AML patients treated with 5-aza before SCT received a median of 5 courses (range 1–19), whilst patients receiving treatment for relapse received 1 and 3 courses, respectively. Ten patients received a nonmyeloablative conditioning regimen, 1 received a conventional conditioning regimen, 2 patients are still in the process of donor search and the other 2 patients received 5-aza after an autologous stem cell transplantation relapse.All MDS patients engrafted and are in complete remission (CR) after a median of 696 days of follow-up (range 377–1227). One of those patients died because of aGvHD. Nine of 12 AML patients receiving 5-aza prior to SCT are alive after a median 373 days follow-up (133–995). One patient showing refractoriness to 3 different lines of treatment died from disease progression after 211 days. All patients receiving 5-aza as treatment for early relapse are dead, 41 and 401 days after starting treatment. Most interestingly, AML patients receiving 5-aza as maintenance of an already-achieved CR while awaiting transplantation did not experience disease progression despite the median time they remained on this treatment was prolonged (9 months). Graft-versus-host disease ≥ grade II was seen in 3 patients. No graft failures were seen and all patients who received an allogeneic stem cell transplantation remain in complete response.The use of 5-aza for maintaining or achieving a response in patients with AML who are awaiting SCT is a safe procedure and adds flexibility to schedule the treatment without the need to administer potentially toxic therapy. The use of 5-aza before transplant did not appear to interfere either with engraftment, incidence of GvHD or short-term relapse after transplant.No relevant conflicts of interest to declare.

From 2006 to 2011, 38 patients (23 males, 15 females) diagnosed as AML according to the WHO criteria1 received treatment with 5-aza (75 mg/m2 SQ daily, 5–7 days) at our institution as on-label or compassionate use program. Twenty-four patients (median age 68 years, range 37–85) had primary AML (pAML). Most of them (n=18) had failed to prior standard AML treatment: one line in 12 cases, 2 lines in 5 (including stem cell transplant [SCT] in 2 cases), and 3 lines in one. Fourteen additional patients (median age 68.3; range 32–88) had secondary AML (sAML); among them 8 previously treated: 6 patients had received one line of standard treatment before 5-aza, 1 patient 2 lines, and 1 patient 3 different lines. Twenty-two pAML and 14 sAML cases were screened for the presence of karyotype abnormalities. Screening for gene mutations [FLT3 internal tandem duplication (FLT3/ITD, nucleophosmin-1 gene mutation (NPM1), MLL partial tandem duplication, CCAAT/enhancer binding protein alpha mutation (CEBPA), AML1-ETO and CBFB-MYH11] was performed prior to starting 5-aza whenever possible. The response to treatment was usually assessed between the 4th and 6th courses, and classified according to WHO criteria.Patients received a median 7 courses (range 1–19) of standard-dose 5-aza. Within the pAML group, 13 patients responded [8 complete responses (CR) and 5 partial responses (PR)], and 4 patients with sAML responded (2 CR and 2 PR). Two patients in the pAML group and 1 patient with sAML subsequently received an SCT. After a median 218 days (10–792) follow-up in the pAML group, and 246 (19–995) in the sAML group, 66.7% patients with pAML and 28.6% with sAML were alive. Overall, no significant differences were seen in the rate of patients achieving CR or PR between the pAML and the sAML groups; despite this, the estimate 2-year survival was significantly higher in patients with pAML (p=0.01). Prior exposure to chemotherapy or other forms of treatment had no impact on response or survival. An abnormal karyotype (present in 12 pAML and 8 sAML patients) did not influence the response to treatment. All mutation analysis yielded negative results in sAML cases. In pAML cases, 3/20 were positive for FLT3/ITD, 5/19 for NPM1 and 1/19 for MLL. Most interestingly, NPM1 mutations in the absence of FLT3/ITD, were significantly (p=0.05) associated with improved response rate (5/5) in patients with pAML with no deaths being observed in this group.Our results show a higher probability of survival after 5-aza treatment in patients with pAML compared to sAML. The presence of NPM1 mutations appeared to identify a subset of pAML patients that, despite having failed first line treatment, may be particularly sensitive to this therapy. If confirmed in larger series, this finding would be of the utmost interest for offering these patients a low toxicity rescue therapy or a maintenance strategy with his agent.No relevant conflicts of interest to declare.

Abstract 4267

Abstract 3562

To validate the recent ELN classification in a large series of AML patients and to investigate if the inclusion of MK improved the prognostic stratification.804 consecutive patients treated under the CETLAM AML-99 (n=353) and CETLAM-03 (n=451) trials were analyzed. The two protocols included idarubicin, intermediate-dose cytarabine and etoposide as induction and mitoxantrone and intermediate-dose cytarabine as consolidation. G-CSF priming was given in the CETLAM-03 trial. Following, risk-adapted treatment with chemotherapy or hematopoietic transplantation was administered. Parameters analyzed were relapse rate (REL), leukemia-free survival (LFS) and overall survival (OS).Median age of the series was 46 years (range 16–60). Median follow-up of patients alive was 15 months. The ELN classification resulted in different prognostic risk groups. At 5 years, ELN favorable risk category had an OS of 60±4%, intermediate-I of 32±%, intermediate-II of 46±% and adverse of 17±3% (p<0.001). REL was comparable in the intermediate-I and adverse groups, 59±6% and 63±6% respectively, which translated into similar LFS. In contrast to the partial predictive value of the ELN proposal in our series, particularly in the intermediate categories, modified criteria identified 5 significantly different genetic risk groups: a) patients with RUNX1-RUNX1-T1 or CBFB-MYH11, b) patients with CEBPA or NPM1 mutations without FLT3-ITD, c) patients with intermediate cytogenetics of the MRC classification without mutations in CEBPA, NPM1 nor FLT3-ITD, and with FLT3-ITD, d) adverse MRC cytogenetics without MK and, e) patients with MK. Overall survival at 5 years for the 5 groups was 66±5%, 59±5%, 32±4%, 15±5%, and 4±4%, respectively (p<0.001).In the present study, the ELN genetic classification did not discriminate the prognosis of patients in the intermediate-I and intermediate-II categories. In contrast, genetic grouping that considered CBF AML, favorable mutations in the intermediate cytogenetics category and that separated adverse karyotype with or without MK translated into significantly different OS. This classification, together with the study of mutations recently described and the expression of certain genes may contribute to a more precise prognostic stratification and risk-adapted therapy.No relevant conflicts of interest to declare.

To compare the results of two consecutive trials for primary AML and to analyze the factors influencing the outcome.Adult patients between 17 and 60 years of age with de novo AML, diagnosed between 1999 and 2009, were included in the CETLAM AML-99 and AML-03 trials. Induction chemotherapy (CT) included one or two courses of idarubicin 12 mg/m2 IV days 1,3,5, cytarabine 500 mg/m2/12h over 2h IV days 1,3,5,7 and etoposide 100 mg/m2 IV days 1,2,3. This was followed by one consolidation with mitoxantrone 12 mg/m2 IV from day 4 to 6, and cytarabine 500 mg/m2/12h IV from day 1–6. In the AML 03 trial, patients also received G-CSF priming, 150 mg/m2 subcutaneously (SC) from day 0 to the last day of induction and consolidation CT. Postremission therapy consisted of high-dose cytarabine (CBF AML), autologous or allogeneic hematopoietic transplantation depending on cytogenetics, courses to complete remission (CR), and in the AML-03 protocol also based on molecular abnormalities involving FLT3 or MLL genes and/or the persistence of minimal residual disease after consolidation.Overall, 788 patients were included, 353 in the AML-99 trial and 435 in the AML-03. Median age of the patients was 46 years (range 17–60). There were no differences between patients included in the two protocols regarding age, gender, leukocyte counts, cytogenetics and proportion of favourable and unfavourable molecular cases in the group with intermediate-risk karyotype. The main results achieved appear in the table.Multivariate analysis confirmed the favourable impact of AML-03 protocol on outcome. Other significant factors influencing survival were age, leukocyte counts and cytogenetics.G-CSF priming improved the CR rate of adult patients with primary AML and favourable or unfavourable cytogenetics. This fact and a more precise risk-adapted therapy taking into account genetic data and MRD studies translated into improved overall survival.No relevant conflicts of interest to declare.

Abstract 1712

Abstract 1066

Recently, the cooperative group HOVON-SAKK has refined the prognostic impact of cytogenetic abnormalities in acute myeloid leukemia (AML) by introducing the concept of monosomal karyotype (MK). This consists of ≥ 2 autosomal monosomies or one autosomal monosomy in addition to a structural alteration. In their experience, MK would explain the poor prognosis of AML with a complex karyotype.To investigate the prognostic impact of MK in patients with primary (de novo) AML enrolled in the Spanish CETLAM group protocols (AML 94/99/03). Also, to determine whether considering MK added predictive value to the cytogenetic classification of the Medical Research Council (MRC).Retrospective analysis of data from 1149 AML patients. Chromosomal formula was centrally reviewed with karyotypes being classified by the presence of MK and allocated into the MRC risk categories. Complete remission (CR) rate, disease-free survival (DFS) and overall survival (OS) were calculated.The karyotype was assessable in 904 (79%) of the 1149 cases. In 145 of the 904 cases (16%), abnormalities involving CBF gene were detected and in 437 (48%) the karyotype was normal (NK). In 253 (28%) additional patients the karyotype was not monosomal; of them, 61 (24%) belonged to the unfavorable MRC with 17 cases harboring a complex karyotype ≥ 5 abnormalities, 7 cases with rearrangements 3q, 13 cases with -7, 9 cases with 5q abnormalities and 16 cases with t(6;9)). The remaining 69 (7.7%) patients had a MK; of them, 59 (85.5%) were from the unfavorable MRC category and included 43 cases with complex karyotype ≥ 5 abnormalities, 6 cases with rearrangements 3q, 5 cases with -7, 5 cases with alterations of 5q). The following table summarizes the results in terms of CR rate, DFS and OS:The addition of MK to the MRC cytogenetic classification refines the prognostic prediction. In our series, the dismal outcome of patients with MK is confirmed; these patients had worse prognosis than those with adverse cytogenetics without MK. Alternative treatment strategies are mandatory for MK+ patients.Supported in part by grants: GR1-01075, ECO07/90065, PI080672 and RD06/0020/0101.No relevant conflicts of interest to declare.

To analyze the prognostic impact of cytogenetics and main molecular abnormalities on the achievement of complete remission (CR), in patients with primary (de novo) AML (M3 excluded).Between december-2003 and july-2009, 605 patients up to 70 years-old were included in the CETLAM AML-03 protocol. Induction therapy consisted in one or two courses of idarubicin, intermediate dose ara-C and etoposide, in addition to G-CSF priming from day 0. Cytogenetics classification was as in the MRC studies: Favorable prognosis (FP), intermediate (IP) and adverse (AP). In the IP group, molecular analysis of NPM1 (NPM1+) mutations, CEBPA mutations and internal tandem duplication of FLT3 gene (ITD/FLT3) was performed. In the AP group, the absence (MK-) or presence of monosomal karyotype (MK+) was studied; MK+ was defined as 2 or more autosomal monosomies, or one monosomy and ≥1 structural alteration.Median age of the series was 53 years (range, 16-73). In 538 (89%) patients cytogenetic data were available; of them, 64 (10,5%) had FP, 375 (61,8) IP (included 255 with normal cytogenetics) and 99 (16,3%) AP. In the FP group, 33 (5,4%) had the AML1/ETO fusion and 31 (5,1%) the CBF/MYH11. In the IP group, 121 (31%) of 279 patients studied were NPM1+, 100 (26,7%) of 346 were DIT/FLT3+ and 22 (6%) of 235 analyzed were CEBPA+. In patients with AP, 47 were MK- and 33 MK+. Overall, 447 (73,8%) of 588 patients evaluable at the moment of the analysis achieved a CR. CR rates according cytogenetics were: FP 92,2%, IP 76,5% and AP 69,4%, p=0.01. In AML, with AML1-ETO+ and CBF/MYH11+, CR rates were 91% and 93.5%, respectively; of note no chemorefractory cases were observed. In the IP group, CR rates according to mutational status were: NPM1+/FLT3- 91.2%, CEBPA+/FLT3- 94.4%, no mutations 79.1% and DIT/FLT3+ 69.7% (p=0.003). Again, no refractoriness was observed in patients in IP patients belonging to the two groups with favourable molecular profile (p=0.003). In patients with AP, CR rate was 76.1% if MK- and 65.6% if MK+ (p=0.46). The prognostic impact of the herein described cytogenetic and molecular findings was confirmed in multivariate analyses.Genetic characterization is nowadays mandatory in AML. CR rate is high and refractoriness exceptional in the presence of AML1-ETO or CBF/MYH11 rearrangements, or NPM1 or CEBPA mutations without DIT/FLT3. In contrast, CR probability is lower in AP group patients, mainly in those with MK+. These patients require new strategies within clinical trials.Supported in part by grants: GR1-01075, ECO07/90065, PI080672 and RD06/0020/0101.No relevant conflicts of interest to declare.

Abstract 4711

Abstract 1003