Prognostic significance of concurrent gene mutations in intensively treated patients with IDH-mutated AML: an ALFA study.

In patients with isocitrate dehydrogenase (IDH)-mutated acute myeloid leukemia (AML) treated by intensive chemotherapy (IC), prognostic significance of co-occurring genetic alterations and allogeneic hematopoietic stem cell transplantation (HSCT) are of particular interest with the advent of IDH1/2 mutant inhibitors. We retrospectively analyzed 319 patients with newly diagnosed AML (127 with IDH1, 135 with IDH2R140, and 57 with IDH2R172 mutations) treated with IC in 3 Acute Leukemia French Association prospective trials. In each IDH subgroup, we analyzed the prognostic impact of clinical and genetic covariates, and the role of HSCT. In patients with IDH1 mutations, the presence of NPM1 mutations was the only variable predicting improved overall survival (OS) in multivariate analysis (P < .0001). In IDH2R140-mutated AML, normal karyotype (P = .008) and NPM1 mutations (P = .01) predicted better OS. NPM1 mutations were associated with better disease-free survival (DFS; P = .0009), whereas the presence of DNMT3A mutations was associated with shorter DFS (P = .0006). In IDH2R172-mutated AML, platelet count was the only variable retained in the multivariate model for OS (P = .002). Among nonfavorable European LeukemiaNet 2010-eligible patients, 71 (36%) underwent HSCT in first complete remission (CR1) and had longer OS (P = .03) and DFS (P = .02) than nontransplanted patients. Future clinical trials testing frontline IDH inhibitors combined with IC may consider stratification on NPM1 mutational status, the primary prognostic factor in IDH1- or IDH2R140-mutated AML. HSCT improve OS of nonfavorable IDH1/2-mutated AML and should be fully integrated into the treatment strategy.

Genetic identification of patients with AML older than 60 years achieving long-term survival with intensive chemotherapy.

To design a simple and reproducible classifier predicting the overall survival (OS) of patients with acute myeloid leukemia (AML) ≥60 years of age treated with 7 + 3, we sequenced 37 genes in 471 patients from the ALFA1200 (Acute Leukemia French Association) study (median age, 68 years). Mutation patterns and OS differed between the 84 patients with poor-risk cytogenetics and the 387 patients with good (n = 13), intermediate (n = 339), or unmeasured (n = 35) cytogenetic risk. TP53 (hazards ratio [HR], 2.49; P = .0003) and KRAS (HR, 3.60; P = .001) mutations independently worsened the OS of patients with poor-risk cytogenetics. In those without poor-risk cytogenetics, NPM1 (HR, 0.57; P = .0004), FLT3 internal tandem duplications with low (HR, 1.85; P = .0005) or high (HR, 3.51; P < 10-4) allelic ratio, DNMT3A (HR, 1.86; P < 10-4), NRAS (HR, 1.54; P = .019), and ASXL1 (HR, 1.89; P = .0003) mutations independently predicted OS. Combining cytogenetic risk and mutations in these 7 genes, 39.1% of patients could be assigned to a "go-go" tier with a 2-year OS of 66.1%, 7.6% to the "no-go" group (2-year OS 2.8%), and 3.3% of to the "slow-go" group (2-year OS of 39.1%; P < 10-5). Across 3 independent validation cohorts, 31.2% to 37.7% and 11.2% to 13.5% of patients were assigned to the go-go and the no-go tiers, respectively, with significant differences in OS between tiers in all 3 trial cohorts (HDF [Hauts-de-France], n = 141, P = .003; and SAL [Study Alliance Leukemia], n = 46; AMLSG [AML Study Group], n = 223, both P < 10-5). The ALFA decision tool is a simple, robust, and discriminant prognostic model for AML patients ≥60 years of age treated with intensive chemotherapy. This model can instruct the design of trials comparing the 7 + 3 standard of care with less intensive regimens.

A personalized approach to guide allogeneic stem cell transplantation in younger adults with acute myeloid leukemia.

A multistage model instructed by a large dataset (knowledge bank [KB] algorithm) has recently been developed to improve outcome predictions and tailor therapeutic decisions, including hematopoietic stem cell transplantation (HSCT) in acute myeloid leukemia (AML). We assessed the performance of the KB in guiding HSCT decisions in first complete remission (CR1) in 656 AML patients younger than 60 years from the ALFA-0702 trial (NCT00932412). KB predictions of overall survival (OS) were superior to those of European LeukemiaNet (ELN) 2017 risk stratification (C-index, 68.9 vs 63.0). Among patients reaching CR1, HSCT in CR1, as a time-dependent covariate, was detrimental in those with favorable ELN 2017 risk and those with negative NPM1 minimal residual disease (MRD; interaction tests, P = .01 and P = .02, respectively). Using KB simulations of survival at 5 years in a scenario without HSCT in CR1 (KB score), we identified, in a similar time-dependent analysis, a significant interaction between KB score and HSCT, with HSCT in CR1 being detrimental only in patients with a good prognosis based on KB simulations (KB score ≥40; interaction test, P = .01). We could finally integrate ELN 2017, NPM1 MRD, and KB scores to sort 545 CR1 patients into 278 (51.0%) HSCT candidates and 267 (49.0%) chemotherapy-only candidates. In both time-dependent and 6-month landmark analyses, HSCT significantly improved OS in HSCT candidates, whereas it significantly shortened OS in chemotherapy-only candidates. Integrating KB predictions with ELN 2017 and MRD may thus represent a promising approach to optimize HSCT timing in younger AML patients.

Frugal alignment-free identification of FLT3-internal tandem duplications with FiLT3r.

BACKGROUND: Internal tandem duplications in the FLT3 gene, termed FLT3-ITDs, are useful molecular markers in acute myeloid leukemia (AML) for patient risk stratification and follow-up. FLT3-ITDs are increasingly screened through high-throughput sequencing (HTS) raising the need for robust and efficient algorithms. We developed a new algorithm, which performs no alignment and uses little resources, to identify and quantify FLT3-ITDs in HTS data. RESULTS: Our algorithm (FiLT3r) focuses on the k-mers from reads covering FLT3 exons 14 and 15. We show that those k-mers bring enough information to accurately detect, determine the length and quantify FLT3-ITD duplications. We compare the performances of FiLT3r to state-of-the-art alternatives and to fragment analysis, the gold standard method, on a cohort of 185 AML patients sequenced with capture-based HTS. On this dataset FiLT3r is more precise (no false positive nor false negative) than the other software evaluated. We also assess the software on public RNA-Seq data, which confirms the previous results and shows that FiLT3r requires little resources compared to other software. CONCLUSION: FiLT3r is a free software available at https://gitlab.univ-lille.fr/filt3r/filt3r . The repository also contains a Snakefile to reproduce our experiments. We show that FiLT3r detects FLT3-ITDs better than other software while using less memory and time.

Mutational profile and benefit of gemtuzumab ozogamicin in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a highly heterogeneous disease both in terms of genetic background and response to chemotherapy. Although molecular aberrations are routinely used to stratify AML patients into prognostic subgroups when receiving standard chemotherapy, the predictive value of the genetic background and co-occurring mutations remains to be assessed when using newly approved antileukemic drugs. In the present study, we retrospectively addressed the question of the predictive value of molecular events on the benefit of the addition of gemtuzumab ozogamicin (GO) to standard front-line chemotherapy. Using the more recent European LeukemiaNet (ELN) 2017 risk classification, we confirmed that the benefit of GO was restricted to the favorable (hazard ratio [HR], 0.54, 95% confidence interval [CI], 0.30-0.98) and intermediate (HR, 0.57; 95% CI, 0.33-1.00) risk categories, whereas it did not influence the outcome of patients within the adverse risk subgroup (HR, 0.93; 95% CI, 0.61-1.43). Interestingly, the benefit of GO was significant for patients with activating signaling mutations (HR, 0.43; 95% CI, 0.28-0.65), which correlated with higher CD33 expression levels. These results suggest that molecular aberrations could be critical for future differentially tailored treatments based on integrated genetic profiles that are able to predict the benefit of GO on outcome.

Minimal residual disease monitoring in acute myeloid leukemia with non-A/B/D-NPM1 mutations by digital polymerase chain reaction: feasibility and clinical use.

Not available.

Comprehensive mutational profiling of core binding factor acute myeloid leukemia.

Acute myeloid leukemia (AML) with t(8;21) or inv(16) have been recognized as unique entities within AML and are usually reported together as core binding factor AML (CBF-AML). However, there is considerable clinical and biological heterogeneity within this group of diseases, and relapse incidence reaches up to 40%. Moreover, translocations involving CBFs are not sufficient to induce AML on its own and the full spectrum of mutations coexisting with CBF translocations has not been elucidated. To address these issues, we performed extensive mutational analysis by high-throughput sequencing in 215 patients with CBF-AML enrolled in the Phase 3 Trial of Systematic Versus Response-adapted Timed-Sequential Induction in Patients With Core Binding Factor Acute Myeloid Leukemia and Treating Patients with Childhood Acute Myeloid Leukemia with Interleukin-2 trials (age, 1-60 years). Mutations in genes activating tyrosine kinase signaling (including KIT, N/KRAS, and FLT3) were frequent in both subtypes of CBF-AML. In contrast, mutations in genes that regulate chromatin conformation or encode members of the cohesin complex were observed with high frequencies in t(8;21) AML (42% and 18%, respectively), whereas they were nearly absent in inv(16) AML. High KIT mutant allele ratios defined a group of t(8;21) AML patients with poor prognosis, whereas high N/KRAS mutant allele ratios were associated with the lack of KIT or FLT3 mutations and a favorable outcome. In addition, mutations in epigenetic modifying or cohesin genes were associated with a poor prognosis in patients with tyrosine kinase pathway mutations, suggesting synergic cooperation between these events. These data suggest that diverse cooperating mutations may influence CBF-AML pathophysiology as well as clinical behavior and point to potential unique pathogenesis of t(8;21) vs inv(16) AML.

Clinical relevance of IDH1/2 mutant allele burden during follow-up in acute myeloid leukemia. A study by the French ALFA group.

Assessment of minimal residual disease has emerged as a powerful prognostic factor in acute myeloid leukemia. In this study, we investigated the potential of IDH1/2 mutations as targets for minimal residual disease assessment in acute myeloid leukemia, since these mutations collectively occur in 15-20% of cases of acute myeloid leukemia and now represent druggable targets. We employed droplet digital polymerase chain reaction assays to quantify IDH1R132, IDH2R140, and IDH2R172 mutations on genomic DNA in 322 samples from 103 adult patients with primary IDH1/2 mutant acute myeloid leukemia and enrolled on Acute Leukemia French Association (ALFA) - 0701 or -0702 clinical trials. The median IDH1/2 mutant allele fraction in bone marrow samples was 42.3% (range, 8.2 - 49.9%) at diagnosis of acute myeloid leukemia, and below the detection limit of 0.2% (range, <0.2 - 39.3%) in complete remission after induction therapy. In univariate analysis, the presence of a normal karyotype, a NPM1 mutation, and an IDH1/2 mutant allele fraction <0.2% in bone marrow after induction therapy were statistically significant predictors of longer disease-free survival. In multivariate analysis, these three variables remained significantly predictive of disease-free survival. In 7/103 (7%) patients, IDH1/2 mutations persisted at high levels in complete remission, consistent with the presence of an IDH1/2 mutation in pre-leukemic hematopoietic stem cells. Five out of these seven patients subsequently relapsed or progressed toward myelodysplastic syndrome, suggesting that patients carrying the IDH1/2 mutation in a pre-leukemic clone may be at high risk of hematologic evolution.

Minimal residual disease monitoring in t(8;21) acute myeloid leukemia based on RUNX1-RUNX1T1 fusion quantification on genomic DNA.

Although acute myeloid leukemia (AML) with t(8;21) belongs to the favorable risk AML subset, relapse incidence may reach 30% in those patients. RUNX1-RUNX1T1 fusion transcript is a well-established marker for minimal residual disease (MRD) monitoring. In this study, we investigated the feasibility and performances of RUNX1-RUNX1T1 DNA as MRD marker in AML with t(8;21). In 17/22 patients with t(8;21)-positive AML treated in the French CBF-2006 trial, breakpoints in RUNX1 and RUNX1T1 were identified using long-range PCR followed by next-generation sequencing. RUNX1-RUNX1T1 DNA quantification was performed by real-time quantitative PCR using patient-specific primers and probe. MRD levels were evaluated in 71 follow-up samples from 16 patients, with a median of four samples [range 2-7] per patient. RUNX1 breakpoints were located in intron 5 in all cases. RUNX1T1 breakpoints were located in intron 1b in 15 cases and in intron 1a in two cases. RUNX1-RUNX1T1 MRD levels measured on DNA and RNA were strongly correlated (r = 0.8, P < 0.0001). Discordant MRD results were observed in 10/71 (14%) of the samples: in three samples from two patients who relapsed, RUNX1-RUNX1T1 was detectable only on DNA, while RUNX1-RUNX1T1 was detectable only on RNA in seven samples. MRD monitoring on genomic DNA is feasible, but with sensitivity variations depending on the patient breakpoint sequence and the qPCR assay efficiency. Although interpretation of the results is easier because it is closely related to the number of leukemic cells, this method greatly increases time, cost and complexity, which limits its interest in routine practice.

Multi-target measurable residual disease assessed by error-corrected sequencing in patients with acute myeloid leukemia: An ALFA study.

The evaluation of measurable residual disease (MRD) in acute myeloid leukemia (AML) using comprehensive mutation analysis by next-generation sequencing (NGS) has been investigated in several studies. However controversial results exist regarding the detection of persisting mutations in DNMT3A, TET2, and ASXL1 (DTA). Benchmarking of NGS-MRD taking into account other molecular MRD strategies has to be done. Here, we performed error-corrected-NGS-MRD in 189 patients homogeneously treated in the ALFA-0702 study (NCT00932412). Persistence of non-DTA mutations (HR = 2.23 for RFS and 2.26 for OS), and DTA mutations (HR = 2.16 for OS) were associated with poorer prognosis in multivariate analysis. Persistence of at least two mutations in complete remission (CR) was associated with a higher cumulative incidence of relapse (CIR) (HR = 3.71, p < 0.0001), lower RFS (HR = 3.36, p < 0.0001) and OS (HR = 3.81, p = 0.00023) whereas persistence of only one mutation was not. In 100 analyzable patients, WT1-MRD, but not NGS-MRD, was an independent factor for RFS and OS. In the subset of 67 NPM1 mutated patients, both NPM1 mutation detection (p = 0.0059) and NGS-MRD (p = 0.035) status were associated with CIR. We conclude that detectable NGS-MRD including DTA mutations correlates with unfavorable prognosis in AML. Its integration with alternative MRD strategies in AML management warrants further investigations.

Outcome of older patients with acute myeloid leukemia in first relapse.

To provide data for future drug evaluation, we analyzed the outcome of 393 patients aged 50 years or older (median, 64 years) with AML in first relapse after treatment in recent ALFA trials. Salvage options were retrospectively classified as follows: best supportive care (BSC), low-dose cytarabine (LDAC), gemtuzumab ozogamicin (GO), intensive chemotherapy (ICT), or ICT combined with GO. Second complete remission (CR2) rate was 31% and median post-relapse survival was 6.8 months (0, 17, 42.5, 53, and 80% and 3.2, 5.6, 8.9, 9, and 19.8 months in BSC, LDAC, GO, ICT, and ICT + GO subsets, respectively). Age, performance status, WBC, CR1 duration, and favorable AML karyotype, but not other cytogenetic or molecular features, influenced post-relapse outcome. Multivariate adjustment and propensity score matching showed that intensive salvage (ICT/ICT+GO/GO versus LDAC/BSC) was associated with longer post-relapse survival, at least in patients with CR1 duration ≥12 months (P = 0.001 and 0.0005, respectively). Of interest, GO appeared to be as effective as standard ICT, and ICT + GO combination more effective than standard ICT. In conclusion, older patients with CR1 duration ≥12 months appeared to benefit from intensive salvage and results observed with GO-containing salvage suggest that GO combination studies should be actively pursued in this setting.

LSC17 score complements genetics and measurable residual disease in acute myeloid leukemia: an ALFA study.

Whether the LSC17 gene expression can improve risk stratification in the context of next generation sequencing-based risk stratification and measurable residual disease (MRD) in patients with intensively treated AML has not been explored. We analyzed LSC17 in 504 adult patients prospectively treated in the ALFA-0702 trial. RUNX1 or TP53 mutations were associated with higher LSC1 scores while CEBPA and NPM1 mutations were associated with lower scores. Patients with high LSC17 scores had a lower rate of complete response (CR) in a multivariable analysis (odds ratio, 0.41; P = .0007), accounting for European LeukemiaNet 2022 (ELN22), age, and white blood cell count (WBC). LSC17-high status was associated with shorter overall survival (OS) (3-year OS: 70.0% vs 52.7% in patients with LSC17-low status; P < .0001). In a multivariable analysis considering ELN22, age, and WBC, patients with LSC17-high status had shorter disease-free survival (DFS) (hazard ratio [HR], 1.36; P = .048) than those with LSC17-low status. In 123 patients with NPM1-mutated AML in CR, LSC17-high status predicted poorer DFS (HR, 2.34; P = .01), independent of age, WBC, ELN22 risk, and NPM1-MRD. LSC-low status and negative NPM1-MRD identified a subset comprising 48% of patients with mutated NPM1 with a 3-year OS from CR of 93.1% compared with 60.7% in those with LSC17-high status and/or positive NPM1-MRD (P = .0001). Overall, LSC17 assessment refines genetic risk stratification in adult patients with AML treated intensively. Combined with MRD, LSC17 identifies a subset of patients with NPM1-mutated AML with excellent clinical outcome.

UBTF tandem duplications define a distinct subtype of adult de novo acute myeloid leukemia.

Tandem duplications (TDs) of the UBTF gene have been recently described as a recurrent alteration in pediatric acute myeloid leukemia (AML). Here, by screening 1946 newly diagnosed adult AML, we found that UBTF-TDs occur in about 3% of patients aged 18-60 years, in a mutually exclusive pattern with other known AML subtype-defining alterations. The characteristics of 59 adults with UBTF-TD AML included young age (median 37 years), low bone marrow (BM) blast infiltration (median 25%), and high rates of WT1 mutations (61%), FLT3-ITDs (51%) and trisomy 8 (29%). BM morphology frequently demonstrates dysmyelopoiesis albeit modulated by the co-occurrence of FLT3-ITD. UBTF-TD patients have lower complete remission (CR) rates (57% after 1 course and 76% after 2 courses of intensive chemotherapy [ICT]) than UBTF-wild-type patients. In patients enrolled in the ALFA-0702 study (n = 614 patients including 21 with UBTF-TD AML), the 3-year disease-free survival (DFS) and overall survival of UBTF-TD patients were 42.9% (95%CI: 23.4-78.5%) and 57.1% (95%CI: 39.5-82.8%) and did not significantly differ from those of ELN 2022 intermediate/adverse risk patients. Finally, the study of paired diagnosis and relapsed/refractory AML samples suggests that WT1-mutated clones are frequently selected under ICT. This study supports the recognition of UBTF-TD AML as a new AML entity in adults.

Antifungal Prophylaxis in AML Patients Receiving Intensive Induction Chemotherapy: A Prospective Observational Study From the Acute Leukaemia French Association (ALFA) Group.

BACKGROUND: Although recommended in patients with acute myeloblastic leukaemia (AML) after induction chemotherapy, real-life use of antifungal prophylaxis (AFP) is different among centres. MATERIALS AND METHODS: This is an ancillary study to a randomized trial on intensive induction chemotherapy in AML patients (ALFA-0702/NCT00932412), where AFP with posaconazole was recommended. IFIs were graded by investigators and by central reviewers according to the revised EORTC definitions. Experts conclusions were compared to the investigators' ones. RESULTS: A total of 677 patients were included. Four AFP strategies were reported: Group-1: no AFP (n = 203, 30%), Group-2: posaconazole (n = 241, 36%), Group-3: posaconazole with other AFP (n = 142, 21%), Group-4: other AFP (n = 91, 13%). Experts graded more IFI than investigators: proven/probable IFI, 9.0% (n = 61) versus 6.2% (n = 42). The cumulative incidence at day60 of probable/proven IFI was 13.9% (Group-1); 7.9% (Group-2); 5.6% (Group-3); and 6.6% (Group-4). IFI onset was 26 (19-31) days after induction in Groups 2-3, versus 16 (9-25) days in Group 1 and 20 (12-24) days in Group 4 (P< .001). After a median follow-up of 27.5 months (0.4-73.4), the mortality rate was 38.3%, with 5.4% attributed to IFI. In multivariate analysis, IFI occurrence was an independent risk of death (HR5.63, 95%-CI 2.62-12.08, P< .001). EORTC recommendations were applied in only 57% of patients. In patients without IFI, the rate of AML complete remission was higher. CONCLUSIONS: In AML patients, AFP delayed the onset of IFI in addition of decreasing their rate. The frequent misidentification of IFI impacts their appropriate management according to recommendations. hematological remission was more frequent in patients without IFI.

Early detection of WT1 measurable residual disease identifies high-risk patients, independent of transplantation in AML.

WT1 overexpression is frequently identified in acute myeloid leukemia (AML) and has been reported to be a potential marker for monitoring measurable residual disease (MRD). We evaluated the use of postinduction WT1 MRD level as a prognostic factor, as well as the interaction between postinduction WT1 MRD response and the effect of allogeneic stem cell transplantation (allo-SCT) in the first complete remission (CR). In the ALFA-0702 trial, patients with AML, aged 18 to 59, had a prospective quantification of WT1 MRD. The occurrence of a WT1 MRD ratio >2.5% in bone marrow or >0.5% in peripheral blood was defined as MRDhigh, and ratios below these thresholds were defined as MRDlow. The prognostic value of MRD after induction chemotherapy was assessed in 314 patients in first CR by comparing the risk of relapse, the relapse-free survival (RFS), and the overall survival (OS). Interaction between MRD response and the allo-SCT effect was evaluated in patients by comparing the influence of allo-SCT on the outcomes of patients with MRDhigh with those with MRDlow. The results showed that patients with MRDhigh after induction had a higher risk of relapse and a shorter RFS and OS. The MRD response remained of strong prognostic value in the subset of 225 patients with intermediate-/unfavorable-risk AML who were eligible for allo-SCT, because patients with MRDhigh had a significantly higher risk of relapse resulting in worse RFS and OS. The effect of allo-SCT was higher in patients with MRDlow than in those with MRDhigh, but not significantly different. The early WT1 MRD response highlights a population of high-risk patients in need of additional therapy.

Clonal dominance is an adverse prognostic factor in acute myeloid leukemia treated with intensive chemotherapy.

Intra-tumor heterogeneity portends poor outcome in many cancers. In AML, a higher number of drivers worsens prognosis. The Shannon Index is a robust metric of clonal heterogeneity that accounts for the number of clones, but also their relative abundance. We show that a Shannon Index can be estimated from bulk sequencing, which is correlated (ρ = 0.76) with clonal diversity from single-colony genotyping. In a discovery cohort of 292 patients with sequencing of 43 genes, a higher number of drivers (HR = 1.18, P = 0.028) and a lower Shannon Index (HR = 0.68, P = 0.048), the latter reflecting clonal dominance, are independently associated with worse OS independently of European LeukemiaNet 2017 risk. These findings are validated in an independent cohort of 1184 patients with 111-gene sequencing (number of drivers HR = 1.16, P = 1 × 10-5, Shannon Index HR = 0.81, P = 0.007). By re-interrogating paired diagnosis/relapse exomes from 50 cytogenetically normal AMLs, we find clonal dominance at diagnosis to be correlated with the gain of a significantly higher number of mutations at relapse (P = 6 × 10-6), hence with clonal sweeping. Our results suggest that clonal dominance at diagnosis is associated with the presence of a leukemic phenotype allowing rapid expansion of new clones and driving relapse after chemotherapy.

Added prognostic value of secondary AML-like gene mutations in ELN intermediate-risk older AML: ALFA-1200 study results.

In this study, we aimed to refine prognostication of older with acute myeloid leukemia (AML) after intensive chemotherapy. Five hundred and nine patients aged 60 years or older (median age, 68 years) were prospectively enrolled in the intensive Acute Leukemia French Association (ALFA)-1200 trial between 2012 and 2016, and 471 patient samples were submitted to multigene analysis. Mutations in any of 8 genes frequently altered in myelodysplastic syndromes (MDS), including ASXL1, SRSF2, STAG2, BCOR, U2AF1, EZH2, SF3B1, and ZRSR2, defined a secondary AML (sAML)-like disease, as reported. Of the samples analyzed, 48% included sAML-like gene mutations. These mutations were associated with a shorter event-free survival, both overall (hazard ratio, 1.46; 95% confidence interval, 1.19-1.79; P < .001) and within the European LeukemiaNet (ELN)-2017 intermediate-risk subgroup (hazard ratio, 1.52; 95% confidence interval, 1.01-2.28; P = .044), which excludes ASXL1-mutated cases by definition. We therefore included patients with intermediate-risk AML carrying sAML-like mutations in a single high-risk patients group together with adverse-risk patients with AML, whereas other intermediate-risk patients were included in a standard-risk group together with favorable-risk patients (high-risk/standard-risk patient ratio, 1.00). Using this 2-class risk assessment, we observed that transplantation prolonged overall survival from remission in patients with high-risk AML only, not in patients with standard-risk AML. Routine analysis of sAML-like gene mutations may thus improve the definition of high-risk older patients with AML, and better identify the half of older patients who clearly derive survival benefit from allogeneic transplantation in first remission. This trial was registered at www.clinicaltrials.gov as #NCT01966497.

Clofarabine Improves Relapse-Free Survival of Acute Myeloid Leukemia in Younger Adults with Micro-Complex Karyotype.

Acute myeloid leukemia (AML) encompasses heterogeneous entities with dismal outcomes. Intermediate and unfavorable-risk AML represent the most difficult-to-treat entities. We recently reported the benefit of the clofarabine-based consolidation (CLARA) regimen compared to the standard high-dose cytarabine (HDAC) regimen in younger AML patients. Here, we aimed at assessing the clinical significance of single-nucleotide polymorphism (SNP)-array alterations and their interactions with chemotherapy regimens. A SNP-array was successfully performed in 187 out of the 221 intent-to-treat patients (CLARA arm: n = 92 patients, HDAC arm: n = 95 patients). The CLARA regimen did not significantly improve relapse-free survival (RFS) among patients who displayed a complex karyotype when compared to the HDAC regimen (4-year RFS (4y-RFS): 36.4% vs. 18.8%, respectively; p = 0.134). Defining micro-complex karyotypes from at least four SNP-array lesions enabled us to refine and enlarge the subset of adverse patients. In such patients, the CLARA regimen significantly improved RFS compared to the HDAC regimen (4y-RFS: 44.4% vs. 13.8%, respectively; p = 0.004). From our study cohort, 8% of patients displayed TP53 mutations, which were associated with an impaired RFS (4y-RFS: 20.0% vs 43.7%; p = 0.029). In a multivariate analysis, micro-complex karyotypes remained the sole poor prognostic factor in the HDAC arm (hazard ratio (HR) = 2.324 (95% confidence interval (CI) = 1.337-4.041), p = 0.003). The SNP array represents a powerful and reproductive approach to refine adverse AML patients that may benefit from alternative consolidation regimens.