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PURPOSE Hydroxyurea (HY) is a reference treatment of advanced myeloproliferative neoplasms. We conducted a randomized phase III trial comparing decitabine (DAC) and HY in advanced myeloproliferative chronic myelomonocytic leukemias (CMML). PATIENTS AND METHODS Newly diagnosed myeloproliferative CMML patients with advanced disease were randomly assigned 1:1 to intravenous DAC (20 mg/m2/d days 1-5) or HY (1-4 g/d) in 28-day cycles. The primary end point was event-free survival (EFS), events being death and acute myelomonocytic leukemia (AML) transformation or progression. RESULTS One-hundred seventy patients received DAC (n = 84) or HY (n = 86). Median age was 72 and 74 years, and median WBC count 32.5 × 109/L and 31.2 × 109/L in the DAC and HY arms, respectively. Thirty-three percent of DAC and 31% of HY patients had CMML-2. Patients received a median of five DAC and six HY cycles. With a median follow-up of 17.5 months, median EFS was 12.1 months in the DAC arm and 10.3 months in the HY arm (hazard ratio [HR], 0.83; 95% CI, 0.59 to 1.16; P = .27). There was no significant interaction between treatment effect and blast or platelet count, anemia, CMML Prognostic Scoring System, Groupe Francophone des Myelodysplasies, or CMML Prognostic Scoring System–mol risk. Fifty-three (63%) DAC patients achieved a response compared with 30 (35%) HY patients ( P = .0004). Median duration of response was similar in both arms (DAC, 16.3 months; HY, 17.4 months; P = .90). Median overall survival was 18.4 months in the DAC arm and 21.9 months in the HY arm ( P = .67). Compared with HY, DAC significantly reduced the risk of CMML progression or transformation to acute myelomonocytic leukemia (cause-specific HR, 0.62; 95% CI, 0.41 to 0.94; P = .005) at the expense of death without progression or transformation (cause-specific HR, 1.55; 95% CI, 0.82 to 2.9; P = .04). CONCLUSION Compared with HY, frontline treatment with DAC did not improve EFS in patients with advanced myeloproliferative CMML (ClinicalTrials.gov identifier: NCT02214407 ).

International audience; Purpose: Infertility in adolescents and young adult (AYA) survivors of malignant disease remains a major long-term adverse effect, but semen collection for fertility preservation in fertility centers is not always feasible and makes AYAs uncomfortable. We evaluated the feasibility of collecting sperm samples on the ward versus in fertility centers. Methods: Consecutive hospitalized AYA-aged male patients in the Hematology AYA unit (Saint-Louis Hospital, France) between August 2010 and June 2016 with hematological disease and indication of semen collection (n = 95) were included in this retrospective study. Semen quality was analyzed according to World Health Organization guidelines and was compared according to semen collection place: on the ward (n = 46) or in fertility center (n = 49). Results: The median age was median age 19.1 years (range: 13.7-33.3; interquartile range: 17.1-22.8) and 85 patients successfully collected semen. Sperm collection failure was ∼11% and was comparable between the two modalities as were main sperm quality characteristics (semen volume, sperm concentration, total sperm count, progressive motility and vitality, sperm morphology, and multiple anomalies index). Oligospermia was significantly higher in the samples obtained in fertility center (47.7%) than on the ward (26.8%), p = 0.047. Average frozen straws were comparable, 12.2 ± 6.4 on the ward versus 11.9 ± 6.3 in fertility center. Conclusion: Semen collection on the ward is feasible and would be particularly interesting for AYA male patients without altering semen quality characteristics.

Selinexor is a first-in-class inhibitor of the nuclear exportin XPO1 that was recently approved by the US Food and Drug Administration for the treatment of multiple myeloma and diffuse large B-cell lymphoma. In relapsed/refractory acute myeloid leukemia (AML), selinexor has shown promising activity, suggesting that selinexor-based combination therapies may have clinical potential. Here, motivated by the hypothesis that selinexor's nuclear sequestration of diverse substrates imposes pleiotropic fitness effects on AML cells, we systematically catalog the pro- and anti-fitness consequences of selinexor treatment. We discover that selinexor activates PI3Kγ-dependent AKT signaling in AML by upregulating the purinergic receptor P2RY2. Inhibiting this axis potentiates the anti-leukemic effects of selinexor in AML cell lines, patient-derived primary cultures and multiple mouse models of AML. In a syngeneic, MLL-AF9-driven mouse model of AML, treatment with selinexor and ipatasertib outperforms both standard-of-care chemotherapy and chemotherapy with selinexor. Together, these findings establish drug-induced P2RY2-AKT signaling as an actionable consequence of XPO1 inhibition in AML.

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.

The independent prognostic impact of specific dysplastic features in acute myeloid leukemia (AML) remains controversial and may vary between genomic subtypes. We apply a machine learning framework to dissect the relative contribution of centrally reviewed dysplastic features and oncogenetics in 190 patients with de novo AML treated in ALFA clinical trials. One hundred and thirty-five (71%) patients achieved complete response after the first induction course (CR). Dysgranulopoiesis, dyserythropoiesis and dysmegakaryopoiesis were assessable in 84%, 83% and 63% patients, respectively. Multi-lineage dysplasia was present in 27% of assessable patients. Micromegakaryocytes (q = 0.01), hypolobulated megakaryocytes (q = 0.08) and hyposegmented granulocytes (q = 0.08) were associated with higher ELN-2017 risk. Using a supervised learning algorithm, the relative importance of morphological variables (34%) for the prediction of CR was higher than demographic (5%), clinical (2%), cytogenetic (25%), molecular (29%), and treatment (5%) variables. Though dysplasias had limited predictive impact on survival, a multivariate logistic regression identified the presence of hypolobulated megakaryocytes (p = 0.014) and micromegakaryocytes (p = 0.035) as predicting lower CR rates, independently of monosomy 7 (p = 0.013), TP53 (p = 0.004), and NPM1 mutations (p = 0.025). Assessment of these specific dysmegakarypoiesis traits, for which we identify a transcriptomic signature, may thus guide treatment allocation in AML.

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.

Background Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) comprise several rare hematologic malignancies with shared concomitant dysplastic and proliferative clinicopathologic features of bone marrow failure and propensity of acute leukemic transformation, and have significant impact on patient quality of life. The only approved disease-modifying therapies for any of the MDS/MPN are DNA methyltransferase inhibitors (DNMTi) for patients with dysplastic CMML, and still, outcomes are generally poor, making this an important area of unmet clinical need. Due to both the rarity and the heterogeneous nature of MDS/MPN, they have been challenging to study in dedicated prospective studies. Thus, refining first-line treatment strategies has been difficult, and optimal salvage treatments following DNMTi failure have also not been rigorously studied. ABNL-MARRO (A Basket study of Novel therapy for untreated MDS/MPN and Relapsed/Refractory Overlap Syndromes) is an international cooperation that leverages the expertise of the MDS/MPN International Working Group (IWG) and provides the framework for collaborative studies to advance treatment of MDS/MPN and to explore clinical and pathologic markers of disease severity, prognosis, and treatment response. Methods ABNL MARRO 001 (AM-001) is an open label, randomly allocated phase 1/2 study that will test novel treatment combinations in MDS/MPNs, beginning with the novel targeted agent itacitinib, a selective JAK1 inhibitor, combined with ASTX727, a fixed dose oral combination of the DNMTi decitabine and the cytidine deaminase inhibitor cedazuridine to improve decitabine bioavailability. Discussion Beyond the primary objectives of the study to evaluate the safety and efficacy of novel treatment combinations in MDS/MPN, the study will (i) Establish the ABNL MARRO infrastructure for future prospective studies, (ii) Forge innovative scientific research that will improve our understanding of pathogenetic mechanisms of disease, and (iii) Inform the clinical application of diagnostic criteria, risk stratification and prognostication tools, as well as response assessments in this heterogeneous patient population. Trial registration This trial was registered with ClinicalTrials.gov on August 19, 2019 (Registration No. NCT04061421).

International audience

Summary Background Genome-edited donor-derived allogeneic anti-CD19 chimeric antigen receptor (CAR) T cells offer a novel form of CAR-T-cell product that is available for immediate clinical use, thereby broadening access and applicability. UCART19 is one such product investigated in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Two multicentre phase 1 studies aimed to investigate the feasibility, safety, and antileukaemic activity of UCART19 in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Methods We enrolled paediatric or adult patients in two ongoing, multicentre, phase 1 clinical trials to evaluate the safety and antileukaemic activity of UCART19. All patients underwent lymphodepletion with fludarabine and cyclophosphamide with or without alemtuzumab, then children received UCART19 at 1·1–2·3 × 106 cells per kg and adults received UCART19 doses of 6 × 106 cells, 6–8 × 107 cells, or 1·8–2·4 × 108 cells in a dose-escalation study. The primary outcome measure was adverse events in the period between first infusion and data cutoff. These studies were registered at ClinicalTrials.gov, NCT02808442 and NCT02746952. Findings Between June 3, 2016, and Oct 23, 2018, seven children and 14 adults were enrolled in the two studies and received UCART19. Cytokine release syndrome was the most common adverse event and was observed in 19 patients (91%); three (14%) had grade 3–4 cytokine release syndrome. Other adverse events were grade 1 or 2 neurotoxicity in eight patients (38%), grade 1 acute skin graft-versus-host disease in two patients (10%), and grade 4 prolonged cytopenia in six patients (32%). Two treatment-related deaths occurred; one caused by neutropenic sepsis in a patient with concurrent cytokine release syndrome and one from pulmonary haemorrhage in a patient with persistent cytopenia. 14 (67%) of 21 patients had a complete response or complete response with incomplete haematological recovery 28 days after infusion. Patients not receiving alemtuzumab (n=4) showed no UCART19 expansion or antileukaemic activity. The median duration of response was 4·1 months with ten (71%) of 14 responders proceeding to a subsequent allogeneic stem-cell transplant. Progression-free survival at 6 months was 27%, and overall survival was 55%. Interpretation These two studies show, for the first time, the feasibility of using allogeneic, genome-edited CAR T cells to treat patients with aggressive leukaemia. UCART19 exhibited in-vivo expansion and antileukaemic activity with a manageable safety profile in heavily pretreated paediatric and adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. The results this study are an encouraging step forward for the field of allogeneic CAR T cells, and UCART19 offers the opportunity to treat patients with rapidly progressive disease and where autologous CAR-T-cell therapy is unavailable. Funding Servier.

Isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) mutations in Myeloid Neoplams (MNs) exhibit DNA hypermethylation via 2-hydroxyglutarate (2HG) over-production. Clinical impact of azacitidine (AZA) re...

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.

By querying metabolic pathways associated with leukemic stemness and survival in multiple AML datasets, we nominated SLC7A11 encoding the xCT cystine importer as a putative AML dependency. Genetic and chemical inhibition of SLC7A11 impaired the viability and clonogenic capacity of AML cell lines in a cysteine-dependent manner. Sulfasalazine, a broadly available drug with xCT inhibitory activity, had anti-leukemic activity against primary AML samples in ex vivo cultures. Multiple metabolic pathways were impacted upon xCT inhibition, resulting in depletion of glutathione pools in leukemic cells and oxidative stress-dependent cell death, only in part through ferroptosis. Higher expression of cysteine metabolism genes and greater cystine dependency was noted in NPM1-mutated AMLs. Among eight anti-leukemic drugs, the anthracycline daunorubicin was identified as the top synergistic agent in combination with sulfasalazine in vitro. Addition of sulfasalazine at a clinically relevant concentration significantly augmented the anti-leukemic activity of a daunorubicin-cytarabine combination in a panel of 45 primary samples enriched in NPM1-mutated AML. These results were confirmed in vivo in a patient-derived xenograft model. Collectively, our results nominate cystine import as a druggable target in AML and raise the possibility to repurpose sulfasalazine for the treatment of AML, notably in combination with chemotherapy.

Functional precision medicine in AML often relies on short-term in vitro drug sensitivity screening (DSS) of primary patient cells in standard culture conditions. We designed a niche-like DSS assay combining physiologic hypoxia (O2 3%) and mesenchymal stromal cell (MSC) co-culture with multiparameter flow cytometry to enumerate lymphocytes and differentiating (CD11/CD14/CD15+) or leukemic stem cell (LSC)-enriched (GPR56+) cells within the leukemic bulk. After functional validation of GPR56 expression as a surrogate for LSC enrichment, the assay identified three patterns of response, including cytotoxicity on blasts sparing LSCs, induction of differentiation, and selective impairment of LSCs. We refined our niche-like culture by including plasma-like amino-acid and cytokine concentrations identified by targeted metabolomics and proteomics of primary AML bone marrow plasma samples. Systematic interrogation revealed distinct contributions of each niche-like component to leukemic outgrowth and drug response. Short-term niche-like culture preserved clonal architecture and transcriptional states of primary leukemic cells. In a cohort of 45 AML samples enriched for NPM1c AML, the niche-like multiparametric assay could predict morphologically (p = 0.02) and molecular (NPM1c MRD, p = 0.04) response to anthracycline-cytarabine induction chemotherapy. In this cohort, a 23-drug screen nominated ruxolitinib as a sensitizer to anthracycline-cytarabine. This finding was validated in an NPM1c PDX model.

Simple Summary Acute myeloid leukemias (AML) results from the accumulation of genetic and epigenetic alterations, often in the context of an aging hematopoietic environment. The development of high-throughput sequencing—and more recently, of single-cell technologies—has shed light on the intratumoral diversity of leukemic cells. Taking AML as a model disease, we review the multiple sources of heterogeneity of leukemic cells and discuss the definition of a leukemic clone. After introducing the two dimensions contributing to clonal diversity, namely, richness (number of leukemic clones) and evenness (distribution of clone sizes), we discuss the mechanisms at the origin of clonal emergence and the causes of clonal dynamics including neutral drift, and cell-intrinsic and -extrinsic influences on clonal fitness. After reviewing the prognostic role of leukemic diversity on patients’ outcome, we discuss how a better understanding of AML as an evolutionary process could lead to the design of novel therapeutic strategies for this disease. Abstract Acute myeloid leukemias (AML) results from the accumulation of genetic and epigenetic alterations, often in the context of an aging hematopoietic environment. The development of high-throughput sequencing—and more recently, of single-cell technologies—has shed light on the intratumoral diversity of leukemic cells. Taking AML as a model disease, we review the multiple sources of genetic, epigenetic, and functional heterogeneity of leukemic cells and discuss the definition of a leukemic clone extending its definition beyond genetics. After introducing the two dimensions contributing to clonal diversity, namely, richness (number of leukemic clones) and evenness (distribution of clone sizes), we discuss the mechanisms at the origin of clonal emergence (mutation rate, number of generations, and effective size of the leukemic population) and the causes of clonal dynamics. We discuss the possible role of neutral drift, but also of cell-intrinsic and -extrinsic influences on clonal fitness. After reviewing available data on the prognostic role of genetic and epigenetic diversity of leukemic cells on patients’ outcome, we discuss how a better understanding of AML as an evolutionary process could lead to the design of novel therapeutic strategies in this disease.

Hyperleukocytosis in acute myeloid leukemia (AML) is associated with inferior outcomes. There is limited high quality evidence to support the benefits of leukapheresis. We retrospectively collected data from patients with newly-diagnosed AML who presented with a white cell count (WBC) >50 x 10(9)/L to 12 centers in the United States and Europe from 2006 to 2017 and received intensive chemotherapy. Logistic regression models estimated odds ratios for 30-day mortality and achievement of composite complete remission (CRc). Cox proportional hazard models estimated hazard ratios for overall survival (OS). Among 779 patients, clinical leukostasis was reported in 27%, and leukapheresis was used in 113 patients (15%). Thirty-day mortality was 16.7% (95% CI: 13.9-19.3%). Median OS was 12.6 months (95% CI: 11.5-14.9) among all patients, and 4.5 months (95% CI: 2.7-7.1) among those >= 65 years. Use of leukapheresis did not significantly impact 30-day mortality, achievement of CRc, or OS in multivariate analysis based on available data or in analysis based on multiple imputation. Among patients with investigator-adjudicated clinical leukostasis, there were statistically significant improvements in 30-day mortality and OS with leukapheresis in unadjusted analysis, but not in multivariate analysis. Given the significant resource use, cost, and potential complications of leukapheresis, randomized studies are needed to evaluate its value.

Since the demonstration that poor prednisone response was associated with an increased relapse risk, early evaluation of in vivo tumor burden reduction has been established as the most powerful pro...

Germline DDX41 mutations are involved in familial myelodysplastic syndromes (MDSs) and acute myeloid leukemias (AMLs). We analyzed the prevalence and characteristics of DDX41-related myeloid malignancies in an unselected cohort of 1385 patients with MDS or AML. Using targeted next-generation sequencing, we identified 28 different germline DDX41 variants in 43 unrelated patients, which we classified as causal (n = 21) or unknown significance (n = 7) variants. We focused on the 33 patients having causal variants, representing 2.4% of our cohort. The median age was 69 years; most patients were men (79%). Only 9 patients (27%) had a family history of hematological malignancy, and 15 (46%) had a personal history of cytopenia years before MDS/AML diagnosis. Most patients had a normal karyotype (85%), and the most frequent somatic alteration was a second DDX41 mutation (79%). High-risk DDX41 MDS/AML patients treated with intensive chemotherapy (n = 9) or azacitidine (n = 11) had an overall response rate of 100% or 73%, respectively, with a median overall survival of 5.2 years. Our study highlights that germline DDX41 mutations are relatively common in adult MDS/AML, often without known family history, arguing for systematic screening. Salient features of DDX41-related myeloid malignancies include male preponderance, frequent preexisting cytopenia, additional somatic DDX41 mutation, and relatively good outcome.

The role of the vascular microenvironment is increasingly studied in acute myeloid leukaemia (AML). Complex interactions between endothelial cells (ECs) and pre-leukaemic cells may contribute to the clonal evolution of pre-leukaemic stem cells in the bone marrow niche and to the proliferation, survival and chemoresistance of leukaemic cells. Through the expression of different adhesion molecules, ECs play a key role in the development of specific acute complications of AML, including leukostasis, acute respiratory failure, acute kidney injury or neurological complications. Moreover, in newly diagnosed patients, leukaemic cells promote endothelial activation and subsequent disseminated intravascular coagulation. Mechanisms of this bi-directional dialogue between leukaemic cells and ECs will reveal possible therapeutic targets to be explored to improve the survival of AML patients.

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.

Prognosis of acute myeloid leukemia (AML) patients depends on patient-related features, disease manifestations at the time of presentation, and intrinsic disease-related genetic features, such as cytogenetic abnormalities and driver mutations. Prognostic stratification also depends on the therapeutic strategy and on response to treatment, including measurable residual disease assessment. This chapter reviews the influence of prognostic factors measured at the diagnosis of AML, with an emphasis on disease-related factors. The role of measurable residual disease and how prognostic stratification affects treatment decisions are covered in other chapters.

International audience; 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.

Islands of CD123high cells have been commonly described in the bone marrow of patients with chronic myelomonocytic leukemia (CMML). Using a multiparameter flow cytometry assay, we detected an excess of CD123+ mononucleated cells that are lineage-negative, CD45+, CD11c−, CD33−, HLA-DR+, BDCA-2+, BDCA-4+ in the bone marrow of 32/159 (20%) patients. Conventional and electron microscopy, flow cytometry detection of cell surface markers, gene expression analyses, and the ability to synthesize interferon alpha in response to Toll-like receptor agonists identified these cells as bona fide plasmacytoid dendritic cells (pDCs). Whole-exome sequencing of sorted monocytes and pDCs identified somatic mutations in genes of the oncogenic RAS pathway in the two cell types of every patient. CD34+ cells could generate high amount of pDCs in the absence of FMS-like tyrosine kinase 3-ligand (FLT3L). Finally, an excess of pDCs correlates with regulatory T cell accumulation and an increased risk of acute leukemia transformation. These results demonstrate the FLT3L-independent accumulation of clonal pDCs in the bone marrow of CMML patients with mutations affecting the RAS pathway, which is associated with a higher risk of disease progression.

Patients with primary refractory or relapsed-acute myeloid leukemia (RR-AML), particularly older adults, have dismal outcomes and limited therapy options [1]. Given the tolerability of hypomethylat...

Treatment with azacitidine (AZA) has been suggested to be of benefit for higher-risk myelodysplastic syndrome (HR-MDS) patients with chromosome 7 abnormalities (Abn 7). This retrospective study of 235 HR-MDS patients with Abn 7 treated with AZA (n = 115) versus best supportive care (BSC; n = 120), assessed AZA treatment as a time-varying variable in multivariable analysis. A Cox Regression model with time-interaction terms of overall survival (OS) at different time points confirmed that, while chromosome 7 cytogenetic categories (complex karyotype [CK] versus non-CK) and International Prognostic Scoring System risk (high versus intermediate-2) retained poor prognosis over time, AZA treatment had a favourable impact on OS during the first 3 years of treatment compared to BSC (Hazard ratio [HR] 0·5 P

Context: Systemic inflammatory and auto-immune diseases (SIAD) are observed in 25% of patients with MDS or CMML, who harbor a high frequency of mutations in TET2, IDH1/2 and SRSF2 as we previously reported (Zhao et al, Leukemia 2021). Recently, the identification of mutations in UBA1 in patients with autoinflammatory disorders, some of whom have dysplastic bone marrow, defined novel disease called VEXAS syndrome (Beck et al, NEJM 2020). Objective: To explore the prevalence of UBA1 mutations in our initial cohort of MDS/CMML patients with SIAD (n=85) (Zhao et al, Leukemia 2021). Design and Patients: All male patients for whom material was available (n=33) were analyzed for the presence of UBA1 mutations. Primary Outcome: UBA1 mutations screening with Sanger sequencing. Results: Four out of 33 (12%) patients had UBA1 mutations. All of them had MDS without excess of blasts. Cytomorphologic review of bone marrow smears showed numerous vacuoles in precursors in all 4 cases. Karyotype was normal in 3/4 patients, and one patient had deletion 9q. One patient also had somatic mutations in DNMT3A (VAF 11%) and TP53 (VAF 2%), and another patient had a mutation of TET2 (VAF 18%). Three patients in our MDS/CMML SIAD cohort had relapsing polychondritis, and 2 of them had UBA1 mutations, while 6 patients from our initial SIAD cohort had a diagnosis of Sweet syndrome, including 2 with UBA1 mutations. Three out of 4mut patients had steroid refractory SIAD and were heavily treated with other immunosuppressive therapies including methotrexate, azathioprine or cytokine targeting agents. At last follow-up, none of the 4 patients with UBA1 mutations had MDS progression, and one of them had died from a stroke, 2.4 years after MDS diagnosis. Conclusions: Our retrospective study represents the first assessment of VEXAS syndrome among patients with myeloid malignancies associated with SIAD. The low prevalence of UBA1 mutations in our cohort suggests that other pathological mechanisms may drive inflammation in the large majority of MDS/CMML patients with associated SIAD, likely in relation with mutations in epigenetic regulators TET2/IDH and SRSF2 as we previously proposed.

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic malignancy that may deserve specific management. Defined by a persistent peripheral blood monocytosis ≥1 × 109/L and monocytes accounting for ≥10% of the white blood cells, this aging-associated disease combines cell proliferation as a consequence of myeloid progenitor hypersensitivity to granulocyte-macrophage colony-stimulating factor with myeloid cell dysplasia and ineffective hematopoiesis. The only curative option for CMML remains allogeneic stem cell transplantation. When transplantation is excluded, CMML is stratified into myelodysplastic (white blood cell count

Context. Functional precision medicine is gaining momentum in AML, notably through ex vivo drug sensitivity screening (DSS) of primary patient (pt) cells (Pemovska Cancer Discov 2013, Tyner Nature 2018). The DSS landscape differs across genetic AML subgroups (Tyner Nature 2016), of which NPM1mut is the most frequent (Papaemmanuil NEJM 2016). DSS in AML has mostly been done in standard conditions, with overall viability as unique endpoint. Niche signals, which can be partly mimicked in vitro, convey drug resistance in vivo. Drugs can induce a variety of cell fates in AML. Induction of differentiation rather than killing of blasts, can result in false negative results in global viability assays. Persistence of leukemic stem cells (LSC) represents a major cause of treatment failure. GPR56 is a ubiquitous surface marker enriching for LSCs and stable upon short-term ex vivo culture (Pabst Blood 2016). Objectives. To develop an ex vivo niche-like multiparametric DSS platform for primary AML cells. To validate its clinical relevance in NPM1mut pts treated with conventional DNR-AraC chemotherapy. To discover new sensitizers to DNR-AraC chemotherapy in NPM1mut AML. Results. We designed an MFC panel to count viable blasts and measure their differentiation (CD11b/CD14/CD15) and stemness (GPR56) after exclusion of residual lymphocytes (Figure 1A). We validated GPR56 expression as stemness marker based on increased retention of GPR56+ cells in niche-like coculture combining hypoxia (O2 3%) and MSC compared to standard conditions (p To further mimic in vivo conditions, we derived a MEMa-based plasma-like medium (PLM) based on targeted metabolomics (Figure 1E) and electro-chemoluminescent cytokine assays of 29 diagnostic AML bone marrow plasma samples compared to conditioned media of primary AML cells cultured in niche-like conditions (MSC, hypoxia). This instructed the design of our custom PLM with dialyzed FBS and defined low-dose (~1 ng/mL range) cytokines (CK) and amino-acid (AA) concentrations. We next investigated the contribution of MSCs, hypoxia, plasma-like AAs and CKs on blasts viability, differentiation, stemness and drug response in 3 NPM1mut AMLs exposed to fixed concentrations of 6 core AML therapies. This analysis uncovered significant interactions between these 4 niche components in dictating blast viability and stemness upon 72h ex vivo culture (Figure 1F) and revealed the distinct contribution of these niche components to drug sensitivity. RNA-seq of primary blasts cultured in niche-like, plasma-like conditions revealed marked enrichment of stemness pathways compared to ex vivo culture in standard conditions. Finally, we explored DNR-AraC (five-point serial dilution) alone or in combination with fixed, clinically relevant concentrations of 24 drugs in 49 primary AML samples (including 34 NPM1mut). Using AUCs of DNR-AraC on lymphocytes as internal control, we first validated our NEXT assay on NPM1 MRD levels in the 34 NPM1mut pts treated frontline with conventional DNR-AraC regimens (Figure 1G). Across all 49 pts, we uncovered 11 different optimal 'third-drugs', stressing the role of our NEXT assay to deploy precision medicine in daily practice. At the population level, we could nominate 3 top combinations, two of which are currently in clinical investigation (Venetoclax and Selinexor). The unpublished sensitizing effect of low dose (0.25µM) Ruxolitinib on DNR-AraC uncovered with our NEXT assay is currently being investigated in PDX models. Conclusion. We designed the NEXT assay, a multiparametric drug screening of AML viability, differentiation and stemness in niche-like culture combining hypoxia, stromal interactions and plasma-like medium. Components of the niche-like culture interact to govern leukemic viability and stemness. Our assay could predict MRD achievement in NPM1mut AML and identifies novel sensitizers to DNR-AraC in these pts. Disclosures Clappier: Amgen: Honoraria, Research Funding. Ades:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; jazz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; novartis: Research Funding; Celgene/BMS: Research Funding. Itzykson:Amgen: Membership on an entity's Board of Directors or advisory committees; Otsuka Pharma: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Stemline: Membership on an entity's Board of Directors or advisory committees; Oncoethix (now Merck): Research Funding; Janssen: Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria; Daiichi Sankyo: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS (Celgene): Honoraria; Sanofi: Honoraria; Astellas: Honoraria.

Introduction :Since the introduction of tyrosine kinase inhibitors (TKIs) the prognosis of Philadelphia positive (Ph+) diseases like chronic myeloid leukemia (CML) dramatically improved (Sasaki K, Lancet Haematol 2015). Nonetheless, myeloid blastic crisis of CML (MBC-CML) and Ph+ acute myeloid leukemia (AML) represent a clinical challenge due to their rarity, the absence of a standard therapy and mutations. Methods :We collected clinical data of patients treated in Paris in 5 different hospitals with confirmed diagnosis in patients with CML successively transformed in MBC-CML, and in patients with MBC-CML straight away or Ph+ AML. We performed descriptive analysis as well as analysis on overall survival (OS) and event-free survival (EFS). Results :We found 64 patients (24 F/40 M) treated since 2001 to present days. 35/64 patients had an history of CML before MBC of which 30 were diagnosed in chronic phase (Sokal risk: low 3 pts, intermediate 8 pts, high 4 pts, NA 15 pts) and 5 in accelerated phase according to ELN classification. Lines of treatment before MBC for these 35 patients were principally TKIs, IFN, hydroxyurea and homoarringtonine: 11 pts experienced only 1 line of treatment, 15 pts 2 lines, 5 pts 3 lines, 1 pt 4 lines and 3 pts 5 lines. Best response before MBC was complete hematological remission (CHR) for 14 pts, complete cytogenetic remission (CCyR) for 7 pts, molecular remission for 6 pts (4 pts MR3, 1 pt MR4, 1 pt CMR TKI free), whereas 8 pts never gained any response. 21/64 pts were in MBC at diagnosis and 8/64 pts were classified as Ph+ AML. At diagnosis of MBC/AML median age was 49 years old (11-73). 12/64 pts had an extramedullary/central nervous system (CNS) involvement of which 2 pts presented a solitary CNS disease and 3 patients had lesions compatible with myeloid sarcomas without marrow blasts. 46/64 pts (72%) received a classical induction therapy (mostly cytarabine + anthracycline combination) combined in 40 pts with a TKI (15 pts Imatinib, 13 pts Dasatinib, 2 Nilotinib and 10 Ponatinib). 11/64 pts (17%) started Azacytidine (1 pt in combination with Imatinib, 2 pts with Nilotinib, 6 pts with Dasatinib, 1 pt with Ponatinib and 1 pt with Venetoclax). 2/64 pts (3%) received Dasatinib monotherapy. 1/64 pt (2%) received ATRA+ATO+Dasatinib combination. 4/64 pts (6%) received only best supportive care. At first revaluation after therapy 47 pts (78%) were in CR/CRi, 9 pts (15%) were refractory, 2 pts (3%) died during induction, 1 pt (2%) induction therapy is ongoing, in 1 pt (2%) lost to follow up. Most patients who obtained CR/CRi after induction continued with consolidations, mostly high-dose Cytarabine associated with a TKI. 41 pts (68%) were transplanted (40 alloHSCT, 1 autoHSCT), 38 pts in first CR (CR1), 1 pt in second CR (CR2) and 2 pts in progressive disease. Notably, 1 pt who had only Dasatinib monotherapy without any form of chemotherapy nor allotransplant is still alive and in second chronic phase after more than two years of follow up. Median follow up for patients who received an active treatment was 23 months. Median OS was 44 months and median EFS was 29 months (figure 1). The only factor whose impact was significant for both OS and EFS in our cohort was transplant (p At last follow up, 30 pts (47%) are still alive (29 in CR, 1 pt with active refractory disease), 30 pts (47%) died, 4 pts (6%) are lost to follow up. Causes of death were progression of disease for 18 pts, sepsis for 7 pts, GVHD for 3 pts, ischemic stroke for 1 pt, cardiovascular complications for 1 pt. Conclusion :We showed here a multicentric experience about an unselected cohort of patients with MBC CML and Ph+ AML who received different treatments according to age, comorbidities, performance status, TKI availability. Survival of this cohort was mostly linked to the possibility to achieve CR and to perform an allotransplant. Already published experiences showed a generical dismal prognosis with median OS which doesn't exceed 1-2 years (16 months, Deau B, Leukemia Research 2011 ; 12 months, Palandri F, Haematologica 2008 ; 6.4 months, Fruehauf S, Cancer 2007) whereas in our real life cohort median OS was longer. For fit and potentially « transplantable » patients, combination with classic chemotherapy plus a TKI seems reasonable and associated with good outcomes in terms of OS and EFS. Disclosures Rousselot: Incyte:Consultancy, Research Funding;Pfizer:Consultancy, Research Funding;Bristol-Myers Squibb:Consultancy;Novartis:Consultancy;Takeda:Consultancy.Itzykson:Jazz Pharmaceuticals:Honoraria, Membership on an entity's Board of Directors or advisory committees;Daiichi Sankyo:Honoraria;BMS (Celgene):Honoraria;Sanofi:Honoraria;Astellas:Honoraria;Oncoethix (now Merck):Research Funding;Novartis:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Janssen:Research Funding;Stemline:Membership on an entity's Board of Directors or advisory committees;Karyopharm:Membership on an entity's Board of Directors or advisory committees;Otsuka Pharma:Membership on an entity's Board of Directors or advisory committees;Amgen:Membership on an entity's Board of Directors or advisory committees;Abbvie:Honoraria.Cayuela:Incyte:Speakers Bureau;Novartis:Speakers Bureau.Rea:BMS:Membership on an entity's Board of Directors or advisory committees;Novartis:Honoraria, Membership on an entity's Board of Directors or advisory committees;Pfizer:Honoraria, Membership on an entity's Board of Directors or advisory committees;Incyte:Honoraria, Membership on an entity's Board of Directors or advisory committees.

Acute myeloid leukemia (AML) is frequently associated with hyperleukocytosis [white blood cell count (WBC) of >50 or >100 × 109/L at presentation] [1]. Hyperleukocytosis also predicts a higher risk...

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.

Chronic Myelomonocytic Leukemias are frequently diagnosed in older adults. Their prognosis is heterogeneous, but several prognostic factors can identify patients with an expected survival of a few years only, including among younger patients eligible for allogeneic stem cell transplantation. Based on the retrospective data available, we discuss how to identify CMML patients for whom curative therapy must be envisaged. We emphasize that, although transplantation remains the only path to cure in CMML, it can be envisaged in only a minority of patients. Despite increased donor availability, its potential remains limited by significant rates of mortality caused both by the procedure and by post-transplantation relapses. We review the options available to bridge patients to transplant, the management of transplantation itself (choice of donor, graft source and condition regimen), and finally the potential for post-transplantation interventions. Our review underscores the need for further prospective studies of allogeneic stem cell transplantation in CMML.

The extensive genomic characterization of acute myeloid leukemia (AML) led to the identification of a vast number of potential therapeutic targets. We review relevant data that have led to recent approval of new targeted therapies in AML and discuss the most promising drugs currently in development in this disease. New formulations of cytotoxic agents, namely CPX-351 and gemtuzumab ozogamicin, improve the outcome of defined subgroup of patients. Midostaurin added to intensive chemotherapy is approved in FLT3-mutated AML. More selective FLT3 inhibitors and the IDH inhibitors enasidenib and ivosidenib have shown significant single agent activity in the relapsed setting, and preliminary results of combination strategies are encouraging. The addition of the BCL2 inhibitor venetoclax appears to markedly improve the results of hypomethylating agents. The therapeutic armamentarium of AML now includes novel cytotoxic drugs, drugs targeting recurrent oncogenes, or functional vulnerabilities of leukemic cells. Further work is required to optimize their integration to the current framework of AML management, including allogeneic stem cell transplantation.

Somatic mutations contribute to the heterogeneous prognosis of chronic myelomonocytic leukemia (CMML). Hypomethylating agents (HMAs) are active in CMML, but analyses of small series failed to identify mutations predicting response or survival. We analyzed a retrospective multi-center cohort of 174 CMML patients treated with a median of 7 cycles of azacitidine (n = 68) or decitabine (n = 106). Sequencing data before treatment initiation were available for all patients, from Sanger (n = 68) or next generation (n = 106) sequencing. Overall response rate (ORR) was 52%, including complete response (CR) in 28 patients (17%). In multivariate analysis, ASXL1 mutations predicted a lower ORR (Odds Ratio [OR] = 0.85, p = 0.037), whereas TET2mut/ASXL1wt genotype predicted a higher CR rate (OR = 1.18, p = 0.011) independently of clinical parameters. With a median follow-up of 36.7 months, overall survival (OS) was 23.0 months. In multivariate analysis, RUNX1mut (Hazard Ratio [HR] = 2.00, p = .011), CBLmut (HR = 1.90, p = 0.03) genotypes and higher WBC (log10(WBC) HR = 2.30, p = .005) independently predicted worse OS while the TET2mut/ASXL1wt predicted better OS (HR = 0.60, p = 0.05). CMML-specific scores CPSS and GFM had limited predictive power. Our results stress the need for robust biomarkers of HMA activity in CMML and for novel treatment strategies in patients with myeloproliferative features and RUNX1 mutations., Highlights • TET2mut/ASXL1wt genotype predicts higher complete response rate and prolonged survival in CMML with hypomethylating agents. • Conversely, RUNX1mut and CBLmut genotypes are associated with poorer outcome, independently of higher leukocyte count. • CPSS and GFM prognostic scores showed modest performance when calculated at initiation of hypomethylating agents. Somatic mutations contribute to the heterogeneous prognosis of chronic myelomonocytic leukemia (CMML). Hypomethylating agents (HMAs) are active in CMML. Response and survival in MDS and AML patients treated with HMAs is difficult to predict. We explore the predictive role of recurrent somatic mutations in a large retrospective cohort of 174 HMA-treated CMMLs. Consistent with MDS studies, we report a higher response rate in TET2mut/ASXL1wt patients. We also identify a CMML-specific molecular pattern (RUNX1mut or CBLmut) associated with shorter survival. Our results can inform treatment decision in CMML, for instance by using HMAs prior to transplant in TET2mut/ASXL1wt patients.

The bromodomain (BRD) and extraterminal (BET) proteins including BRD2, BRD3 and BRD4 have been identified as key targets for leukemia maintenance. A novel oral inhibitor of BRD2/3/4, the thienotriazolodiazepine compound OTX015, suitable for human use, is available. Here we report its biological effects in AML and ALL cell lines and leukemic samples. Exposure to OTX015 lead to cell growth inhibition, cell cycle arrest and apoptosis at submicromolar concentrations in acute leukemia cell lines and patient-derived leukemic cells, as described with the canonical JQ1 BET inhibitor. Treatment with JQ1 and OTX15 induces similar gene expression profiles in sensitive cell lines, including a c-MYC decrease and an HEXIM1 increase. OTX015 exposure also induced a strong decrease of BRD2, BRD4 and c-MYC and increase of HEXIM1 proteins, while BRD3 expression was unchanged. c-MYC, BRD2, BRD3, BRD4 and HEXIM1 mRNA levels did not correlate however with viability following exposure to OTX015. Sequential combinations of OTX015 with other epigenetic modifying drugs, panobinostat and azacitidine have a synergic effect on growth of the KASUMI cell line. Our results indicate that OTX015 and JQ1 have similar biological effects in leukemic cells, supporting OTX015 evaluation in a Phase Ib trial in relapsed/refractory leukemia patients.

Chronic myelomonocytic leukemia (CMML) is an aggressive, clonal bone marrow disorder that induces a persistent monocytosis and in some cases an accumulation of dysplastic granulocytes at various stages of maturation. Because of the combination of monocyte accumulation with myelodysplastic features, the disease is classified by the WHO as an overlap, myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN). The disease annual incidence, ranging between 0.35 and 0.52/105 population in Western countries, may be underestimated as low-risk forms are commonly neglected. CMML is a disease of aging whose median age at diagnosis is 72 years, with a male/female predominance of approximately 2:1 whose origin remains unclear. The disease is infrequent before 50 years, except on the basis of germline alterations, and prognosis could be less severe in these younger patients, probably because younger patients present with fewer comorbidities and are more often eligible for allogeneic stem cell transplantation. Clonal hematopoiesis of indeterminate potential (CHIP), as defined by the occurrence of clonal mutations in otherwise healthy individuals, may be a first step to CMML. In 15–30% of cases, the chronic disease transforms into acute myeloid leukemia (AML). Even in the absence of transformation, the disease outcome is poor with a median overall survival ranging between 16 and 30 months, depending on the series

Azacitidine (AZA) prolonged overall survival (OS) in the AZA-AML-001 trial. However, few subjects were randomized to AZA or intensive chemotherapy (IC). The Medical Research Council (MRC) and the Leukemia Research Foundation (LRF) developed a score for older AML patients receiving IC or non-intensive regimens, whereas the E-ALMA study validated a score for survival and response in elderly patients receiving AZA in daily practice. Both identified three groups with different risk estimates. This analysis evaluates the efficacy of frontline AZA in older AML patients (N = 710) unfit for IC from different national registries (E-ALMA + series) stratified by the MRC/LRF risk score. Median OS of patients categorized as good, standard and poor-risk groups by the MRC/LRF score was 13.4 (95% CI, 10.8-16), 12.4 (95% CI, 9.9-14.8), and 8.1 months (95% CI, 7-9.1), respectively (p = .0001). In conclusion, this is the largest retrospective cohort of older AML patients treated with AZA.

Context. The prognostic value of gene mutations in older AML patients (pts) treated intensively remains unclear. Only one study has explored the role of mutation patterns determined by NGS in older AML pts prospectively treated with various chemotherapies in years 2000-2010 (Eisfeld Leukemia 2018). Methods. Pts older than 60y enrolled in the ALFA-1200 trial (NCT01966497) between 09/2012 and 06/2016 were sequenced with a 37-gene myeloid panel. Pts received one 7+3 course followed by 2 intermediate-dose cytarabine courses. Pts with non-favorable risk were eligible for allogeneic stem cell transplantation (SCT). Variable selection for multivariate analyses was performed by lasso penalized regression including age, gender and log(WBC) as covariates. Results. Sequencing was done in 471 (93%) of the 509 enrolled pts. Median age and WBC count were 68y and 5.3x109/L, respectively (resp). CR (including CRp) was achieved in 341 (72%) pts and 90 underwent RIC-SCT in first CR. With a median follow-up of 25.4 months, median OS was 20.7 months. Pts had a median of 3 mutations (range 1-10). The 17 mostly frequently mutated genes (≥5% of pts, by decreasing frequency: DNMT3A, NPM1, TET2, ASXL1, FLT3, SRSF2, IDH2, RUNX1, NRAS, IDH1, STAG2, BCOR, TP53, PTPN11, U2AF1, EZH2 and KRAS) were retained for prognostic analyses. Genes belonging to a common pathway (eg. NRAS and KRAS) may have divergent prognostic values, preventing biology-informed grouping of mutations. Cytogenetic risk (derived from ELN 2017, Döhner Blood 2017, not considering gene mutations) was favorable (fav), intermediate (int), adverse (adv) and missing in 3%, 72%, 18% and 7% resp. Because of the few pts with fav cytogenetics in our cohort, pts were further grouped into non-adv and adv cytogenetics. CR rates and median OS were 75.6% vs 56.6% and 24.8 vs 9.5 months in pts with non-adv and adv cytogenetics, resp (both p In the 388 pts with non-adv cytogenetics, NPM1 mutations independently predicted improved CR rate (Odds Ratio [OR]=2.3, p=0.014), while mutations in ASXL1 (OR=0.46, p=0.012), RUNX1 (OR=0.46, p=0.013) and NRAS (OR=0.49, p=0.04) had independent adverse predictive value. In univariate analysis the shorter OS of FLT3-ITD pts was confined to allele ratios≥ 0.5 (FLT3-ITDhigh, p=0.02). In a multivariate analysis accounting for clinical covariates, mutations in NPM1 (Hazard Ratio [HR]=0.45, p In the 83 pts with adv cytogenetics, TP53 mutations predicted shorter OS (p=0.004). Among pts with adv cytogenetics, those without TP53 mutation had a median OS of 12.6 months and were thus classified as high risk while the median OS of the 30 pts with adv cytogenetics and TP53 mutations was only 5.4 months, defining very high risk disease. This stratification resulted in improved OS prediction compared to the full molecular ELN 2017 (C-index 0.63 vs 0.58, resp). This stratification also predicted Relapse-Free Survival (RFS, Figure, p Conclusion. In AML patients older than 60y treated intensively, mutations in 7 genes (NPM1, SRSF2, FLT3, DNMT3A, ASLX1, NRAS and TP53) can refine the prognosis of cytogenetic sub-groups. Figure Figure. Disclosures Cluzeau: MENARINI: Consultancy; CELGENE: Consultancy; JAZZ PHARMA: Consultancy.

Validation of response assessment according to international consortium for MDS/MPN criteria in chronic myelomonocytic leukemia treated with hypomethylating agents

Acute erythroleukemia (AEL) is a rare disease typically associated with a poor prognosis. The median survival ranges between 3-9 months from initial diagnosis. Hypomethylating agents (HMAs) have been shown to prolong survival in patients with myelodysplastic syndromes (MDS) and AML, but there is limited data of their efficacy in AEL. We collected data from 210 AEL patients treated at 28 international sites. Overall survival (OS) and PFS were estimated using the Kaplan-Meier method and the log-rank test was used for subgroup comparisons. Survival between treatment groups was compared using the Cox proportional hazards regression model. Eighty-eight patients were treated with HMAs, 44 front line, and 122 with intensive chemotherapy (ICT). ICT led to a higher overall response rate (complete or partial) compared to first-line HMA (72% vs. 46.2%, respectively; p, Publication costs were supported by the University of Salzburg.

Bromodomain and Extra-Terminal inhibitors (BETi) such as OTX015 are active in Acute Myeloid Leukaemias (AML). Their activity on Leukemic Stem Cells (LSCs) is less documented. We interrogated the anti-LSC activity of OTX015 in a niche-like long-term culture in 26 primary AML samples and validated our findings in vivo. OTX015 impaired LSCs in AMLs harbouring Core Binding Factor or KMT2A gene fusions, NPM1 or chromatin/spliceosome genes mutations, but not in those with aneuploidy/TP53 mutations. In four patients, we dissected the transcriptomic footprint of Bet inhibition on LSCs versus blasts. Our results can instruct future clinical trials of BETi in AML.

Background: Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) in adult populations include several rare hematologic malignancies with similar clinicopathologic features that have a significant impact on patient QOL and lead to increased risk of infection, hemorrhage, anemia and transformation to AML (e.g. CMML, aCML, MDS/MPN-RST, and MDS/MPN-U). The only approved therapies for any of the MDS/MPNs are DNA methyltransferase inhibitors (DNMTis) for patients (pts) with CMML. Due to both the rarity and the heterogeneity of MDS/MPNs, it has been challenging to study in dedicated, prospective studies and thus refining treatment strategies has been difficult and optimal salvage treatments in pts who fail DNMTis have also not been rigorously studied. ABNL-MARRO (A Basket study of Novel therapy for untreated MDS/MPN and Relapsed/Refractory Overlap Syndromes) is an international cooperation providing the framework for clinical trials for MDS/MPN, and explore clinical-pathologic biomarkers. Study Design and Methods: The first study within ABNL-MARRO, ABNL MARRO 001 (AM-001), is an open label, randomized phase 1-2 study that will test 3 novel oral treatment combinations in MDS/MPNs, with each of 3 treatment arms including a novel targeted agent and ASTX727, a fixed dose combination of the DNMTi decitabine and the cytidine deaminase inhibitor cedazuridine to improve decitabine oral bioavailability. The novel agents combined with ASTX727 are: a selective JAK1 inhibitor itacitinib, pan PIM inhibitor INCB053914 and LSD1 inhibitor, INCB059872. Each combination will be tested first in a safety run-in (Phase 1b) to determine the RP2D and schedule of each combination therapy using a 3+3 de-escalation design, and a maximum of four dose decrements will be allowed. After the RP2D and schedule has been determined for a given novel drug combination, efficacy of that combination therapy in MDS/MPN pts will then be evaluated in phase 2 using a Simon's Two-Stage design to allow early discontinuation of any futile treatment regimen and to pursue potentially beneficial combinations in larger cohorts of pts. While each of the targeted agents either has undergone or is currently undergoing safety testing in combination with the DNMTi in myeloid diseases, clear rates of expected responses in MDS/MPN are not known. Retrospective studies of DAC or AZA reveal overall response rates (ORR) from 10-56% in CMML (Helbig et al, 2019; Duchman et al, 2018; Coston et al, 2019). The ORR from the ASTX727 single agent phase I study was 30%, but this included only 14% CMML (remainder MDS pts) and 45% of pts with previous treatment with AZA or DAC (Savona et al, 2019). Finally, and importantly, there are insufficient clinical trial data available for pts non-CMML MDS/MPN syndromes. Thus, the criteria for the Simon's Two-Stage design for each arm are based on best estimation from results of above studies. Accordingly, the null hypothesis that the ORR, as per the MDS/MPN Proposed Response Criteria (Savona et al, 2015; combined CR+MR+PR+Clinical benefit - CB), is 35%, will be tested against a one-sided alternative. In the first stage, 14 DNMTI-treatment naïve (TN) pts will be accrued in each AM-001 Arm and will receive treatment at the RP2D and schedule of the novel targeted agent and of ASTX727, as determined in the phase 1. If there are 5 or fewer responses in these 14 pts before the 7th cycle of therapy, the Arm will be stopped for futility. Otherwise, 30 additional pts (including both TN subjects and subjects relapsed after/refractory to other DNMTI-containing therapies) will be accrued for a total of 44. The null hypothesis will be rejected if 21 or more responses are observed in 44 pts before the 7th cycle of therapy. This design yields a type I error rate of 0.05 and power of 80% when the true response rate is 55%. The probability of early termination and expected sample size of any arm is 64% and 25 pts, respectively, assuming low (35% RR) efficacy Beyond the primary objectives of the study to evaluate the safety and efficacy of novel treatment combinations in MDS/MPN, the study will establish the ABNL MARRO infrastructure that leverages the expertise of the MDS/MPN international working group (IWG) for future prospective studies; will forge innovative scientific research that will improve our understanding of pathogenetic etiologies; and will inform the clinical application of diagnosis, risk stratification tools, and response assessments in MDS/MPNs. Disclosures Savona: AbbVie: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Patents & Royalties. Fenaux:Aprea: Research Funding; Jazz: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding. Padron:Incyte: Research Funding. Patnaik:Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees. Platzbecker:Abbvie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Sanz:Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer-Ingelheim: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Helsinn Healthcare: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hoffman - La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen - Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onconova: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Santini:Menarini: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Acceleron: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Honoraria. OffLabel Disclosure: ASTX727, LSD1 inh, PIM inh, JAK1 inh in MDS/MPN

Background High-resolution sequencing has improved prognostication of AML. A multistage model (MM), based on a knowledge bank (KB) of 1540 patients (pts) treated between 2004 and 2010, has been set up to improve outcome prediction and tailor therapeutic decision, including SCT (Gerstung, Nat Genet 2017). Validation of overall survival (OS) predictions by this KB has been reported (Huet, Blood 2018). Given progresses of SCT over the last decades, whether such a KB approach can be harnessed to personalize SCT decision in first remission (CR1) remains unclear. We addressed this question in younger AML pts treated intensively. Methods From 03/2009 to 09/2013, the multicentric ALFA-0702 study (NCT00932412) enrolled 713 pts with de novo AML aged 18-60 years old, excluding APL and CBF AML. Pts with protocol-defined non-favorable risk AML were eligible for SCT from a matched donor (Thomas, J Clin Oncol 2017). High throughput sequencing of 41 genes and ligation-dependent RT-PCR was done in 656 pts (92%). Risk stratification was assessed according to ELN 2017 (Döhner, Blood 2017). Of the 100 variables used by the MM, 3 clinical (splenomegaly, LDH and Hb levels) and 24 genetic variables (genes mutated in at most 5.3% in the KB) were unavailable. After imputation of missing data based on the KB, individualized 5y-OS predictions were done for each patient in 3 scenarios: no SCT, SCT in CR1 or SCT after first relapse, as previously described (Gerstung, Nat Genet 2017). Results Median age at diagnosis was 46 years. Median follow-up was 4.2 years. Overall, 302, 282 and 72 pts were never transplanted, transplanted in CR1 or after relapse, respectively (resp). ELN 2017 risk was favorable (Fav), intermediate (Int) and adverse (Adv) in 31%, 31% and 38% of the 647 evaluable pts, resp. 5y-OS was 77.7%, 58.3% and 42.2% in Fav, Int and Adv pts, resp (Fav versus [vs] Int P Considering SCT in CR1 as a time-dependent variable, there was a significant interaction between ELN 2017 risk and SCT in CR1 (P We investigated the ability of the KB approach to determine the subset of patients that may benefit from SCT in CR1 rather than at relapse (per Gerstung, Nat Genet 2017). An estimated 128 patients (ELN 2017 Fav/Int/Adv in 34.6%, 45.7% and 19.7%) would have a 10% improvement in 5y-OS if allografted in CR1. However, in these 128 pts, the effect of SCT in CR1 on OS did not differ from that in the other 528 pts (interaction test P=0.31). We therefore sought alternative ways to inform SCT decision based on KB predictions. The KB approach predicted a 5y-OS We next combined ELN 2017 risk and KB-predicted OS into a single rule to guide SCT decision. Only pts with both ELN 2017 Int/Adv risk and a KB-predicted 5y-OS Conclusion The Knowledge bank approach predicts OS of younger adults with AML more accurately than ELN 2017. ELN 2017 and KB risk predictions may be combined to optimize indications of SCT in CR1. Figure Disclosures Berthon: JAZZPHARMACEUTICAL: Other: DISCLOSURE BOARD; PFIZER: Other: DISCLOSURE BOARD; CELGEN: Other: DISCLOSURE BOARD. Pigneux:Jazz: Honoraria; Amgen: Honoraria; Novartis: Honoraria; Abbvie: Honoraria; Roche: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria; Daichi: Honoraria; Astellas: Honoraria; Pfizer: Honoraria. Recher:Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Macrogenics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees. Vey:Novartis: Consultancy, Honoraria; Janssen: Honoraria. Thomas:ABBVIE: Honoraria; INCYTE: Honoraria; DAICHI: Honoraria; PFIZER: Honoraria. Dombret:Institut de Recherches Internationales Servier (IRIS): Research Funding; CELGENE: Consultancy, Honoraria; AGIOS: Honoraria.