Acute Myeloid Leukemia In Complete Remission Research Articles

Impact of invasive aspergillosis occurring during first induction therapy on outcome of acute myeloid leukaemia (SEIFEM-12B study).

Acute myeloid leukaemia (AML) patients are at high risk of invasive aspergillosis (IA) after first induction chemotherapy (CHT). Although IA risk factors have been identified, few data are available on impact of IA, occurring during induction phase, on overall AML outcome. The end point of this multicentre, case-control, study was to evaluate whether IA, occurring after first induction CHT, can affect treatment schedule and patient's outcome. We identified 40 AML patients (cases) who developed IA during first induction phase, 31 probable (77.5%) and 9 proven (22.5%). These cases were matched with a control group (80 AML) without IA, balanced according to age, type of CHT, AML characteristics and cytogenetic-molecular risk factors. The overall response rate to induction CHT was the same in the 2 groups. In the 40 cases with IA, the overall response rate to antifungal treatment was favourable (80%) but it was significantly affected by the achievement of leukaemia complete remission (CR) with induction CHT. In fact, in cases with AML responsive to induction CHT, responses of IA to antifungal therapy were 96% compared to 21% in cases of AML not responsive to induction treatment (P<.0001). The adherence to the schedule and full doses of CHT were reported in 35% of cases (14/40) and in 76% of controls (61/80) (P=.0001; OR 6.7; 95% CI 2.7-16.6). After first induction CHT, a significant higher number of cases (15/40; 37.5%) compared to controls (9/80; 11%) could not receive additional cycles of CHT (P=.0011, OR 4.8; 95% CI 1.9-12.3). The IA-related mortality was 22.5%. The median OS of cases was significantly worse than OS of controls with a difference of 12.3months (12.1 vs 24.4months, P=.04). However, the occurrence of IA during first induction phase did not have a significant impact on the OS of cases who achieved a CR of AML with induction CHT which are able to proceed, despite the IA, with their therapeutic program, achieving the same OS as the control group with AML in CR (P=ns). These data show that IA during first induction CHT can delay the subsequent therapeutic program and has a significant impact on OS, specifically in AML patients who did not achieved a CR of AML with the first course of CHT.

Higher TIGIT+CD226- γδ T cells in Patients with Acute Myeloid Leukemia

ABSTRACT The diverse structural and functional heterogeneity of γδ T cells is related to their distinct role in cancer immunity. The different phenotypes of γδ T cells in patients with acute myeloid leukemia (AML) is far from clear. In particular, the expression pattern of co-inhibitory and co-stimulatory receptors on γδ T cells remains unknown. In this study, we analyzed the distribution of γδ T cell subsets by expression of the immune checkpoint co-inhibitor TIGIT (T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain) and its competing co-stimulatory receptor CD226 in AML patients of different clinical statuses (including de novo AML, AML in non-remission (NR), and AML in complete remission (CR)). Our data demonstrated an imbalanced distribution of TIGIT and CD226 on γδ T cells with a decrease in CD226+ γδ T cells and an increase in TIGIT+ γδ T cells in de novo AML patients, while TIGIT−CD226+ γδ T cells were restored in AML patients who achieved CR after chemotherapy. Moreover, the patients who had higher TIGIT+CD226− γδ T cells showed lower overall survival rate for non-M3 AML, which may be considered a novel prognostic immune biomarker. In conclusion, our study reveals for the first time that imbalance in the TIGIT/CD226 axis might be related to different clinical outcomes for AML patients. Abbreviations: AML: acute myeloid leukemia; CR: complete remission; ICs: immune checkpoints; PD-1: programmed death-1; γδ T cells: gamma delta T cells; TCR: T cell receptor; MHC: major histocompatibility complex; TIGIT: T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain; NK: natural killer; PB: Peripheral blood; NR: non-remission; FAB: French-American-British; WHO: World Health Organization; HIs: healthy individuals; OS: overall survival

Characteristic of TIGIT and DNAM-1 Expression on Foxp3+ γδ T Cells in AML Patients.

Foxp3+ γδ regulatory T (γδ Treg) cells promote tumor growth by various mechanisms and induce immuno-senescence. The novel immune checkpoint coinhibitory receptor T cell Ig and ITIM domain (TIGIT) shares similar ligands as the costimulatory receptor DNAX accessory molecule 1 (DNAM-1) and suppresses T cell responses in tumor patients. This study is aimed at characterizing whether the TIGIT/DNAM-1 axis is involved in the distribution and expression of Foxp3+ γδ Treg cell subsets in acute myeloid leukemia (AML) patients of different clinical statuses: de novo AML (27 patients), AML in nonremission (NR) (7 patients), and AML in complete remission (CR) (12 patients). Our data demonstrated that the proportions of Foxp3+, TIGIT+Foxp3+, and DNAM-1+Foxp3+ γδ T cells are significantly higher in de novo and NR patients. High levels of TIGIT and DNAM-1 on Foxp3+ γδ T cells correlated with increased Foxp3+ γδ T cell frequencies. In addition, a high TIGIT/DNAM-1 ratio was observed in de novo AML patients and healthy individuals (HIs). Furthermore, the phenotypic abnormalities in Foxp3+, TIGIT+Foxp3+, and DNAM-1+Foxp3+ γδ T cells were restored when the patients achieved CR after chemotherapy. Moreover, higher TIGIT+Foxp3+ γδ T cells were associated with AML patients who had poor overall survival and were an independent risk factor for prognosis. In conclusion, our study reveals for the first time that the TIGIT/DNAM-1 axis may be involved in Foxp3+ γδ Treg cells and indicates the clinical progression and prognosis of AML patients of different clinical statuses, which is considered beneficial for efficient AML immunotherapy.

Increasing Tim-3+CD244+, Tim-3+CD57+, and Tim-3+PD-1+ Tcells in patients with acute myeloid leukemia.

To characterize the distribution of Tcell immunoglobulin mucin-domain-containing-3 (Tim-3) within the exhausted Tcells in patients with newly diagnosed acute myeloid leukemia (AML) and AML in complete remission. Tim-3 expression and coexpression with PD-1, CD244, and CD57 in CD3+, CD4+, and CD8+Tcells were analyzed by multicolored fluorescent flow cytometry in peripheral blood from 28 newly diagnosed, untreated AML patient and 12 cases with AML in complete remission, 23 healthy individuals served as control. Increasing Tim-3+CD244+ and Tim-3+CD57+ in CD3+, CD4+, and CD8+ Tcells were found in AML and AML-CR groups in comparison with healthy controls. Similarly, increasing Tim-3 coexpression PD-1+ CD3+/CD4+/CD8+ Tcells were found in AML group. A high tendency of PD-1+Tim-3+CD3+/CD4+/CD8+ Tcells was detected in the AML-M4 subtype group followed by the M2 group, and a low tendency was found in the M3 group. Moreover, Tim-3+CD244+CD8+ Tcells were found to be significantly higher in the M4 than that in M3 group. Dynamic changes of Tim-3+ Tcells in AML patients who achieved CR after chemotherapy at different time points showed that Tim-3+ Tcell subsets were evidently decreased; however, they remained at a higher level in most AML-CR patients. We made a novel observation on distribution of Tim-3+CD244+, Tim-3+CD57+, and Tim-3+PD-1+ Tcells in patients with AML. Chemotherapy is incapable of resolving immunosuppression in some cases with AML in CR status.

Effect of the Thiotepa Dose in the TBF Conditioning Regimen in Patients Undergoing Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia in Complete Remission: A Report From the EBMT Acute Leukemia Working Party

BackgroundAllogeneic stem cell transplantation is a potentially curative therapy for patients with acute myeloid leukemia (AML) after achieving complete remission (CR). The aim of this study is to evaluate the optimal dose of thiotepa, administered as part of the thiotepa-busulfan-fludarabine (TBF) conditioning regimen for allogeneic stem cell transplantation in adults with AML in CR. Patients and MethodsIn a retrospective multicenter analysis, we identified 240 patients allotransplanted from matched related or unrelated donors or T replete haplo-identical donors. We compared the transplantation outcomes of patients who received 5 mg/kg thiotepa and 2 days of intravenous busulfan at 6.4 mg/kg (T1B2F) versus those who received 10 mg/kg thiotepa with 2 days of intravenous busulfan at 6.4 mg/kg (T2B2F). The median follow-up was 20 months. ResultsOn univariate analysis, the incidence of acute graft versus host disease (GVHD) grade II to IV was significantly lower in the T1B2F group (19%) versus 32% in the T2B2F group (P = .029). This result was confirmed on multivariate analysis; acute GVHD was higher for patients receiving T2B2F (hazard ratio, 2.22; P = .024). No significant change in non-relapse mortality, progression-free survival, or overall survival was observed between the 2 groups. ConclusionT2B2F is associated with a higher incidence of acute GVHD compared with T1B2F. These results suggest that a lower dose-intensity of thiotepa and busulfan in the TBF regimen may yield better results in patients with AML in CR.

Diagnostic Value of miR-34a in Bone Marrow Mononuclear Cells of Acute Myeloid Leukemia Patients.

The current study aims to analyze the expression of miR-34a in bone marrow mononuclear cells (BMMCs) of acute myeloid leukemia (AML) patients and its possible role in the development of leukemia. Real-time fluorescent quantitative PCR was used to detect the expression of miR-34a in bone marrow of 40 patients with initial treatment of AML, 22 patients with complete remission AML, 13 patients with refractory recurrence, 20 patients with non-hematological tumors and healthy persons. Pearson's correlation was performed to analyze the correlation between the expression level of miR-34a and clinical indicators in patients. The expression of miR-34a in the initial treatment group, complete remission group and refractory relapse group of AML patients was higher than that in the control group. In addition, the expression of miR-34a in the complete remission group was higher than that in the initial treatment group. Moreover, the expression of miR-34a in the refractory relapse group was lower than that in the initial treatment group. The expression level of miR-34a in initial treatment AML group was negatively correlated with the number of bone marrow primary immature cells, but not with the number of peripheral blood leukocytes, platelet count, hemoglobin content, age, gender, and chromosomal abnormalities. The expression of miR-34a in bone marrow mononuclear cells of patients with AML was down-regulated and related to tumor load. It may play an important role in the occurrence and development of leukemia and may become a new molecular marker for the diagnosis of AML.

Comparison of a New Reduced Toxicity Myeloablative Treosulfan and Fludarabine Preparative Regimen with Myeloablative Busulfan or Melphalan in Combination with Fludarabine in Older Patients with Acute Myeloid Leukemia or Myelodysplastic Syndromes: A Retrospective Matched Pair Analysis of Patients from a Prospective Randomized Trial and the European Blood and Marrow Transplantation Society Registry

Background The best preparative regimen for the growing number of older acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) patients undergoing allogeneic hematopoietic cell transplantation (HCT) from matched related (MRD) or unrelated donors (MUD) remains undefined. A large randomized phase III trial (MC-FludT.14/L study: ClinicalTrials.gov Identifier: NCT00822393) recently demonstrated that myeloablative intravenous (IV) treosulfan (10 g/m² IV on days -4 to -2) in combination with fludarabine (TreoFlu) improves outcome in older and/or comorbid patients with AML in complete remission (CR) or MDS compared with the reference reduced intensity busulfan (0.8 mg/kg IV in 6-hour intervals on days -4 and -3) and fludarabine (30 mg/m² IV on days -6 to -2 in each study arm) regimen. The beneficial effect of the TreoFlu regimen resulted from a significantly reduced non-relapse mortality (NRM) and translated to improved event-free survival (EFS) and overall survival (OS) (Beelen DW et al The Lancet Haematology, 2019). These results raised the question, how this new regimen compares to broadly applied myeloablative regimens, namely busulfan (0.8 mg/kg IV in 6-hour intervals over 4 days) plus cyclophosphamide (120 mg/kg IV over 2 days) (BuCy) or melphalan (140 mg/m² IV over 1 day or 2 days) plus fludarabine (MelFlu) in older AML and MDS patients. To address this question, we performed a comparative analysis of MC-FludT.14/L study patients treated with the TreoFlu regimen and similar patients of the European Blood and Marrow Transplantation Society (EBMT) registry, who underwent HCT from MRD or MUD after the BuCy or MelFlu regimen between 2010 and 2016. Patients and Methods Inclusion criteria were essentially the same as for the MC-FludT.14/L-study (patient age 50 to 70 years [yrs], primary or secondary AML in CR or MDS, Karnofsky-index ≥ 60%, MRD or MUD, 1st HCT). The study objectives were to compare OS, relapse incidence (RI), and NRM at 2 yrs after HCT between the TreoFlu regimen and the BuCy or MelFlu regimen. A total of 1493 EBMT registry patients (median age 58 yrs, AML: n=1135 [76%], MDS: n=358 [24%]) were identified for the comparison with the 252 MC-FludT.14/L patients (median age 61 yrs, AML: n=174 [69%], MDS: n=78 [31%]). A 1:1 matching method based on propensity scores (PS) with 14 patient-, donor-, and disease-characteristics was used to reduce confounding due to differences between regimens and was performed separately for AML and MDS patients. With the exception of comparison between the TreoFlu and BuCy regimen in AML patients, a significantly higher proportion of patients in the TreoFlu regimen subsets had a HCT-comorbidity index &gt; 2 compared to patient subsets treated with the BuCy or MelFlu regimen. Results For patients with AML, the 2-yrs OS estimate was significantly higher after the TreoFlu compared with the BuCy regimen (76.4%, 95%-confidence interval [95%-CI]: 66.8% - 85.9% vs 49.2%, 95%-CI: 36.4% - 62.1%, p&lt;0.001) and MelFlu regimen (72.7%, 95%-CI: 63.7% - 80.7% vs 58.7%, 95%-CI: 48.3% - 69.1%, p=0.04). This was clearly related to the significantly lower 2-yrs NRM estimate after the TreoFlu compared with the BuCy regimen (3.9%, 95-CI: 0% - 8.2% vs 23.5%, 95%-CI: 13.1% - 33.9%, p&lt;0.001) and MelFlu regimen (6.4%, 95-CI: 1.8% - 11.0% vs 17.5%, 95%-CI: 9.6% - 25.5%, p&lt;0.02). For patients with MDS, the differences of the 2-yrs OS and NRM estimates between patient subsets were similar, but were only significant for the comparison of the OS estimate between the TreoFlu and BuCy regimen (72.0%, 95%-CI: 54.4% - 89.6% vs 30.5, 95%-CI: 6.1% - 54.9%, p&lt;0.01). The adjusted hazard ratios of 2-yrs overall mortality and NRM between regimens including all eligible patients by multivariate sensitivity analysis based on Cox proportional hazards models are given in the table below. Notably, no differences between the respective 2-yrs RI were detectable when comparing these patient subsets. Conclusion In older AML and MDS patients, the new TreoFlu regimen compares favorable to the broadly applied myeloablative BuCy and MelFlu regimens. The substantially lower 2-yrs NRM estimate supports its superior tolerability in this patient population. This large retrospective comparative analysis provides a basis for properly designed randomized trials of the new toxicity reduced myeloablative TreoFlu regimen in comparison with other myeloablative regimens in this target population. Table Disclosures Beelen: Medac GmbH Wedel Germany: Consultancy, Honoraria. Stoelzel:Neovii: Other: Travel funding; Shire: Consultancy, Other: Travel funding; JAZZ Pharmaceuticals: Consultancy. Dreger:MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; Neovii, Riemser: Research Funding; AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy.

Reduced Intensity Conditioning and Dual T-Cell Modulation Improves Gvhd Free, Relapse Free Survival in AML Patients Compared with Myeloablative Conditioning

BACKGROUND The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute myeloid leukemia (AML) relies on the antileukemic effect of the conditioning regimen and the graft-versus leukemia (GVL) effect mediated by donor T-cells. Leveraging the GVL effect while reducing toxicity enables reduced intensity conditioning (RIC) to be used to older or frail patients, but may lead to higher rates of graft-versus-host disease (GVHD), impairing later quality of life. Novel T-cell modulation strategies may limit the incidence of GVHD while preserving antileukemic activity leading to better outcomes. Herein, we compare the outcomes of AML patients treated with myeloablative (MAC) and RIC regimens including patients receiving dual T-cell depletion using Anti-Thymocyte Globulin (ATG) and Post-Transplant Cyclophosphamide (PTCy). METHODS Between 2013 and 2018, 362 adults with AML in complete remission underwent allo-HSCT and were included in the study. Overall, 112 (31%) patients received MAC and 250 (69%) received RIC regimens. MAC consisted of Flu(4), Bu (4mg) and 400cGy of total body irradiation (TBI). RIC regimen consisted on Flu (4), Bu (2) and 200cGy TBI in 249 recipients and one received clofarabine/busulfan. One hundred seventy-one (68.4%) the recipients who received RIC regimen, received a novel dual T-cell depletion strategy using ATG (total dose of 4.5mg/kg in 130 patients and 2mg/kg in 41 recipients), PTCy, and cyclosporine for GVHD prophylaxis. Peripheral blood stem cell (PBSC) grafts were used in 98.9% of the recipients. Data was collected retrospectively and updated on April 2019. The cumulative incidence of GVHD was assessed accounting relapse and death as competing events. A multivariate analysis for overall survival (OS), relapse-free survival (RFS) and GVHD-Free/RFS (GFRFS) was conducted controlled by those variables found to be significant in univariate analysis. RESULTS Baseline information is summarized in Table 1. The incidence of grade II-IV and III-IV acute GVHD at day +100, and moderate/severe chronic GVHD at 1 year was respectively: 28.6%, 10.5%, and 18.4%. RIC was associated with a significantly lower cumulative incidence of clinically relevant acute and chronic GVHD (P&lt;0.05). Main outcome information is summarized in tables 1 and 2, and displayed graphically in figures A-F. With a median follow-up of 3.7 years, 68 (18.8%) recipients relapsed and 160 (44.2%) died. The 2-years OS, RFS, and GRFS were 53.8%, 50.8%, and 33.8%, respectively. OS, RFS, non-relapse mortality, and cumulative incidence of relapse were not significantly affected by regimen intensity (P&gt;0.05). However, RIC regimens were associated with superior GRFS. Forty-three (12.7%) recipients had a high Disease Risk Index (DRI). Conditioning intensity was not a significant risk factor for OS (HR 0.9; P=0.931) or RFS (HR 1; P=0.902) in this group of patients. Tables 3 and 4 show the results from multivariate analysis for OS, RFS, and GFRFS. Older patients, those with high DRI, or recipients of 9/10 matched unrelated donor (MUD) grafts had significantly worse OS and RFS. GVHD prophylaxis with dual T-cell modulation (ATG-PTCy-CsA) was the only protective parameter for a better GRFS (HR 0.5; P=0.005). CONCLUSION In AML patients, RIC with PBSC allografts and dual T-cell modulation with ATG and PTCy led to superior GRFS when compared with MAC regimens. Reduction in the cumulative incidence of clinically significant acute and chronic GVHD may be possible without compromising on the efficacy of the GVL effect. The use of this GVHD prophylaxis strategy, along with mitigation of conditioning toxicity by using RIC, may result in better quality of life. Further investigations would be done with the use of this novel GVHD prophylaxis in the setting of MAC regiments. Dual T-cell suppression leads to increased infectious complications including viral reactivations. The use of lower doses of ATG, or individualized dosing strategies based on lymphocyte count may help to further optimize this strategy. Disclosures Michelis: CSL Behring: Other: Financial Support. Mattsson:Celgene: Honoraria; Therakos: Honoraria; Gilead: Honoraria.

Weight Adjusted Urinary Creatinine Excretion Predicts Transplant Outcomes in Adult Patients with Acute Myeloid Leukemia in Complete Remission

Background: Sarcopenia, the loss of muscle mass, has been recognized as a prognostic factor for cancer patients. For example, low body mass index (BMI) was reported to be a risk of poor overall survival (OS) among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. However, low BMI was not associated with high non-relapse mortality (NRM) rate, and BMI may not directly reflect the physical condition. (Bone Marrow Transplant. 2014;49:1505-12). To evaluate the clinical impact of the muscle volume on the prognosis of allo-HSCT recipients, other biomarkers that directly reflect muscle mass may be warranted. Urinary creatinine excretion (UCE) has been reported to estimate muscle mass and have prognostic value for kidney transplant patients (Transplantation. 2008;86:391-8.). There is no report to evaluate clinical impact of UCE on the prognosis of allo-HSCT recipients. Therefore, we retrospectively analyzed the association between pre-transplant UCE and the transplant outcomes. Methods: We included 173 adult patients with acute myeloid leukemia (AML) in complete remission (CR) who underwent first allo-HSCT from 2006 to 2017 at our institute and measured UCE before allo-HSCT. Concerned the possibility of urine storage failure, two patients with low total daily urine volume (&lt;0.5L/day) were excluded from this analysis. Therefore, we investigated the remaining 171 patients. In order to correct the physical disparities of individual patients, we evaluated the clinical impact of weight adjusted UCE (WA-UCE) ,i.e UCE / body weight [μmol/kg/day] (Intensive Care Med. 2018;44:1699-708.). We used receiver operating characteristics curve in order to determine the cutoff value of the WA-UCE and classified the patients into the high and low WA-UCE group. We evaluated transplant outcomes such as OS, progression-free survival (PFS), NRM, and cumulative incidence of relapse (CIR) between two groups. Results: The median age at allo-HSCT was 52 (range, 18-73) and there were more male patients (n=111) than female patients (n=60). Regarding cytogenetic risk, 15 (9.1%), 112 (65.8%), and 38 (23.0%) were categorized as favorable, intermediate, and poor risk, respectively (There were five patients without cytogenetic data). The median follow-up period of survivors was 704 (range, 9 to 3,857) days. We defined the cutoff value of the weight adjusted UCE as 148 μmol/kg/day in male and 128 μmol/kg/day in female. Among 171 patients, 90 patients (male = 59, female = 31) were in the high WA-UCE group and 81 patients (male = 52, female = 29) were in the low WA-UCE group. We found no significant differences between two groups in terms of the number of relapse before allo-HSCT, cytogenetic risks, conditioning regimens, hematopoietic cell transplantation comorbidity index, donor-recipient HLA matching, donor source, or estimated glomerular filtration rate. On the other hand, patient's age at allo-HSCT was significantly younger (low vs. high WA-UCE group: median, 53 [range, 18 - 73] vs. 48 [range, 19 - 68] years, P = 0.02) and BMI was lower (low vs. high WA-UCE group: median, 22.3 [range, 15.4 - 38.8] vs. 21.9 [range, 15.4 - 29.3] kg/m2, P = 0.003) in high WA-UCE group. In univariate analysis, we observed a significant difference in OS, PFS, and NRM between two groups (low vs. high WA-UCE group: 1-year OS, 60.1% vs. 80.9%, P &lt; 0.01; 1-year PFS, 54.1% vs. 70.9%, P = 0.02; 1-year NRM, 24.8% vs. 12.3%, P = 0.02) (Figure1). On the other hand, there was no significant difference in 1-year CIR between two groups (low vs. high WA-UCE group: 21.1% vs. 16.8%, P = 0.63). In our cohort, the low BMI (&lt; 18.5 kg/m2) was not significantly associated with OS, PFS, CIR, and NRM (low vs. high BMI group: 1-year OS, 77.6% vs. 69.9%, P = 0.51; 1-year PFS, 74.1% vs. 60.9%, P = 0.45; 1-year CIR, 14.8% vs. 19.5%, P = 0.02, 1-year NRM, 11.1% vs. 19.5%, P = 0.70) In multivariate analysis, the low WA-UCE was an independent risk factor for OS (Hazard ratio (HR) [95% confidence interval (CI)]; 2.29 [1.38 - 3.80], P &lt; 0.01), PFS (HR [95% CI]; 1.76 [1.11 - 2.79], P = 0.02), and NRM (HR [95% CI]; 2.22 [1.13 - 4.36], P = 0.02) (table1). Conclusion: In allo-HSCT adult recipients with AML in CR, low WA-UCE before transplantation was associated with poor prognosis, which related to high NRM within 1 year. WA-UCE can be an independent, objective, simple, and reliable biomarker for evaluating muscle mass and predicting transplant outcome. Disclosures No relevant conflicts of interest to declare.

Allogeneic peripheral blood stem cell transplantation with anti-thymocyte globulin versus allogeneic bone marrow transplantation without anti-thymocyte globulin.

We compared severe graft-versus-host-disease (GvHD) free and relapse-free survival and other transplantation outcomes of acute myeloid leukemia (AML) patients given bone marrow (BM) without anti-thymocyte globulin (ATG) versus peripheral blood stem cells (PBSC) with ATG after myeloablative conditioning. In the cohort of patients receiving grafts from a human leukocyte antigen (HLA)-matched sibling donor, patients given PBSC with ATG (n=1,021) and those given BM without ATG (n=1,633) presented comparable severe GvHD-free relapse-free survival (GRSF)(hazard ratio [HR]=0.9, 95% confidence interval [CI]: 0.8-1.1, P=0.5) and overall survival (HR=1.0, 95% CI: 0.8-1.2, P=0.8). They had however, a lower incidence of chronic GvHD (cGvHD) (HR=0.7, 95% CI: 0.6-0.9, P=0.01). In the cohort of patients receiving grafts from HLA-matched unrelated donor , patients given PBSC with ATG (n=2,318) had better severe GvHD-free and relapse-free survival (GRFS) than those given BM without ATG (n=303) (HR=0.8, 95% CI: 0.6-0.9, P=0.001). They also had a lower incidence of cGvHD (HR=0.6, 95% CI: 0.5-0.8, P=0.0006) and better overall survival (HR=0.8, 95% CI: 0.6-1.0, P=0.04). In summary, these data suggest that PBSC with ATG results in comparable (in the case of sibling donor) or significantly better (in the case of unrelated donor) severe GRFS than BM without ATG in patients with AML in complete remission receiving grafts after myeloablative conditioning.

PB1751 HOW WE TREAT PATIENT WITH CHRONIC LYMPHOCYTIC LEUKEMIA AND ACUTE MYELOID LEUKEMIA DEVELOPED FROM MYELODYSPLASTIC SYNDROME

Background:According to various authors, the frequency of concurrent myelodysplastic syndrome (MDS) in patients with chronic lymphocytic leukemia (CLL) is 5%. The observation of patients with combination of lympho‐ and myeloproliferative diseases is clinical interest, due to the rare occurrence, poorer outcomes and absence of optimal treatment strategy for this category of patients.Aims:We present a case of a 71‐year‐old woman with CLL and acute myeloid leukemia (AML) developed from MDS.Methods:The baseline diagnosis CLL III stage (Rai) was established in 2016 at 68 years. FISH: trisomy12 – 9%; del13 – 20.5%; del17p – 17.5%. CT scan demonstrated lymphadenopathy (axillary, epitrochlear, mediastinal, paraaortic). The first line therapy: Ibrutinib 420 mg daily, and Rituximab 375 mg/m2 D1 C1 and 500 mg/m2 D1 C2‐6 of each 28‐day cycle. Despite the treatment, patient still had moderate/severe anemia without reduction of transfusion dependency. The disease evaluation (DE) after cycle 6 of therapy showed the presence of 13.4% blasts and dysplasia in erythroid, granulocyte and megakaryocyte lines (≥10%) in BM. Flow cytometry (FCM) of BM demonstrated the population of myeloid blasts. The BM's biopsy showed combined lesions: MDS with excess of blasts‐2 and CLL (5‐7% of infiltrate). The lymph nodes, spleen and liver were normal sizes by CT scan. The response of CLL was evaluated as partial remission (PR) and the second diagnosis was established: MDS with excess of blasts‐2 (IPSS: high risk, IPSS‐R: very high risk). Azacytidine 75 mg/m2 D1‐7 of each 28‐day cycle, SC was started. Simultaneous, therapy with ibrutinib 420 mg daily was ongoing. After 4 cycles of treatment the patient became transfusion independent; HB level stabilized at 110–115 g/L; BM blasts decreased to 9.8%, and dysplasia changes persisted only in granulocyte line. We observed the decrease of minimal residual disease (MRD) of CLL: 8.6%→5.4%→3.8%. The toxicity grade 3‐4 during therapy was not observed. However, after 8 cycle of therapy the results of laboratory tests showed transformation to AML: HB–73 g/L, WBC–1.6x109/L (NEUT–27%, BANDS–1%, LYM–66%, MON–6%), PLT–44x109/L; BM blasts–24%; FCM of BM ‐ population of myeloid blasts; normal karyotype 46, XX; mutations in genes FLT3, NMP1, BCR/ABL, CBFb/MYH1, RUNX1, TP53, IDH1/2, c‐KIT, ASXL1 were not detected. Treatment with ibrutinib was stopped. Cytozar 38 mg D1‐10 of each 28‐day cycle, SC, and venetoclax 600 mg daily were started.Results:After 1stcycle of therapy: complete remission (CR) with incomplete BM recovery. After 2ndcycle – complete BM recovery. By FCM MRD negative status (MRDneg) AML and MRD positive status (MRDpos) CLL were detected. Patient is ongoing to intake cytozar and venetoclax. Presently, the MRDneg CR of AML and MRDneg PR of CLL are lasting.Summary/Conclusion:Our findings suggest that use of targeted drug in the treatment of patients with AML and CLL is possible and very effective. Also, treatment combination of low dose cytozar with venetoclax is powerful and shows clinical significance. Due to the small number of patients with this combined pathology, further studies are needed to confirm the results obtained.

Decreased SATB1 expression promotes AML cell proliferation through NF-\u03baB activation

BackgroundSpecial AT-rich sequence-binding protein 1 (SATB1) is a chromatin-remodeling protein that regulates gene expressions in different types of cancer. Up-regulation of SATB1 is linked with progression of tumors. Our previous study showed that SATB1 expression was decreased in T cell leukemia/lymphoma. The contrary roles of SATB1 in solid organ tumors and hematology malignancy may provide hints to study the function of SATB1.MethodsTo characterize SATB1 mRNA and protein expression in acute myeloid leukemia (AML), we performed qRT-PCR and Western blot on bone marrow mononuclear cells from 52 newly diagnosed AML patients. Stable HL-60 cell lines with knockdown of SATB1 by shRNAs sequences (HL-60 SATB1-shRNA1 and HL-60 SATB1-shRNA2) were established. Cell proliferation, cell cycle and cell invasiveness were analyzed. Murine model was established using HL-60 SATB1-shRNAs treated nude mice and tumorigenicity was compared to study the role of SATB1 in vivo. Global gene expression profiles were analyzed in HL-60 cells with SATB1 knockdown to investigate the mechanisms underlying the regulation of AML cell growth by SATB1.ResultsWe found that SATB1 expression was significantly decreased in patients with AML compared to normal control, and was increased after complete remission of AML. Knockdown of SATB1 enhanced the proliferation of HL-60 cells and accelerated S phase entry in vitro, and promoted the tumor growth in vivo. Global gene expression profiles were analyzed in HL-60 cells with SATB1 knockdown and the differentially expressed genes were involved in NF-κB, MAPK and PI3 K/Akt signaling pathways. Nuclear NF-κB p65 levels were significantly increased in SATB1 depleted HL-60 cells.ConclusionsDecreased SATB1 expression promotes AML cell proliferation through NF-κB activation. SATB1 could be a predictor for better response to treatment in AML.

A Study Evaluating the Safety and Efficacy of Idasanutlin in Combination With Cytarabine and Daunorubicin in Patients Newly Diagnosed With Acute Myeloid Leukemia (AML) and the Safety and Efficacy of Idasanutlin in the Maintenance of First AML Complete Remission

A Study Evaluating the Safety and Efficacy of Idasanutlin in Combination With Cytarabine and Daunorubicin in Patients Newly Diagnosed With Acute Myeloid Leukemia (AML) and the Safety and Efficacy of Idasanutlin in the Maintenance of First AML Complete Remission

Allogeneic Hematopoietic Stem Cell Transplantation in Older Patients with Acute Myeloid Leukemia: Analysis of the Francophone Society for Stem Cell Transplantation and Cell Therapy

Background: Nowadays acute myeloid leukemia (AML) patients above the age of 60 years are often candidates for Allogeneic Hematopoietic Stem Cell Transplantation (HSCT). However, little is known about the outcomes of HSCT in this particular population, due to the low number of HSCT with robust follow-up, the heterogeneity between centers, as well as reports usually mixing AML and other diseases such as myelodysplastic syndrome. We used the database of the Francophone society for stem cell transplantation and cellular therapy to address this question in a large cohort of patients in a recent time period.Patients and methods: 1167 consecutive patients aged ≥60 years with AML in complete remission (CR), transplanted between January 1st 2006 and January 1st 2016, reported to ProMISe (Project Manager Internet Server), an internet-based system shared by 36 Francophone transplantation centers, were reviewed. Classical post-HSCT endpoints were studied such as engraftment, acute and chronic graft-versus-host disease (GvHD), non-relapse mortality (NRM), relapse rate, leukemia free survival (LFS) as well as overall survival (OS). Cytogenetic risk was assessed according to the European Leukemia Network 2017 for patients in first complete remission. Data were analyzed using proportional hazards models and proportional sub-distribution hazards models in presence of competing risks.Results: Patients' Characteristics are detailed in Table 1. The median age at HSCT was 62.9 years (Interquartile range -IQR 61.9-66.1). Patients aged ≥60 years but less of 65 represented 63.8% of the population with 68.2% of patients transplanted in the recent period (2011-2016). Most patient had de novo AML (91.6%), in first CR (76.9%) with intermediate risk (83.8%) according to ELN-2017 classification. A matched unrelated donor (MUD) was used in 45 % of transplants and the majority of patients received peripheral blood stem cells (83.7%). Half of the patients received fludarabine and 2 days busulfan as conditioning regimen. The majority of patients (70.9%) received anti-thymocyte globuline (ATG). Engraftment occurred in 1089 patients (93.3%; 95%CI, 91.9-94.8). Day 100 cumulative incidence of grade II-IV acute GVHD was 24.6% (15.7% grade II; 5.8% grade III; 3% grade IV). At last follow up, 378 patients had developed chronic GVHD (severe in 37.2% of them; 95%CI, 34.0-40.3). With a median follow-up of 3.5 years (95%CI, 3.1-3.7 years), overall survival (OS) and LFS probabilities at 3 years were 50.7% (95%CI, 47.7-54.0) and 44.8% (95%CI, 41.8-48.1), respectively. In multivariable analysis, the only factor associated with worse OS was the use of a mismatched unrelated donor compare to MUD [Hazard Ratio (HR): 1.35 (95% CI, 1.01 to 1.80), p=0.04]. At 3 years, relapse incidence was 34.4% (95% CI, 31.5-37.4). The use of a sibling donor compared to MUD [Sub-distribution Hazard Ratio (SHR): : 1.49 (95% CI, 1.19 to 1.87), p<0.001], poor risk AML in CR1 according to ELN classification [SHR: 1.49 (95% CI, 1.10 to 2.02), p=0.01], as well as the use of ATG in the conditioning regimen [SHR: 1.57 (95% CI, 1.21 to 2.05), p<0.001] were associated with a higher risk of relapse. During the study, 534 patients died (main causes of death was relapse, 53%); leading to a CI of NRM of 20.7% at 3 years (95%CI, 18.2-23.2). A karnofsky score above 90% [SHR: 0.74 (95% CI, 0.56 to 0.98), p=0.04] and the use of a sibling donor compare to MUD [SHR : 0.43(95% CI, 0.30 to 0.63), p<0.001] were associated with reduced NRM.Conclusion: With more than 3 years follow-up, which is long enough for our results to be considered to be robust, the use of a mismatched unrelated donor was the only factor associated with worse overall survival in this population of AML patients aged of 60 years or more. Relapse appeared as the first cause of death, independently related to AML ELN poor risk classification, but also to the use of a sibling donor and of ATG in the conditioning regimen. This study highlights the major role of alloreactivity in this particular population, where modulation of T-cell alloreactivity as well as donor choice should be urgently addressed in well-designed prospective trials. [Display omitted] DisclosuresPeffault De Latour:Amgen Inc.: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer Inc.: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding. Chalandon:Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel costs.

Clinical Characteristics of GNB1 and GNAS Mutations in an Unselected Cohort of 6,343 Patients with Hematologic Abnormalities

Genes encoding the alpha (GNAS) and beta (GNB1) subunits of the heterotrimeric G-protein complex are recurrently mutated in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Alterations in G-protein coupled receptors can affect signaling via the PI3K/AKT/mTOR and RAS/MAPK pathways, suggesting that GNB1/GNAS mutations may function similarly to mutations in RAS and tyrosine kinases in myeloid disease progression. However, unlike RAS mutations, GNB1/GNAS mutations are among the most commonly affected genes in clonal hematopoiesis of indeterminate potential (CHIP), suggestive of a distinct functional role in myeloid disease initiation.We evaluated 6343 unique patients who received gene panel sequencing at our institution as part of a diagnostic evaluation of known or suspected hematologic malignancy. We identified 68 patients that had at least 1 sample with a mutation in GNB1 (N =42), GNAS (N=24) or both (N=2) (Figure 1). Twenty-six patients had multiple samples (range 2-10) obtained at serial timepoints during the course of progression and treatment. GNB1 mutations affected codon 57 (K57E/M/N/T) in 38 out of 42 cases; the remaining were G53E, D76G, I81V, and K89R. GNAS mutations affected codon 201 (R201H/C) in 23 out of 24 cases.Forty patients had active myeloid neoplasms [AML (N=10), MDS (N=13), MPN (N=11), MDS/MPN (N=5), BPDCN (N=1)]. The distribution of myeloid diagnoses was similar among patients with GNB1 or GNAS mutations. Analysis of serial samples showed that GNB1/GNAS mutations were frequently acquired at the time of leukemic transformation and clinical progression. Among 5 patients with secondary AML, 2 patients acquired GNB1/GNAS mutations at the time of transformation from MDS to AML, and 3 patients were found to have GNB1/GNAS mutations in high-risk MDS prior to subsequent transformation to AML. After induction chemotherapy for AML, two patients had expanded or newly acquired GNB1 mutations at time of treatment failure.Notably, 15 out of the 40 (37.5%) patients with active myeloid disease had co-mutations in the MPN-associated genes JAK2, CALR, and MPL. Eleven of these patients had a clinical diagnosis of MPN, including myelofibrosis (n=5), essential thrombocytosis (n=3), polycythemia vera (n=2), and systemic mastocytosis (n=1). In the context of underlying oncogenic kinase alterations including JAK2 V617F, GNB1 mutations have been shown to promote resistance to kinase inhibitors in vitro. Fourteen out of fifteen patients had no history of ruxolitinib therapy, suggesting that these mutations arise during the course of disease progression in the absence of therapeutic selection pressures. The impact of GNB1/GNAS mutations on the clinical response to JAK inhibitors has not been evaluated.Twenty-eight patients in the cohort (41%) had no evidence of active myeloid disease, including 14 patients with a lymphoid malignancy [mature B-cell neoplasms (n=8), mature T cell neoplasms (n=3), plasma cell neoplasms (n=2), acute lymphoblastic leukemia (n=1)], 6 patients with AML in complete remission, and 8 patients without a clinical diagnosis of hematologic malignancy. Four of the AML patients had a GNAS or GNB1 mutation that was newly acquired or persistent at the time of complete remission following induction chemotherapy. All 4 patients underwent allogeneic stem cell transplant (HSCT) based on disease risk at diagnosis and are alive with median follow up of 2.5 years. In 1 patient, a new GNB1 mutation was identified immediately after HSCT in the context of 100% donor chimerism, suggesting donor-engrafted CHIP. All 8 patients without hematologic malignancy were evaluated for cytopenias or cytoses at the time of the identification of the GNB1/GNAS mutation.GNB1 and GNAS are recurrently mutated in diverse clinical and genetic contexts. In patients with active myeloid disease, MPN-associated mutations were common and GNB1/GNAS mutations were newly acquired at the time of clinical progression, suggesting a functional role similar to other gene mutations that activate mitogenic signaling pathways. However, many GNB1 and GNAS mutations are seen as sole mutations in the absence of active myeloid disease, suggesting that unlike other signaling mutations they can drive initiation of clonal hematopoiesis. The diverse clinical spectrum of patients with GNB1/GNAS mutations suggests that these mutations have distinct, context dependent effects in hematopoietic cells. [Display omitted] DisclosuresKim:Aushon Biosciences: Consultancy; LabCorp, Inc.: Consultancy; Papgene, Inc: Consultancy. Lane:N-of-one: Consultancy; Stemline Therapeutics: Research Funding.

Abstract B62: Immune gene expression profiling identifies predictors of relapse in childhood acute myeloid leukemia

Abstract Tumor phenotypes are dictated not only by the neoplastic cell component, but also by the tumor microenvironment (TME), which includes immune and inflammatory cells. Acute myeloid leukemia (AML) is the second most common leukemia of childhood. Although intensive multi-agent chemotherapy in conjunction with improved supportive care has increased survival rates to 70%, 30-40% of children with AML relapse and only one-third of them will survive to adulthood. Investigation of new therapeutic strategies for high-risk AML, including immunotherapy, remains a priority and is being actively pursued. Importantly, AML-induced immune suppression poses a fundamental barrier to successful immune-based interventions. We previously showed that in vitro treatment of primary AML cells with interferon (IFN)-γ induces functional indoleamine 2,3-dioxygenase-1 (IDO1), a molecule with potent immunosuppressive properties, in 50% of unselected cases (IFN-γ responders). With a median follow-up of 8 years, IFN-γ responders experienced a significantly shorter event-free survival and overall survival (OS). Herein, we aimed to get insights into the immune landscape of childhood AML using multi-scale immune profiling strategies with the aim to identify molecular circuits that can be targeted to revert leukemia-induced immune dysfunction and improve clinical outcome. We employed a novel high-throughput digital platform, the nCounter system (nanoString Technologies, Seattle, USA), and Optimized Multi-color Immuno-phenotyping Panels (OMIPs) to comprehensively characterize the bone marrow immune infiltrate in 34 children diagnosed with non-promyelocytic AML (17 males, 17 females; median age at diagnosis=10 years; 28 de novo AML, 4 infant leukemia, 1 secondary AML, 1 congenital leukemia; 7 patients with favorable-risk cytogenetics, 21 patients with intermediate-risk cytogenetics and 6 patients with unfavorable-risk cytogenetics). The RNA Pan-Cancer Immune Profiling Panel, which includes 109 cell surface markers for 24 immune cell types, 30 cancer testis antigens, and &amp;gt;500 immune response genes, allowed us to measure immune gene expression levels on the clinic-ready nCounter® FLEX platform (nanoString Technologies). Transcriptomic data were normalized and analyzed using the nSolver software package. Relapse-free survival (RFS) and OS were selected as covariates. For immune phenotyping studies, viable bone marrow mononuclear cells were labeled with fluorochrome-conjugated antibodies and then analyzed on a 10-color Gallios flow cytometer (Beckman Coulter Life Sciences, Buckinghamshire, UK) with standard settings. Hierarchical clustering of immune gene expression data highlighted patient subgroups with heightened expression of T-cell and natural killer (NK)-cell function genes, as well as Toll-like receptor (TLR) genes, interleukin genes and tumor necrosis factor (TNF) family genes. Patients with high levels of CD8A mRNA also expressed IFNG, CXCL9, CXCL10, FOXP3 and negative checkpoints, including LAG3, CTLA4, IDO1 and CD279 (PD-L1), consistent with T-cell inflamed phenotypes that might underpin the establishment of adaptive immune resistance mechanisms of immune escape. In-depth phenotyping studies showed higher percentages of bone marrow-resident naïve B cells, plasmablasts, intermediate and non-conventional monocytes, plasmacytoid dendritic cells (DCs) and CXCR3-expressing Th1 cells at diagnosis compared with complete remission (CR). By contrast, both type 1 and type 2 myeloid DCs were more represented in the TME of patients with AML in CR. The frequencies of innate lymphoid cells (ILCs) and Vγ9+Vδ2+ T cells were not significantly different when comparing diagnosis and CR samples. Relapses occurred in 71.4% of children with “inflamed” AML compared with 28.6% of patients with “non-inflamed” AML (p=0.012; two-sided Fisher’s exact test). Importantly, RFS was remarkably shorter in patients with inflamed compared with non-inflamed AML (median RFS=394 days vs. undefined; hazard ratio = 0.266; 95% CI=0.11-0.64; p=0.0039, log-rank test). A non-significant association with OS was also observed. In conclusion, inflamed or “hot” AMLs are associated with shorter RFS and might be amenable to immunotherapy approaches tailored to the bone marrow TME, including PD-1/PD-L1 blockade and/or small-molecule IDO1 inhibitors. Grant support: Roger Counter Foundation, Dorset, UK and Qatar National Research Fund (grant #NPRP8-2297-3-494). Citation Format: Jayakumar Vadakekolathu, Gemma A. Foulds, Tasleema Patel, Stephen Reeder, Alan Graham Pockley, Sarah K. Tasian, Sergio Rutella. Immune gene expression profiling identifies predictors of relapse in childhood acute myeloid leukemia [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr B62.

Dysregulation of miR-200s clusters as potential prognostic biomarkers in acute myeloid leukemia

BackgroundIncreasing studies showed that miR-200 family (miR-200s) clusters are aberrantly expressed in multiple human cancers, and miR-200s clusters function as tumor suppressor genes by affecting cell proliferation, self-renewal, differentiation, division and apoptosis. Herein, we aimed to investigate the expression and clinical implication of miR-200s clusters in acute myeloid leukemia (AML).MethodsRT-qPCR was performed to detect expression of miR-200s clusters in 19 healthy donors, 98 newly diagnosed AML patients, and 35 AML patients achieved complete remission (CR).ResultsExpression of miR-200a/200b/429 cluster but not miR-200c/141 cluster was decreased in newly diagnosed AML patients as compared to healthy donors and AML patients achieved CR. Although no significant differences were observed between miR-200s clusters and most of the features, low expression of miR-200s clusters seems to be associated with higher white blood cells especially for miR-200a/200b. Of the five members of miR-200s clusters, low expression of miR-200b/429/200c was found to be associated with lower CR rate. Logistic regression analysis further revealed that low expression of miR-429 acted as an independent risk factor for CR in AML. Based on Kaplan–Meier analysis, low expression of miR-200b/429/200c was associated with shorter OS, whereas miR-200a/141 had a trend. Moreover, multivariate analysis of Cox regression models confirmed the independently prognostic value of miR-200b expression for OS in AML.ConclusionsExpression of miR-200a/200b/429 cluster was frequently down-regulated in AML, and low expression of miR-429 as an independent risk factor for CR, whereas low expression of miR-200b as an independent prognostic biomarker for OS.

Capturing the complexity of the immune microenvironment of acute myeloid leukemia with 3D biology technology.

50 Background: Tumor phenotypes are dictated not only by the neoplastic cell component, but also by the tumor microenvironment (TME), which includes immune and inflammatory cells. We characterized the immune ecosystem of the bone marrow (BM) TME in patients with acute myeloid leukemia (AML) to correlate transcriptomic and proteomic profiles with patient outcome. Methods: We used the nCounter system (NanoString Technologies) to characterize BM specimens from 42 children and 28 adults with AML. Ninety BM samples (63 from de novo AML, 18 from AML in complete remission [CR] and 9 from relapsed AML) were analyzed using the RNA Pan-Cancer Immune Profiling Panel. In situ leukemia-immune system interactions were visualized using Digital Spatial Profiling (DSP). Results: Hierarchical clustering identified subgroups with heightened expression of lymphocyte-associated genes, including NK cell and cytotoxicity genes (“immune-enriched” samples). They also expressed CD8A, IFNG, FOXP3, the cell chemoattractants CXCL9, CXCL10, and inhibitory molecules including IDO1 and the immune checkpoints LAG3, CTLA4 and PD-L1. Conversely, ‘immune-depleted’ samples over-expressed genes associated with mast cell functions and CD8 T-cell exhaustion and showed low expression of T-cell and B-cell genes. Importantly, relapse-free survival (RFS) and overall survival (OS) were significantly shorter in patients with “immune-enriched” compared with “immune-depleted” AMLs (2.2 vs. 18.3 months, p = 0.0064, and 6.3 vs. 22.4 months, p = 0.017, respectively). DSP of the BM TME showed the co-localization of CD8 T cells with FoxP3 Treg cells and PD-L1- and VISTA-expressing cell types, an immune landscape which is consistent with the establishment of adaptive immune resistance mechanisms of immune escape. Conclusions: Our study has identified heterogeneous immune profiles in children and adults with AML. From a clinical standpoint, ‘immune enriched’ AMLs might be amenable to immunotherapy approaches tailored to the BM microenvironment, including blockade of co-inhibitory molecules and/or small-molecule IDO1 inhibitors. Grant support: Roger Counter Foundation, UK; Qatar National Research Fund (#NPRP8-2297-3-494).

Functional role of DNMT3A mutation in acute myeloid leukemia

A current broad spectrum of genomic studies on acute myeloid leukemia (AML) has demonstrated that a gene encoding for DNA methyltransferase, specifically DNA methyltransferase 3 alpha (DNMT3A) is frequently mutated. However, DNMT3A variants are present in elderly healthy individuals and patients with AML in complete remission, which suggests that DNMT3A mutations may contribute to pre-leukemic clonal hematopoiesis. Although DNMT3A mutation has been thought to play a pivotal role in AML pathogenesis through the loss of DNA methylation functionality, other potential disease-related mechanisms are poorly understood. We identified that DNMT3A Arg882 mutation has two distinct mechanisms for developing clonal hematopoiesis and leukemia: (1) DNA methylation-dependent effect, which caused up-regulation of the anterior Hoxb cluster and many hematopoietic stem cell (HSC) -related genes, with hypo-methylation of the promoter-associated CpG island; and (2) DNA methylation-independent effect with enhanced recruitment of polycomb repressive complex 1 (PRC1) that subsequently suppressed the expression of an array of differentiation-associated genes. Through these mechanisms, DNMT3A mutations were shown to inhibit the differentiation of HSCs and leukemic cells. These results identified PRC1 as a promising candidate for the development of therapeutic strategies in mutant DNMT3A-associated AML. Here, we review recent studies on AML with a focus on the clinical features and functional roles of DNMT3A mutations, and discuss future challenges to effectively cure DNMT3A mutation-associated hematopoietic disorders.

Higher Tim-3 expression concurrent with PD-1 in exhausted CD4+ and CD8+T cells in patients with acute myeloid leukemia

T cell dysfunctionality is a characteristic of patients with leukemia and plays an important role in leukemia progression. Increasing data showed immune checkpoint which mediate suppression and exhaustion of T cells play the crucial role in tumor immunosuppression. Upregulating Tim-3 and PD-1 could be identified on exhausted T cell in mice with acute myeloid leukemia (AML). Our previous study also showed co-expression of PD-1 and CD244,CD57-exhausted T cells in patients with AML, and found a particular influence on CD8+T cells.In this study,we further investigated the characteristics of the distribution of TIM,and the co-expression with PD-1, CD244, and CD57 on CD3+, CD4+ and CD8+ T cells from patients with de novo AML and AML in complete remission (CR).