non-APL Acute Myeloid Leukemia Patients Research Articles

Influence on therapeutic outcome of platelet count at diagnosis in patients with de novo non-APL acute myeloid leukemia

BackgroundPlatelet (PLT) count at diagnosis plays an important role in cancer development and progression in solid tumors. However, it remains controversial whether PLT count at diagnosis influences therapeutic outcome in patients with non-acute promyelocytic leukemia (APL) acute myeloid leukemia (AML).MethodsThis study analyzed the relationship between PLT count at diagnosis and genetic mutations in a cohort of 330 newly diagnosed non-APL AML patients. The impact of PLT count on complete remission, minimal residual disease status and relapse-free survival (RFS) were evaluated after chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT).ResultsOur studies showed that patients with DNMT3A mutations have a higher PLT count at diagnosis, while patients with CEBPA biallelic mutations or t(8;21)(q22; q22) translocation had lower PLT count at diagnosis. Furthermore, non-APL AML patients with high platelet count (> 65 × 109/L) at diagnosis had worse response to induction chemotherapy and RFS than those with low PLT count. In addition, allo-HSCT could not absolutely attenuated the negative impact of high PLT count on the survival of non-APL AML patients.ConclusionPLT count at diagnosis has a predictive value for therapeutic outcome for non-APL AML patients.

Prognostic value of combined WT1 and multiparameter flow cytometry assessment for measurable residual disease after induction in non-APL acute myeloid leukemia

The objective of this study was to investigate the expression pattern of Wilms tumor 1 (WT1) gene at diagnosis, complete remission (CR) and relapse status in non-acute promyelocytic leukemia (non-APL) acute myeloid leukemia (AML) patients, and further explore the prognostic value of measurable residual disease (MRD) assessment by WT1 gene and multiparameter flow cytometry (MFC). Our results showed that the average expression level of WT1 was 4026 ± 616.1 copies/104 ABL at diagnosis, 155.3 ± 36.03 copies/104 ABL at CR, and 1766 ± 238.8 copies/104 ABL at relapse, with statistically significant differences (p = .000). ROC analysis showed that WT1 expression levels were 118.1 copies/104 ABL and MFC-MRD was 0.155%, which had good predictive efficacy for relapse of patients during consolidation therapy. Both WT1-MRD and MFC-MRD had a significant impact on relapse-free survival (RFS) and overall survival (OS). Patients with WT1-MRD positive or MFC-MRD positive were associated with worse RFS (HR 3.840, 95% CI 1.582–9.320, p = .003), (HR 4.464, 95% CI 1.841–10.984, p = .001) and worse OS (HR 2.963, 95% CI 1.058–8.295, p = .039), (HR 3.590, 95% CI 1.254–10.280, p = .017). Besides, compared with patients who were negative for both WT1-MRD and MFC-MRD, patients who were positive both WT1-MRD and MFC-MRD were associated with worse RFS (HR 6.200, 95% CI 2.206–17.430, p = .001) and worse OS (HR 4.886, 95% CI 1.388–17.197, p = .013). This study demonstrates that combined assessment of MRD by WT1 and MFC improves relapse and prognosis prediction in non-APL AML patients, and may help guide interventions for disease relapse.

At What Point Are Long-Term (>5 Years) Survivors of APL Safe? A Study from the SEER Database.

Acute promyelocytic leukemia (APL) is a highly curable cancer, but it is not clear whether it is also necessary to monitor long-term toxicity in "cured" patients who survive for more than five years, which is critical to ensuring maximum survival in APL patients. A total of 1952 APL 5-year survivors and 5973 non-APL acute myeloid leukemia (AML) 5-year survivors were included from the Surveillance, Epidemiology, and End Results (SEER) database. The standardized mortality ratio (SMR) was calculated to measure the risk of death. Cumulative mortality is calculated as the incidence of specific causes of death under competing risk events. The SMR of all causes of death in >5-year survivors of APL was higher than that of the general population only at 60-119 months (SMR, 1.41). This was mainly because a significant increase in mortality from AML (SMR, 87.67) and second malignant neoplasms (SMNs) (SMR, 1.56) was found only at 60-119 months. However, there was no higher risk of death from non-cancer-related disease in >5-year survivors of APL than that of the general population (SMR, 0.89). The SMR of all-cause deaths in >5-year survivors of non-APL AML decreased year by year and was no higher than that of the general population until after 216 months. The cumulative incidence of AML-related death, SMN-related death, and non-cancer-related death was significantly lower in APL patients than in non-APL AML patients throughout the follow-up period. Compared with the general population, the risk of death of patients with APL was higher within 5 to 10 years but not higher over 10 years. Therefore, we believe that long-term survivors of APL are safe after 10 years.

Homoharringtonine-Based Induction Regimens Combined with ATRA-Based Maintenance in Chinese Pediatric AML: A Report from the Cclg-AML 2015 Protocol Study

Introduction Acute myeloid leukemia (AML) is a heterogeneous group of hematological malignancy. Classical induction therapy of DAE composed of etoposide (VP-16), cytarabine arabinoside (Ara-C) and anthracycline (DNR) is commonly applied in childhood AML, but etoposide has been reported to increase the risk of secondary cancer, especially for AML with MLL rearrangement. Although homoharringtonine (HHT) is commonly used for the treatment of Chinese adult AML, the efficacy and safety of HHT-based induction therapy have not been confirmed for childhood AML. And whether survival of pediatric AML will benefit from maintenance therapy without increasing toxicity is a matter of debate. All-trans retinoic acid (ATRA)-based therapy has been less reported and verified among non-APL AML patients. Here, we seek to evaluate the efficacy and safety of HHT-based induction regimens combined ATRA-based maintenance therapy for Chinese childhood AML (Chinese Clinical Trial Registry: ChiCTR-IPR-15006816). Methods The 2015 open-label, multicenter, randomized Chinese Children's Leukemia Group (CCLG) study was performed across 35 centers in China between July 2015 and October 2019. Newly diagnosed 0- to 18-year-old children with AML were first randomly assigned to receive HHT-based (H arm) or etoposide-based (E arm) induction regimens [HHT (3 mg/m2 per day from days 1 to 5) or VP-16 (100 mg/m2 per day from days 1 to 5) combined with DA regimen (D: 40 mg/m2 per day on days 1, 3 and 5; A: 100 mg/m2 every 12 hours from day 1 to 7)] and then randomly allocated to receive cytarabine-based (AC arm) or ATRA-based (AT arm) maintenance therapy. The primary endpoint is the complete remission (CR) rate after two courses of induction therapy between H arm and E arm. The secondary endpoints include the 3-year overall survival (OS) and 3-year event-free survival (EFS) of patients in the intent-to-treat population among four arms (H+AT arm, H+AC arm, E+AT arm and E+AC arm). What we should explained is that the study was initially designed as a multicenter randomized controlled trial, however, due to a shortage of HHT, which lasted for half a year in some local hospitals, we had to give priority to ensuring patient benefit and assign these patients to the E arm until HHT became available, and then patients in the H arm were supplemented in those hospitals. So patients were unevenly distributed among the four arms. Results We enrolled 1253 intent-to-treat de novo AML patients, of whom 895 were included in the induction therapy analysis, and 554 received maintenance therapy (Figure 1). The median age was 75.0 months (IQR 36.0-118.0), and 57% of the patients were male. The median follow-up time was 29.4 months (IQR 8.4-47.4). 185 of 1253 patients (14.8%) were lost to follow-up, of whom 70.0% patients have been followed for over 12 months. The CR rates were 88.3% in the H arm versus 83.3% in the E arm (p=0.03). The CR rate of patients with t(8;21)/AML1-ETO was higher in the H arm than in the E arm (94.7% vs. 87.5%, p=0.018). According to the intention-to-treat analysis, the 3-year OS and EFS were significantly higher in the H arm than in the E arm [3-year OS: 69.2% vs. 62.8%, p=0.025 (Figure 2); 3-year EFS 61.1% vs. 53.4%, p=0.022]. Among patients who were enrolled in maintenance therapy (per-protocol population), the 3-year EFS (H+AT arm: 70.7%, 95% CI 61.1-78.3; H+AC arm: 74.8%, 95% CI 67.0-81.0, p=0.933; E+AC arm: 72.9%, 95% CI 65.1-79.2, p=0.789; E+AT arm: 66.2%, 95% CI 56.8-74.0, p=0.336) did not differ significantly across the four arms. In subgroup analysis, patients with AML1-ETO positivity in the H+AT arm had significantly better OS (82.4% vs. 66.4%, p=0.043) and EFS (73.6% vs. 52.8%, p=0.013) than those in the E+AC arm. Conclusions Our study demonstrated, in childhood AML, HHT-based induction regimens (DAH) could significantly obtain higher complete remission rate compared with patients who received etoposide-based regimens, especially for those with AML1-ETO positive. And The HTT-based regimen resulted in a significantly improved 3-year OS and EFS compared with VP-16-based regimen. More patients with AML1-ETO positive who took DAH achieved complete remission, and these patients had longer overall survival and event-free survival, than those who took DAE. And ATRA-based maintenance has comparable effects to cytarabine-based maintenance in terms of OS and EFS. ATRA may be an alternative option for pediatric AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

AML-230 Predictive Value of CD34-Positive versus CD34-Negative Leukemic Stem Cells on Survival Outcome in Acute Myeloid Leukemia

Leukemic stem cells (LSCs) have emerged as a potential factor contributing to an overall dismal outcome in acute myeloid leukemia (AML). In this study, using flowcytometric immunophenotyping (FCMI), we have demonstrated LSC identification and quantification in both the CD34+ and CD34-compartments to find its relevance in predicting treatment outcomes. Furthermore, we correlated the impact of LSC quantification at diagnosis as a predictor of long-term survival. This is a prospective analysis of patients diagnosed with AML (per standard WHO criteria). Tertiary care cancer center. A total of 161 patients with a diagnosis of non-acute promyelocytic leukemia (non-APL) AML patients diagnosed over a period of two years (January 2019 to December 2020) were evaluated. Bone marrow aspirates collected in EDTA were processed for FCMI using a stain-lyse-wash technique with a singletube, 10-color comprehensive antibody panel. LSCs were identified primarily in the CD34+CD38- compartment; however, in a substantial number of CD34- AML, LSCs were segregated from the CD34-CD38- compartment using CD117 as an alternate gating marker and CD123, CD33, and CD11b as LSC-specific markers in all cases. 1. CD34+ versus CD34-LSC and 2. Baseline LSC% as a predictor of survival. LSCs were identified in 82.6% (133/161) of patients. CD34+ LSCs and CD34- LSCs were isolated in 82.53% (104/126) and 82.85% (29/35) of cases, respectively. The median survival times (in weeks) in CD34- LSCs was higher than in CD34+ LSCs; EFS (54 vs. 47; P=0.27), RFS (79 vs. 48; P=0.14), and OS (121 vs. 71; P=0.41) were found to be comparable in both groups. Furthermore, the total study cohort was divided into three groups based on diagnostic LSC percentage, i.e., LSCneg (LSC% <0.004%), LSClow (LSC%=0.004%-0.892%), and LSChigh (LSC% >0.892%). The LSChigh group had significantly shorter OS, EFS, and RFS compared to the LSClow and LSCneg groups. This study confirms the presence of LSCs beyond the usual CD34+CD38- compartment; however, there is no difference in survival outcomes in both groups. Also, LSC quantification is a powerful and independent prognostic parameter in AML predicting long-term survival and risk of relapse.

P480: NKG2D-MEDIATED ANTI-TUMOR IMMUNITY CONTRIBUTES TO THE FAVORABLE PROGNOSIS IN APL

Background: Acute myeloid leukemia (AML) is an aggressive hematological malignancy with a poor prognosis. Acute promyelocytic leukemia (APL) is a unique subtype of AML, with PML-RARA fusion caused by t(15;17)(q22;q12) translocation, and is now considered a highly curable disease. Exploring the difference between APL and non-APL AML, may shed new insight on the treatment of AML. NKG2D is an activating receptor on NK cells that recognizes ligands on the surface of tumor cells and plays a crucial role in tumor cell killing. Prior studies have demonstrated that one mechanism of AML immune evasion is downregulation of NKG2D ligands (NKG2DL) or secretion of receptor-blocking soluble ligands. Whereas, reports on NKG2DL expression in APL are still lacking. In this study, we investigate the differences of NKG2DL expression on APL and non-APL cells. Aims: Exploring the difference between APL and non-APL AML, may shed new insight on the treatment of AML. Methods: Bone marrow samples were derived from de novo APL and non-APL AML patients, diagnosed according to French-American-British (FAB) criteria in The First Affiliated Hospital of Xi’an Jiao Tong University. Flow cytometry was performed with the anti-NKG2DL mAbs (MIC-A/B-PE, ULBP-1-APC, ULBP-2/5/6-PerCP). Leukemic blasts were identified using the CD45/SSC gating procedure. Non-APL AML patients were divided into high or low group based on the median expression levels of NKG2DL for survival analysis. Results: Totally 46 patients comprising of 23 APL and 23 non-APL AML were enrolled in this study. There was no significant difference in the baseline characteristics between the two groups. All non‐APL AML cells had low or no NKG2DL surface expression, while most APL cells expressed high NKG2DL levels. In particular, just two APL patients was negative for the NKG2DL but positive for CD34. The median percentage of NKG2DL among non-APL AML cells and APL cells were 1.2% vs 20.3% in MIC-A/B (P<0.01), 1.1% vs 54.8% in ULBP-1 (P=0.017), and 3.8% vs 36.35% in ULBP-2/5/6 (P<0.01). (Fig.1) 23 non-APL AML patients were enrolled for study inclusion; one patient dropped out due to cerebral infarction. The median follow-up time was 17.2 weeks. The high ULBP-2/5/6 group showed a superior overall survival rate compared to the low ULBP-2/5/6 group (P < 0.01), but there was no significant difference between high and low MIC-A/B groups (P = 0.31) or between the high and low ULBP-1 groups (P = 0.52). Image:Summary/Conclusion: NKG2DL was decreased significantly on the surface of non-APL AML cells compared with APL cells. These results may indicate that NKG2D-mediated anti-tumor immunity contributes to the favorable prognosis in APL, while immune escape is an underlying mechanism for unfavorable prognosis in non-APL AML. NKG2DL may be used as a potential biomarker to predict prognosis of patients with non-APL AML, and upregulation of its expression could improve the clinical efficacy. Further studies with larger sample size and longer follow-up are required to confirm our conclusion.

Interplay between hypertriglyceridemia and acute promyelocytic leukemia mediated by the cooperation of peroxisome proliferator-activated receptor-α with the PML/RAR α fusion protein on super-enhancers.

Patients with newly diagnosed acute promyelocytic leukemia (APL) are often obese or overweight, accompanied by metabolic disorders, such as dyslipidemia. However, the link between dyslipidemia and leukemia is obscure. Here, we conducted a retrospective study containing 1,412 cases (319 newly diagnosed APL patients, 393 newly diagnosed non-APL acute myeloid leukemia patients, and 700 non-tumor controls) and found that APL patients had higher triglyceride levels than non- APL and control groups. Using clinical data, we revealed that hypertriglyceridemia served as a risk factor for early death in APL patients, and there was a positive correlation between triglyceride levels and leukocyte counts. RNA sequencing analysis of APL patients having high or normal triglyceride levels highlighted the contribution of peroxisome proliferatoractivated receptor-α (PPARα), a crucial regulator of cell metabolism and a transcription factor involved in cancer development. The genome-wide chromatin occupancy of PPARα revealed that PPARα co-existed with PML/RARα within the super-enhancer regions to promote cell proliferation. PPARα knockdown affected the expression of target genes responsible for APL proliferation, including FLT3, and functionally inhibited the proliferation of APL cells. Moreover, in vivo results in mice having high fat diet-induced high triglyceride levels supported the connection between high triglyceride levels and the leukemic burden, as well as the involvement of PPARα-mediated-FLT3 activation in the proliferation of APL cells. Our findings shed light on the association between APL proliferation and high triglyceride levels and provide a genetic link to PPARα-mediated hyperlipidemia in APL.

Methylation of DNA Repair Genes as a Prognostic Biomarker in AML of a TCGA-LAML Cohort.

Dysregulation of DNA damage response and altered DNA methylation in acute myeloid leukemia (AML) have been reported, but the impact of methylation of DNA repair genes has not yet been researched. We aimed to predict the prognosis of non-APL AML patients based on the known CpG site methylation levels of DNA repair genes through The Cancer Genome Atlas AML project (TCGA-LAML). We utilized TCGA-LAML cohort (174 non-APL AML) for the methylation data of 22 DNA repair genes. In univariate analysis among 174 non-APL AML patients of the TCGA-LAML cohort, the hypermethylation of MLH1, RAD51, and ATM showed superior overall survival (OS) than non-hypermethylated groups, while hypermethylation of RAD23A, RAD23B, MLH1, MSH2, BRCA1, BRCA2, RAD50, and PARP1 was associated with poor OS. We demonstrated that CpG hypermethylation levels of DNA repair genes differed according to the AML cytogenetic risk groups. In multivariate analysis, hypermethylation of MLH1 and RAD51 showed better OS than non-hypermethylated patients, but hypermethylation of MSH2 and RAD50 showed worse OS than non-hypermethylated patients. Methylation of 4 DNA repair genes, such as MLH1, RAD51, MSH2, and RAD50, have the potential to be independent risk factors in non-APL AML patients.

All-trans retinoic acid induces differentiation in primary acute myeloid leukemia blasts carrying an inversion of chromosome 16

All-trans retinoic acid (ATRA)-based therapy for acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML), is the most successful example of differentiation therapy. Although ATRA can induce differentiation in some non-APL AML cell lines and primary blasts, clinical results of adding ATRA to standard therapy in non-APL AML patients have been inconsistent, probably due to use of different regimens and lack of diagnostic tools for identifying which patients may be sensitive to ATRA. In this study, we exposed primary blasts obtained from non-APL AML patients to ATRA to test for differentiation potential in vitro. We observed increased expression of differentiation markers, indicating a response to ATRA, in four out of fifteen primary AML samples. Three samples in which CD11b increased in response to ATRA had an inversion of chromosome 16 as well as the CBFB-MYH11 fusion gene, and the fourth sample was from a patient with KMT2A-rearranged, therapy-related AML. In conclusion, we identified a subgroup of non-APL AML patients with inv(16) and CBFB-MYH11 as the most sensitive to ATRA-mediated differentiation in vitro, and our results can help identify patients who may benefit from ATRA treatment.

Case Report: ANXA2 Associated Life-Threatening Coagulopathy With Hyperfibrinolysis in a Patient With Non-APL Acute Myeloid Leukemia

Patients with acute promyelocytic leukemia (APL) often present with potentially life-threatening hemorrhagic diathesis. The underlying pathomechanisms of APL-associated coagulopathy are complex. However, two pathways considered to be APL-specific had been identified: 1) annexin A2 (ANXA2)-associated hyperfibrinolysis and 2) podoplanin (PDPN)-mediated platelet activation and aggregation. In contrast, since disseminated intravascular coagulation (DIC) is far less frequent in patients with non-APL acute myeloid leukemia (AML), the pathophysiology of AML-associated hemorrhagic disorders is not well understood. Furthermore, the potential threat of coagulopathy in non-APL AML patients may be underestimated. Herein, we report a patient with non-APL AML presenting with severe coagulopathy with hyperfibrinolysis. Since his clinical course resembled a prototypical APL-associated hemorrhagic disorder, we hypothesized pathophysiological similarities. Performing multiparametric flow cytometry (MFC) and immunofluorescence imaging (IF) studies, we found the patient’s bone-marrow mononuclear cells (BM-MNC) to express ANXA2 - a biomarker previously thought to be APL-specific. In addition, whole-exome sequencing (WES) on sorted BM-MNC (leukemia-associated immunophenotype (LAIP)1: ANXAlo, LAIP2: ANXAhi) demonstrated high intra-tumor heterogeneity. Since ANXA2 regulation is not well understood, further research to determine the coagulopathy-initiating events in AML and APL is indicated. Moreover, ANXA2 and PDPN MFC assessment as a tool to determine the risk of life-threatening DIC in AML and APL patients should be evaluated.

CDK6 Is a Potential Prognostic Biomarker in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a threatening hematological malignant disease in which new successful approaches in therapy are needed. Cyclin-dependent kinase 6 (CDK6), a regulatory enzyme of the cell cycle that plays an important role in leukemogenesis and the maintenance of leukemia stem cells (LSC), has the potential to predict the prognosis of AML. By analyzing public databases, we observed that the messenger RNA (mRNA) levels of CDK6 were significantly overexpressed in AML cell lines and non-acute promyelocytic leukemia (non-APL) AML patients when compared to healthy donors. Furthermore, CDK6 expression was significantly reduced in AML patients who achieved complete remission (CR) compared to that at the time of diagnosis in our validated cohort. The expression of CDK6 was tightly correlated with peripheral blood blasts, French–American–British (FAB) subtypes, CCAAT-enhancer-binding protein α (CEBPA) mutation, and chromosomal abnormalities of t(8;21). However, the clinical significance and effects of CDK6 expression on the prognosis of non-APL AML patients remain uncertain. We found that CDK6 expression was inversely correlated with overall survival (OS) among non-APL AML patients using the Kaplan–Meier analysis. CDK6 was also found to be positively associated with genes identified to contribute to the development of leukemia, including CCND2, DNMT3B, SOX4, and IKZF2, as well as being negatively associated with anticancer microRNAs, including miR-187, miR-9, miR-582, miR708, and miR-362. In summary, our study revealed that CDK6 might be a potential diagnostic and prognostic biomarker in non-APL AML patients.

Comprehensive DNA repair gene expression analysis and its prognostic significance in acute myeloid leukemia

ABSTRACT Background Deficiency in DNA damage response (DDR) pathway and accumulation of DNA damage increases mutation rates resulting in genomic instability and eventually increases the risk of cancer. The aim of our study was to investigate expressions of DNA repair genes as new prognostic biomarkers in acute myeloid leukemia (AML). Methods We utilized The Cancer Genome Atlas AML project (TCGA-LAML cohort, 15 acute promyelocytic leukemia (APL) and 155 non-APL AML) for the expression data of DNA repair genes. For validation, clinical samples (Ewha study group, 9 APL and 72 non-APL AML patients) were analyzed for the expression of 22 DNA repair genes using a custom RT2 Profiler PCR Array. Results APL patients presented significantly lower expression of DNA repair genes than non-APL AML patients in both study groups. Among non-APL AML patients, high expression levels of PARP1, XRCC1, and RAD51 were associated with poor overall survival (OS) probability in both study groups. Furthermore, Cox regression analysis showed that increased expression levels of PARP1, XRCC1, RAD51, BRCA1 and MRE11A could be independent risk factors for OS in the Ewha study group. Among non-APL patients of the Ewha study group, the OS probability of DDR-overexpressed group with at least one gene or more showing Z score greater than 1.5 was poorer than that of DDR non-overexpressed group. Conclusion In the current study, the DNA repair gene expression profile of APL patients was different from that of non-APL AML patients. Overexpression of DNA repair genes could be a poor prognostic biomarker in non-APL AML.

ALL-174: Analysis of Elderly Patients (≥70 Years Old) with Acute Leukemia in the Era of Targeted Therapy

Background Analysis of SEER database shows that the median age of acute myeloid leukemia (AML) patients at diagnosis is 68 years, with ~1/3 of patients older than 75 years. Although acute lymphoblastic leukemia (ALL) is mainly a disease of the younger population, ~12% of patients are older than 65 years old at diagnosis. Elderly patients suffer from increased toxicity compared to younger patients translating into a need for reduction in chemotherapy dose intensity as well as a higher rate of early death. Elderly patients, 70 years of age and older, receiving intensive chemotherapy have an extremely poor outcome with reported median overall survival (OS) of approximately 4 months in ALL and 6-12 months in AML. Within the last couple of years a flurry of targeted therapies has been introduced into clinical practice and new treatment opportunities for older patients have become available. We sought to investigate the pattern of targeted therapy utilization and clinical trial enrollment in the older patients with acute leukemia in our center. Methods A single center retrospective analysis of patients aged ≥ 70 years with newly diagnosed acute leukemia treated at a the hemato-oncology admission unit in a large tertiary center between 4/2011 and 4/2019. Results 52 patients [AML (n=44 including 3 acute promyelocytic leukemia), ALL (n=5), mixed phenotype acute leukemia (n=2) and blastic plasmacytoid dendritic cell neoplasm (n=1)] were included in the analysis. 44% of the entire cohort received novel approaches with 26.9% of patients enrolled in clinical trials and 30.7% receiving targeted therapy in the off-trial setting (in all lines of therapies). Due to the small cohort of non-AML patients, we present herein in detail the results of the non-APL AML patients only (Table 1). Most of the AML patients had high-risk features such as therapy related AML (n=12), AML with myelodysplastic-related changes (n=9). Adverse risk cytogenetics was observed in 13 patients. 17 patients (41%) received intensive chemotherapy, mainly the “3+7” induction regimen with daunorubicin 60mg/m2/day. 58.6% were considered ineligible for intensive chemotherapy due to age and comorbidities, third of those patients were enrolled into clinical trials, and two-thirds received either Azacitidine alone, LDAC alone, or in combination with venetoclax. The most used targeted agent was venetoclax (combined with either azacytidine or LDAC) which was given to 12 patients (all lines of therapies) achieving 1-year OS of 50%. The complete remission (CR) rate for patients receiving intensive chemotherapy was 41% and the 1-year OS was 47.1% with a median OS of 10.3 months compared to 37.5% CR and a median OS of 3.7 months for patients receiving non-intensive therapy (95% CI, 1.4-6, p=0.072, Figure 1a). Patients who received either targeted therapy or were enrolled upfront into a clinical trial had a 1-year OS of 44.4%. Four patients, median age of 73.5 years (70.7-73.7 years), underwent hematopoietic stem-cell transplantation in first remission , receiving non-myeloablative conditioning, with median OS of 75% at 1 year of follow-up. In a subgroup analysis of octogenerians (≥ 80 years old), all 11 patients were diagnosed with AML, and 63% of them had either therapy-related AML or AML with myelodysplastic-related changes. All received non-intensive therapy with 36% receiving either targeted therapy or enrolled into a clinical trial. Interestingly, although the1-year OS of the octogenerians was 36%, those on a clinical trial or receiving targeted therapy had 1-year OS of 91%. For the entire cohort (including non-AML patients), patients who were either enrolled into a clinical trial or received targeted therapy had 1-year OS of 47.8% with a median OS of 10.3 months compared to 37.9% and median OS of 4.2 months 1-year OS for those who did not receive targeted therapy or were not enrolled into a clinical trial (95% CI, 1.8-18.8, p=0.618, Figure 1b). Conclusions Patients over 70 years of age with acute leukemia seem to benefit from the administration of targeted therapy and/or enrollment into clinical trials compared to standard approaches. This holds true also for octogenerians. If this is not feasible, a selected group of carefully chosen patients might benefit from intensive therapy as well. Download : Download high-res image (249KB) Download : Download full-size image Disclosures Wolach: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker.

Use of Minimal Residual Disease in Acute Myeloid Leukemia Therapy.

The expanding availability of minimal or more precisely measurable residual disease (MRD) assessment in acute myeloid leukemia (AML) with its possible implications for therapeutic decisions is of high interest to clinicians treating AML patients. A variety of mostly retrospective studies have shown that AML patients with a positive MRD test, assessed by different techniques at defined cutoffs and time-points, are at significantly higher risk of relapse and experience shorter overall survival compared to MRD-negative patients. How this valuable information may be adapted in the daily routine of patients' treatment to distinguish individuals who need more aggressive therapy from the ones who can be spared additional therapy to avoid treatment-related toxicities is still being investigated. With the exception of MRD analyses in acute promyelocitic leukemia (APL), the clinical implications of MRD tests for the individual AML patient are still mostly unknown. We currently lack hard evidence that MRD-based therapy modulation during treatment or pre-emptive intervention in MRD-positive patients after therapy would improve outcomes in non-APL AML patients. These questions will be evaluated in prospective randomized clinical trials. Today, however, some conclusions with regard to MRD assessment in AML can be drawn from the published data and are reviewed in this article.

Analysis of Elderly Patients (≥70 years old) with Acute Leukemia in the Era of Targeted Therapy

Background Analysis of SEER database shows that the median age of acute myeloid leukemia (AML) patients at diagnosis is 68 years, with ~1/3 of patients older than 75 years. Although acute lymphoblastic leukemia (ALL) is mainly a disease of the younger population, ~12% of patients are older than 65 years old at diagnosis. Elderly patients suffer from increased toxicity compared to younger patients translating into a need for reduction in chemotherapy dose intensity as well as a higher rate of early death. Elderly patients, 70 years of age and older, receiving intensive chemotherapy have an extremely poor outcome with reported median overall survival (OS) of approximately 4 months in ALL and 6-12 months in AML. Within the last couple of years a flurry of targeted therapies has been introduced into clinical practice and new treatment opportunities for older patients have become available. We sought to investigate the pattern of targeted therapy utilization and clinical trial enrollment in the older patients with acute leukemia in our center. Methods A single center retrospective analysis of patients aged ≥ 70 years with newly diagnosed acute leukemia treated at a the hemato-oncology admission unit in a large tertiary center between 4/2011 and 4/2019. Results 52 patients [AML (n=44 including 3 acute promyelocytic leukemia), ALL (n=5), mixed phenotype acute leukemia (n=2) and blastic plasmacytoid dendritic cell neoplasm (n=1)] were included in the analysis. 44% of the entire cohort received novel approaches with 26.9% of patients enrolled in clinical trials and 30.7% receiving targeted therapy in the off-trial setting (in all lines of therapies). Due to the small cohort of non-AML patients, we present herein in detail the results of the non-APL AML patients only (Table 1). Most of the AML patients had high-risk features such as therapy related AML (n=12), AML with myelodysplastic-related changes (n=9). Adverse risk cytogenetics was observed in 13 patients. 17 patients (41%) received intensive chemotherapy, mainly the "3+7" induction regimen with daunorubicin 60mg/m2/day. 58.6% were considered ineligible for intensive chemotherapy due to age and comorbidities, third of those patients were enrolled into clinical trials, and two-thirds received either Azacitidine alone, LDAC alone, or in combination with venetoclax. The most used targeted agent was venetoclax (combined with either azacytidine or LDAC) which was given to 12 patients (all lines of therapies) achieving 1-year OS of 50%. The complete remission (CR) rate for patients receiving intensive chemotherapy was 41% and the 1-year OS was 47.1% with a median OS of 10.3 months compared to 37.5% CR and a median OS of 3.7 months for patients receiving non-intensive therapy (95% CI, 1.4-6, p=0.072, Figure 1a). Patients who received either targeted therapy or were enrolled upfront into a clinical trial had a 1-year OS of 44.4%. Four patients, median age of 73.5 years (70.7-73.7 years), underwent hematopoietic stem-cell transplantation in first remission , receiving non-myeloablative conditioning, with median OS of 75% at 1 year of follow-up. In a subgroup analysis of octogenerians (≥ 80 years old), all 11 patients were diagnosed with AML, and 63% of them had either therapy-related AML or AML with myelodysplastic-related changes. All received non-intensive therapy with 36% receiving either targeted therapy or enrolled into a clinical trial. Interestingly, although the1-year OS of the octogenerians was 36%, those on a clinical trial or receiving targeted therapy had 1-year OS of 91%. For the entire cohort (including non-AML patients), patients who were either enrolled into a clinical trial or received targeted therapy had 1-year OS of 47.8% with a median OS of 10.3 months compared to 37.9% and median OS of 4.2 months 1-year OS for those who did not receive targeted therapy or were not enrolled into a clinical trial (95% CI, 1.8-18.8, p=0.618, Figure 1b). Conclusions Patients over 70 years of age with acute leukemia seem to benefit from the administration of targeted therapy and/or enrollment into clinical trials compared to standard approaches. This holds true also for octogenerians. If this is not feasible, a selected group of carefully chosen patients might benefit from intensive therapy as well. Disclosures Wolach: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Speaker.

Low Expression of Pseudogene POU5F1B Affects Diagnosis and Prognosis in Acute Myeloid Leukemia (AML).

BackgroundThe transcription factor Oct-4 is necessary for maintaining pluripotency and self-renewal of embryonic stem cells, and POU5F1B is a processed pseudogene of Oct-4 with coding capacity. The purpose of this study is to evaluate the expression and clinical implication of POU5F1B in AML.Material/MethodsThe expression of the POU5F1B transcript was evaluated in 175 newly diagnosed AML patients and 39 healthy controls by use of real-time quantitative PCR (RQ-PCR).ResultsPOU5F1B was underexpressed in AML compared with controls (P<0.001). The receiver operating characteristic (ROC) curve revealed that the POU5F1B transcript level was able to differentiate AML patients from healthy individuals (AUC=0.682). In non-APL AML patients, the POU5F1Blow group had significantly higher WBC than the POU5F1Bhigh group (20.2×109 vs. 4.6×109 L−1, P=0.021). Among whole-cohort AML, non-APL AML, and intermediate-risk AML, POU5F1Bhigh patients had obviously higher complete remission (CR) rates than POU5F1Blow patients (P=0.012, P=0.012 and P=0.027). In addition, Kaplan-Meier analysis demonstrated better overall survival (OS, P=0.019, P=0.007 and P=0.046, respectively) in POU5F1Bhigh patients compared with POU5F1Blow patients. Furthermore, in multivariate survival analysis, POU5F1B was independently associated with OS in non-APL AML patients and intermediate-risk AML as a favorable prognostic factor.ConclusionsPOU5F1B was frequently underexpressed in AML, and might contribute to the diagnosis and prognosis of AML.

The Genes for Tissue Factor F3 and Nuclear Receptor 4A Are Down-Regulated in Early Death Acute Promyelocytic Leukemia Patients

Introduction: Acute promyelocytic leukemia (APL) patients are successfully treated via differentiation therapy with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Attempts to apply ATRA-based differentiation therapy to non-APL acute myeloid leukemia (AML) patients have not been effective so far (Johnson & Redner, 2015). Furthermore, 10-30% of the APL patients suffer an early death (ED) within 30 days, due to hemorrhages, infections, differentiation syndrome and thrombosis. Different risk factors have been identified, but the underlying mechanisms and successful treatment of ED in APL patients still have not been established (Kwaan et al., 2014, Lehmann et al., 2017). Hence, it is highly important to identify novel risk factors to understand the mechanistic processes in APL ED patients.Methods: To identify target genes, 50 bp single-read RNA sequencing (RNAseq) of 6 ED and 9 APL controls (cohort #1; n=15) and 4 ED and 5 APL controls (cohort #2; n=9) was executed. Samples were taken from patients with confirmed diagnosis of APL before beginning of treatment. Cohort #1 consisted of 15 patients: median age 60 years (range 37-73 years), 10 high-risk patients and 5 low/intermediate-risk patients according to Sanz score. Patients of cohort #1 were treated according to the AIDA2000 protocol of the Study Alliance Leukemia (SAL) study group. Cohort #2 consisted of 9 patients: median age 55 years (range 36-79 years), 4 high-risk patients and 5 low/intermediate-risk patients. Most patients of cohort 2 were treated according to the AIDA2000 (SAL) or APL0406 protocol. Gene validation was performed via RT-qPCR. PML-RARα variants were determined by Mentype AMLplexQS (Biotype). Survival and RT-qPCR analyses were performed with 64 non-APL AML patients´ samples treated within the clinical trial of the AMLSG HD98B study (Schlenk et al., 2004). In this trial, all patients received ICE (idarubicin, cytarabine, etoposide) chemotherapy. The patients were randomly assigned to ATRA or no ATRA. In our cohort, 26 patients had received ICE-ATRA, whereas 38 only ICE. Amaxa nucleofector technology was used for overexpression of PML-RARα bcr1 or bcr3 variant in U937 cells. NB4 or AML cells treated with 1 µM ATRA up to 72 h or 1-2 µM ATO up to 48 h were analyzed via flow cytometry, CellTiter-Glo viability assay, RT-qPCR or Western blot.Results: RNAseq of cohorts 1 and 2 showed F3 (Tissue Factor) and members of nuclear receptor 4A family, NR4A1/2/3, significantly downregulated in ED compared to control APL cases. GSEA analysis further identified a gene family including F3 and members of nuclear receptor 4A family, NR4A1/2/3, co-regulated upon leukotriene and thrombin treatment. Downregulation of F3 was further validated by RT-qPCR. Analysis of PML-RARα variants in APL control and ED cases (n=38, Chi-square p < 0.041) showed a significant enrichment of the short variant bcr3 in ED APL. Artificial overexpression of the short bcr3 and long bcr1 PML/RARα variant in U937 further revealed a correlation between bcr3 and downregulation of NR4A2/3. Moreover, treatment of the APL NB4 cell line with ATRA or ATO induced further downregulation of F3 but upregulation of NR4A2/3 transcripts. ATRA treatment induced the same effects on F3 and NR4A3 protein levels, while ATO led not only to a decrease of F3 but also NR4A3 protein levels.We next sought to address the role of F3 and NR4A in non-APL AML. In 5 non-APL AML cell lines high F3 transcript and protein levels were positively correlated with a better response to ATRA treatment in vitro. Consistently, analyzing samples taken from the AMLSG HD98B trial, AML patients with high F3 but also NR4A3 transcript levels treated with ICE chemotherapy showed a significantly prolonged overall survival upon additional ATRA treatment in vivo (Log-rank p < 0.008).Conclusions: Expression of F3 and NR4A1/2/3 is downregulated in APL ED and decreased expression of NR4A2/3 is associated with short PML-RARα variant bcr3, which is significantly enriched in ED APL. Since NR4A members are associated with coagulation and inflammation, they may be important F3-related factors, contributing to the bcr3 ED APL phenotype. As ATRA and ATO treatment is known to further inhibit F3 expression, alternative therapies not inhibiting F3 expression could be worthwhile in APL ED patients. Moreover, F3 and NR4A3 expression levels seem to be highly relevant as marker for the prediction of ATRA response in non-APL AML patients. [Display omitted] DisclosuresPlatzbecker:Celgene: Research Funding. Thiede:Novartis: Honoraria, Research Funding; AgenDix: Other: Ownership. Schlenk:Pfizer: Research Funding, Speakers Bureau.

Early Results from a Biomarker-Directed Phase 2 Trial of Sy-1425 in Combination with Azacitidine or Daratumumab in Non-APL Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

Early Results from a Biomarker-Directed Phase 2 Trial of Sy-1425 in Combination with Azacitidine or Daratumumab in Non-APL Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS)

Successful treatment of disseminated intravascular coagulation by recombinant human soluble thrombomodulin in patients with acute myeloid leukemia.

Disseminated intravascular coagulation (DIC) is a life-threatening condition that frequently occurs in patients with hematologic malignancies. Currently, recombinant human soluble thrombomodulin (rTM) is a therapeutic DIC drug that is manufactured and sold in Japan only. We evaluated the efficacy of rTM compared to that of gabexate mesilate (GM), which was previously used routinely for treating DIC in Japan, in patients with acute myeloid leukemia (AML). This retrospective study enrolled 43 AML patients, including 17 with acute promyelocytic leukemia (APL), that was complicated with DIC. DIC resolution rates in non-APL AML and rTM-treated APL patients were 68.4% and 81.8%, respectively. In non-APL AML patients, the duration of rTM administration was significantly shorter than that of GM (7 vs 11 days), suggesting that rTM could improve DIC earlier than GM, although rTM was used in patients with more severe DIC. Moreover, treatment with rTM significantly improved DIC score, fibrinogen, fibrin/fibrinogen degradation product (FDP), and prothrombin time (PT) ratio. Conversely, treatment with GM only improved the DIC score and FDP. In APL patients, the duration of rTM administration was also significantly shorter than that of GM. No severe side effects associated with the progression of bleeding were observed during rTM administration. These findings suggest that rTM is safe, and its anti-DIC effects are more prompt than GM for treating AML patients with DIC.

Methylation-independent ITGA2 overexpression is associated with poor prognosis in de novo acute myeloid leukemia.

Previous studies have been indicated that integrin α2 (ITGA2) may be important in cell migration, invasion, survival, and angiogenesis. However, the correlation between ITGA2 expression and acute myeloid leukemia (AML) is still unclear. Real-time quantitative polymerase chain reaction was carried out to analyze ITGA2 messenger RNA level. Methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing PCR were performed to detect the methylation of ITGA2 promoter. ITGA2 expression was significantly upregulated in 134 de novo AML patients compared with 33 controls (p = 0.007). ITGA2high group had markedly lower complete remission (CR) rate than ITGA2low group (p = 0.011). Furthermore, the overall survival in ITGA2high patients was significantly shorter than ITGA2low patients throughout AML cohort, non-acute promyelocytic leukemia (APL) and cytogenetic normal-AML (p = 0.001, 0.002, and 0.044, respectively). Multivariate analysis confirmed that ITGA2 overexpression served as an independent prognostic factor in both whole-cohort AML patients (p = 0.018) and non-APL AML patients (p = 0.021). Besides, ITGA2 expression level was significantly decreased in AML patients after CR (p = 0.011), and was returned at the time of relapse phase (p = 0.021). Moreover, unmethylated ITGA2 promoter was identified in normal controls, leukemia cell lines, and primary leukemia cells with low or high ITGA2 expression. In conclusions, methylation-independent ITGA2 overexpression is associated with poor prognosis in AML.