Acute Myelogenous Leukemia Therapy Research Articles

Therapeutic Targeting of TIM-4-L with Engineered T Cells for Acute Myeloid Leukemia.

Disruption of lipid bilayer asymmetry is a common feature observed in cancer cells and offers novel routes for therapeutic targeting. We used the natural immune receptor TIM-4 to interrogate for loss of plasma membrane phospholipid polarity in primary acute myelogenous leukemia (AML) samples and evaluated the anti-leukemic activity of TIM-4-L-directed T-cell therapy in preclinical AML models. We performed FACS analysis on 33 primary AML bone marrow specimens and correlated TIM-4-L expression frequency and intensity with molecular disease characteristics. Using Kasumi-1 and MV-4-11 AML cell lines, we further tested the anti-leukemic effects of TIM-4-L-directed engineered T cells in vitro and in vivo. We found that 86% of untreated AML blasts displayed upregulation of cell surface TIM-4-L. These observations were agnostic to AML genetic classification, as samples with mutations in TP53, ASXL1, and RUNX1 displayed TIM-4-L upregulation similar to that seen in favorable and intermediate subtypes. TIM-4-L dysregulation was also stably present in AML cell lines. To evaluate the potential of targeting upregulated TIM-4-L with adoptive T-cell therapy, we constructed TIM-4-L-directed engineered T cells, which demonstrated potent anti-leukemic effects, effectively eliminating AML cell lines with a range of endogenous TIM-4-L expression levels both in vitro and in vivo. These results highlight TIM-4-L as a highly prevalent target on AML across a range of genetic classifications and novel target for T-cell-based therapy in AML. Further investigations into the role of TIM-4-L in AML pathogenesis and its potential as an anti-leukemic target for clinical development are warranted.

Financial Trends of AML Patients over the Past Decade

Background: Over the past 30 years, the incidence of acute myelogenous leukemia (AML) has progressively increased across the globe, and until recently, therapeutic options were primarily limited to the standard “7 + 3” cytotoxic chemotherapy. The economic burden associated with the management of AML has steadily increased and significantly escalated with the introduction of new targeted therapies. To our knowledge, there are very few studies that have looked at the major drivers of cost in AML treatment over the past decade and how they have evolved. Methods: We conducted a retrospective review with IRB approval of all the medical costs associated with the initial course of chemotherapy, administered in the hospital setting, in newly diagnosed AML patients at the Georgia Cancer Center (GCC) from 2011 to 2022. All medical costs were obtained through the accounting system at Augusta University Medical Center (AUMC) using the Patient Billing Department. Every direct cost from the patient's first to last day of hospitalization during which they received induction was included. Results: A total of 183 patients were identified. Patients were excluded for the following reasons: 3 patients left to receive induction elsewhere, and 2 patients left against medical advice for unclear reasons. A total of 178 newly diagnosed AML patients fit the above criteria during this period with a median age of 61 years. The median length of stay (LOS) of these 178 patients was 30 days. Between 2011 to 2016, 71 patients were treated and had a median age of 65 years, while 107 patients were treated between 2017 to 2022 with a median age of 57 years. Major drivers of total direct cost were identified which included inpatient bed (~40%), medications (~20%), blood bank products (~15%), and lab tests (~14%). Medication costs were further reviewed with breakdown as follows: chemotherapy (~3%), antibiotics (~10%), and all other medications (~7%). These medication costs were based on 340B pricing. The average and median direct costs from the above categories were compared from 2011-2016 to 2017-2022 (Table 1). The 2017-2022 group had significantly lower median and average bed cost, blood bank product cost, and overall total cost. The LOS was also noted to be shorter in the 2017-2022 group. We then analyzed the subset of patients (n=64) who received standard induction chemotherapy and excluded patients who required reinduction (n=8) or who died during induction (n=13). The same trends were identified in this subset analysis. AML patients with FLT3 mutations, which consisted of 41 of the total 178 patients, were of particular interest given the increased number of targeted therapies that have been approved since 2017. This was investigated further by comparing the direct average and median costs of the categories noted above between the 2011-2016 group with 11 FLT3+ AML patients to the 2017-2022 group with 30 FLT3+ AML patients (Table 2). The average and median medication costs, including chemotherapy, antibiotics, and all other medications, were higher in the 2017-2022 group. This resulted in the total direct cost being higher in the 2017-2022 group despite having lower blood bank and inpatient bed costs. Conclusion: Over the past decade, many significant changes have occurred in several of the driving factors associated with the cost of AML therapy. Still, there has been a decrease in length of stay, inpatient bed costs, blood bank costs, and overall total costs from 2017-2022 compared to 2011-2016. In the subset of FLT3+ AML patients, there was a shift in the financial landscape with an increase in medication costs that influenced the overall cost. It is likely that the economic impact from this will continue to grow as novel therapies become more available and the number of patients being treated continues to increase.

Targeting Unc51-like Autophagy Activating Kinase 1 (ULK1) Overcomes Adaptive Drug Resistance in Acute Myelogenous Leukemia.

ULK1 drives a cell-intrinsic adaptive resistance in AML and targeting ULK1-mediated autophagy can synergize with existing and emerging AML therapies to overcome drug-resistance and induce apoptosis.

Specific Nucleotide Substitutions and Stressors Erode Highly Conserved Genomic Regions in Acute Myelogenous Leukemia

Background: "Leukemia stressors” refer to extrinsic factors that may facilitate clonal progression. We previously reported that smoking initiates unique leukemogenic signatures in acute myelogenous leukemia (AML) characterized by a higher proportion of C>A and G>A single base substitutions (SBS) [Hoang. ASH. 2021]. These G>A SBS are known to be particularly prevalent in CpG islands due to cytosine methylation. However, toxic smoking metabolites could potentially induce specific genomic signatures in patients with AML that resemble COSMIC SBS4 in lung cancer [i.e. enrichment in C>A transversion], and spontaneous C>T SBS1 signatures within specific genomic clusters or nodes. In this study, we investigate how these SBS1/SBS4 signatures distribute within hot-spot regions and evaluate whether G>A mutations (mut), commonly observed in methylated CpG islands, are differentially expressed in AML patients who are older and/or are smokers. In our study, these hot-spot regions or nodes were referenced as a genomic pool 1 (GP1). Methods: After IRB approval, the incidence of specific SBS densities were investigated in vulnerable hot-spot regions affected by exogenous [SBS4] and endogenous [SBS1] mutagenesis. Next generation sequencing (NGS) was used in patients to obtain data regarding specific mutation types and locations. In known gene exons, we examined genomic coordinates corresponding to individual mut. COSMIC browser allowed genomic coordinate examination to "aggregate” mut within putative "vulnerable exon neighborhoods". "Hot-spot neighborhoods” were described as genomic pool 1 (GP1). Descriptive and inferential statistics were used to analyze data, which was obtained from a single institution. Results: 80 patients (pt) diagnosed with hematopoietic malignancies with available next generation sequencing (NGS) were selected for analysis. 73/80 (91%) were AML pt. The median age was 63 years (y) (range, 22-88). 42% and 64% of pt were smokers and older than 63 y, respectively. With respect to specific hot spots or nodes, AML pt showed increased G>A mutagenicity in GP1 cluster 1 (Fig 1). Specifically, for G>A, smoking increased the rate from 18.4% to 37.5% (p=0.01) (Fig 1 A and B). Age > 63 y led to an increased mutagenicity rate of 17.1% to 30.5% (p=0.03) (Fig 1 C and D). A synergistic effect in mutagenicity was observed when combining age > 63 y plus smoking (10.3% to 41.9%, p=0.01) (Fig 1. E and F). In regards to hotspots in specific genes, smoking has the ability to increase NRAS (G>A), P53 (G>A) and SRSF2 (C>A) frequencies within GP1. Interestingly, smoking increased C>A mutagenicity in the SRSF2 gene in GP1 from 50% vs 82%. Conclusions: Our data suggests that aging and smoking globally and locally erode the AML genome by potentially accelerating cytosine methylation and thus G>A mutagenicity, most likely in CpG islands within genes like NRAS and P53. These genes likely contain hot spots aggregated in GP1 that, when mutated, can de-stabilize the genome and increase the risk of AML. Importantly, we observed similar COSMIC SBS4 substitutions seen in lung cancer associated with C>A transversions in older AML pt who had a history of smoking, which is specifically found in the SRSF2 gene. Overall, our data advances our understanding on how risk factors for AML affect the human AML genome. These have strong implications for AML prevention, pathogenesis and therapy. Future studies should be aimed at identifying other intrinsic and extrinsic risk factors for AML seeking to explore their specific mutational patterns and locations within the human genome. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Long-Term Outcomes After Transplantation for Acute Myelogenous Leukemia.

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in the Journal of Clinical Oncology, to patients seen in their own clinical practice.Hematopoietic stem-cell transplantation (HSCT) has been used for more than four decades as consolidation therapy in acute myelogenous leukemia (AML). Allogeneic HSCT is almost universally used today, and autologous HSCT nearly disappeared from daily practice. Improvement in transplantation strategies, supportive care, and increased donor source availability led to increased numbers of long-term survivors after HSCT. In the accompanying paper of this ground rounds, Armenian and coworkers analyzed the burden of late complications after HSCT for AML in a large cohort of patients and compared severe/life-threatening conditions with those of siblings. This study reinforces the need for prolonged clinical follow-up of transplanted patients otherwise nearly cured of their original disease for late malignant and nonmalignant complications.

Expression of CD123 Related Long Non-coding RNA in Acute Myeloid Leukemia Bone Marrow Mononuclear Cells and Its Clinical Significance.

Acute myelogenous leukemia (AML) is a very common hematopoietic malignancy. Hematopoietic stem cell transplantation can improve the therapeutic effect of AML, but the 5-year survival rate is very low. CD123 imbalance, abnormal gene expression, and epigenetics play an important role in the pathogenesis of AML. This research was to explore the differential expression of CD123-related long non-coding RNA (lncRNA) in AML bone marrow mononuclear cells and provide a theoretical basis for targeted therapy of AML. High-throughput sequencing was performed to screen differentially expressed lncRNA in bone marrow mononuclear immunophenotypes of CD123+ and CD123- from patients with primary AML, and real-time quantitative PCR was adopted for screening and validation. There were 933 differentially expressed lncRNAs in the CD123+ group and the CD123- group, 407 lncRNAs were up-regulated and 463 lncRNAs were down-regulated in the CD123+ group. 14 lncRNAs with more than 2 times of difference were screened for identification, and it was found that compared with CD123- group, there was no substantial difference in the expression of JHDM1D-AS1, LINC01355, CASC15, FAM13A-AS1, HSPC324, LOC339803, LINC00877, and MAG12-AS3 in CD123+ group (P>0.05). The expressions of LOC101929698, BaALC-AS2, BOLA3-AS1, and FBX19-AS1 were considerably up-regulated (P<0.05), while the expressions of LOC100132249 and LINC02085 were considerably down-regulated (P<0.05). In summary, differentially expressed lncRNAs in bone marrow samples of CD123+ and CD123- group of newly diagnosed AML patients may be involved in the process of AML and seriously affect the prognosis of patients.

AML Cell Vaccines Co-Expressing CD80 and IL-15/IL-15 Receptor Alpha Induce Activation and Cytolytic Activity in Post Remission Autologous Patient PBMC Ex Vivo

There is a critical need for more effective therapy for acute myelogenous leukemia (AML). Although many patients achieve remission, most relapse with poor outcomes. Even after allogeneic Stem Cell Transplantation (SCT), 30-50% of patients relapse due to the persistence of residual disease.To address the poor immunogenicity of AML cells and the diminished immune responsiveness of patients, our candidate autologous AML vaccine is lentivirally engineered, in each patient's leukemic cells, to express CD80, IL-15, and IL-15 Receptor alpha (IL-15Rα). In prior studies in a syngeneic 32Dp210 murine AML model, CD80-mediated co-stimulation of T-cells combined with immune activation by the IL-15/IL-15Rα heterodimer showed unprecedented synergy in induction of anti-leukemic cytolytic activity (Shi, Y. et al, 2018). This was observed in both ex vivo co-culture and in vivo where vaccinated leukemic mice had >80% cure rates. No local skin, organ, or systemic toxicity was observed, nor was there evidence of systemic cytokine release of IL-6 or TNFα after SC or IV injection of up to 10 8 transduced irradiated AML cells.We confirmed the feasibility of producing patient-derived AML vaccines by transduction of 16 independent AML samples with a tri-cistronic lentiviral vector (TLV) that contains human CD80, IL-15 and IL-15Rα. Transduction levels were 11-71% of cells (median 38.6%).To define the minimum transduction level required for PBMC activation and to assess synergy of co-expressed human CD80, IL-15, and IL-15Rα, allogenic U937 leukemia cells were initially used as stimulators. Transduced U937 (U937-TLV) had high-level surface expression of CD80 and IL-15, secreted IL-15 (7 ng/ml/24 hours from 2 x 10 6 cells/ml) and activated CD3+ T-cells from an AML patient (Fig.1). Mixtures of irradiated U937-TLV with non-transduced U937 were created at fixed ratios (100%, 80%, 40%, 20%, 10%, 5%, 0%) for overnight co-culture with patient PBMC. At 24 hours, the T-cells were analyzed for activation by measurement of the frequency of CD69+ CD4 or CD8 T cells (Fig. 1), normalized to expression of unstimulated PBMC (0%) and the percentage of maximal CD69 expression with 100% U937-TLV (100%). Background levels of activation due to the presence of allogenic U937 were negligible. Co-culture with as little as 10% transduced U937-TLV reliably activated patient T-cells. To assess the synergy of CD80, IL-15 and IL-15Rα expression, parallel experiments were performed with PBMC co-cultured in IL-15 containing supernatants from U937-TLV cells (Fig. 1). The frequencies of activated T-cells were significantly higher after co-culture with U937/U937-TLV cells than after stimulation with IL-15-containing supernatants from similar ratios of U937/U937-TLV, confirming the synergy of CD80 and IL-15/IL-15Rα in the transduced cells.To better, model the clinical setting, we assessed induction of immune responses of patient T cells to autologous transduced AML. PBMC were stimulated with transduced or non-transduced autologous AML cells vs stimulation with allogeneic U937-TLV, or with anti-CD3/CD28 beads to define maximal stimulation. Negative controls included culture of PBMC alone. All patients had T-cell activation, as measured by induction of CD69, HLA-DR and CD95 (Fas) expression, although there was heterogeneity in the nature of responses, e.g., disparate induction of the markers in individual patients (Fig. 2A and B). Induction of cytotoxic effector pathways was confirmed by detection of CD178 (FasL) and perforin expression (Figure 2C and D). Overall, all patients' PBMC had the capacity to mount T-cell responses of similar magnitude to both allogeneic U937-TLV and autologous vaccine.These studies establish that autologous AML cells transduced with CD80, IL-15 and IL-15Rα can elicit specific anti-leukemic T-cell responses, even in the face of prior lymphodepleting chemotherapy. A strength of this autologous vaccine strategy is that it is agnostic to which AML proteins are immunogenic for each patient. Although uniformly detected, there was heterogeneity in the induction of activation markers and effector pathways, which may reflect host and/or disease-related differences. The mechanisms underlying differences in the nature of responses in patients will be important to understand and will provide the basis for future immune correlative studies for our Phase 1 vaccine trial in transplant ineligible AML patients. [Display omitted] DisclosuresKohn: Lyrik Therapeutics: Membership on an entity's Board of Directors or advisory committees; MyoGene Bio: Membership on an entity's Board of Directors or advisory committees; ImmunoVec: Membership on an entity's Board of Directors or advisory committees; Pluto Immunotherapeutics: Membership on an entity's Board of Directors or advisory committees; Allogene: Membership on an entity's Board of Directors or advisory committees; UC Regents: Patents & Royalties; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Sangamo Biosciences: Membership on an entity's Board of Directors or advisory committees.

Phase 1/2, Open-Label, Dose Escalation, Dose Expansion Study of Menin Inhibitor DSP-5336 in Adult Patients (pts) with Acute Leukemia with and without Mixed-Lineage Leukemia (MLL)-Rearrangement or Nucleophosmin 1 (NPM1) Mutation

Relapsed or refractory acute leukemia (AL) in adults, including acute myelogenous leukemia (AML) and acute lymphocytic leukemia (ALL), still represents a significant unmet need. Once AML or ALL relapses after initial treatment, the prognosis is extremely limited, with median survival <6 mo for AML and <1 y for ALL. This is especially true of AML or ALL with MLL rearrangements (MLLr) or relapsed AML with NPM1 mutations. Translocations of the MLL gene, found in approximately 5% to 10% of adult patients with AL, result in an aggressive subtype of leukemia, with a median overall survival (OS) of approximately 9 months and a very high rate of relapse after standard induction therapy for AML or ALL. The NPM1 mutation (NPM1m) is seen in approximately 30-35% of adult AML cases, most commonly in de novo AML, and is associated with a more favorable prognosis in newly diagnosed AML. However, this favorable prognostic effect is lost in the presence of concomitant FLT3-internal tandem duplication (ITD) mutations, which are seen in 40% to 50% of AML with mutated NPM1.These genomic alterations have been the focus for the development of DSP-5336, a novel small-molecule oral therapy that prevents binding of the menin protein to MLL fusion proteins that drive leukemogenesis.In nonclinical studies, DSP-5336 showed selective cell growth inhibitory activity against humanAL cell lines with MLLr or NPM1m. In addition, evidence of antitumor activity and survival advantage was demonstrated in 3 AML xenograft models with MLLr and/or NPM1m. Treatment with DSP-5336 may result in the reduction of leukemic cells, offering therapeutic benefits that include achieving complete remission and prolonged survival in patients with relapsed or refractory AML with MLLr or NPM1m or pts with relapsed or refractory ALL with MLLr.An open-label, single-arm, phase 1/2 study (NCT04988555) of DSP-5336 is being started to evaluate the safety and efficacy of DSP-5336 and determine the recommended phase 2 dose (RP2D) in adults aged ≥18 y with relapsed/refractory AML or ALL after at least one line of standard therapy, including hematopoietic stem cell transplant. Key inclusion criteria are ECOG performance status 0-2 and adequate cardiac, renal, and hepatic function. Patients on the strong CYP3A4 inhibitors ketoconazole, itraconazole, or isavuconazole, are excluded unless they can be safely taken off these medications or switched to another antifungal medication at least 7 days prior to start of study treatment.Patients will be dosed twice daily for 28 days per cycle. The study design is depicted below in Figure 1. In phase 1, 21-30 pts will be enrolled into multiple ascending dose cohorts (1-6 pts per dose level), with dose escalation determined using a two-parameter Bayesian logistic regression model. Determination of the RP2D will be informed by the maximum biologic effect or maximum tolerated dose, whichever is lower. The phase 2 study will include arm A (relapsed or refractory AML with MLLr) and arm B (relapsed or refractory AML with NPM1m) (Figure 1). Patients will be treated at the RP2D to evaluate clinical activity and safety, which will be monitored using Bayesian posterior probability to optimize enrollment with Bayesian stopping rules. Bayesian monitoring of responses will be started after the first 10 enrolled patients are evaluable for efficacy. Study endpoints are summarized in Table 1. [Display omitted] DisclosuresDaver: Genentech: Consultancy, Research Funding; Gilead Sciences, Inc.: Consultancy, Research Funding; Sevier: Consultancy, Research Funding; Hanmi: Research Funding; Trillium: Consultancy, Research Funding; Trovagene: Consultancy, Research Funding; Novartis: Consultancy; ImmunoGen: Consultancy, Research Funding; FATE Therapeutics: Research Funding; Glycomimetics: Research Funding; Abbvie: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Novimmune: Research Funding; Jazz Pharmaceuticals: Consultancy, Other: Data Monitoring Committee member; Dava Oncology (Arog): Consultancy; Celgene: Consultancy; Syndax: Consultancy; Shattuck Labs: Consultancy; Agios: Consultancy; Kite Pharmaceuticals: Consultancy; SOBI: Consultancy; STAR Therapeutics: Consultancy; Karyopharm: Research Funding; Newave: Research Funding. Affinito: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Cai: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Dobrowolska: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Dow: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Eguchi: Sumitomo Dainippon Pharma: Current Employment. Song: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Stoudemire: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Watanbe: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment. Komarnitsky: Sumitomo Dainippon Pharma Oncology, Inc: Current Employment.

Systematic review and meta-analysis of clinical efficacy of drug therapy for acute myelogenous leukemia.

A meta-analysis was performed to examine the clinical efficacy of drugs in the treatment of acute myelogenous leukemia (AML). combinations of terms of "acute myeloid leukemia", "fludara", "cytarabine", "cladribine", "aclacinomycin", "granulocyte colony-stimulating factor (G-CSF)", and "hyaluronic acid" were searched in Chinese databases. "acute myelogenous leukemia", "fludara", "cytarabine", "cladribine", "aclacinomycin", "granulocyte colony-stimulating factor", and "hyaluronic acid" were searched in English databases. Review Manager 5.3 was employed for the meta-analysis. Ultimately, 12 articles were included. Most of the articles had a low-risk bias, and were of medium or high quality. The complete remission rates were tested for heterogeneity [chi-square test (Chi2) =4.10, degrees of freedom (df)=10, I2=0%; P=0.94]. The fixed effect model analysis showed that the difference between experimental participants and controls was considerable [Z=13.15, odds ratio (OR) =12.82, 95% confidence interval (CI): (8.77, 18.76); P<0.01]. The overall effective rates were tested for heterogeneity (Chi2=1.58, df=7, I2=0%; P=0.98), and difference between experimental participants and controls was considerable [Z=10.70, OR =1.32, 95% CI: (7.32,17.89); P<0.01]. The overall adverse reaction rates were tested for heterogeneity (Chi2=0.42, df=5, I2=0%; P=0.99), and the difference between experimental participants and controls was considerable [Z=5.00, OR =0.38, 95% CI: (0.26, 0.55); P<0.01]. The circles of some studies in the funnel diagrams were symmetrical with the midline, the accuracy of included trials was high, the publications were not biased, and the final conclusions were reliable. This meta-analysis showed that drug treatments of AML can improve complete remission and total effective rates and reduce adverse reaction rates, and thus are worthy of clinical promotion.

Suppression of mTOR Signaling Attenuates Apoptotic Effects Induced By the NEDD8-Activating Enzyme Inhibitor Pevonedistat (MLN4924) in Acute Myeloid Leukemia Cells

Acute myelogenous leukemia (AML) is a heterogeneous disease and often relapses after standard chemotherapy. Therefore, novel therapies for AML are needed. Recently, the NEDD8 conjugation pathway and the mammalian target of rapamycin (mTOR) signaling pathway have emerged as important regulatory pathways for cancer therapy. Since some components of the mTORC1/2 pathways such as Deptor are neddylation targets, we postulated that combined exposure to NEDD8-activating enzyme (NAE) inhibitor pevonedistat and the dual mTORC1/2 inhibitor sapanisertib (TAK-228) might have additive or synergistic effects in AML.To test pevonedistat and sapanisertib effects on AML cells, we used the agents alone or in combination followed by assessment of proliferation, apoptosis and signal transduction in human AML cell lines as well as in primary cells. By AnnexinV/7AAD flow cytometry analysis, we found that pevonedistat significantly induced AML cell death and apoptosis in a time- and dose-dependent manner. Western blot showed that poly (ADP-ribose) polymerase (PARP) and caspases 3/8/9 were cleaved, indicating that pevonedistat-treated cells were actively undergoing apoptosis. Among the six AML cell lines (HL-60, KG1a, Molm-13, MV4-11, THP-1 and U937) tested, MV4-11 was the most sensitive cell line (IC50 <25nM) and KG1a was the least sensitive cell line (IC50 >1000nM) after 48 hours of exposure. The average IC50 on primary AML blast cells (5 primary samples) was 400nM at 48 hours. Western blot analysis showed that the neddylated cullin levels were markedly decreased confirming inhibition of the NEDD8 conjugation pathway by pevonedistat. We also found that pevonedistat induced morphologic changes and increased CD11b expression in Molm-13 and MV4-11 cells, indicating cell differentiation.The effects of pevonedistat on AML cells could be attenuated by pre- or co-treatment with the mTORC1/2 inhibitor sapanisertib. We found that sapanisertib alone induced limited cell death in most AML cell lines and primary AML patient blasts. The results from XTT assay and flow cytometry analysis indicated that sapanisertib alone significantly decreased cell size, arrested cells in G0-G1 phase and reduced protein content of AML cells but did not induce robust apoptosis. This suggested that through inactivating mTOR signal pathway, sapanisertib suppressed cell activity and induced a dormant/quiescent status and thereby attenuated the apoptotic effects of pevonedistat. With concurrent pevonedistat and sapanisertib exposure, the expression of apoptotic mediators such as cleaved PARP and caspases 3 were decreased compare to pevonedistat treatment alone (See Figure).To confirm the role of mTOR inhibition on pevonedistat-induced AML apoptosis, we targeted mTORC1/2 by knocking down mTOR expression with small hairpin RNAs (shRNA). Downregulation of mTOR expression mirrored the effects of sapanisertib. mTOR inhibition by shRNAs resulted in decreased AML cell size and arrest of cells in G0-G1 phase. In addition, pevonedistat-induced cell death was significantly impeded in the cells infected with mTOR shRNA lentivirus compared to scrambled shRNA (p<0.01). Therefore, we validated that mTOR signal inactivation protects AML cells from NAE inhibitor pevonedistat-induced apoptosis using both pharmaceutical and genetic approaches. To further study the mechanism behind mTOR inhibition inducing resistance to pevonedistat, we tested rapamycin, an mTORC1 inhibitor. Concurrent exposure to rapamycin did not significantly alter the effects of pevonedistat and did not change cell size and cell cycle status. In addition, rapamycin did not inhibit the phosphorylation of 4E-BP1, suggesting that mTORC1 inhibition alone may be insufficient to inhibit the effects of pevonedistat, and suggesting a role for mTORC2.Taken together, our data demonstrate that the NEDDylation pathway inhibitor pevonedistat has strong potential as a therapeutic agent for AML therapy via apoptosis induction. However, when AML cells are arrested in G0-G1 with reduced proliferation rates by dual mTORC1/2-inhibition, the ability of pevonedistat to induce apoptosis is suppressed. Whether this is due solely to the cytostatic effects of dual mTOR inhibitors or also involves other mechanisms remains uncertain. While both sapanisertib and pevonedistat have clear anti-leukemia effects, their concurrent use may inhibit NAE inhibitor-induced apoptosis. [Display omitted] DisclosuresLiesveld:Onconova: Honoraria; Seattle Genetics: Honoraria.

Clinical Outcomes in Patients with FLT3-ITD-Mutated Relapsed/Refractory Acute Myelogenous Leukemia Undergoing Hematopoietic Stem Cell Transplantation after Quizartinib or Salvage Chemotherapy in the QuANTUM-R Trial

Despite the substantial clinical activity of fms-related tyrosine kinase 3 (FLT3) inhibitors in relapsed or refractory (R/R) FLT3-ITD‒positive acute myelogenous leukemia (AML), durable remissions and prolonged survival in this population require allogeneic hematopoietic stem cell transplantation (allo-HSCT). Quizartinib, a once-daily oral, highly potent, and selective FLT3 inhibitor, significantly prolonged overall survival (OS) and improved clinical benefit compared with salvage chemotherapy (median OS, 6.2 months versus 4.7 months; hazard ratio [HR], .76; 95% confidence interval [CI], .58 to .98; P=.018; composite complete remission [CRc] rate, 48% versus 27%; median duration of CRc, 2.8 months versus 1.2 months; mortality rate, .8% versus 14% by day 30, 7% versus 24% by day 60) in patients with R/R FLT3-ITD AML in the phase 3 QuANTUM-R trial. In this post hoc analysis, we described the characteristics of and clinical outcomes in patients who underwent on-study HSCT in QuANTUM-R at the investigator's discretion and institutional practices. Of 367 randomized patients, 78 (32%) in the quizartinib arm and 14 (11%) in the salvage chemotherapy arm underwent on-study allo-HSCT without any intervening therapy for AML after quizartinib or study-specified salvage chemotherapy. Pooled data of patients from both treatment arms showed a longer median overall survival (OS) in transplant recipients versus those treated without allo-HSCT (12.2 months versus 4.4 months; HR, .315; 95% CI, .233 to .427). Pooled data also showed a longer median OS in patients with a last recorded response of CRc before allo-HSCT versus patients without a CRc (20.1 months versus 8.8 months; HR, .506; 95% CI, .296 to .864). By treatment arm, the median OS was 25.1 months with quizartinib and 20.1 months with salvage chemotherapy in patients with a last recorded response of CRc before allo-HSCT. Forty-eight patients in the quizartinib arm continued quizartinib treatment after allo-HSCT. In the 31 patients with a last recorded response of CRc before allo-HSCT who continued quizartinib after allo-HSCT, the median OS was 27.1 months. Continuation of quizartinib after allo-HSCT was tolerable, and no new safety signals were identified. These results suggest that post-transplantation survival following salvage chemotherapy and quizartinib treatment are similar. However, quizartinib response occurs more frequently than with salvage chemotherapy, potentially allowing more patients to undergo transplantation and achieve durable clinical benefit. In addition, post-transplant quizartinib was found to be tolerable and may be associated with prolonged survival in some patients, highlighting its potential value in the management of patients with FLT3-ITD R/R AML.

Outcome of Allogeneic Hematopoietic Cell Transplantation after Venetoclax and Hypomethylating Agent Therapy for Acute Myelogenous Leukemia

The combination of hypomethylating agents with the selective Bcl-2 inhibitor venetoclax (HMA-VEN) has emerged as a highly active regimen in patients with acute myelogenous leukemia (AML) in both the upfront and relapsed/refractory (r/r) settings. We report our early experience with a cohort of patients who were able to proceed to allogeneic hematopoietic cell transplantation (alloHCT) after HMA-VEN therapy. Thirty-two patients with AML (19 r/r and 13 de novo) with a median age of 62 years underwent alloHCT after HMA-VEN therapy. Twenty-two (68.8%) were in complete remission (CR)/CR with incomplete count recovery at time of HCT. With a median follow up of 14.4 months, the 1-year overall survival (OS) was 62.5%, and disease-free survival was 43.8%. The 1-year nonrelapse mortality rate was 18.8%, and the cumulative incidence of relapse was 37.5%. Among patients who underwent alloHCT in CR, the 1-year OS was 77.3%, and the cumulative incidence of nonrelapse mortality was 9.1%. The cumulative incidence of grade II-IV acute graft-versus-host disease was 43.8%. We conclude that alloHCT after HMA-VEN is therapy associated with favorable allogeneic HCT outcomes in newly diagnosed older patients with AML, as well as those with r/r AML.

Randomized Trial of Intermediate-dose Cytarabine in Induction and Consolidation Therapy in Adults with Acute Myeloid Leukemia.

Cytarabine, 100-200 mg/mE+2/day, is commonly used in induction therapy of acute myelogenous leukemia (AML). Whether a higher dose of cytarabine would be more effective is unknown. Also, there is controversy whether high-dose cytarabine is better than an intermediate-dose combined with other drugs for post-remission therapy. In this open-label, randomized controlled, parallel group study, roles of intermediate-dose cytarabine were investigated. Subjects with AML age 15-55 years were randomized to receive daunorubicin, omacetaxine mepesuccinate, and conventional- or intermediate-dose cytarabine. Subjects achieving complete remission were randomized to receive 3 courses of high-dose cytarabine or 2 courses of intermediate-dose cytarabine with daunorubicin in the 1st and mitoxantrone in the 2nd course. The primary endpoint was disease-free survival (DFS). 591 subjects were randomized to intermediate- (N = 295) or conventional-dose (N = 296) cytarabine group. Three-year DFSs were 67% [95% confidence interval (CI), 61-73] in the intermediate-dose cohort compared with 54% (95% CI, 48-61) in the conventional-dose cohort [Hazard Ratio (HR), 0.67; 95%CI, 0.51-0.89; P = 0.005). Three-year survivals were 68% (95%CI, 63-74) and 59% (95%CI, 53-65; HR, 0.720; 95%CI, 0.56-0.94; P = 0.014). Two courses of intermediate-dose cytarabine with daunorubicin or mitoxantrone resulted in similar DFS and survival as three courses of high-dose cytarabine when used for post-remission therapy. Induction therapy with intermediate-dose cytarabine with daunorubicin and omacetaxine mepesuccinate increases DFS and survival in persons with AML ages 15-55 years compared with conventional-dose cytarabine.See related commentary by Watts and Bradley, p. 3073.

Heme Oxygenase 1-Targeted Hybrid Nanoparticle for Chemo- and Immuno-Combination Therapy in Acute Myelogenous Leukemia.

Acute myelogenous leukemia (AML) is a fatal blood cancer with high patient mortality. Daunorubicin and cytarabine are first‐line chemotherapy for AML, with bone marrow transplantation in most cases. Recently, cancer immunotherapy has been challenged in AML and leukemia‐niche myeloid cells are promising targets for the AML immunotherapy. Heme oxygenase 1 (HO1) is an antioxidative and cytoprotective enzyme inducing chemo‐resistant AML and has been focused as an immune checkpoint molecule in tumor microenvironments. Herein, lipid‐polymer hybrid nanoparticle (hNP) is loaded with tin mesoporphyrin (SnMP), a HO1‐inhibitor, and non‐covalently modified with an engineered antibody for leukemic cell‐targeted delivery. HO1‐inhibiting T‐hNP (T‐hNP/SnMP) enhances chemo‐sensitivity in human leukemia cells. In a human AML‐bearing orthotopic mouse model, intravenously injected T‐hNP not only actively targets to human leukemia cells but passively targets to CD11b+ myeloid cells in a bone marrow niche. The T‐hNP/SnMP enhances the chemo‐therapeutic effect of daunorubicin and boosts immune response by reprogramming bone marrow myeloid cells resulting from the recruitment of the monocyte‐lineage and induction of inflammatory genes. The ex vivo study demonstrates an enhanced immune response of HO1‐inhibited bone marrow CD11b+ myeloid cells against apoptotic leukemia cells. Collectively, HO1‐inhibiting dual cell‐targeted T‐hNP/SnMP has a strong potential as a novel therapeutic in AML.

New advances in targeted therapy and immunotherapy of acute myelogenous leukemia

Acute myelogenous leukemia (AML) is a highly heterogeneous malignant hematologic disease, and it is mainly treated with traditional chemotherapy, but the efficacy is limited and the patients with worse performance status and comorbidities can not be treated with chemotherapy. Gene changes play an important role in the diagnosis and prognosis of AML, and these gene changes also provide targets for molecular targeted therapy. Meanwhlie, immunotherapy has achieved certain curative effects in AML and has a promising prospect. In this review, targeted therapy and immunotherapy of AML reported in 61st American Society of Hematology (ASH) Annual Meeting are summarized. Key words: Leukemia, myelogenous, acute; Immunotherapy; Gene change; Molecular targeted therapy

Hypomethylating Agent Maintenance Therapy after Allogeneic Stem Cell Transplant Improves Transplant Outcome in High Risk Acute Myelogenous Leukemia

Background: Allogeneic hematopoietic stem cell transplant (HSCT) is the only potential curative modality for high risk acute myelogenous leukemia (AML). However, relapse disease remains to be the main reason of failure of allogeneic HSCT. Salvage therapy for relapse AML after allogeneic HSCT is limited and rarely successful. Prognosis is poor with a 2-year survival rate of less than 20%. As majority of relapses occur within first 6 months after transplant, effective preventive intervention given early post allogeneic HSCT may be crucial. An ideal drug for pharmacologic maintenance is difficult to achieve as it should have activity against the disease without excessive myelosuppression or eradication of donor cells, and has minimal or low risk of exacerbation of graft-versus-host disease or additional toxicity. Azacitidine and decitabine are hypomethylating agents (HMAs), which work epigenetically to modulate various genes, including tumor suppressor genes. They have been shown to have benefits in improvement of event free survival and overall survival in relapse AML. Similar benefits have also been reported when low dose azacitadine was given after allogeneic stem cell transplant as a maintenance therapy. Method: This is a single institutional study carried out at the Bone Marrow Transplant Program at the University of Oklahoma Health Science Center. It was started as a case control study in June 2014 when post-transplant azacitadine protocol was initiated, and continues on as a prospective study. Subjects over 18 years old with high risk AML based on cytogenetic and molecular mutation undergoing allogeneic HSCT were enrolled from September 2013 to July 2018. The study is to compare outcome in patients received post-transplant low dose azacitidine at 32mg/m2 on days 1-5 every 28 days for 4 cycles initiating between 6-8 weeks post-transplant versus post-transplant observation. Multivariable cox proportional hazards model was derived to adjust for covariates that differ between the two treatment arms and was used to analyze time to relapse and overall survival in both arms; then our results were graphed using Kaplan Meier Plot. Results: This study included 49 patients undergoing allogeneic HSCT for high risk AML. They were divided into 2 groups with 31 patients received post-transplant azacitidine, and 18 patients did not (prior to initiation of post-transplant azacitadine protocol, control). Our Analysis concluded a greater proportion of deaths among the control group (88.89%) compared to the azacitidine group (25.81%). Majority of deaths in the control group was due to relapse (12 of 16 deaths). Relapse rate was higher in the control group (66.67%) as compared to azacitidine group (25.81%) with statistically significant improvement in time to relapse in the azacitidine group (not reach (NR)) versus 4.1 months in the control arm (log-rank p-value &lt;0.0001) which was described in Figure (1). Median Overall survival was 7.6 months in control arm versus 27.4 months in the 8 patients who relapsed in azacitidine arm (log-rank p-value&lt;0.0001). (Figure 2) Among the 29 subjects from both arms who were relapse-free, overall survival differed between the two treatment groups (log-rank p-value 0.003). Median survival time among those in the control group was 9.8 months. For the azacitidine arm, only 2 events occurred among the 23 relapse-free subjects while the remaining 21 subjects were censored (Figure 3). Among other transplant-related factors, disease status was not differed among the two groups (p=0.411), but conditioning regimen was (p=0.019) with a greater proportion of reduced intensity conditioning (RIC) in the control group (55.56%) than azacitadine group (22.58) (Table 1). After adjusting for conditioning regimen, hazard of relapse was 5.26 (1.99,13.93) times greater (p value&lt;0.001) and death was 5.41 (1.99,13.93) times greater (p value&lt;0.001) in the control group than azacitadine group. In our analysis, cause of death was not statistically significantly different among the two arms (p-value 0.325). Use of azacitidine post-HSCT did not increase the risk of GVHD or infections (table 2). Implications: Low dose azacitidine maintenance therapy after allogeneic stem cell transplant in high risk acute myelogenous leukemia decreases relapse rate, time to relapse and improved overall survival without increasing adverse events and no increased risk of graft-versus-host disease or infections. Disclosures No relevant conflicts of interest to declare.

Acceleration of AML Progression By Cigarette Smoke Exposure or Condensate Exposure and Associated DNA Methylation Alterations

Subsets of acute myelogenous leukemia (AML) are characterized by molecular alterations with prognostic significance, however, little is known about how modifiable behaviors, such as cigarette smoking, intersect with genetic factors. Mutations rendering the Fms-like tyrosine kinase 3 (FLT3) constitutively active, such as internal tandem duplication (ITD), are associated with refractory disease and therapy resistance. Inhibition of the FLT3 kinase shows some benefit in this population, as highlighted by the FDA approvals of midostaurin and gilteritinib, but overall outcomes remain poor. Cigarette smoke exposure (CSE) also marks a population of patients with poor prognosis. Current and former smokers who develop AML are known to have worse survival as compared to never smokers (Alfayez M., et al. ASCO 2019), but the impact of FLT3 mutation and subsequent associated treatment response has not been studied. Also, the underlying mechanism of how history of cigarette smoking influences leukemia biology and response to therapy is poorly understood. In order to model a history of smoking in AML patients, NOD-SCID mice (n=25) were exposed to CSE using a smoking robot for 2 hours, 5 days/week, for 2 weeks. Mice were then inoculated via tail-vein injection with luciferase tagged human FLT3-ITD cells and leukemia burden was monitored through noninvasive imaging. CSE continued through the duration of the experiment, post engraftment. Control "non-smoking" mice (n=15) were only injected with leukemia cells. Within one week post leukemic introduction, a significant increase in leukemic burden as measured by bioluminescence was apparent in mice exposed to CSE versus control mice (P-value&lt;0.0001). To model the impact of smoking cessation upon diagnosis of AML in patients, experiments were modified to halt CSE once leukemic engraftment was detectable by non-invasive imaging. Smoking cessation versus continuous smoke exposure yielded reduced relative leukemic burden. Mice with continuous smoke exposure had higher rates of leukemia compared to mice who ceased smoking (n=10) one week prior (P-value =0.0064). These rapid changes in leukemic burden suggest that CSE may prime the microenvironment to promote leukemia progression or directly affect leukemia cells. To address the latter possibility, human AML cells were exposed to cigarette smoke condensate (CSC), which contains the chemicals present in cigarettes, for two weeks before introducing the cells into mice. A significant increase in leukemic burden was observed in mice injected cells exposed to CSC compared to mice injected with unexposed leukemia cells (P-value &lt;0.001), highlighting a direct role for the chemicals in cigarettes on in vivo leukemia proliferative factors. Smokers are known to carry altered global DNA methylation signatures that persist decades after quitting. To measure DNA methylation changes in the in vivo models described above, we examined spleens of non-smoking and smoke exposed mice by reduced representative bisulfite sequencing (RRBS). Sequences were mapped to either the human or mouse genome, (enabling identification of leukemia specific versus microenvironment specific alterations) and were compared in the smoking and non-smoking mice. Over 200 genes exhibited significant DNA methylation alterations in their promoter regions. Genes involved in RNA polymerase activity and chromatin remodeling were highly represented amongst those with altered DNA methylation. The clinical significance of our observations was confirmed in a cohort of 58 treatment naïve FLT3-ITD AML patients at MD Anderson receiving intensive induction therapy: 41 never smokers and 17 ever smokers. Smokers had significantly reduced survival as compared to the never smokers (median overall survival of 18 vs 23 months, P-value 0.0092). Collectively our findings indicate that short-term CSE is sufficient to alter DNA methylation patterns and accelerate the early progression of FLT3-ITD AML in vivo. Smoking cessation upon diagnosis may slow leukemic growth relative to smoking throughout AML therapy prompting the consideration of behavioral interventions for smokers with AML. Improved understanding of the mechanism of leukemic progression and drug resistance from CSE is expected to lead to improved treatment paradigms designed for patients with a history of cigarette smoking. Disclosures Konopleva: Genentech: Honoraria, Research Funding; Kisoji: Consultancy, Honoraria; F. Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Ascentage: Research Funding; Reata Pharmaceuticals: Equity Ownership, Patents &amp; Royalties; Ablynx: Research Funding; Cellectis: Research Funding; Amgen: Consultancy, Honoraria; Calithera: Research Funding; Stemline Therapeutics: Consultancy, Honoraria, Research Funding; Forty-Seven: Consultancy, Honoraria; Eli Lilly: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Astra Zeneca: Research Funding; Agios: Research Funding. Jabbour:Cyclacel LTD: Research Funding; Pfizer: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; BMS: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding. DiNardo:agios: Consultancy, Honoraria; abbvie: Consultancy, Honoraria; jazz: Honoraria; medimmune: Honoraria; notable labs: Membership on an entity's Board of Directors or advisory committees; daiichi sankyo: Honoraria; syros: Honoraria; celgene: Consultancy, Honoraria.

Isolated Bilateral Ear and Scalp Rash After Cytarabine Therapy for Acute Myelogenous Leukemia: A Report and Literature Review

Isolated Bilateral Ear and Scalp Rash After Cytarabine Therapy for Acute Myelogenous Leukemia: A Report and Literature Review

Effects of Neddylation and mTOR Inhibition in Acute Myelogenous Leukemia

Acute myelogenous leukemia (AML) is a heterogeneous disease and often relapses after standard chemotherapy. Recently, the neddylation (NEDD8) and the mammalian target of rapamycin (mTOR) signaling pathways have emerged as promising pharmaceutical targets for AML therapy. However, the interaction of these two pathways remains unclear. Here we evaluated the effects of pevonedistat, an inhibitor of the NEDD8 activating enzyme (NAE), and sapanisertib (TAK-228), an inhibitor of mTORC1 and mTORC2 as single agents or in combination on AML cell lines. We found that inhibition of neddylation with pevonedistat partially inhibited mTOR signaling transduction and vice versa, inhibition of mTOR signaling with sapanisertib partially inhibited neddylation in AML cell lines. Pevonedistat alone was able to induce cytotoxicity in most AML cell lines as well as in primary AML, whereas sapanisertib alone decreased cell metabolic activity, reduced cell size and arrested cells in G0 phase with only minimal induction of cell death. In addition, pevonedistat was able to induce cell differentiation, arrest cells in G2/M cell cycle phases, and induce DNA re-replication and damage. However, co-treatment with sapanisertib suppressed pevonedistat induced apoptosis, differentiation, S/G2/M arrest, and DNA damage. Taken together, our data demonstrate that pevonedistat and sapanisertib exhibit distinct anti-tumor effects on AML cells, i.e. cytotoxic and cytostatic effects, respectively; however, sapanisertib can attenuate pevonedistat-induced cellular responses in AML cells. Understanding mTOR and neddylation pathway interaction could provide therapeutic strategies for treatment of AML and other malignancies.

The expression of PTEN and INPP4B and their clinical significance in patients with acute myeloid leukemia

This study investigates the expression of phosphatase and tensin homolog (PTEN) and Inositol polyphosphate 4-phosphatase type II (INPP4B) in children with acute myeloid leukemia. The levels of PTEN and INPP4B in bone marrow, from 95 acute myelogenous leukemia (AML) patients and 84 controls, respectively, were assessed by immunohistochemistry, quantitative polymerase chain reaction (qPCR), and Western blot. The prognosis was followed up and investigated and the correlation analysis was made. We found that the expression levels of PTEN and INPP4B were significantly lower in the AML group than those in the control group ( P &lt; 0.05). The survival time was lower in PTEN and INPP4B negative children relative to PTEN and INPP4B positive children ( P &lt; 0.05). In AML patients, INPP4B and PTEN expression was positively correlated (r = 0.552, P = 0.000). In conclusion, the levels of INPP4B and PTEN were reduced significantly and correlated positively in AML patients accompanying with abnormal karyotypes. The current investigation of INPP4B and PTEN could give new insight into targeted therapy for AML.