Agents In Acute Myeloid Leukemia Research Articles

Abstract 3904: Multiplexed flow cytometry based immunophenotyping paired with functional ex vivo (MFLEX) drug profiling informs potential efficacy of therapeutic agents in acute myeloid leukemia

Abstract Introduction: Acute Myeloid Leukemia (AML) is a heterogenous hematological malignancy with a complex clonal architecture that requires in-depth immunophenotyping for disease characterization. Conventional AML ex vivo models for preclinical drug screening lack functional readouts that provide single cell level data to identify drug activity in defined AML subsets with unique immune signatures. Here, we present a novel platform that links Multiparameter Flow cytometry with high-throughput EX vivo drug screening (MFLEX) in AML patient-derived cell models to simultaneously detect phenotypic changes and predict cell-subset specific drug responses in AML. Method: We developed a 21-color high-dimensional immune profiling panel that captures AML heterogeneity by delineating primitive and mature AML blasts along with normal hematopoietic lineages. The panel also includes markers for functional measurement of apoptosis, proliferation, differentiation, and expression of BCL2 family proteins in lymphoid and myeloid cell subsets. Ex vivo culture conditions were optimized using physiologically relevant stroma-free cytokine-rich media that supports primary AML cells with minimal phenotypic shift, allowing for high throughput functional drug sensitivity testing. Timepoints and dosing conditions for AML standard of care (SoC) agents were optimized to support combination screens. Multi-parameter datasets were analysed for functional differences and visualized using dimension reduction methods. Results: We tested MFLEX on clinically annotated AML samples to understand sensitivity profiles to venetoclax and combination partners: 5-azacytidine, cytarabine, fludarabine and gilteritinib. We identified distinct drug sensitivity profiles for venetoclax in AML patients with varying leukemic differentiation states where M0/M1 subtypes were more sensitive to therapy than M4/M5. We also observed cell lineage specific sensitivities, with myeloid blast being more sensitive to venetoclax compared to autologous CD4+ and CD8+ T-cells and this observed difference was correlated with higher expression of BCL2. Our platform demonstrated that patients who previously failed venetoclax therapy could benefit from a combination with 5-azacytidine or fludarabine and this was patient-specific. We further evaluated MFLEX’s predictive value for patient clinical response by systematically comparing venetoclax sensitivity in patient-derived xenograft models in vivo vs ex vivo and found a high correlation between drug responses. Conclusion: We have established a unique, immune drug screening platform, MFLEX, that has high translational value and can be implemented in clinical trials to identify drug response patterns, novel combinations, and potential biomarkers of response for patient stratification in AML. Citation Format: Reecha Shah, Heba Wander, Michelle Hsueh, Muskan Floren, Wei Liu, Patricia Cheung, Courtney Andersen, Michael White, Nathan Kingston, Pablo Morentin Gutierrez, Lisa Drew, Giulia Fabbri, Elena Bibikova, Daniel Auclair. Multiplexed flow cytometry based immunophenotyping paired with functional ex vivo (MFLEX) drug profiling informs potential efficacy of therapeutic agents in acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3904.

Abstract 264: Differentiation therapy: Esculetin as a potent agent to alter cellular plasticity of leukemic & solid tumor stem cells

Abstract Background The “Differentiation therapy” has been emerging as a promising and more effective strategy against acute leukemia relapses. Objective In extension to the revolutionising therapeutic outcomes of All Trans Retinoic Acid (ATRA) to induce terminal differentiation of Acute Promyelocytic Leukemic (APL) blast cells, we decipher the potential effect of a natural compound “Esculetin” to serve as a differentiating agent in Acute Myeloid Leukemia (AML) as well as solid tumour cells. Underlaying role of Wnt signaling pathways in esculetin mediated blast cell differentiation was also evaluated. Methods Human acute myeloid leukemic cells (Kasumi-1) with t(8;21/AML-ETO) translocation were used as a model system. Growth inhibitory and cytotoxic activity of esculetin were analysed using growth kinetics and MTT assay. Morphological alterations, cell scatter characteristics, NBT reduction assay and cell surface marker expression pat- terns were analysed to detect terminally differentiated phenotypes. We employed RT2profiler PCR array system for the analysis of transcriptome profile of Wnt signaling components. Calcium inhibitors (TMB8 and Amlodipine) and Transforming growth factor beta (TGF-β) were used to modulate the Wnt signaling axes. To investigate whether esculetin exerts the similar effects on the invasive solid tumour cancer stem cells subset, we used a cellular model system of colon carcinoma HCT116 cells reflecting EMT phenotype. Results We illustrate cytotoxic as well as blast cell differentiation potential of esculetin on Kasumi-1 cells. Morphological alterations akin to neutrophilic differentiation as well as the corresponding acquisition of myeloid lineage markers indicate terminal differentiation potential of esculetin in leukemic blast cells. Exposure to esculetin also resulted in downregulation of canonical Wnt axis while upto ~ 21 fold upregulation of non-canonical axis associated genes. Esculetin also showed potential to revert the CSC marker expressions and concurrent EMT consistent with reduced functional aggressiveness in colon cancer cells. Conclusions Our study highlights the importance of selective use of calcium pools as well as “axis shift” of the canonical to non-canonical Wnt signaling upon esculetin treatment which might abrogate the inherent proliferation to release maturation arrest and induce the differentiation in leukemic blast cells as well as CSC stem cells. The current findings provide further therapeutic interventions to consider esculetin as a potent differentiating agent to counteract relapses. Citation Format: Ankit Mathur, Daman Saluja. Differentiation therapy: Esculetin as a potent agent to alter cellular plasticity of leukemic & solid tumor stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 264.

High Dose Cytosine Arabinoside- Induced Asymptomatic Bradycardia

Cytosine Arabinoside (Cytarabine) is commonly used agents in acute myeloid leukemia (AML). Cardiovascular side effects are not common during treatment. We aimed to present asymptomatic bradycardia developed during the first consolidation treatment in a patient with acute myeloid leukemia. A 34-year-old male patient was diagnosed with AML in February. After induction chemotherapy, high dose cytarabine treatment was started at 2x1.5 grams/m² for consolidation treatment. On the 11th day of the treatment, his pulse decreased to 39 beats/min. On the 12th day after the initiation of high dose cytosine arabinoside treatment (6 days after chemotherapy treatment ends), the patient's pulse rate was above 50/min, and there was no bradycardia in the following days. Other causes of other causes of bradycardia were excluded. It was reported that the patient had sinus bradycardia with an ejection fraction of 65% and his heart rate was rhythmic. There are seven patients with acute myeloid leukemia, one patient with acute lymphoblastic leukemia, one patient with non-Hodgkin's lymphoma, and one patient with Hodgkin's lymphoma who reported high dose cytosine arabinoside associated bradycardia. In addition, one patient with acute myeloid leukemia developed bradycardia with low dose cytosine arabinoside. Our case is the 11th case in the literature that develops bradycardia due to cytarabine.

In-silico Design and Development of Multi-Target Agents Targeting Glycogen Synthase Kinase-3 Beta and Vascular Endothelial Growth Factor Receptor 2 for Acute Myeloid Leukemia

This research focuses on the in-silico design of multi-target agents for acute myeloid leukemia (AML), targeting GSK-3β and VEGFR2. Using TTD data, we selected a promising target pair and considered 20,818 agents. Ligand-based screening in ChEMBL identified compounds with diverse structures and favorable interactions. Protein structures (GSK-3β: PDB ID 1Q5K, VEGFR2: PDB ID 3QTK) underwent rigorous quality assessment, indicating high-quality models. Molecular docking revealed varied affinities, with CHEMBL183504 showing strong affinity for GSK-3β in pocket C1, and CHEMBL185922 for VEGFR2 in pocket 2. CHEMBL181959 exhibited dual affinity. Further experimental validation is needed. In conclusion, this study provides insights for AML therapy, guiding compound selection and structural quality assessment for potential drug development

The pharmacodynamic and mechanistic foundation for the antineoplastic effects of GFH009, a potent and highly selective CDK9 inhibitor for the treatment of hematologic malignancies.

To evade cell cycle controls, malignant cells rely upon rapid expression of select proteins to mitigate proapoptotic signals resulting from damage caused by both cancer treatments and unchecked over-proliferation. Cyclin-dependent kinase 9 (CDK9)-dependent signaling induces transcription of downstream oncogenes promoting tumor growth, especially in hyperproliferative 'oncogene-addicted' cancers, such as human hematological malignancies (HHMs). GFH009, a potent, highly selective CDK9 small molecule inhibitor, demonstrated antiproliferative activity in assorted HHM-derived cell lines, inducing apoptosis at IC50 values below 0.2 μM in 7/10 lines tested. GFH009 inhibited tumor growth at all doses compared to controls and induced apoptosis in a dose-dependent manner. Twice-weekly injections of GFH009 maleate at 10 mg/kg significantly prolonged the survival of MV-4-11 xenograft-bearing rodents, while their body weight remained stable. There was marked reduction of MCL-1 and c-MYC protein expression post-drug exposure both in vitro and in vivo. Through rapid 'on-off' CDK9 inhibition, GFH009 exerts a proapoptotic effect on HHM preclinical models triggered by dynamic deprivation of crucial cell survival signals. Our results mechanistically establish CDK9 as a targetable vulnerability in assorted HHMs and, along with the previously shown superior class kinome selectivity of GFH009 vs other CDK9 inhibitors, strongly support the rationale for currently ongoing clinical studies with this agent in acute myeloid leukemia and other HHMs.

P12-1 Hypomethylating agent for acute myeloid leukemia, the efficacy and its effect towards mortality rate: Systematic review

P12-1 Hypomethylating agent for acute myeloid leukemia, the efficacy and its effect towards mortality rate: Systematic review

Development of nanoparticles for the Novel anticancer therapeutic agents for Acute Myeloid Leukemia

Acute myeloid leukaemia is becoming more predominant in blood cancer in geriatrics people groups. In 2017, four new therapeutic candidates have been approved by the FDA: Enasidenib, CPX 351, Midostaurin, and Gemtuzumab ozogamicin; with the approval of Venetoclax and Daurismo, additional advances were achieved in 2018. Ivosidenib and gilteritinib were also accepted as single-agent therapy in persistent and recurrent AML 2018. Most of the anticancer drugs belong to Biopharmaceutical classification system-II (BSC), and BCS class-IV has poor bioavailability because of solubility issues. We will overcome this problem by preparing nanoparticles of this drug by using different nanoparticle preparation methods.

Esculetin releases maturation arrest and induces terminal differentiation in leukemic blast cells by altering the Wnt signaling axes

BackgroundThe “Differentiation therapy” has been emerging as a promising and more effective strategy against acute leukemia relapses.ObjectiveIn extension to the revolutionising therapeutic outcomes of All Trans Retinoic Acid (ATRA) to induce terminal differentiation of Acute Promyelocytic Leukemic (APL) blast cells, we decipher the potential effect of a natural compound “Esculetin” to serve as a differentiating agent in Acute Myeloid Leukemia (AML). Underlaying role of Wnt signaling pathways in esculetin mediated blast cell differentiation was also evaluated.MethodsHuman acute myeloid leukemic cells (Kasumi-1) with t(8;21/AML-ETO) translocation were used as a model system. Growth inhibitory and cytotoxic activity of esculetin were analysed using growth kinetics and MTT assay. Morphological alterations, cell scatter characteristics, NBT reduction assay and cell surface marker expression patterns were analysed to detect terminally differentiated phenotypes. We employed RT2profiler PCR array system for the analysis of transcriptome profile of Wnt signaling components. Calcium inhibitors (TMB8 and Amlodipine) and Transforming growth factor beta (TGF-β) were used to modulate the Wnt signaling axes.ResultsWe illustrate cytotoxic as well as blast cell differentiation potential of esculetin on Kasumi-1 cells. Morphological alterations akin to neutrophilic differentiation as well as the corresponding acquisition of myeloid lineage markers indicate terminal differentiation potential of esculetin in leukemic blast cells. Exposure to esculetin also resulted in downregulation of canonical Wnt axis while upto ~ 21 fold upregulation of non-canonical axis associated genes.ConclusionsOur study highlights the importance of selective use of calcium pools as well as “axis shift” of the canonical to non-canonical Wnt signaling upon esculetin treatment which might abrogate the inherent proliferation to release maturation arrest and induce the differentiation in leukemic blast cells. The current findings provide further therapeutic interventions to consider esculetin as a potent differentiating agent to counteract AML relapses.

Arsenic Trioxide: Pharmacological Applications

Background: Arsenic trioxide is a chemical compound that has been used as a treatment for various diseases. Despite being potentially toxic, this compound has been used as a therapy to treat Acute Myeloid Leukemia and is being investigated as a possible treatment for different types of cancer. Objectives: The present review aims to describe the use and studies reported in the literature of Arsenic Trioxide as a possible therapeutic agent for Acute Myeloid Leukemia, Acute Promyelocytic Leukemia, Chronic Myeloid Leukemia, Multiple Myeloma, Myelodysplastic Syndrome, Hepatocellular Carcinoma, Lung Cancer, Neuroblastoma, Breast Cancer, Aplastic Hepatitis C, and HIV-1. Methods: A systematic review was conducted using databases (Elsevier, Google Scholar, PubMed) to compile documents published before December 2023. Results: Multiple pharmacological applications of arsenic trioxide have been reported to treat acute and chronic myeloid leukemia. Arsenic trioxide has been shown to inhibit angiogenesis, which helps treat multiple myeloma. Several studies have shown and suggested the effectiveness of arsenic trioxide as a treatment of hepatocellular carcinoma, lung cancer, neuroblastoma, prostate cancer, breast cancer, aplastic anemia, hepatitis C, and HIV-1.Conclusion: Despite potentially toxic effects, Arsenic compounds are therapeutic agents for multiple diseases, from syphilis to cancer. In recent years, more efficient ways have been investigated to deliver and find the specific dose to treat the disease, causing the fewest possible adverse effects.

DNA methylation landscape reveals LIN7A as a decitabine-responsive marker in patients with t(8;21) acute myeloid leukemia

BackgroundDespite its inconsistent response rate, decitabine, a demethylating agent, is often used as a non-intensive alternative therapeutic agent for acute myeloid leukemia (AML). It has been reported that relapsed/refractory AML patients with t(8;21) translocation achieved better clinical outcomes with a decitabine-based combination regimen than other AML subtypes; however, the mechanisms underlying this phenomenon remain unknown. Herein, the DNA methylation landscape of de novo patients with the t(8;21) translocation was compared with that of patients without the translocation. Moreover, the methylation changes induced by decitabine-based combination regimens in de novo/complete remission paired samples were investigated to elucidate the mechanisms underlying the better responses observed in t(8;21) AML patients treated with decitabine.MethodsThirty-three bone marrow samples from 28 non-M3 AML patients were subjected to DNA methylation sequencing to identify the differentially methylated regions and genes of interest. TCGA-AML Genome Atlas-AML transcriptome dataset was used to identify decitabine-sensitive genes that were downregulated following exposure to a decitabine-based regimen. In addition, the effect of decitabine-sensitive gene on cell apoptosis was examined in vitro using Kasumi-1 and SKNO-1 cells.ResultsA total of 1377 differentially methylated regions that specifically responsive to decitabine in t(8;21) AML were identified, of which 210 showed hypomethylation patterns following decitabine treatment aligned with the promoter regions of 72 genes. And the methylation-silencing genes, LIN7A, CEBPA, BASP1, and EMB were identified as critical decitabine-sensitive genes in t(8;21) AML. Moreover, AML patients with hypermethylated LIN7A and reduced LIN7A expression had poor clinical outcomes. Meanwhile, the downregulation of LIN7A inhibited decitabine/cytarabine combination treatment-induced apoptosis in t(8;21) AML cells in vitro.ConclusionThe findings of this study suggest that LIN7A is a decitabine-sensitive gene in t(8;21) AML patients that may serve as a prognostic biomarker for decitabine-based therapy.

Therapeutic Effect of Bortezomib Combined with Dag Regimen in Hyperleukocytic Acute Myeloid Leukemia

AbstractIntroduction: Hyperleukocytic acute myeloid leukemia(HAML) is a high-risk type of acute myeloid leukemia (AML), with white blood cell counts exceeding 100 x 10 ^ 9/L in peripheral blood, accounting for approximately 5%-20% of AML.Bortezomib is the first proteasome inhibitor approved by the US FDA for clinical use.The efficacy of either single agent or in combination with other agents for acute myeloid leukemia is inconclusive. DAG is commonly used as a classical chemotherapy regimen for acute myeloid leukemia.We have found that bortezomib has a therapeutic effect on acute myeloid leukemia in clinical empirical medication, so we investigated the therapeutic effect of bortezomib combined with DAG regimen on HAML. Methods:Primary hyperleukocytic leukemia cells were isolated from bone marrow of hyperleukocytic acute myeloid leukemia patients using ficoll liquid, then the primary hyperleukocytic leukemia cells were treated with bortezomib (0 nm, 5 nm, 10 nm, 20 nm, 50 nm), DAG, and bortezomib combined with DAG regimens at different concentration gradients.Cell viability was detected by flow cytometry. The HAML patient-derived xenograft (PDX) model were used to evaluate the in vivo effect of bortezomib combined with DAG regimen using the same dosing regimen as the clinical medication regimen: bortezomib 1.3 mg/m2, subcutaneous injection, 4 times a course, d1, 4, 8, and 11; doxorubicin liposome injection 5 mg/m2, intravenous drip, every other day, 5 times in total; cytarabine 10 mg/m2, subcutaneous injection, d1-14 every 12 h; and G-CSF 200 μg/m2 per day, subcutaneous injection, d1-14 days. Results: With the increase of concentration gradient, the apoptosis of HAML leukemia cells induced by bortezomib alone and DAG alone was gradually enhanced, while the viable cell count of bortezomib combined with DAG was much lower than that of bortezomib alone or DAG alone. In animal experiments, flow cytometry showed that the ratio of human leukaemia cells in bone marrow blood decreased revealed the most significant decrease in the bortezomib combined with DAG group, absolute counts of CD45 cells in the bone marrow cells of mice in each group also revealed the most significant decrease in the bortezomib combined with DAG group. Morphological examination of myelocyte smears revealed significantly fewer myeloblasts in the bortezomib combined with DAG group than in the other groups. The survival rate in the bortezomib combined with DAG group was better than in the bortezomib alone or DAG alonefor the HAML PDX model. Conclusion:Bortezomib combined with DAG regimen has synergistic killing effect on HAML and may serve as a certain clinical prospect in the treatment of hyperleukocytic acute myeloid leukemia. Disclosures No relevant conflicts of interest to declare.

Venetoclax-Resistant MV4-11 Leukemic Cells Activate PI3K/AKT Pathway for Metabolic Reprogramming and Redox Adaptation for Survival.

Venetoclax (ABT199) is a selective B-cell lymphoma 2 (BCL-2) inhibitor. The US FDA recently approved it to be used in combination with low-dose cytarabine or hypomethylating agents in acute myeloid leukemia (AML) or elderly patients non-eligible for chemotherapy. However, acquiring resistance to venetoclax in AML patients is the primary cause of treatment failure. To understand the molecular mechanisms inherent in the resistance to BCL-2 inhibitors, we generated a venetoclax-resistant cell line model and assessed the consequences of this resistance on its metabolic pathways. Untargeted metabolomics data displayed a notable impact of resistance on the PI3K/AKT pathway, the Warburg effect, glycolysis, the TCA cycle, and redox metabolism. The resistant cells showed increased NADPH and reduced glutathione levels, switching their energy metabolism towards glycolysis. PI3K/AKT pathway inhibition shifted resistant cells towards oxidative phosphorylation (OXPHOS). Our results provide a metabolic map of resistant cells that can be used to design novel metabolic targets to challenge venetoclax resistance in AML.

Novel inhibitor of hematopoietic cell kinase as a potential therapeutic agent for acute myeloid leukemia.

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are characterized by risk of relapses, poor survival, unwanted side effects and high toxicity with the current therapies. In light of these facts, there are efforts to develop new drugs specific for deregulated molecules that participate in leukemia pathogenesis. Hematopoietic cell kinase (HCK), an Src kinase family member, is overexpressed on hematopoietic stem cells of MDS and de novo AML patients and involved in the oncogenic process. Thus, we investigated in vitro, ex vivo and in vivo effects of a novel chemical compound targeting HCK inhibition (iHCK-37), in combination with the most used drugs for the treatment of MDS and de novo AML, 5-Azacytidine and Cytarabine. Herein, the combination treatment with iHCK-37 and 5-Azacytidine or Cytarabine demonstrated additive effects against leukemia cells, compared to either drug alone. iHCK-37 plus 5-Azacytidine or Cytarabine treatment was able to reduce the activation of oncogenic pathways, MAPK/ERK and PI3K/AKT, leading to reduction of ERK and AKT phosphorylation, and increased BAX and decreased BCL-XL protein expression. Moreover, treatment with iHCK-37 reduced MDS and AML CD34-positive cell numbers inside a 3D-structure but did not affect normal CD34-positive cell numbers. In vivo analysis showed that leukemic mice treated with iHCK-37 had reduced ERK and AKT proteins phosphorylation levels and leukocyte numbers. In conclusion, the iHCK-37 inhibitor has anti-neoplastic activity in leukemia cells without altering apoptosis and survival rate of normal cells, suggesting on-target malignant cell killing activity as a single agent or in combination with 5-Azacytidine or Cytarabine.

The Evolution of Research and Therapy With Hypomethylating Agents in Acute Myeloid Leukemia and Myelodysplastic Syndrome: New Directions for Old Drugs.

Azacitidine and decitabine are cytosine analogs that function as DNA methyltransferase inhibitors. These agents, commonly referred to as "hypomethylating agents," are widely used for the treatment of myelodysplastic syndrome and acute myeloid leukemia (AML). In this review, we discuss the clinical development of these drugs, including the early studies that led to the optimization of their doses and schedules, and the pivotal studies that led to their regulatory approval, both as monotherapy and in combination with venetoclax for older adults with AML who are unfit for intensive chemotherapy. We also review the more recent development of oral hypomethylating agent formulations and the novel oral strategies being developed in myelodysplastic syndrome and AML.

Venetoclax and hypomethylating agents in older/unfit patients with blastic plasmacytoid dendritic cell neoplasm

Venetoclax and hypomethylating agents in older/unfit patients with blastic plasmacytoid dendritic cell neoplasm

The Clinical Oncolytic Reovirus Formulation Reolysin Synergistically Augments the Anti-Leukemic Activity of Azacitidine

Despite the recent development of new agents for acute myeloid leukemia (AML) therapy, novel approaches are still needed for patients that do not benefit sufficiently from existing regimens. Reolysin (Pelareorep) is a proprietary clinical formulation of the naturally occurring oncolytic reovirus that is non-pathogenic and preferentially replicates in cancer cells, but not in normal tissue. Although Reolysin has been investigated in over 30 adult clinical trials and is very well tolerated when given alone and in combination with chemotherapy, it has never been evaluated for AML therapy. Our major goal was to determine the efficacy and mechanism of action of Reolysin alone and in combination with azacitidine in AML models and primary patient specimens. Reolysin exhibited dose-dependent effects against AML cells with respect to the reduction in leukemia cell viability and induction of apoptosis in all 8 cell lines evaluated. The combination of Reolysin with azacitidine yielded synergistic benefit across all cell lines that was dramatically superior to single agent treatments (p<0.001). The benefit of combination treatment was confirmed in primary AML specimens (N=14 to date). RNASeq-based transcriptome and gene ontology (GO) analyses of the pharmacodynamic effects of each agent and the combination revealed that the Reolysin and azacitidine combination potently altered multiple genes in the immune response pathway (p<0.001). qRT-PCR analyses and ELISA assays confirmed the broad immunomodulatory effects of the Reolysin plus azacitidine combination. Immune priming strategies that can turn “immune cold” cancers to “immune hot” may significantly augment the benefit of many therapeutic approaches. Basic leucine zipper transcription factor ATF-like 2 (BATF2) is a key tumor suppressor that is absent in AML and certain other malignancies. Its deficiency promotes immune escape of cancer cells. BATF2 exhibits anticancer activity through upregulation of interleukin-12 and the activation of CD8+ T cells and therefore represents a novel new target in anticancer treatment with immune checkpoint inhibitors. Our transcriptome analyses identified BATF2 as one of the most significantly upregulated genes in AML cells following treatment with the Reolysin plus azacitidine combination (p<0.0001). Additional mechanistic studies confirmed that BATF2 induction was a key driver of the anti-leukemic effects of combination treatment. Finally, Reolysin (5 x 10 8 TCID50 IV 1x per week), azacitidine (5 mg/kg SC 2x per week), and the combination were administered to mice bearing MOLM-13 FLT3-ITD+ xenografts for 19 days to assess the efficacy and tolerability of each treatment. Combination treatment was well tolerated and antagonized disease progression significantly more effectively than either monotherapy (p<0.01). Additional in vivo studies more rigorously assessing the immunomodulatory effects of Reolysin and azacitidine in immune competent mice are underway. Our collective data demonstrate that Reolysin is a safe and well tolerated agent with potent immunomodulatory effects that synergistically augments the anti-AML effects of azacitidine. A phase I investigator-initiated clinical trial further investigating the safety and preliminary efficacy of this combination in patients with AML is currently being planned. DisclosuresNo relevant conflicts of interest to declare.

The Sustainability of Price Dynamics in Precision Hematology

Background:Despite the promise of targeted agents in hematology, the high price of cancer therapies is a rapidly evolving problem. Until now, the increase in price of targeted anti-cancer treatments used in common hematological malignancies has not been evaluated. Here, we report patterns in price changes from 2015-2019 for multiple in-class anticancer medications for common hematologic malignancies.Methods:We utilized the publicly available Medicare Part D provider utilization and payment database from 2015 to 2019. We extracted drug prices (using generic names) for commonly used targeted anticancer agents for acute myeloid leukemia, chronic myeloid leukemia, chronic lymphocytic leukemia, B-cell lymphomas, and multiple myeloma. The primary outcome was the correlation of average change in Medicare spending per dosage unit among the multiple brand-name medications within each class available. We additionally calculated compound annual growth rates (CAGRs) [i.e. mean annual growth rates over a specified period of time] for medication costs within each class, and compared it with the consumer price index (CPI) (a measure of the average change over time in the prices of consumer items) and inflation rate. Agents without in-class competitor were excluded. CPI and inflation rates came from U.S. Bureau of Labor Statistics.Results:The study included 6 BCR-ABL inhibitors (1 generic), 2 BTK inhibitors, 2 IDH inhibitors, 2 FLT3 inhibitors, 3 IMIDs, 3 PI, 2 PI3K inhibitors, and 5 anti-CD20 monoclonal antibodies.The median (range) Pearson correlation coefficient values for drugs within each class were -0.155 (-0.984-0.992) for BCR-ABLi, -0.362 for BTKi, 0.234 (0.215-0.999) for IMIDs, 0.899 (-0.034-0.988) for PIs, and 0.954 (0.847-0.999) for anti-CD20 antibodies. The median correlation coefficient for BCR-ABLi was 0.751 if generic imatinib was excluded. The correlation coefficient between 2 nd and 3 rd generation IMIDs was 0.999. Non-generic BCR-ABLi and anti-CD20 antibodies showed strong linear association in price increase between two drugs within the same class. Due to drug novelty, coefficient could not be calculated for therapies with 2 or fewer data points (midostaurin, gilteritinib, enasidenib, ivosidenib, idelalisib, duvelisib). There was no significant correlation between expenditure for BTKi, PIs, and IMIDs.The median CAGRs in costs over this 5-year period were: were 6.29% for BCR-ABLi, 18.36% for BTKi, 2.69% for IDHi, 4.23% for FLT3i, 10.63% for IMIDs, 5.11% for PIs, 5.79% for PI3Ki, and 5.85% for anti-CD20s. The median CAGR in costs for modern precision-driven cancer therapeutic classes outpaced CPI (2.26%/year), and the average inflation rate (1.90%/year).Conclusions:Increase in cost within the same class should be weighed against incremental clinical benefit for the patients. For non-generic BCR-ABLi and anti-CD20 antibodies, despite there being several agents, the rise in drug expenditures correlated closely, calling into question the true value of within-class competition. There is an urgent need for drug pricing reform given the average expenditure of Medicare part D, and ultimately out-of-pocket costs for our patients with cancer continues to trend upwards. Increased advocacy efforts are needed to ensure precision therapeutics remains an attainable and sustainable goal. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The path to approval for oral hypomethylating agents in acute myeloid leukemia and myelodysplastic syndromes.

Two oral hypomethylating agents, oral azacitidine (CC-486) and decitabine/cedazuridine (ASTX727), have recently entered the clinical domain. CC-486 has been shown to improve overall survival as maintenance therapy for older patients with acute myeloid leukemia in complete remission, whereas the combination of decitabine with cedazuridine, a cytidine deaminase inhibitor, is indicated for the treatment of adult patients with myelodysplastic syndromes and chronic myelomonocytic leukemia with intermediate-1, or higher, International Prognostic Scoring System risk. This article briefly summarizes the clinical development of both drugs, the pivotal studies that led to their approval and some of the issues faced in extending the use of these drugs to other indications.

Novel AXL‑targeted agents overcome FLT3 inhibitor resistance in FLT3‑ITD+ acute myeloid leukemia cells

AXL receptor tyrosine kinase (AXL) upregulation mediates drug resistance in several types of human cancer and has become a therapeutic target worthy of exploration. The present study investigated AXL antigen expression and the effects of novel AXL-targeted agents in acute myeloid leukemia (AML) cells. AXL antigen expression in drug-sensitive and drug-resistant human AML cell lines, and AML blast cells from 57 patients with different clinical characteristics, was analyzed by flow cytometry and compared. Furthermore, the effects of the novel AXL antibody DAXL-88, antibody-drug conjugate DAXL-88-monomethyl auristatin E (MMAE), AXL small molecule inhibitor R428 and their combination with FMS-like tyrosine kinase 3 (FLT3) inhibitor quizartinib (AC220) in AML cells were analyzed by Cell Counting Kit-8 assay, flow cytometry and western blotting. The present study revealed that AXL antigen expression was upregulated in FLT3-internal tandem duplication (ITD)/tyrosine kinase domain mutation-positive (TKD)+ AML blast cells compared with FLT3-ITD/TKD− AML cells. Additionally, AXL antigen expression was markedly upregulated in the AC220-resistant FLT3-ITD+ MV4-11 cell line (MV4-11/AC220) and in FLT3 inhibitor-resistant blast cells from a patient with FLT3-ITD+ AML compared with parental sensitive cells. The AXL-targeted agents DAXL-88, DAXL-88-MMAE and R428 exhibited dose-dependent cytotoxic effects on FLT3-mutant AML cell lines (THP-1, MV4-11 and MV4-11/AC220) and blast cells from patients with FLT3-ITD+ AML. Combinations of AXL-targeted agents with AC220 exerted synergistic cytotoxic effects and induced apoptosis in MV4-11/AC220 cells and FLT3 inhibitor-resistant blast cells. The antileukemic effect of DAXL-88 and DAXL-88-MMAE may rely on their ability to block AXL, FLT3 and their downstream signaling pathways. The present study demonstrated the association between AXL antigen expression upregulation and drug resistance in FLT3-ITD+ AML, and proposed a method for overcoming FLT3 inhibitor resistance of FLT3-ITD+ AML using novel AXL-targeted agents.

Strategizing the Treatment Approach to Acute Myeloid Leukemia

For decades acute myeloid leukemia, the primary acute leukemia affecting adults, had limited treatment options. Since 2017, we have seen discovery and development in cytogenetic and molecular classification of acute myeloid leukemia, improved understanding of cell signaling pathways, and development of new treatment for acute myeloid leukemia. These new treatments include novel combinations of agents and therapy targeting molecular alterations improving rates of remission and overall survival. Treatment discovery provides therapeutic opportunity to older patients and populations previously excluded from intense induction chemotherapy. In this review, we discuss the timing of first therapy, non-intense treatment regimens achieving remission, and new targets for directed therapy. We reference key clinical trials to expand our discussion of newly approved agents for acute myeloid leukemia. In this review, we highlight the discovery of treatment strategies to improve patient outcomes and ongoing research in leukemia.