439 Dual modes of action for anti-TIM-3 antibody MBG453 in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML): preclinical evidence for immune-mediated and anti-leukemic activity

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A465-A465
Author(s):  
Catherine Sabatos-Peyton ◽  
Tyler Longmire ◽  
Lisa Baker ◽  
Nidhi Patel ◽  
Anne-Sophie Wavreille ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Leukemic Stem Cells ◽  
Self Renewal ◽  
Immune Mediated ◽  
Acute Myeloid ◽  
Cell Stem Cell

BackgroundTIM-3 is expressed on leukemic stem cells (LSCs) and blasts in AML,1 2 and TIM-3 expression on MDS blasts correlates with disease progression.3 Functional evidence for TIM-3 in AML was established with an anti-TIM-3 antibody which inhibited engraftment and development of human AML in immuno-deficient murine hosts.1 TIM-3 promotes an autocrine stimulatory loop via the TIM-3/Galectin-9 interaction, supporting LSC self-renewal.4 In addition to its cell-autonomous role on LSCs/blasts, TIM-3 also has a critical role in immune system regulation, in adaptive (CD4+ and CD8+ T effector cells, regulatory T cells) and innate (macrophages, dendritic cells, NK cells) immune responses.5 MBG453 is a high-affinity, humanized anti-TIM-3 IgG4 antibody (Ab) (stabilized hinge, S228P), which blocks the binding of TIM-3 to phosphatidylserine (PtdSer). Recent results from a multi-center, open label phase Ib dose-escalation study (NCT03066648) in patients with high-risk MDS and no prior hypomethylating agent therapy evaluating MBG453 in combination with decitabine demonstrated encouraging preliminary efficacy with an overall response rate of 58%,6 and MBG453 combined with azacitidine also showed encouraging response rates.7 Preclinical experiments were undertaken to define the mechanism of action of the hypomethylating agent and anti-TIM-3 combination.MethodsTHP-1 cells (a human monocytic AML cell line) were pre-treated with decitabine and co-cultured with anti-CD3 activated healthy human donor peripheral blood mononuclear cells (PBMCs) in an Incucyte-based assay to measure cell killing. The ability of MBG453 to mediate antibody-dependent cellular phagocytosis (ADCP) was measured by determining the phagocytic uptake of an engineered TIM-3-overexpressing Raji cell line in the presence of MBG453 by phorbol 12-myristate 13-acetate (PMA)-activated THP-1 cells. Patient-derived AML xenograft studies were undertaken in immune-deficient murine hosts to evaluate the combination of decitabine and MBG453.ResultsMBG453 was determined to partially block the TIM-3/Galectin-9 interaction in a plate-based MSD (Meso Scale Discovery) assay, supported by a crystal structure of human TIM-3.8 Pre-treatment of THP-1 cells with decitabine enhanced sensitivity to immune-mediated killing in the presence of MBG453. MBG453 was determined to mediate modest ADCP, relative to controls. MBG453 did not enhance the anti-leukemic activity of decitabine in patient-derived xenograft studies in immuno-deficient hosts.ConclusionsTaken together, these results support both direct anti-leukemic effects and immune-mediated modulation by MBG453. Further studies are ongoing to determine: (1) whether MBG453 can mediate physiologically relevant ADCP of TIM-3-expressing leukemic cells; and (2) the potential of MBG453 to impact the autocrine feedback loop of TIM-3/Galectin-9.Ethics ApprovalThe human tissue used in these studies was under the Novartis Institutes of BioMedical Research Ethics Board IRB, Approval Number 201252867.ReferencesKikushige Y, Shima T, Takayanagi S, et al. TIM-3 is a promising target to selectively kill acute myeloid leukemia stem cells. Cell Stem Cell 2010;7(6):708–717.Jan M, Chao MP, Cha AC, et al. Prospective separation of normal and leukemic stem cells based on differential expression of TIM3, a human acute myeloid leukemia stem cell marker. Proc Natl Acad Sci USA 2011; 108(12): 5009–5014.Asayama T, Tamura H, Ishibashi M, et al. Functional expression of Tim-3 on blasts and clinical impact of its ligand galectin-9 in myelodysplastic syndromes. Oncotarget 2017;8(51): 88904–88917.Kikushige Y, Miyamoto T, Yuda J, et al. A TIM-3/Gal-9 autocrine stimulatory loop drives self-renewal of human myeloid leukemia stem cells and leukemic progression. Cell Stem Cell 2015; 17(3):341–352.Acharya N, Sabatos-Peyton C, Anderson AC. Tim-3 finds its place in the cancer immunotherapy landscape. J Immunother Cancer 2020; 8(1):e000911.Borate U, Esteve J, Porkka K, et al. Phase Ib Study of the Anti-TIM-3 Antibody MBG453 in combination with decitabine in patients with high-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Blood 2019;134 (Supplement_1):570.Borate U, Esteve J, Porkka K, et al. Abstract S185: Anti-TIM-3 antibody MBG453 in combination with hypomethylating agents (HMAs) in patients (pts) with high-risk myelodysplastic syndrome (HR-MDS) and acute myeloid leukemia (AML): a Phase 1 study. EHA 2020.Sabatos-Peyton C. MBG453: A high affinity, ligand-blocking anti-TIM-3 monoclonal Ab. AACR 2016.

Co-Existence of LMPP-Like and GMP-Like Leukemia Stem Cells In Acute Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 91-91
Author(s):  
Nicolas Goardon ◽  
Emmanuele Marchi ◽  
Lynn Quek ◽  
Anna Schuh ◽  
Petter Woll ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Leukemic Stem Cell ◽  
Self Renewal ◽  
Two Populations ◽  
Acute Myeloid

Abstract Abstract 91 In normal and leukemic hemopoiesis, stem cells differentiate through intermediate progenitors into terminal cells. In human Acute Myeloid Leukemia (AML), there is uncertainty about: (i) whether there is more than one leukemic stem cell (LSC) population in any one individual patient; (ii) how homogeneous AML LSCs populations are at a molecular and cellular level and (iii) the relationship between AML LSCs and normal stem/progenitor populations. Answers to these questions will clarify the molecular pathways important in the stepwise transformation of normal HSCs/progenitors. We have studied 82 primary human CD34+ AML samples (spanning a range of FAB subtypes, cytogenetic categories and FLT3 and NPM1 mutation states) and 8 age-matched control marrow samples. In ∼80% of AML cases, two expanded populations with hemopoietic progenitor immunophenotype coexist in most patients. One population is CD34+CD38-CD90-CD45RA+ (CD38-CD45RA+) and the other CD34+CD38+CD110-CD45RA+ (GMP-like). Both populations from 7/8 patients have leukemic stem cell (LSC) activity in primary and secondary xenograft assays with no LSC activity in CD34- compartment. The two CD34+ LSC populations are hierarchically ordered, with CD38-CD45RA+ LSC giving rise to CD38+CD45RA+ LSC in vivo and in vitro. Limit dilution analysis shows that CD38-CD45RA+LSCs are more potent by 8–10 fold. From 18 patients, we isolated both CD38-CD45RA+ and GMP-like LSC populations. Global mRNA expression profiles of FACS-sorted CD38-CD45RA+ and GMP-like populations from the same patient allowed comparison of the two populations within each patient (negating the effect of genetic/epigenetic changes between patients). Using a paired t-test, 748 genes were differentially expressed between CD38-CD45RA+ and GMP-like LSCs and separated the two populations in most patients in 3D PCA. This was confirmed by independent quantitative measures of difference in gene expression using a non-parametric rank product analysis with a false discovery rate of 0.01. Thus, the two AML LSC populations are molecularly distinct. We then compared LSC profiles with those from 4 different adult marrow normal stem/progenitor cells to identify the normal stem/progenitor cell populations which the two AML LSC populations are most similar to at a molecular level. We first obtained a 2626 gene set by ANOVA, that maximally distinguished normal stem and progenitor populations. Next, the expression profiles of 22 CD38-CD45RA+ and 21 GMP-like AML LSC populations were distributed by 3D PCA using this ANOVA gene set. This showed that AML LSCs were most closely related to their normal counterpart progenitor population and not normal HSC. This data was confirmed quantitatively by a classifier analysis and hierarchical clustering. Taken together, the two LSC populations are hierarchically ordered, molecularly distinct and their gene expression profiles do not map most closely to normal HSCs but rather to their counterpart normal progenitor populations. Finally, as global expression profiles of CD38-CD45RA+ AML LSC resemble normal CD38-CD45RA+ cells, we defined the functional potential of these normal cells. This had not been previously determined. Using colony and limiting dilution liquid culture assays, we showed that single normal CD38-CD45RA+ cells have granulocyte and macrophage (GM), lymphoid (T and B cell) but not megakaryocyte-erythroid (MK-E) potential. Furthermore, gene expression studies on 10 cells showed that CD38-CD45RA+ cells express lymphoid and GM but not Mk-E genes. Taken together, normal CD38-CD45RA+ cells are most similar to mouse lymphoid primed multi-potential progenitor cells (LMPP) cells and distinct from the recently identified human Macrophage Lymphoid progenitor (MLP) population. In summary, for the first time, we show the co-existence of LMPP-like and GMP-like LSCs in CD34+ AML. Thus, CD34+ AML is a progenitor disease where LSCs have acquired abnormal self-renewal potential (Figure 1). Going forward, this work provides a platform for determining pathological LSCs self-renewal and tracking LSCs post treatment, both of which will impact on leukemia biology and therapy. Disclosures: No relevant conflicts of interest to declare.

Identification and Purification of Leukemic Stem-Like Cells in Acute Myeloid Leukemia Cell Line

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4734-4734
Author(s):  
Miaorong She ◽  
Xingqing Niu ◽  
Xilin Chen ◽  
Guo Kunyuan ◽  
Maohua Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Cell Line ◽  
Myeloid Leukemia ◽  
Critical Role ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Leukemic Stem Cells ◽  
Self Renewal ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is initiated and maintained by a rare population of (leukemic stem cells) LSCs. LSCs play the central role in the relapse and refractory of AML and highlight the critical need for the new therapeutic strategies to directly target the LSC population for ultimately curing leukemia which is it is important to identify and study LSCs. However, relatively little is known about the unique molecular mechanisms of survival and self-renewal of LSCs because of very small number of LSCs in bone marrow. In this study, we investigated whether established leukemia cell lines contain LSCs. We showed that leukemia cell line contain leukemic stem-like cells which have been phenotypically restricted within the CD34+CD38− fraction. We demonstrated that CD34+CD38− cells could generate CD34+CD38+ cells in culture medium and had proliferation function. Moreover, CD34+CD38− cells had self-renewal potential both in vitro soft agar colonies formation assay and in vivo NOD/SCID mouse xenotransplant model serial transplantation. Furthermore, CD34+CD38− cells isolated from leukemia cell line were found resistant to conventional chemotherapy and NK cells-mediated cytotoxicity and these were related to up-regulation of ABCG2 and MRP-1 and antiapoptotic proteins of Bcl2. Down-regulation of NKG2D ligand also played a critical role in NK cytotoxicity resistance. Taken together, our studies provide a novel cell model for leukemic stem cells research. Our data also shed light on mechanism of double resistant to resistant to chemotherapy and NK cell immunotherapy, which was helpful for developing novel effective strategies for LSCs.

Targeting the 5-Lipoxygenase as a Novel Principle of Stem Cell Therapy In Acute Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1846-1846
Author(s):  
Jessica Roos ◽  
Astrid Fischer ◽  
Dieter Steinhilber ◽  
Hubert Serve ◽  
Oliver Ottmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Cell Therapy ◽  
Stem Cell Therapy ◽  
Myeloid Leukemia ◽  
Reversible Inhibitor ◽  
Leukemic Stem Cells ◽  
Acute Myeloid

Abstract Abstract 1846 Chromosomal translocations such as t(15;17), t(8,21) or t(6;9) lead to the formation of chimeric genes encoding the PML/RAR, AML-1/ETO or DEK/CAN fusion proteins (FP). These FP are able to induce and to maintain acute myeloid leukemia (AML) by both blocking terminal differentiation of early hematopoietic progenitors and increasing the self renewal potential of the leukemic stem cells (LSC). LSCs are potential therapeutic targets and it is of great importance to elucidate which signaling pathways control their development and maintenance. Recently it has been shown that the presence of the 5-Lipoxygenase activity (5-LO) is indispensable for the induction and the maintenance of the BCR/ABL induced CML-like disease in mice. Its depletion or inhibition impairs the LSCs in the CML-like disease. 5-LO is the key enzyme in the biosynthesis pathway of leukotrienes, a group of proinflammatory lipid mediators derived from arachidonic acid. Furthermore we have shown that Sulindac sulfide, a dual Cycloxygenase/5 –LO inhibitor, was able, at 5-LO inhibitory concentrations, to interfere with the stem cell capacity of PML/RAR-positive LSC. It also overcame the differentiation block in PML/RAR-positive HSC. To disclose whether a “leukemic stem cell therapy” in AML is feasible if based on selectively targeting the 5-LO, we used two different selective 5-LO inhibitors, Zileuton and CJ-13,610, in a PML/RAR- and DEK/CAN-positive leukemia model. Zileuton, an anti-asthmatic drug, is a reversible inhibitor of 5-LO activity which leads to the inhibition of leukotrienes (LTB4, LTC4, LTD4, and LTE4) formation. CJ-13,610 is novel non redox, non iron chelating 5-LO inhibitor. As stem cell models we used Sca-1+/lin-murine HSC retrovirally transduced either with PML/RAR or DEK/CAN. Here we report that both Zileuton and CJ -13,610 at clinically feasible concentrations of 0.3 – 3μM interfered with the aberrant replating efficiency of PML/RAR and DEK/CAN expressing HSCs; ii.) inhibited the short-term stem cell (ST-HSC) capacity of PMR/RAR- and DEK/CAN-positive HSCs as assessed by colony forming unit-spleen day 12 assays in lethally irradiated recipient mice; and iii.) reduced the frequency of long-term HSC in a long term competitive repopulation stem cell assays. The effects of both compounds were not due related to the induction of apoptosis. Interestingly, on normal control HSC both Zileuton and CJ-13,610 exhibited a “paradox” effect by increasing ST-HSC as well as LT-HSC capacity. Our here presented data establish the inhibition of 5-LO by selective inhibitors as a feasible approach of molecular stem cell therapy in AML. Furthermore it strongly suggest an important role of leukotrienes for the maintenance of leukemic stem cells. The exact mechanisms by which the inhibition of 5-LO interferes with the LSC have still to be disclosed. Disclosures: Off Label Use: The use of anti-inflammatory drugs such as Zileuton and CJ-13610 as novel approach for stem cell treatment in AML is discussed.

scholarly journals Escape From Treatment; the Different Faces of Leukemic Stem Cells and Therapy Resistance in Acute Myeloid Leukemia

2021 ◽  
Vol 11 ◽  
Author(s):  
Noortje van Gils ◽  
Fedor Denkers ◽  
Linda Smit
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Therapy Response ◽  
Therapy Resistance ◽  
Leukemia Cells ◽  
Leukemic Stem Cells ◽  
Acute Myeloid

Standard induction chemotherapy, consisting of an anthracycline and cytarabine, has been the first-line therapy for many years to treat acute myeloid leukemia (AML). Although this treatment induces complete remissions in the majority of patients, many face a relapse (adaptive resistance) or have refractory disease (primary resistance). Moreover, older patients are often unfit for cytotoxic-based treatment. AML relapse is due to the survival of therapy-resistant leukemia cells (minimal residual disease, MRD). Leukemia cells with stem cell features, named leukemic stem cells (LSCs), residing within MRD are thought to be at the origin of relapse initiation. It is increasingly recognized that leukemia “persisters” are caused by intra-leukemic heterogeneity and non-genetic factors leading to plasticity in therapy response. The BCL2 inhibitor venetoclax, combined with hypomethylating agents or low dose cytarabine, represents an important new therapy especially for older AML patients. However, often there is also a small population of AML cells refractory to venetoclax treatment. As AML MRD reflects the sum of therapy resistance mechanisms, the different faces of treatment “persisters” and LSCs might be exploited to reach an optimal therapy response and prevent the initiation of relapse. Here, we describe the different epigenetic, transcriptional, and metabolic states of therapy sensitive and resistant AML (stem) cell populations and LSCs, how these cell states are influenced by the microenvironment and affect treatment outcome of AML. Moreover, we discuss potential strategies to target dynamic treatment resistance and LSCs.

scholarly journals Rspo-LGR4 Cooperates with HOXA9 to Sustain Self-Renewal in Acute Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2669-2669
Author(s):  
Nunki Hassan ◽  
Basit Salik ◽  
Alastair Duly ◽  
Jenny Yingzi Wang
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Myeloid Differentiation ◽  
Beta Catenin ◽  
Leukemic Stem Cells ◽  
Self Renewal ◽  
Differentiation Block ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is associated with high relapse rates and poor survival, with limited response to conventional cancer therapy and lacking effective targeting of highly self-renewing leukemic stem cells (LSCs). The mechanism underlying the high self-renewal activity of LSCs that determines the aggressiveness of disease remains poorly understood. Although we and others have previously demonstrated the clinical significance of aberrant WNT/β-catenin signaling in AML (Science, 327:1650-1653, 2010; Cancer Cell, 18:606-618, 2010), its pharmacologically tractable components essential for the regulation of LSC self-renewal have not yet been determined. Our studies discover, for the first time, a critical link between R-spondin (RSPO)-LGR4/HOXA9 and WNT/β-catenin pathways in AML LSCs. Microarray data analysis of 183 AML patient samples showed a significant positive correlation between expression of LGR4 and HOXA9 (r=0.546, P<0.0001). LGR4 exerted a cell-of-origin-specific function in promoting aberrant self-renewal and AML progression in vivo through cooperating with HOXA9, a poor prognostic predictor. We observed that LGR4 itself was not able to fully transform normal hematopoietic stem/progenitor cells (HSPCs), but instead cooperated with HOXA9 in HSPCs to accelerate disease onset producing a highly aggressive short latency AML in vivo. LGR4 and HOXA9 were epigenetically upregulated and their coexpression was an essential determinant of RSPO-LGR4 oncogenic activity. RSPO/WNT3 ligands could serve as stem cell growth factors to sustain myeloid differentiation block and to promote proliferation of CD34+ LSC-enriched subpopulations in primary AML patient specimens co-expressing LGR4 and HOXA9. Conversely, CRISPR/Cas9-mediated knockout of LGR4 not only suppressed RSPO/WNT3 signals and markedly decreased nuclear active β-catenin, but also reduced tumor burden in a patient-derived xenograft (PDX) mouse model of relapsed AML. Importantly, this study is the first to demonstrate that pharmacological inhibition of RSPO3-LGR4 signaling by a clinical-grade anti-RSPO3 monoclonal antibody induced LSC differentiation and consequently prevented tumor growth in AML PDX mice but did not affect normal human stem cell compartment in NSG mice. Together, our findings support a critical role for RSPO-LGR4 in the Wnt/β-catenin signaling pathway to promote AML leukemogenesis. Aberrant activation of RSPO-LGR4 is crucial for enhancing the self-renewal potential and myeloid differentiation block, which contribute to an aggressive leukemia phenotype through cooperating with HOXA9. Genetic and pharmacological targeting of this pathway impairs LSC self-renewal and survival and impedes AML development in murine models and patient-derived xenografts, highlighting the therapeutic value of targeting RSPO-LGR4 signaling in AML. References: Wang Y, et al. The Wnt/beta-catenin pathway is required for the development of leukemia stem cells in AML. Science. 2010;327:1650-1653. Yeung J, et al. Beta-catenin mediates the establishment and drug resistance of MLL leukemic stem cells. Cancer Cell. 2010;18:606-618. Disclosures No relevant conflicts of interest to declare.

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