scholarly journals Dual CXCR4 and E-Selectin Inhibition (GMI-1359) Rapidly Increases AML Cellular Motility Prior to Intravasation and Vascular Niche Depletion Observed By Intravital Bone Marrow Two-Photon Microscopy

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 14-15
Author(s):  
Tomasz Zal ◽  
Malgorzata Anna Zal ◽  
Mateusz Rytelewski ◽  
Kyung Hee Chang ◽  
Rodrigo Jacamo ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Bone Marrow ◽  
Board Of Directors ◽  
Research Funding ◽  
Leukemia Cell ◽  
Myelogenous Leukemia ◽  
Cellular Motility ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Vascular Niche

BACKGROUND: Acute myelogenous leukemia (AML) cells that reside in bone marrow (BM) receive a great deal of protection from the cytotoxic effects of therapeutic agents. In contrast, the circulating leukemia cells are typically more chemosensitive compared to those embedded in BM niches. The BM homing of AML cells is mediated by multiple adhesive and chemokinetic interactions including, respectively, by sialylated glycoproteins on the cancer cells binding to E-selectin on the endothelium and by CXCR4-mediated sensing of SDF-1/CXCL12 gradients. Consequently, both E-selectin and CXCR4 inhibitors have been pursued as targets for add-on therapeutic strategies aimed to "mobilize" AML cells out of the BM. A next generation "mobilizing" agent GMI-1359 combines, in one molecular structure, the E-selectin and CXCR4 inhibitory moieties. In a previous study, GMI-1359 markedly reduced leukemia cell adhesion to endothelial cells, leukemia cellularity in BM (Zhang et al., 2016) and it enhanced the survival of cytarabine/daunorubicin therapy in a FLT3-mutated AML model (Zhang et al., 2015). APPROACH: Here, we used intravital 2-photon microscopy of calvarial BM to study the behavioral response of AML cells to the dual CXCR4 and E-selectin inhibition (GMI-1359) in vivo. We used a mTurquoise2 fluorescence-tagged transplantable mouse AML model (characterized by MLL, ENL-FLT3, ITD, p53-/-). To delineate the bone and vascular niches, the syngeneic immune-competent recipient mice harbored cell lineage fluorescence reporter genes such as Col2.3-GFP, hCD2-DsRed and CD11c-EYFP with the bone collagen and blood highlighted by, respectively, second harmonic generation (SHG) and fluorescent dextran. Intravenously infused AML cells (5x10E4) homed to BM where they gradually displaced most endogenous cells. In this experimental system, GMI-1359 or vehicle were infused into the tail vein while recording AML cell motilities in calvarial BM stroma in 3-D over 4 hours. RESULTS: In untreated or control vehicle treated mice, AML cells were slowly motile, migrating with the average velocity of ~2 µm/min. Cellular trajectories were random within the average 400 µm confinement radius corresponding to the size of BM cavities. Most AML cells localized in the vascular niche, defined as within a 50 µm distance to the nearest blood vessel. A minority of AML cells were also present in the proximity to osteoblasts and the bone (i.e. in the bone niche). In contrast, GMI-1359 infusion resulted in a 66% increase of the average speed of cellular motility of AML cells within 20 min and up to 100% increase within 3.5 hours. The motility pattern remained largely random within the bone cavity confinement volume and was concentrated in the vicinity of vasculature. Thereafter, we observed multiple instances of AML cell intravasation into the capillary lumens followed by several minute-long vessel wall attachment and sudden outflow. This cellular dynamics resulted in a substantial, yet structurally biased decrease of BM AML cellularity whereby the vascular niche was emptied preferentially whilst the bone niche remained populated by AML cells. In no case we observed a complete BM depletion of AML cells. Interestingly, as we reported before, a single, CXCR4-only inhibitor caused a protracted (24-48 h) depletion of AML cells in BM without significant cellular motility enhancement. CONCLUSIONS: Our observations reveal an unexpected mechanism of action by a dual E-selectin/CXCR4 inhibitor involving cellular migratory motility enhancement in BM stroma prior to AML cell intravasation. We envisage that, besides the designed blocking of E-selectin and CXCR4 molecules from binding their corresponding ligands, the dual moiety GMI-1359 agent has a capacity to generate motility-enhancing signals in AML cells that single inhibitors do not seem to trigger. Among several mechanisms possible, this action could involve E-selectin and CXCR4 crosslinking by a dual moiety molecular structure or binding avidity enhancement, requiring further investigation. In addition, our results highlight a likely mechanism of AML resistance to therapeutic "mobilization", one that involves cancer cell persistence in the bone/osteoblastic niches. Disclosures Zal: Daiichi-Sankyo: Research Funding; Moleculin Biotech, Inc.: Research Funding. Fogler:GlycoMimetics: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Magnani:GlycoMimetics, Inc.: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Andreeff:Daiichi-Sankyo; Jazz Pharmaceuticals; Celgene; Amgen; AstraZeneca; 6 Dimensions Capital: Consultancy; Daiichi-Sankyo; Breast Cancer Research Foundation; CPRIT; NIH/NCI; Amgen; AstraZeneca: Research Funding; Amgen: Research Funding; Centre for Drug Research & Development; Cancer UK; NCI-CTEP; German Research Council; Leukemia Lymphoma Foundation (LLS); NCI-RDCRN (Rare Disease Clin Network); CLL Founcdation; BioLineRx; SentiBio; Aptose Biosciences, Inc: Membership on an entity's Board of Directors or advisory committees.

scholarly journals LSD1 Inhibitor CPI-482 Shows Efficacy and Prolongs Survival in Mouse Models of AML and Post-MPN AML in the Context of Constitutive JAK-STAT Pathway Activation

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 50-51
Author(s):  
Raajit K. Rampal ◽  
John P. McGrath ◽  
Aishwarya Krishnan ◽  
Bing Li ◽  
Wenbin Xiao ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Myelogenous Leukemia ◽  
Publicly Traded ◽  
Private Company ◽  
Advisory Committees ◽  
Pathway Activation ◽  
Stat Pathway

Several novel mechanism-based therapeutic modalities are currently being clinically investigated for the treatment of patients with acute myelogenous leukemia (AML), including agents that exploit genomic vulnerabilities, attenuate leukemia stem cell populations and/or or synergize with anti-leukemic cytotoxic/epigenetic therapies. Lysine-specific demethylase 1 (LSD1) is an enzyme that functions in transcriptional repression by catalyzing the removal of histone H3 lysine 4 methylation, a histone modification associated with transcriptionally competent gene enhancers and transcriptional start sites. Small molecule mediated inhibition of LSD1 alters the chromatin state and the transcriptional output of LSD1 target genes. Transcriptional 'reprogramming' by LSD1 inhibitors either causes a direct impact on cell fate and/or renders malignant cells more susceptible to the treatment with other cancer therapeutic agents. LSD1 inhibitors have shown encouraging phenotypic effects in myelogenous leukemia (AML) models but the key molecular determinants governing LSD1 inhibitor sensitivity remain to be further investigated. Here, we explored the in vitro sensitivity of 350 cancer cell lines to our LSD1 inhibitor CPI-482 to identify potential hyper-responder cell contexts. Four AML cell lines showed high sensitivity with low nanomolar concentration GI50s, each of which contained either a JAK2V617F mutation or a genetic aberration that resulted in JAK-STAT pathway activation. Oral administration of LSD1 inhibitor CPI-482 on a once daily or a once weekly dosing schedule resulted in significant tumor growth inhibition in SET-2 and HEL 92.1.7 JAK2 mutant AML xenograft mouse models. Given the unmet need and poor prognosis in post-MPN secondary AML (sAML) we then explored CPI-482 in a tertiary transplant post-MPN AML retroviral transduction murine model (Jak2V617F retrovirus transduced intoTp53 null bone marrow). Jak2V617F/Tp53 null spleen cells were transplanted into lethally irradiated recipient mice along with wild-type donor support whole bone marrow cells. Mice were randomized to treatment with vehicle, Ruxolitinib (60mg/kg twice daily) or CPI-482 (60mg/kg weekly). Once-weekly treatment with CPI-482 significantly improved survival compared to vehicle (p<0.001) or ruxolitinib (p<0.043) (Figure 1A). Spleen weights were significantly reduced by CPI-482 compared to ruxolitinib (p<0.05;Figure 2B). The white blood cell count was unchanged in mice treated with CPI-482 but increased in both vehicle and ruxolitinib treated mice. Evaluation at the time of terminal take-down of mice demonstrated a significant increase in the proportion of lineage positive cells in both the bone marrow and spleen (compared to vehicle, p<0.05) consistent with restoration of normal hematopoiesis (Figure 1D). Histopathologic evaluation of the spleen demonstrated marked reduction in infiltration by blast cells, restoration of lymphoid follicles, emergence of megakaryocytes (Figure 1E), and modest reductions in reticulin fibrosis in CPI-482 treated mice, which was not observed in ruxolitinib treated mice. Mice tolerated treatment with CPI-482 well, with no changes in weights of treated mice (Figure 1F). Treatment of the JAK2V617F mutant AML cell lines SET-2 and HEL with CPI-482 resulted in specific transcriptional effects, including increased expression of the myeloid differentiation markers LY96 and CD86 and inflammatory response genes. CPI-482 also resulted in upregulation of genes that are repressed by the HOXA9 oncogene in other leukemia contexts. The induction of specific CPI-482 mediated gene expression and phenotypic changes was recapitulated by knockdown of the transcription factor GFI1B, suggesting that, consistent with prior findings in other leukemia contexts, LSD1 functionally cooperates with GFI1B in JAK2V617F mutant AML cells. These data provide support for a potential therapeutic impact of the LSD1 inhibitor CPI-482 in AML and sAML in the context of the JAK2V617F mutation, and thus extend the previous findings that LSD1 inhibitors may have utility in JAK2V617F mutated malignant proliferative neoplasms. Given the pressing need for new therapies for sAML which evolves from a pre-existing MPN, we believe these data form the rationale for a mechanism based clinical trial in this adverse risk myeloid malignancy. Figure Disclosures Rampal: Pharmaessentia: Consultancy; Galecto: Consultancy; Abbvie: Consultancy; Stemline: Consultancy, Research Funding; Constellation: Research Funding; Incyte: Consultancy, Research Funding; Celgene: Consultancy; Promedior: Consultancy; CTI Biopharma: Consultancy; Jazz Pharmaceuticals: Consultancy; Blueprint: Consultancy. McGrath:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Xiao:Stemline Therapeutics: Research Funding. Nikom:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Wang:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Levine:Imago: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Isoplexis: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Lilly: Consultancy, Honoraria; Janssen: Consultancy; Astellas: Consultancy; Morphosys: Consultancy; Novartis: Consultancy; Amgen: Honoraria; Gilead: Honoraria; Prelude Therapeutics: Research Funding; Qiagen: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Loxo: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees. Trojer:Constellation Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company.

Anti-CD74 Antibody hLL1 Is Associated with Lymphoma and Chronic Lymphocytic Leukemia Cell Effects In Vivo

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1796-1796
Author(s):  
Felipe Samaniego ◽  
Jillian F Wise ◽  
Luis Fayad ◽  
Michelle Fanale ◽  
Fredrick Hagemeister ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Research Funding ◽  
Bone Marrow Involvement ◽  
Leukemia Cell ◽  
B Cell Lymphoma ◽  
Cancer Development ◽  
Antigenic Peptides ◽  
Advisory Committees

Abstract Abstract 1796 Background: CD74 is the invariant chain of the MHCII complex and has an established role as a chaperone protein, which also prevents premature loading of antigenic peptides to the MHC. More recently, CD74 has been implicated as having a role in cancer development by its mediating the prosurvival signaling of the ligand macrophage migration inhibitory factor (MIF) stimulation and it's associated higher level expression in chemoresistant cancers. Blocking of CD74, the receptor for MIF, or its downstream target, a4b1 integrin has been reported to block the homing of CLL cells to bone marrow. The hLL1 antibody (Milatuzumab; Immunomedics, Inc, Morris Plains, NJ) shows promising anti-cancer activity, with eradiation of lymphoma and myeloma xenografts in mice through an undefined mechanism of action. Because of this apparent central role in cancer development, we examined CLL cells of patients (pts) treated with humanized anti-CD74 antibody hLL1. Study Design: Adults with relapsed non-Hodgkin's lymphoma or CLL, who had at least one prior therapy, were enrolled on this phase I-II trial. Patient criteria; ANC 1000, hemoglobin 9, platelets 50,000, adequate organ function, ECOG performance of 1–2, provided informed consent. The hLL1 antibody, in 4 or 8 mg/kg dosages, was administered intravenously over 4 hours, two or three times per wk for 4 wks. Results: Seven pts (4 male) with a median age 65 (range 57–72) with a median 2 (range 1–4) prior chemotherapy treatments were enrolled. Histologies included showed 1 pts with large B cell lymphoma, 5 with pts with SLL/CLL (5) and 1 with marginal zone lymphoma. All pts completed therapy except one who received 5 of 8 doses of planned therapy; 2 pts received dose escalated hLL1 at 8 mg/kg. The hLL1 was well-tolerated with some infusion related side effects, which responded to medications. All other patients maintained adequate hematologic indices, which did not prevent completing the initial therapy plan. Tumor responses were: one partial response, 1 progression, 1 non-evaluable, and 4 with stable disease. Pts' tumor cells were analyzed by reverse-phase protein analysis for activation status of 120 signaling proteins. In 4 of 4 pts with CLL, hLL1 therapy was associated with consistently lower phosphorylated levels of Akt T308 and Notch3; but whether this effect was caused by other concurrent medications could not be ruled out. All the pts who had elevated lymphocyte counts (with bone marrow involvement) showed a rise in lymphocyte counts (Figure) during treatment with hLL1 therapy and then returned to baseline or below baseline after completing infusion. Interestingly, the blocking of CD74 has been shown to interfere with the homing of CLL cells to bone marrow through the binding of CD74-dependent a4b1 integrin. The binding of CLL a4b1 integrin to stroma is a potent cell survival stimulus. To ascertain this mechanisms of CD74 hLL1 antibody induced release of lymphocytes, we analyzed migration of CLL cells in transwell towards MIF. CLL cells without hLL1 exposure had a 2–3 fold cell number migration towards MIF indicating these cells have an intact CD74 receptor mechanism. This analysis suggests that hLL1 targets CLL cells in vivo and interferes with homing of CLL. Follow up analyses will examine whether CLL cells of hLL1-treated pts downregulate a4b1 integrin mediate binding and alter binding to bone marrow stroma. Uncovering such actions are important steps in the elucidation of hLL1's mechanisms of action and for the development of targeted therapies for hematopoietic cancers. Disclosures: Fanale: Novartis Corporation: Honoraria, Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MedImmune: Research Funding; Millenium: Research Funding. Goldenberg:Immunomedics, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

scholarly journals The Metabolomic Status of the Differentiating Myeloid Lineage in MDS with Low and High Bone Marrow Blast Counts

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 32-33
Author(s):  
Aikaterini Poulaki ◽  
Theodora Katsila ◽  
Ioanna E Stergiou ◽  
Stavroula Giannouli ◽  
Jose Carlos Gόmez Tamayo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Warburg Effect ◽  
Research Funding ◽  
Metabolic Reprogramming ◽  
Negative Ion ◽  
Advisory Committees ◽  
Myeloid Lineage ◽  
Epigenetic Modifier ◽  
Cellular Fate

Despite its major role in cellular biology, metabolism has only recently acquired a principal role in the research of the most profound cellular cycle disturbance, cancerous transformation. Myelodysplastic syndromes (MDS), a massively heterogeneous group of Hematopoietic Stem/ Progenitor Cell (HSC/HPC) disorders lie at the interface of normal differentiation and malignant transformation and have thus drew great attention due to their polymorphic presentation and elusive pathophysiology. Failure to establish a direct etiopathogenic relationship with specific genetic aberrations, along with the novel finding of a highly deregulated HIF1 activity by several unrelated research groups worldwide, including ours, urged us to investigate the metabolomic status of human bone marrow derived differentiating myeloid lineage in comparison with one another as well as with control samples. BM aspiration samples collected from 14 previously untreated MDS patients (10 patients with <5% (1 SLD, 8MLD, 1del5q, group 1- G1) and 4 with >5% BM blasts (2 EB1, 2 EB2group 2 - G2)) and 5 age matched controls. Myeloid lineage cells were isolated through ficoll bilayer protocol. All samples contained homogenous myeloid lineage subpopulations, assessedthrough optical microscopy. Two different metabolite extraction protocols were applied. The one with the best metabolites yield (50% MeOH, 30% ACN, 20% H2O) was chosen. LC-MS/MS analysis was performed using UPLC 1290 system (Agilent Technologies) coupled to a TripleTOF 5600+ mass spectrometer (SCIEX) equipped with SWATH acquisition, SelexION technology and an electrospray ionization source (ESI). A threshold of a minimum of three samples expressing a given metabolite was set against data sparsity. Data tables were scaled by data centering and setting unit variance. Log2 Foldcalculation and PLS analysis were performed for the two datasets (positive and negative ion-modes). R2 and Q2 for positive ion-mode and negative-ion mode analyses were determined. Both datasets were merged in a unique data table by taking into account maximum absolute log2 foldvalues, when a metabolite was found in both datasets. Warburg effect was evidently present in both the G1 and G2 vs control comparisons, yet the role of this stem like aerobic glycolysis seems markedly different in the two groups. While in the G2 group it serves to rescue glucose from complete burn in the mitochondrion and thus shuts it towards nucleotide synthesis (Pentose Phosphate Pathway found upregulated) with the added benefit of increased reduced Glutathione synthesis and improved redox state, in the G1 group proves detrimental. This greatly variable effect of the same phenomenon in the cellular fate lies upon the quality and functionality of the cellular mitochondrial content. G2 precursors presented functional mitochondrial (decreased NAD/NADH and FAD/FADH2) contrary to the G1 ones (Table). Failing TCA cycle, with increased NAD/NADH and FAD/FADH2 ratios and markedly increased ADP/ATP levels leads to FAs accumulation due to failure of effective adequate β oxidation. The uncontrolled increase in the NAD/NADH ratio stimulates upper glycolysis into a turbo mode further increasing the ADP/ATP, depleting cellular energy contents, engaging it to a never-ending deadly metabolism. The enormous abundance of upper glycolytic intermediates is relieved through phospholipid and ceramide synthesis, all found massively upregulated in both the MDS vs control yet also in the G1 vs G2 comparisons. FAs, mostly phospholipid and ceramide accumulation, interrupt the mitochondrial membrane lipidome further incapacitating metabolic integrity and inducing their autophagic degradation which further stimulates the Warburg effect. This type of metabolic reprogramming is eventually targeted to epigenetic modifier production, increased S-adenosyl-methionine, the major methyl group donor, 2-HydroxyGlutarate, a potent epigenetic modifier and notorious oncometabolite, Acetyl-Lysine, the major acetyl- group donor, even glutathione. We therefore present a model of an uncontrolled Warburg effect which in the G1 group confers premature death of the hematopoietic precursors, the ineffective hematopoiesis of MDS. Yet, under the pressure of the vastly upregulated epigenetic modifiers cellular fate changes, the G1 precursors adapt and transform to the G2 ones yet eventually to Acute Myeloid Leukemia blasts. Table Disclosures Vassilopoulos: Genesis pharma SA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.

scholarly journals p53 Mediated Bone Marrow Mesenchymal Stem Cell Expansion Supports Acute Myeloid Leukemia Development

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 523-523
Author(s):  
Rasoul Pourebrahimabadi ◽  
Zoe Alaniz ◽  
Lauren B Ostermann ◽  
Hung Alex Luong ◽  
Rafael Heinz Montoya ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Osteoblast Differentiation ◽  
Hematopoietic Cells ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Mdm2 Inhibitor ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a heterogeneous disease that develops within a complex microenvironment. Reciprocal interactions between the bone marrow mesenchymal stem/stromal cells (BM-MSCs) and AML cells can promote AML progression and resistance to chemotherapy (Jacamo et al., 2014). We have recently reported that BM-MSCs derived from AML patients (n=103) highly express p53 and p21 compared to their normal counterparts (n=73 p<0.0001) (Hematologica, 2018). To assess the function of p53 in BM-MSCs, we generated traceable lineage specific mouse models targeting Mdm2 or Trp53 alleles in MSCs (Osx-Cre;mTmG;p53fl/fl and Osx-Cre;mTmG;Mdm2fl/+) or hematopoietic cells (Vav-Cre;mTmG;p53fl/fl and Vav-Cre;mTmG;Mdm2fl/+). Homozygote deletion of Mdm2 (Osx-Cre;Mdm2fl/fl) resulted in death at birth and displayed skeletal defects as well as lack of intramedullary hematopoiesis. Heterozygote deletion of Mdm2 in MSCs was dispensable for normal hematopoiesis in adult mice, however, resulted in bone marrow failure and thrombocytopenia after irradiation. Homozygote deletion of Mdm2 in hematopoietic cells (Vav-Cre;Mdm2fl/fl) was embryonically lethal but the heterozygotes were radiosensitive. We next sought to examine if p53 levels in BM-MSCs change after cellular stress imposed by AML. We generated a traceable syngeneic AML model using AML-ETO leukemia cells transplanted into Osx-Cre;mTmG mice. We found that p53 was highly induced in BM-MSCs of AML mice, further confirming our findings in primary patient samples. The population of BM-MSCs was significantly increased in bone marrow Osx-Cre;mTmG transplanted with syngeneic AML cells. Tunnel staining of bone marrow samples in this traceable syngeneic AML model showed a block in apoptosis of BM-MSCs suggesting that the expansion of BM-MSCs in AML is partly due to inhibition of apoptosis. As the leukemia progressed the number of Td-Tomato positive cells which represents hematopoietic lineage and endothelial cells were significantly decreased indicating failure of normal hematopoiesis induced by leukemia. SA-β-gal activity was significantly induced in osteoblasts derived from leukemia mice in comparison to normal mice further supporting our observation in human leukemia samples that AML induces senescence of BM-MSCs. To examine the effect of p53 on the senescence associated secretory profile (SASP) of BM-MSCs, we measured fifteen SASP cytokines by qPCR and found significant decrease in Ccl4, Cxcl12, S100a8, Il6 and Il1b upon p53 deletion in BM-MSCs (Osx-Cre;mTmG;p53fl/fl) compared to p53 wildtype mice. To functionally evaluate the effects of p53 in BM-MSCs on AML, we deleted p53 in BM-MSCs (Osx-Cre;mTmG;p53fl/fl) and transplanted them with syngeneic AML-ETO-Turquoise AML cells. Deletion of p53 in BM-MSCs strongly inhibited the expansion of BM-MSCs in AML and resulted in osteoblast differentiation. This suggests that expansion of BM-MSCs in AML is dependent on p53 and that deletion of p53 results in osteoblast differentiation of BM-MSCs. Importantly, deletion of p53 in BM-MSCs significantly increased the survival of AML mice. We further evaluated the effect of a Mdm2 inhibitor, DS-5272, on BM-MSCs in our traceable mouse models. DS-5272 treatment of Osx-cre;Mdm2fl/+ mice resulted in complete loss of normal hematopoietic cells indicating a non-cell autonomous regulation of apoptosis of hematopoietic cells mediated by p53 in BM-MSCs. Loss of p53 in BM-MSCs (Osx-Cre;p53fl/fl) completely rescued hematopoietic failure following Mdm2 inhibitor treatment. In conclusion, we identified p53 activation as a novel mechanism by which BM-MSCs regulate proliferation and apoptosis of hematopoietic cells. This knowledge highlights a new mechanism of hematopoietic failure after AML therapy and informs new therapeutic strategies to eliminate AML. Disclosures Khoury: Angle: Research Funding; Stemline Therapeutics: Research Funding; Kiromic: Research Funding. Bueso-Ramos:Incyte: Consultancy. Andreeff:BiolineRx: Membership on an entity's Board of Directors or advisory committees; CLL Foundation: Membership on an entity's Board of Directors or advisory committees; NCI-RDCRN (Rare Disease Cliln Network): Membership on an entity's Board of Directors or advisory committees; Leukemia Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; German Research Council: Membership on an entity's Board of Directors or advisory committees; NCI-CTEP: Membership on an entity's Board of Directors or advisory committees; Cancer UK: Membership on an entity's Board of Directors or advisory committees; Center for Drug Research & Development: Membership on an entity's Board of Directors or advisory committees; NIH/NCI: Research Funding; CPRIT: Research Funding; Breast Cancer Research Foundation: Research Funding; Oncolyze: Equity Ownership; Oncoceutics: Equity Ownership; Senti Bio: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Eutropics: Equity Ownership; Aptose: Equity Ownership; Reata: Equity Ownership; 6 Dimensions Capital: Consultancy; AstaZeneca: Consultancy; Amgen: Consultancy; Daiichi Sankyo, Inc.: Consultancy, Patents & Royalties: Patents licensed, royalty bearing, Research Funding; Jazz Pharmaceuticals: Consultancy; Celgene: Consultancy. OffLabel Disclosure: Mdm2 inhibitor-DS 5272

scholarly journals Transplantation for Congenital Sideroblastic Anaemia Is Feasible and Offers Outcomes Comparable to Other Transfusion Dependent Anaemias. a Joint Retrospective Study of the Paediatric Diseases and Severe Aplastic Anaemia Working Parties (PDWP/SAAWP) of EBMT

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 45-47
Author(s):  
Josu de la Fuente ◽  
Dirk-Jan Eikema ◽  
Paul Bosman ◽  
Robert F Wynn ◽  
Miguel Díaz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Board Of Directors ◽  
Research Funding ◽  
Graft Failure ◽  
Chronic Gvhd ◽  
Conditioning Regimen ◽  
Response To Treatment ◽  
Variable Response ◽  
Advisory Committees ◽  
Grade Ii

Congenital sideroblastic anaemias (CSA) are a rare group of disorders characterized by the presence of pathologic iron deposits within the mitochondria of erythroid precursors (ring sideroblasts) in the bone marrow due to heterogenous germline mutations leading to defects in mitochondrial heme synthesis, iron-sulfur (Fe-S) cluster biogenesis, or protein synthesis. Patients present with anaemia and relative reticulocytopenia, and systemic iron overload secondary to chronic ineffective erythropoiesis, leading to end-organ damage. The disease is heterogenous underlying the genetic variability and the variable response to treatment. Although a number of CSA patients have received a bone marrow transplant, the outcomes and toxicities are not known. This status makes it very difficult to understand the role of BMT in the management of CSA. A search in the EBMT database identified 28 patients receiving a HSCT for CSA between 1998 to 2018 by 24 participating centres. The median year of transplantation was 2014 (IQR 2004-2016). The distribution was equal between males (n=14) and females (n=14). The median age at transplantation was 7 years of age (3-10 years). Fifteen patients had a sibling HSCT (88%), one a family matched donor HSCT (6%) and one an unrelated matched (6%), the type of transplant being unknown in others (n=11). The source of stem cells was bone marrow in 20 cases (74%), peripheral blood in 4 cases (15%), cord blood in 2 (7%) and combined bone marrow and cord in one (4%). Five cases had a Bu/Cy based conditioning regimen, 4 had Bu/fludarabine based regimen and three fludarabine/treosulfan based conditioning with the rest having a variety of approaches. Eighty-six percent of cases had serotherapy with ATG or alemtuzumab. The median follow-up was 31.6 months (95% CI, 12.2-74.1%). The overall survival at 12 and 24 months was 88% (76-100) and 82% (66-99), respectively (figure 1). The median neutrophil engraftment was 18 (15-21) days and platelet engraftment >20 x 109/L was 29 (20-51) days, with a graft failure incidence of 7% (0-17) at 12 months. Two patients suffered from VOD. There were four deaths, three of which were related to transplant complications. The event free survival (survival without graft failure, relapse and second transplant) at 12 and 24 months was 85% (72-99) (figure 2). Six patients developed acute GvHD grade II and one case grade III; giving a grade II/III incidence of 28% (10-46). There was one case of limited and one of chronic GvHD, giving an incidence of 11% (0-26%) at 12 months and 24 months. In conclusion, whilst HSCT for CSA is a rare occurrence, these data demonstrate that HSCT for this condition is feasible and the outcomes are in keeping with those obtained for transplantation for transfusion dependent anaemias during the same time-period. Disclosures Handgretinger: Amgen: Honoraria. Moraleda:Gilead: Consultancy, Other: Travel Expenses; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy, Other: Travel Expenses; Sandoz: Consultancy, Other: Travel Expenses; Takeda: Consultancy, Other: Travel Expenses. Risitano:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Jazz: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees; Samsung: Membership on an entity's Board of Directors or advisory committees; Amyndas: Consultancy; RA pharma: Research Funding; Biocryst: Membership on an entity's Board of Directors or advisory committees; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees; Pfizer: Speakers Bureau. Peffault De Latour:Amgen: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Apellis: Membership on an entity's Board of Directors or advisory committees; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

scholarly journals Effect of Moderate and Severe Hemophilia a on Daily Life in Children and Their Caregivers: A CHESS Paediatrics Study Analysis

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 43-45
Author(s):  
Kate Khair ◽  
Francis Nissen ◽  
Mariabeth Silkey ◽  
Tom Burke ◽  
Aijing Shang ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Disease Burden ◽  
Hemophilia A ◽  
Daily Life ◽  
Social Activity ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Lost Work ◽  
Hours Of Work

Introduction: Hemophilia A (HA) is a congenital bleeding disorder, caused by a deficiency in clotting factor VIII (FVIII) and characterized by uncontrolled bleeding and progressive joint damage. This analysis assesses the impact of disease burden on the daily life of children with hemophilia A (CwHA) and their caregivers, addressing a deficit of current research on this topic. Methods: The Cost of Haemophilia in Europe: a Socioeconomic Survey in a Paediatric Population (CHESS Paediatrics) is a retrospective, burden-of-illness study in children with moderate and severe HA (defined by endogenous FVIII [IU/dL] relative to normal; moderate, 1-5%; severe, <1%) across France, Germany, Italy, Spain and the UK. CwHA were recruited and stratified by both age group (0-5 years:6-11 years:12-17 years=1:1:1) and disease severity (severe:moderate=approximately 2:1, prioritizing children with severe HA [CwSHA]). Data for this analysis were captured from physicians, children, and their caregivers. Physicians completed online case report forms for treated children, and the child and/or their caregivers completed a paper-based questionnaire utilizing 5-point Likert scales. For CwHA aged 0-7, the questionnaire was completed by the caregiver, while for CwHA aged 8-17, children and caregivers completed different sections. Hours of care provided by the caregiver and work lost by the caregiver were reported as median values due to non-normal data distribution. Informed consent was obtained for all participants. Upon review, the study was approved by the University of Chester ethical committee. Results: Data from child/caregiver questionnaires were available for 196 CwHA (moderate, 25.5%; severe, 74.5%); the majority of these children, as expected, were receiving prophylaxis (72.4%), and did not have FVIII inhibitors (89.8%; Table 1). There was a direct impact of disease burden on CwHA, particularly with regard to physical and social activities (Figure 1). Overall, it was agreed or strongly agreed by the child or caregiver that 48.0% and 57.5% of children with moderate HA (CwMHA) and CwSHA respectively, have reduced physical activity due to HA, and 46.0% and 57.5%, respectively, have reduced social activity due to HA. A total of 36.0% and 61.0% of CwMHA and CwSHA, respectively, had adapted their treatment in anticipation of physical or social activity (Table 1). Furthermore, 34.0% of CwMHA and 55.4% of CwSHA were frustrated due to their disease, and many (CwMHA, 36.0%; CwSHA, 50.7%) felt that they had missed opportunities (Figure 1). For 66.0% of CwMHA and 76.0% of CwSHA, it was reported that their daily life was compromised due to their HA. Caregivers provided a median (interquartile range [IQR]) of 19.0 (10.0-59.5) and 12.0 (5.0-20.0) hours a week of care for the hemophilia-related needs of their CwMHA (n=30) or CwSHA (n=105), respectively. Of those who responded, 17.4% (n=4/23) and 25.0% (n=20/80) of caregivers to CwMHA or CwSHA, respectively, stated they have lost work due to their caregiving duty. This was more than twice as common for caregivers in families with multiple CwHA (42.9%, n=9/21 responses) compared with those in families with one CwHA (18.5%, n=15/81 responses). Median (IQR) hours of work per week estimated to be lost were 20.0 (17.0-22.0) for caregivers of CwMHA (n=4) and 12.5 (4.50-20.0) for caregivers of CwSHA (n=20). Conclusions: In conclusion, both children and caregivers make sacrifices in their daily lives due to HA; many CwHA reported reduced physical and social activities, fewer opportunities and feelings of frustration due to their HA. Caregivers reported spending a significant number of hours caring for their child and some reported losing work due to their caring responsibilities. However, some outcomes may be limited by the small number of respondents and narrow response options, particularly those regarding the caregiver burden. Responses on the hours of work lost may be subject to selection bias, as caregivers who have lost work may be more likely to respond to this question. Additionally, as this question is targeted at caregivers in employment, it is unknown if some caregivers have left employment due to their caregiving responsibilities. According to this analysis, children/caregivers are frequently required to adapt the child's treatment before the child engages in activities. Overall, the burden of disease was similar in children with moderate and severe HA. Disclosures Khair: Takeda: Honoraria, Speakers Bureau; Bayer: Consultancy, Honoraria, Speakers Bureau; Biomarin: Consultancy; HCD Economics: Consultancy; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Medikhair: Membership on an entity's Board of Directors or advisory committees; Sobi: Consultancy, Honoraria, Research Funding, Speakers Bureau; CSL Behring: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; Haemnet: Membership on an entity's Board of Directors or advisory committees. Nissen:GSK: Research Funding; Novartis: Research Funding; Actelion: Consultancy; F. Hoffmann-La Roche Ltd: Current Employment. Silkey:Aerotek AG: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Burke:HCD Economics: Current Employment; University of Chester: Current Employment; F. Hoffmann-La Roche Ltd: Consultancy. Shang:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company, Other: All authors received support for third party writing assistance, furnished by Scott Battle, PhD, provided by F. Hoffmann-La Roche, Basel, Switzerland.. Aizenas:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. Meier:F. Hoffmann-La Roche Ltd: Current Employment, Current equity holder in publicly-traded company. O'Hara:HCD Economics: Current Employment, Current equity holder in private company; F. Hoffmann-La Roche Ltd: Consultancy. Noone:Research Investigator PROBE: Research Funding; Healthcare Decision Consultants: Membership on an entity's Board of Directors or advisory committees; European Haemophilia Consortium: Membership on an entity's Board of Directors or advisory committees.

scholarly journals To Treat or Not to Treat? Understanding Treatment Patterns in Patients with Lower-Risk Myelofibrosis at the Time of Enrollment in the MOST Study

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 49-51
Author(s):  
Rami S. Komrokji ◽  
Brady L. Stein ◽  
Robyn M. Scherber ◽  
Patricia Kalafut ◽  
Haobo Ren ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Lower Risk ◽  
Research Funding ◽  
Symptom Burden ◽  
Risk Groups ◽  
Treatment Patterns ◽  
Low Risk ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Therapy Initiation

Background: Myelofibrosis (MF) is a chronic Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) characterized by extramedullary hematopoiesis, bone marrow fibrosis, splenomegaly, constitutional symptoms, and diminished quality of life. Treatment decisions may involve a variety of factors including prognosis and symptomatology. Data regarding real-world disease and demographic factors that contribute to therapy initiation and choice in pts with lower risk MF are limited. This analysis of data from the ongoing Myelofibrosis and Essential Thrombocythemia Observational STudy (MOST; NCT02953704) assessed whether these factors differ for lower risk pts who were treated vs untreated at enrollment. Methods: MOST is a longitudinal, noninterventional, prospective, observational study in pts with MF or essential thrombocythemia enrolled at clinical practices within the US. Pts included in the analysis (≥18 y), had low risk MF by the Dynamic International Prognostic Scoring System (DIPSS; Blood. 2010;115:1703), or intermediate-1 (INT-1) risk by age >65 y alone. Pt data were entered into an electronic case report form during usual-care visits over a planned 36-month observation period. Pt-reported symptom burden was assessed using the MPN-Symptom Assessment Form (MPN-SAF); Total Symptom Score (TSS) was calculated (0 [absent] to 100 [worst imaginable]; J Clin Oncol. 2012;30:4098). Data were analyzed with basic descriptive and inferential statistics. Results: Of 233 pts with MF enrolled at 124 sites between 11/29/2016 and 03/29/2019, 205 were included in this analysis; 28 were excluded for being INT-1 risk for reasons other than age. Of the 205 pts, 85 (41.5%) were low- and 120 (58.5%) were INT-1 risk; 56.5% (48/85) and 59.2% (71/120), respectively, were being treated at enrollment. Pt characteristics are listed in Table 1A. Fewer low- vs INT-1 risk pts were JAK2 V617F or MPL positive, and more were CALR positive. The proportion of pts with palpable splenomegaly was similar for treated low- and INT-1 risk pts. In low risk pts, the proportion of pts with palpable splenomegaly was higher in untreated vs treated pts; whereas, in INT-1 risk pts, the opposite was observed (ie, lower proportion in untreated vs treated pts). Blood counts were generally similar across cohorts, except median leukocytes were lower for low risk treated pts and platelet counts were elevated in low- vs INT-1 risk pts. The proportion of pts with comorbidities was similar across cohorts, except for fewer cardiovascular comorbidities in low- vs INT-1 risk pts. Mean TSS was lower in low- vs INT-1 risk pts, but the proportion of pts with TSS ≥20 was greater in treated vs untreated pts in both low- and INT-1 risk groups. Fatigue was the most severe pt-reported symptom in all cohorts. Differences in mean TSS and individual symptom scores between risk groups were not significant (P > 0.05), except itching was worse among INT-1 risk pts (P=0.03). Physician-reported signs and symptoms were generally more frequent for untreated vs treated pts, irrespective of risk (all P > 0.05). Most low risk (69.4%) and INT-1 risk pts (61.2%) who were currently untreated at enrollment had not received any prior MF-directed treatment (Table 1B); the most common prior treatment among currently untreated pts was hydroxyurea (HU) in both risk groups. Of currently treated pts, HU was the most common MF-directed monotherapy at enrollment in low-risk pts, and ruxolitinib was most common in INT-1 risk pts. No low risk pts and few INT-1 risk pts were currently receiving >1 MF-directed therapy at enrollment. Conclusion: These real-world data from pts with MF enrolled in MOST show that a substantial proportion of both low- and INT-1 risk pts who had received treatment before enrollment were not being treated at the time of enrollment. Although watch-and-wait is a therapeutic option, the finding that many of these lower risk pts had in fact received prior therapies suggests an unmet need for effective and tolerable second-line treatment options. Treated pts had greater pt-reported symptom burden vs untreated pts, which suggests that high symptom burden may contribute to the decision for treatment. Prospective studies are needed to evaluate symptom burden change with therapy initiation. In this regard, future analyses of data from MOST are planned to assess the longitudinal evolution of the clinical characteristics, treatment patterns, and management of pts with MF. Disclosures Komrokji: Geron: Honoraria; Agios: Honoraria, Speakers Bureau; AbbVie: Honoraria; Incyte: Honoraria; Novartis: Honoraria; BMS: Honoraria, Speakers Bureau; JAZZ: Honoraria, Speakers Bureau; Acceleron: Honoraria. Stein:Incyte: Research Funding; Kartos: Other: educational content presented; Constellation Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Pharmaessentia: Membership on an entity's Board of Directors or advisory committees. Scherber:Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. Kalafut:Incyte: Current Employment, Current equity holder in publicly-traded company. Ren:Incyte: Current Employment, Current equity holder in publicly-traded company. Verstovsek:Incyte Corporation: Consultancy, Research Funding; Roche: Research Funding; Genentech: Research Funding; Blueprint Medicines Corp: Research Funding; CTI Biopharma Corp: Research Funding; NS Pharma: Research Funding; ItalPharma: Research Funding; Celgene: Consultancy, Research Funding; Gilead: Research Funding; Protagonist Therapeutics: Research Funding; Novartis: Consultancy, Research Funding; Sierra Oncology: Consultancy, Research Funding; PharmaEssentia: Research Funding; AstraZeneca: Research Funding; Promedior: Research Funding.

scholarly journals DYRK1A Is Regulated By Oncogenic KMT2A and Required for Survival of KMT2A-Rearranged Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2742-2742
Author(s):  
Christian Hurtz ◽  
Gerald Wertheim ◽  
Rahul S. Bhansali ◽  
Anne Lehman ◽  
Grace Jeschke ◽  
...  
Keyword(s):  
Gene Expression ◽  
B Cells ◽  
Board Of Directors ◽  
Research Funding ◽  
Lymphoblastic Leukemia ◽  
Leukemia Cell ◽  
Negative Regulator ◽  
Advisory Committees ◽  
Normal Tissues ◽  
Pharmacologic Inhibition

Background: Research efforts have focused upon uncovering critical leukemia-associated genetic alterations that may be amenable to therapeutic targeting with new drugs. Targeting the oncogenic BCR-ABL1 fusion protein in Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (B-ALL) with tyrosine kinase inhibitors to shut down constitutive signaling activation and induce leukemia cell cytotoxicity has remarkably improved patients' survival and has established a precision medicine paradigm for kinase-driven leukemias. However, multiple subtypes of B-ALL are driven through non-tyrosine fusion proteins, including the high-risk KMT2A-rearranged (KMT2A-R) subtype common in infants with B-ALL, leaving many patients with insufficient treatment options. Objectives: KMT2A-R B-ALL is associated with chemoresistance, relapse, and poor survival with a frequency of 75% in infants and 10% in older children/adults with B-ALL. Current intensive multiagent chemotherapy regimens induce significant side effects yet fail to cure the majority of patients, demonstrating continued need for novel therapeutic approaches. The goals of our study were to i) identify signaling molecules required for KMT2A-R B-ALL cell survival, ii) select ALL-associated targets that are not essential in normal tissues, and iii) develop new treatment strategies that may benefit patients with KMT2A-R ALL. Results: We performed a genome-wide kinome CRISPR screen using the pediatric KMT2A-R cell line SEM and identified DYRK1A among other signaling molecules as required for leukemia cell survival. DYRK1A is a member of the dual-specificity tyrosine phosphorylation-regulated kinase family and has been reported as a critical oncogene in a murine Down syndrome (DS) model of megakaryoblastic leukemia. In normal hematopoiesis, DYRK1A controls the transition from proliferation to quiescence during lymphoid development. Deletion of DYRK1A results in increased numbers of B cells in S-G2-M phase, yet also significantly reduces cell proliferation. Meta-analysis of ChIP-Seq data from two KMT2A-AFF1 cell lines (SEM and RS4;11) and a human KMT2A-Aff1-FLAG-transduced ALL model demonstrates that both N-terminal (KMT2AN) and C-terminal (AFF1C) and the FLAG-tagged KMT2A-Aff1 fusion directly bind to the DYRK1A promoter. Gene expression and RT-PCR analyses of SEM cells treated with inhibitors against two important KMT2A fusion complex proteins, DOT1L (histone methyltransferase) and menin (tumor suppressor), demonstrate that only menin inhibition induced DYRK1A downregulation. Interestingly, deletion of germline KMT2A in murine B-cells did not decrease DYRK1A expression. Taken together, these results suggest direct transcriptional regulation through the KMT2A fusion complex. Surprisingly, RNA and protein expression of DYRK1A was reduced in KMT2A-R ALL compared to other B-ALL subtypes. We then identified MYC as a potential negative regulator of DYRK1A that could explain the lower RNA and protein expression levels observed. A gain-of-function experiment showed marked downregulation of DYRK1A when MYC was ectopically expressed in murine B-cells, while loss of MYC resulted in DYRK1A upregulation. Parallel analysis of publicly available gene expression data from children with high-risk B-ALL (NCI TARGET database) showed significantly higher MYC RNA expression levels in KMT2A-R ALL as compared to other ALL subtypes, further validating our findings that MYC acts as a negative regulator of DYRK1A. Finally, to assess pharmacologic inhibition, we treated multiple KMT2A-rearranged ALL cell lines with the novel DYRK1A inhibitor EHT 1610 and identified sensitivity to DYRK1A inhibition. We then queried the Achilles database and identified that DYRK1A is not a common essential gene in normal tissues, suggesting minimal potential for on-target/off-tumor effects of DYRK1A inhibition. Conclusions: We identified a novel mechanism in KMT2A-R ALL in which DYRK1A is positively regulated by the KMT2A fusion protein and negatively regulated by MYC. Genetic deletion and pharmacologic inhibition of DYRK1A resulted in significant growth disadvantage of KMT2A-R ALL cells. While further studies are needed, we predict that combining DYRK1A inhibitors with chemotherapy could decrease relapse risk and improve long-term survival of patients with KMT2A-R B-ALL. Disclosures Crispino: MPN Research Foundation: Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Consultancy; Scholar Rock: Research Funding; Forma Therapeutics: Research Funding. Tasian:Incyte Corportation: Research Funding; Gilead Sciences: Research Funding; Aleta Biotherapeutics: Membership on an entity's Board of Directors or advisory committees. Carroll:Astellas Pharmaceuticals: Research Funding; Incyte: Research Funding; Janssen Pharmaceuticals: Consultancy.

scholarly journals Increased Early Mortality after Fludarabine and Melphalan Conditioning with Peripheral Blood Grafts in Haploidentical SCT with Post-Transplant Cyclophosphamide

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4496-4496 ◽  
Author(s):  
Luke Eastburg ◽  
David A. Russler-Germain ◽  
Ramzi Abboud ◽  
Peter Westervelt ◽  
John F. DiPersio ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Early Mortality ◽  
Cell Transplant ◽  
Advisory Committees ◽  
Post Transplant ◽  
Equity Ownership

The use of post-transplant cyclophosphamide (PTCy) in the context of haploidentical stem cell transplant (haplo-SCT) has led to drastically reduced rates of Graft-vs-Host (GvH) disease through selective depletion of highly allo-reactive donor T-cells. Early trials utilized a reduced-intensity Flu/Cy/TBI preparative regimen and bone marrow grafts; however, relapse rates remained relatively high (Luznik et al. BBMT. 2008). This led to the increased use of myeloablative (MA) regimens for haplo-SCT, which have been associated with decreased relapse rates (Bashey et al. J Clin Oncol. 2013). Most studies have used a MA total body irradiation (TBI) based regimen for haplo-SCT. Preparative regimens using fludarabine and melphalan (FluMel), with or without thiotepa, ATG, and/or low dose TBI have also been reported using bone marrow grafts. Reports on the safety and toxicity of FluMel in the haplo-SCT setting with PTCy and peripheral blood stem cell (PBSC) grafts are lacking. In this two-center retrospective analysis, the safety/toxicity of FluMel as conditioning for haplo-SCT was evaluated. We report increased early mortality and toxicity using standard FluMel conditioning and PBSC grafts for patients undergoing haplo-SCT with PTCy. 38 patients at the University of Rochester Medical Center and the Washington University School of Medicine underwent haplo-SCT with FluMel conditioning and PBSC grafts between 2015-2019. Outcomes were measured by retrospective chart review through July 2019. 34 patients (89.5%) received FluMel(140 mg/m2). Two patients received FluMel(100 mg/m2) and two patients received FluMel(140 mg/m2) + ATG. The median age at time of haplo-SCT was 60 years (range 21-73). 20 patients were transplanted for AML, eight for MDS, two for PMF, two for NHL, and five for other malignancies. The median Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI) score was 4 (≥3 indicates high risk). 11 patients had a history of prior stem cell transplant, and 16 patients had active disease prior to their haplo-SCT. Seven patients had sex mismatch with their stem cell donor. Median donor age was 42 (range 21-71). 20 patient deaths occurred by July 2019 with a median follow up of 244 days for surviving patients. Nine patients died before day +100 (D100, "early mortality"), with a D100 non-relapse mortality (NRM) rate of 24%. Median overall and relapse free survival (OS and RFS, respectively) were 197 days (95% CI 142-not reached) and 180 days (95% CI 141-not reached), respectively, for the entire cohort. The 1 year OS and NRM were 29% and 50%. The incidence of grades 2-4cytokine release syndrome (CRS) was 66%, and 52% of these patients were treated with tocilizumab. CRS was strongly associated with early mortality, with D100 NRM of 36% in patients with grade 2-4 CRS compared to 0% in those with grade 0-1. The incidence of acute kidney injury (AKI) was 64% in patients with grade 2-4 CRS, and 8% in those without (p < 0.001). 28% of patients with AKI required dialysis. Grade 2-4 CRS was seen in 54% of patients in remission prior to haplo-SCT and in 92% of those with active disease (p = 0.02). Of the 9 patients with early mortality, 89% had AKI, 44% needed dialysis, and 100% had grade 2-4 CRS, compared to 31%, 10%, and 55% in those without early mortality (p = 0.002, p = 0.02, p = 0.01). Early mortality was not significantly associated with age, HCT-CI score, second transplant, disease status at transplant, total dose of melphalan, volume overload/diuretic use, or post-transplant infection. In conclusion, we observed a very high rate of NRM with FluMel conditioning and PBSC grafts for haplo-SCT with PTCy. The pattern of toxicity was strongly associated with grade 2-4 CRS, AKI, and need for dialysis. These complications may be mediated by excessive inflammation in the context of allo-reactive donor T-cell over-activation. Consistent with this, multiple groups have shown that FluMel conditioning in haplo-SCT is safe when using bone marrow or T-cell depleted grafts. Based on our institutional experiences, we would discourage the use of FluMel as conditioning for haplo-SCT with PTCy with T-cell replete PBSC grafts. Alternative regimens or variations on melphalan-based regimens, such as fractionated melphalan dosing or inclusion of TBI may improve outcomes but further study and randomized controlled trials are needed. This study is limited in its retrospective design and sample size. Figure Disclosures DiPersio: WUGEN: Equity Ownership, Patents & Royalties, Research Funding; Karyopharm Therapeutics: Consultancy; Magenta Therapeutics: Equity Ownership; Celgene: Consultancy; Cellworks Group, Inc.: Membership on an entity's Board of Directors or advisory committees; NeoImmune Tech: Research Funding; Amphivena Therapeutics: Consultancy, Research Funding; Bioline Rx: Research Funding, Speakers Bureau; Macrogenics: Research Funding, Speakers Bureau; Incyte: Consultancy, Research Funding; RiverVest Venture Partners Arch Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees. Liesveld:Onconova: Other: Data safety monitoring board; Abbvie: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Phase II Trial of the Combination of Ixazomib, Lenalidomide, and Dexamethasone in High-Risk Smoldering Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 804-804 ◽  
Author(s):  
Mark Bustoros ◽  
Chia-jen Liu ◽  
Kaitlen Reyes ◽  
Kalvis Hornburg ◽  
Kathleen Guimond ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
High Risk ◽  
Disease Progression ◽  
Board Of Directors ◽  
Rna Sequencing ◽  
Research Funding ◽  
Response Rate ◽  
Advisory Committees ◽  
Equity Ownership

Abstract Background. This study aimed to determine the progression-free survival and response rate using early therapeutic intervention in patients with high-risk smoldering multiple myeloma (SMM) using the combination of ixazomib, lenalidomide, and dexamethasone. Methods. Patients enrolled on study met eligibility for high-risk SMM based on the newly defined criteria proposed by Rajkumar et al., Blood 2014. The treatment plan was designed to be administered on an outpatient basis where patients receive 9 cycles of induction therapy of ixazomib (4mg) at days 1, 8, and 15, in combination with lenalidomide (25mg) at days 1-21 and Dexamethasone at days 1, 8, 15, and 22. This induction phase is followed by ixazomib (4mg) and lenalidomide (15mg) maintenance for another 15 cycles. A treatment cycle is defined as 28 consecutive days, and therapy is administered for a total of 24 cycles total. Bone marrow samples from all patients were obtained before starting therapy for baseline assessment, whole exome sequencing (WES), and RNA sequencing of plasma and bone marrow microenvironment cells. Moreover, blood samples were obtained at screening and before each cycle to isolate cell-free DNA (cfDNA) and circulating tumor cells (CTCs). Stem cell collection is planned for all eligible patients. Results. In total, 26 of the planned 56 patients were enrolled in this study from February 2017 to April 2018. The median age of the patients enrolled was 63 years (range, 41 to 73) with 12 males (46.2%). Interphase fluorescence in situ hybridization (iFISH) was successful in 18 patients. High-risk cytogenetics (defined as the presence of t(4;14), 17p deletion, and 1q gain) were found in 11 patients (61.1%). The median number of cycles completed was 8 cycles (3-15). The most common toxicities were fatigue (69.6%), followed by rash (56.5%), and neutropenia (56.5%). The most common grade 3 adverse events were hypophosphatemia (13%), leukopenia (13%), and neutropenia (8.7%). One patient had grade 4 neutropenia during treatment. Additionally, grade 4 hyperglycemia occurred in another patient. As of this abstract date, the overall response rate (partial response or better) in participants who had at least 3 cycles of treatment was 89% (23/26), with 5 Complete Responses (CR, 19.2%), 9 very good partial responses (VGPR, 34.6%), 9 partial responses (34.6%), and 3 Minimal Responses (MR, 11.5%). None of the patients have shown progression to overt MM to date. Correlative studies including WES of plasma cells and single-cell RNA sequencing of the bone microenvironment cells are ongoing to identify the genomic and transcriptomic predictors for the differential response to therapy as well as for disease evolution. Furthermore, we are analyzing the cfDNA and CTCs of the patients at different time points to investigate their use in monitoring minimal residual disease and disease progression. Conclusion. The combination of ixazomib, lenalidomide, and dexamethasone is an effective and well-tolerated intervention in high-risk smoldering myeloma. The high response rate, convenient schedule with minimal toxicity observed to date are promising in this patient population at high risk of progression to symptomatic disease. Further studies and longer follow up for disease progression are warranted. Disclosures Bustoros: Dava Oncology: Honoraria. Munshi:OncoPep: Other: Board of director. Anderson:C4 Therapeutics: Equity Ownership; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Takeda Millennium: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Oncopep: Equity Ownership. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghobrial:Celgene: Consultancy; Takeda: Consultancy; Janssen: Consultancy; BMS: Consultancy.

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