Tumor Specific Glycosylated CD43 Is a Novel and Highly Specific Target for Acute Myeloid Leukemia and Myelodysplastic Syndrome

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1646-1646
Author(s):  
Marijn A. Gillissen ◽  
Martijn Kedde ◽  
Greta de Jong ◽  
Etsuko Yasuda ◽  
Sophie E. Levie ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
High Risk ◽  
B Cell ◽  
Myeloid Leukemia ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Allogeneic Hsct ◽  
Cell Clones ◽  
Acute Myeloid

Abstract Background: Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are high-risk diseases with a poor prognosis. Even with intensive treatment regimens less than 50% of patients can be cured, and for the majority of patients - those over 65 years of age and/or patients with comorbidities - such intensive regimens are not feasible. Novel therapeutic approaches such as immunotherapy directed against a specific tumor target are highly needed. Aims: The aim of our study was to identify antibodies that are highly specific for AML and to discover novel tumor-specific antigens, widely expressed on AML and MDS but not on healthy hematopoietic and non-hematopoietic cells. Methods: Allogeneic bone marrow transplantation is an immunotherapy with proven therapeutic efficacy. We selected a patient with high-risk AML who remained disease free, now more than 5 years after receiving an allogeneic HSCT and therefore can be considered to have mounted a potent graft versus leukemia response. To study the antibody repertoire of this patient we isolated CD27+ IgG+ memory B lymphocytes, about 2 years after the transplant. These cells were transduced with Bcl-6 and Bcl-xL to generate plasmablast B cell clones that produce antibodies and express the B cell receptor on the cell surface. Supernatants of these B cell clones were used to screen for binding to surface antigens on the AML cell line THP-1. Results: We identified an donor derived IgG1 antibody, AT1413, that specifically bound to AML cell lines THP-1, MOLM-13, SH-2 and others, but not to normal bone marrow cells or non-hematopoietic cells. The antibody also interacted with AML blasts from the allogeneic HSCT patient from whom the antibody was derived, and with leukemic blasts isolated from newly diagnosed AML and MDS patients. Biochemical analysis revealed that AT1413 recognizes a sialylated epitope on CD43 which is specifically expressed on all types of AML and MDS cells, as illustrated by its reactivity with blasts of each of 60 randomly selected AML and MDS patients in our clinic. Since the target it is also expressed by CD34+ hematopoietic progenitor cells obtained from fetal liver and fetal bone marrow, but not by post-natal hematopoietic progenitor cells, it can be considered to be a oncofetal epitope. AT1413 induced antibody-dependent cell-mediated cytotoxicity and complement dependent cytotoxicity of AML cell lines and primary blasts. Summary and conclusion: We have identified oncofetal-sialylated CD43 (CD43os) as a novel tumor-specific target that is widely expressed on AML and MDS blasts. Antibodies against this target have therefore high potential as therapeutic antibodies, either as a naked antibody or manufactured into an antibody-drug conjugate, bispecific T cell engager or CAR (chimeric antigen receptor) T cell. Disclosures Kersten: Celgene: Research Funding; Amgen: Honoraria.

Targeting The Mitochondrial ClpP As a Novel Therapeutic Strategy For Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3937-3937
Author(s):  
Alicia Cole ◽  
Zezhou Wang ◽  
Rachel Mattson ◽  
Etienne Coyaud ◽  
Rose Hurren ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Enzymatic Activity ◽  
Myeloid Leukemia ◽  
Hematopoietic Cells ◽  
Mitochondrial Proteins ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Control Shrna ◽  
Acute Myeloid

Abstract Caseinolytic protease (ClpP) is a mitochondrial enzyme complex with structural similarity to the cytoplasmic proteasome, but little is known about its function in the mitochondria. We identified ClpP as a potential therapeutic target for acute myeloid leukemia (AML) through an shRNA screen to identify mitochondrial proteins that are necessary for the viability of AML cells. We measured ClpP expression in 511 AML samples and 21 samples of normal CD34+ hematopoietic cells using a reverse phase protein array. ClpP was over-expressed in 45% of primary AML samples and expression occurred across FAB subtypes, cytogenetic risk groups, molecular mutations, and CD34+ expression subsets. Next, we evaluated the effects of ClpP knockdown on the growth and viability of AML cells using 3 independent shRNA constructs in lentiviral vectors. In leukemic cell lines that express high levels of ClpP, (OCI-AML2 and K562), knockdown of ClpP reduced growth and viability by > 80%. Importantly, no changes in growth or viability were observed following knockdown of ClpP in HL60 cells, which have lower basal levels of ClpP expression. As a chemical approach to evaluate the effects of ClpP inhibition on AML and normal hematopoietic cells, we synthesized a beta-lactone bacterial ClpP inhibitor, (3RS,4RS)-3-(non-8-en-1-yl)-4-(2-(pyridin-3-yl)ethyl)oxetan-2-one (also known as A2-32-01). Demonstrating specificity for the target, A2-32-01 inhibited the enzymatic activity of human recombinant ClpP, but not chymotrypsin-, trypsin-, or capsase-like enzymatic activity. A2-32-01 induced cell death in TEX, OCI-AML2, and K562 leukemia cells at concentrations that matched its ability to inhibit ClpP activity. Similar to the genetic studies, A2-32-01 did not kill HL60 cells. A2-32-01 was selectively cytotoxic to primary AML cells expressing ClpP over normal hematopoietic cells or AML cells with low ClpP expression. In addition, A2-32-01 reduced the clonogenic growth and bone marrow engraftment of primary AML cells, demonstrating the ability of ClpP inhibition to target AML progenitor/stem cells. Mechanistically, we demonstrated that A2-32-01 disrupted mitochondrial membrane potential in TEX cells and primary AML samples sensitive to A2-32-01, but not in normal hematopoietic cells. To date, the substrates of the mitochondrial ClpP are unknown. Therefore, we defined the interactome map of ClpP in HEK293 cells using mass spectrometry and the BirA tagging method whereby near-neighbors of ClpP are marked with biotin. Fifty-eight mitochondrial proteins preferentially interacted with ClpP over controls and the proteins were primarily components of the respiratory chain and mitochondrial translation apparatus. Thus, ClpP appears to be important to maintain the integrity of mitochondrial respiration. In support of this hypothesis, genetic or chemical ClpP inhibition was cytotoxic to 143B rhabdomyosarcoma cells, but not their rho-zero counterparts that lack mitochondrial DNA and oxidative phosphorylation. Next, we evaluated whether ClpP was required for the growth of AML cells in vivo. We knocked down ClpP in TEX cells with shRNA and injected the cells into the femur of NSGF mice. Compared to cells infected with control shRNA, knockdown of ClpP significantly reduced the engraftment of the cells (control shRNA 15.12 ± 4.576 % vs. ClpP knockdown 0.6180 ± 0.1976 % engraftment). Finally, to evaluate the toxicity of ClpP inhibition, we generated ClpP -/- mice. ClpP -/- mice were viable with normal peripheral blood counts and hematopoietic progenitor cells isolated from their bone marrow showed no significant reduction in clonogenic growth compared to those from wild type mice. Moreover, the abundance of Lin-, Sca-1+, c-kit+ hematopoietic progenitor cells in the bone marrow of ClpP -/- mice was equivalent to that in ClpP +/+ controls. Thus, these data suggest that ClpP inhibition can effectively target a subset of AML, while sparing normal hematopoietic cells. Disclosures: No relevant conflicts of interest to declare.

Prospective Evaluation of Allogeneic Hematopoietic Stem-Cell Transplantation From Matched Related and Matched Unrelated Donors in Younger Adults With High-Risk Acute Myeloid Leukemia: German-Austrian Trial AMLHD98A

2010 ◽  
Vol 28 (30) ◽  
pp. 4642-4648 ◽  
Author(s):  
Richard F. Schlenk ◽  
Konstanze Döhner ◽  
Silja Mack ◽  
Michael Stoppel ◽  
Franz Király ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Younger Adults ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Risk Patients ◽  
Unrelated Donors ◽  
Acute Myeloid

Purpose To assess the impact of allogeneic hematopoietic stem-cell transplantation (HSCT) from matched related donors (MRDs) and matched unrelated donors (MUDs) on outcome in high-risk patients with acute myeloid leukemia (AML) within a prospective multicenter treatment trial. Patients and Methods Between 1998 and 2004, 844 patients (median age, 48 years; range, 16 to 62 years) with AML were enrolled onto protocol AMLHD98A that included a risk-adapted treatment strategy. High risk was defined by the presence of unfavorable cytogenetics and/or by no response to induction therapy. Results Two hundred sixty-seven (32%) of 844 patients were assigned to the high-risk group. Of these 267 patients, 51 patients (19%) achieved complete remission but had adverse cytogenetics, and 216 patients (81%) had no response to induction therapy. Allogeneic HSCT was actually performed in 162 (61%) of 267 high-risk patients, after a median time of 147 days after diagnosis. Graft sources were as follows: MRD (n = 62), MUD (n = 89), haploidentical donor (n = 10), and cord blood (n = 1). The 5-year overall survival rates were 6.5% (95% CI, 3.1% to 13.6%) for patients (n = 105) not proceeding to HSCT and 25.1% (95% CI, 19.1% to 33.0%; from date of transplantation) for patients (n = 162) receiving HSCT. Multivariable analysis including allogeneic HSCT as a time-dependent covariable revealed that allogeneic HSCT significantly improved outcome; there was no difference in outcome between allogeneic HSCT from MRD and MUD. Conclusion Allogeneic HSCT in younger adults with high-risk AML has a significant beneficial impact on outcome, and allogeneic HSCT from MRD and MUD yields similar results.

Flt3 Receptor Inhibition Abolishes Constitutive NFκB Activation in High-Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2434-2434
Author(s):  
Jennifer Grosjean ◽  
Lionel Ades ◽  
Simone Bohrer ◽  
Pierre Fenaux ◽  
Guido Kroemer
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Plasma Membrane ◽  
High Risk ◽  
Myelodysplastic Syndrome ◽  
Myeloid Leukemia ◽  
Bone Marrow Cells ◽  
Constitutive Activation ◽  
Nf Kappab ◽  
Acute Myeloid

Abstract High-risk myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are characterized by the constitutive activation of the anti-apoptotic transcription factor NF-kappaB, via the activation of the IKK complex. We show that constitutive activation of the receptor tyrosine kinase Flt3 is responsible for IKK activation and this activation of the NF-kappaB pathway was found to involve a not yet described phosphorylation of the IKK and IkBa complex involving tyrosine residues compared to serine residues in the classical NF-kappaB pathway. Chemical inhibition or knockdown of Flt3 with small interfering RNAs abolished NF-kappaB activation in MDS and AML cell lines, as well as in primary CD34+ bone marrow cells from patients, causing mitochondrial apoptosis. Epistatic analysis involving the simultaneous inhibition of Flt3 and IKK indicated that both kinases act via the same anti-apoptotic pathway. An IKK2 mutant with a constitutive kinase activity and a plasma membrane-tethered mutant of NEMO that activates IKK1/2 prevented the cytocidal action of Flt3 inhibition. IKK2 and Flt3 physically associated in MDS and AML cells and Flt3 inhibition caused the release of IKK2 from a preferential association with the plasma membrane. Flt3 inhibition only killed CD34+ bone marrow cells from high-risk MDS and AML patients, in correlation with the blast numbers and the NF-kappaB activity, yet had no lethal effect on healthy CD34+ cells or cells from low-risk MDS. These results suggest that Flt3 inhibitors might exert an anti-neoplastic effect in high-risk MDS and AML through inhibition of constitutive NF kappaB activation.

Allogeneic Transplanst for ACUTE Myeloid Leukemia: Cut Off Levels of WT1 Expression in 207 Patients and Pre-Emptive Therapy of Relapse

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1866-1866
Author(s):  
Carmen Di Grazia ◽  
Simona Geroldi ◽  
Raffaella Grasso ◽  
Maurizio Miglino ◽  
Nicoletta Colombo ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cell Transplant ◽  
Allogeneic Hsct ◽  
Group A ◽  
Leukemia Relapse ◽  
Group B ◽  
Acute Myeloid ◽  
Marrow Cells

Abstract Leukemia relapse remains a significant problem in patients with AML undergoing an allogeneic stem cell transplant(HSCT). Wilms Tumour 1 (WT1) expression has been shown to be a sensitive marker of minimal residual disease (MRD), both in patients after induction chemotherapy, as well as in patients undergoing an allogeneic HSCT. Hypotheses. The present study had 2 hypotheses: (1) WT1 expression in marrow cells of AML patients post-HSCT, will predict leukemia relapse and (2) WT1 based pre-emptive immunotherapy (IT) such as abrupt cyclosporin discontinuation and/or donor lymphocyte infusion (DLI), will prevent leukemia relapse. Patients. Bone marrow WT1 expression, was monitored in 207 patients with acute myeloid leukemia (AML) before and monthly after an allogeneic HSCT, until day +150, and then at every other outpatient access. Eligible for IT were patients without acute or chronic GvHD, with increased WT1 expression and a a marrow in hematologic remission. The trigger for IT was 180 WT1 copies in a first group of 122 patients (group A): this was based on the fact that WT1 expression in normal bone marrow is up to 180 copies . In a subsequent group of 85 patients (group B) the cut off for IT, was 100 copies, due to the fact that a first analysis of group A had shown 100 copies to be an earlier predictor of relapse (BJH 2013; 160: 503). DLI were given in escalating doses, starting at 1x105 CD3+ cells/kg in alternative donor grafts and at 1x106/kg in HLA identical grafts. DLI were escalated ½ log every month, in the absence of GvHD, to a maximum dose of 1x107/kg. Sixtyfour patients were eligible for IT, but only 35 received IT: reasons for non intervention were ongoing GHD, unavailable donor and delay in WT1 results. Results-Hypothesis N.1. Following transplantation, WT1 expression, was highly predictive of leukemia relapse: 12 relapses in 99 patients with WT1 < 100 copies /104 abl (12%); 19 relapses in 55 patients with WT1 between 101 and 180 copies (35%) and 37 relapses in 53 patients with WT1 >180 copies (70%) (p<0.0001). The median interval between WT1 positivity and relapse was 75 days in group A and 60 days in group B. Results-Hypothesis N.2. 35 patients received pre-emptive immune intervention, 17 in group A and 18 in group B. The latter had more patients beyond first remission at transplant (56% vs 23%) , more myeloablative regimens (100% vs 65%) and more family haploidentical donors (72% vs 6%); age was comparable. The risk of relapse was 13/17 (76%) for group A and 3/18 (17%) for group B (p<0.001), despite the larger proportion of patients beyond CR1 at transplant. GvHD following DLI occurred in 15% of patients. DLI-related mortality was 0%. The overall 3 year survival for patients in group A and B was 69% vs 47% (p=0.3). The relapse risk in patients of group A eligible but not receiving IT (n=21) was 74%; in group B (n=8) it was 50%. In conclusion, WT1 expression post-transplant is a strong predictor of leukemia relapse in patients with AML, and can be used to trigger pre-emptive immunotherapy, in approximately 50% of eligible patients. IT triggered at a WT1 cut-off level of 100 copies in bone marrow cells, is more effective, as compared to180 copies, in preventing leukemia relapse. Disclosures No relevant conflicts of interest to declare.

scholarly journals Targeted Therapies and Druggable Genetic Anomalies in Acute Myeloid Leukemia: From Diagnostic Tools to Therapeutic Interventions

Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4698
Author(s):  
Francesco Lanza ◽  
Ali Bazarbachi
Keyword(s):  
Acute Myeloid Leukemia ◽  
Progenitor Cells ◽  
Targeted Therapies ◽  
Myeloid Leukemia ◽  
Somatic Mutations ◽  
Therapeutic Interventions ◽  
Hematopoietic Progenitor Cells ◽  
Diagnostic Tools ◽  
Hematopoietic Progenitor ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a clonal disorder resulting from acquired somatic mutations in hematopoietic progenitor cells that lead to the dysregulation of differentiation and the proliferation of hematopoietic cells [...]

scholarly journals Improved outcome in children compared to adolescents and young adults after allogeneic hematopoietic stem cell transplant for acute myeloid leukemia: a retrospective study from the Francophone Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC)

2021 ◽  
Author(s):  
Cécile Pochon ◽  
Marie Detrait ◽  
Jean-Hugues Dalle ◽  
Gérard Michel ◽  
Nathalie Dhédin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Young Adults ◽  
Retrospective Study ◽  
Myeloid Leukemia ◽  
Chronic Gvhd ◽  
Intermediate Risk ◽  
Allogeneic Hsct ◽  
Acute Myeloid

Abstract Background There are currently few data on the outcome of acute myeloid leukemia (AML) in adolescents after allogeneic HSCT. The aim of this study is to describe the outcome and its specific risk factors for children, adolescents and young adults after a first allogeneic HSCT for AML. Methods In this retrospective study, we compared the outcome of AML patients receiving a first allogeneic HSCT between 2005 and 2017 according to their age at transplantation’s time: children (< 15 years, n = 564), adolescent and post-adolescent (APA) patients (15–25 years, n = 647) and young adults (26–40 years; n = 1434). Results With a median follow-up of 4.37 years (min–max 0.18–14.73 years), the probability of 2-year overall survival (OS) was 71.4% in children, 61.1% in APA patients and 62.9% in young adults (p = 0.0009 for intergroup difference). Both relapse and non-relapse mortality (NRM) Cumulative Incidence (CI) estimated at 2 years were different between the age groups (30.8% for children, 35.2% for APA patients and 29.4% for young adults—p = 0.0254, and 7.0% for children, 10.6% for APA patients and 14.2% for young adults, p < 0.0001; respectively). Whilst there was no difference between the three groups for grade I to IV acute GVHD CI at 3 months, the chronic GVHD CI at 2 years was higher in APA patients and young adults (31.4% and 36.4%, respectively) in comparison to the children (17.5%) (p < 0.0001). In multivariable analysis, factors associated with death were AML cytogenetics (HR1.73 [1.29–2.32] for intermediate risk 1, HR 1.50 [1.13–2.01] for intermediate risk 2, HR 2.22 [1.70–2.89] for high cytogenetics risk compared to low risk), use of TBI ≥ 8 Grays (HR 1.33 [1.09–1.61]), disease status at transplant (HR 1.40 [1.10–1.78] for second Complete Remission (CR), HR 2.26 [1.02–4.98] for third CR and HR 3.07 [2.44–3.85] for active disease, compared to first CR), graft source (HR 1.26 [1.05–1.50] for Peripheral Blood Stem Cells compared to Bone Marrow) and donor age (HR 1.01 (1–1.02] by increase of 1 year). Conclusion Age is an independent risk factor for NRM and extensive chronic GVHD. This study suggests that APA patients with AML could be beneficially treated with a chemotherapy-based MAC regimen and bone marrow as a stem cells source.

Prospective Evaluation of Azacitidine Maintenance Following Allogeneic Hematopoietic Stem Cell Transplantation in Patients with High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5476-5476 ◽  
Author(s):  
Harinder Gill ◽  
Albert Kwok Wai Lie ◽  
Yok Lam Kwong ◽  
Anskar Y.H. Leung
Keyword(s):  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
High Risk ◽  
Myeloid Leukemia ◽  
Chronic Gvhd ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Poor Risk ◽  
Acute Myeloid

Abstract Introduction and aim. Relapse following allogeneic hematopoietic stem cell transplantation (HSCT) is a major cause of treatment failure and is associated with a poor prognosis. Overall survivals are around 50% at 5 years following allogeneic HSCT in intermediate and high risk AML. Survivals remain less than 20% in poor-risk and very poor-risk patients based on the cytogenetic profile. Thus, prevention of relapse following allogeneic HSCT remains an unmet clinical need. Low-dose azacitidine maintenance post-HSCT has been shown to augment graft-versus-leukemia effect and may prolong survivals. We aim to prospectively evaluate the effect of azacitidine maintenance following allogeneic HSCT in high risk AML and MDS. Method. Consecutive patients with high-risk acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in remission following first allogeneic HSCT or second allogeneic HSCT (from the original donor) were recruited. High risk AML in this study comprised patients with poor risk karyotype, secondary AML transformed from underlying MDS, presence of fms-like tyrosine kinase 3-internal tandem duplication (FLT3 -ITD) and non-remission before HSCT. Azacitidine was administered at 100mg daily for 3 days per cycle every 28 days until progression or a maximum of 8 cycles. The clinicopathologic and treatment characteristics were determined. The occurrence of graft-versus-host disease (GVHD) was determined. DNA chimerism was determined in the bone marrow before the initiation of azacitidine, after 4th and 8th cycles of azacitidine and at 1 year. DNA chimerism was determined by quantification of polymorphic short tandem repeat sequences. The progression-free survival (PFS) and overall survival (OS) were determined by Kaplan-Meier analysis. Results. Thirty-four patients with high-risk AML (N=31) and MDS (N=3) were recruited. The median duration of follow-up was 14 months (range: 2 - 44 months). Twenty-two patients received azacitidine maintenance after first allogeneic HSCT, whereas 12 patients received azacitidine maintenance after a second allogeneic HSCT from the same donor following relapse from a first allogeneic HSCT For patients receiving azacitidine after first HSCT, at a median follow-up of 18.5 months (range: 5- 36 months), the median PFS was not reached, and the median OS was 32 months (95% confidence interval [C.I.]: 24.85-39.15). The 24-month PFS and OS were 66.1% and 73.2% respectively. Acute and chronic GVHD occurred in 7 (31.8%) and 17 patients (77%). For patients receiving azacitidine after second HSCT, at a median follow-up of 14 months (range: 9 - 46 months), the median PFS and OS were 9 months (95% C.I.:6.94-11.04) and 14 months (range: 11.77 - 16.23 months). The 24-month PFS and OS were 25% and 14% respectively. Acute and chronic GVHD occurred in 1 (8.3%) and 5 (41.7%) patients respectively. In both groups, 100% donor chimerism was achieved during azacitidine maintenance. Conclusion. Azacitidine maintenance following first allogeneic HSCT resulted in favorable 2-year survivals in selected patients with high-risk AML and MDS. Nevertheless, survivals were poor despite azacitidine maintenance after second allogeneic HSCT from the same donor. Full donor chimerism was maintained during azacitidine maintenance. Disclosures No relevant conflicts of interest to declare.

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