Expression of the CAMPATH-1 Antigen (CD52) on CD34+/CD38- Progenitor Cells in Patients with 5q- MDS and in a Subset of AML

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1728-1728
Author(s):  
Katharina Blatt ◽  
Harald Herrmann ◽  
Sabine Cerny-Reiterer ◽  
Susanne Herndlhofer ◽  
Wolfgang R. Sperr ◽  
...  
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Lymphocytic Leukemia ◽  
Target Antigen ◽  
Blood Monocytes ◽  
Trisomy 8 ◽  
Monosomy 7

Abstract Abstract 1728 The target antigen CAMPATH-1 (CD52) is widely expressed in various hematopoietic lineages inlcuding lymphocytes, basophils, and blood monocytes. The anti-CD52 antibody Alemtuzumab is used successfully to treat patients with chemotherapy-refractory chronic lymphocytic leukemia. Based on its strong immunosuppressive effects, Alemtuzumab has also been considered for patients with aplastic anemia and hypoplastic myelodysplastic syndromes (MDS). Indeed, more recently, Alemtuzumab was found to induce major hematologic responses in a group of patients with MDS. Although the immunosuppressive effect was considered to play a role, the exact mechanisms underlying this drug effect remained speculative. In the current study, we asked whether CD34+ bone marrow (BM) progenitor cells in MDS and acute myeloid leukemia (AML) express the CAMPATH-1 antigen. Twelve patients with MDS (5 females, 7 males; median age: 70 years), 25 patients with AML (16 females, 9 males; median age: 62 years), and 34 control cases (normal reactive BM, n=12; idiopathic cytopenia of unknown significance, n=11; chronic myeloid leukemia, CML, n=4; chronic myelomonocytic leukemia, CMML, n=3; JAK2 V617F+ myeloproliferative neoplasms, MPN, n=4) were examined. Surface expression of CD52 on CD34+/CD38+ and CD34+/CD38- BM progenitor cells was analyzed by monoclonal antibodies and multicolor flow cytometry. In the group of MDS, CD52 was detectable on CD34+/CD38- stem cells in 3/4 patients with isolated 5q-. In most of the other MDS patients, CD52 was weakly expressed or not detectable on CD34+/CD38- cells. In AML, CD34+/CD38- cells displayed CD52 in 12/25 patients, namely 3 with complex karyotype including 5q-, 2 with inv(3), one with t(8;21), one with inv(16), one with del13q, one with trisomy 8, one with monosomy 7, and 2 with normal karyotype. Expression of CD52 mRNA in CD34+/CD38- AML stem cells was confirmed by qPCR in all patients tested (n=14). In addition, a good correlation was found between surface CD52 expression and CD52 mRNA expression in AML progenitor fractions. In patients with normal hematopoiesis (n=12) or idiopathic cytopenia (n=11), CD34+/CD38- cells stained weakly positive or negative for CD52. Almost in all cases tested, blood monocytes and blood basophils stained positive for CD52. Together, our data suggest that the target antigen CAMPATH-1 (CD52) is expressed on primitive CD34+/CD38- progenitor cells in MDS, preferentially in 5q- patients, and in a subset of patients with AML. These observations may have clinical implications and explain recently described effects of Alemtuzumab in patients with MDS. Our data also suggest that Alemtuzumab may be an interesting targeted drug in patients with refractory or relapsed AML in whom neoplastic stem cells express the target antigen CD52. Disclosures: No relevant conflicts of interest to declare.

Haploinsufficiency Of SAMD9L, An Endosome Fusion Facilitator, In Mice Induces The Development Of Myeloid Malignancies Mimicking Human Diseases With Monosomy 7

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 227-227
Author(s):  
Hirotaka Matsui ◽  
Akiko Nagamachi ◽  
Akinori Kanai ◽  
Yuko Ozaki ◽  
Hiroaki Honda ◽  
...  
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Early Endosome ◽  
Cytokine Receptors ◽  
Juvenile Myelomonocytic Leukemia ◽  
Self Renewal ◽  
Newborn Mice ◽  
Monosomy 7 ◽  
Deficient Mice

Abstract Monosomy 7 is a common chromosomal abnormality found frequently in MDS and AML. We previously identified a common microdeletion cluster in 7q21.3 in juvenile myelomonocytic leukemia patients. This cluster contains three poorly characterized genes: sterile alpha motif (SAM) domain-9 (SAMD9) which is absent in mice, samd9-like (SAMD9L) and Miki (LOC253012). Although mutations have rarely been seen in these genes, the genes reside proximal to the 7q22 band that is deleted in single copy in nearly 25% of AML and MDS patients. We recently reported that Miki, a centrosomal protein that promotes alignment of chromosomes at metaphase, is a candidate gene responsible for mitotic/nuclear abnormalities observed in MDS patients (Mol Cell 2012). In this study, we established and characterized SAMD9L-deficient mice, along with the analysis of molecular function of SAMD9L protein. Among SAMD9L-/- (n=15) and SAMD9L+/- (n=15) littermates, 13 mice developed myeloid dysplasia, 2 mice developed myeloid leukemia and one mouse developed myeloproliferative disease after the age of 18 months, while all but one SAMD9L+/+ mice (n=23) maintained normal hematopoiesis throughout the 24-month observation period. Infection of MOL4070A retrovirus into newborn mice developed myeloid leukemia within 15 months preferentially in SAMD9L-deficient genetic background with Evi1 and Fbxl10 (encoding a H3K36 demethylase) genes as common virus integration sites. While bone marrow (BM) cells from SAMD9L+/+ mice (12 weeks old) formed fewer colonies by the third replating, cells from SAMD9L-deficient mice continued to form similar numbers and sizes of well-differentiated colonies beyond the 7th plating. The excess number of colonies formed was reduced by retrovirus-mediated forced expression of Samd9L. These data suggested enhanced self-renewal and/or delays in differentiation of SAMD9L-deficient stem cells. In addition, enhanced reconstitution ability of SAMD9L-deficient stem cells was demonstrated by competitive repopulation assay using the Ly5 congenic mouse system, where irradiated Ly5.1 mice were transplanted with long term-LSK cells from SAMD9L+/+ or SAMD9L-deficient Ly5.2 mice (10 weeks old) together with BM cells from SAMD9L+/+Ly5.1 mice. This was confirmed by limiting-dilution transplants, results of which showed a higher frequency of multi-lineage repopulating cells at 8 weeks in SAMD9L-/- donor BM. Moreover, growth advantage in the presence of cytokines was evident in liquid cultures of SAMD9L-deficient BM progenitor cells. Hypersensitivity of SAMD9L-deficient BM progenitors to cytokines was also shown in in vivo experiments, in which SAMD9L-deficient mice injected with cyclophosphamide (day 0) and G-CSF (days 1-4) showed significantly higher WBC counts than SAMD9L+/+ mice at the nadir (day 3). These findings suggested that SAMD9L-deficiency sensitizes hematopoietic progenitors to cytokines. Immunostaining using SAMD9L antibody showed a vesicular pattern of SAMD9L localization in approximately 15% of BM progenitor cells that overlapped with the localization of EEA1, an early endosomal protein. In SAMD9L-/- fibroblasts, while rapid endocytosis of PDGF-receptor (PDGFR) by PDGF stimulation occurred in a time-course similar to that in SAMD9L+/+ cells, homotypic fusion of endosomes containing PDGFR delayed. Inhibition of endosome fusion in SAMD9L-/- cells lead to the accumulation of PDGFR that were remained to be phosphorylated in early endosome, resulting in the prolonged activation of cytokine signals. Accumulation of cytokine receptors in early endosome and persistent cytokine signals were also found in BM progenitors obtained from SAMD9L-deficient mice. These observations suggest that SAMD9L is a crucial component of a protein complex that facilitates the degradation of cytokine receptors through the homotypic fusion of endosomes. Collectively, our study suggests the contribution of haploinsufficiency of SAMD9L to the pathogenesis of myeloid diseases harboring -7/7q- through the prolonged activation of cytokine signals that results in the enhancement of stem cell self-renewal and/or delay in differentiation of early progenitors. Deletion of other haploinsufficient tumor-suppressor genes that reside in 7q would collaborate with the deficiency of SAMD9L for myeloid leukemogenesis. Disclosures: No relevant conflicts of interest to declare.

Phenotyping of Neoplastic (CD34+/CD38−/CD123+) Stem Cells in Myeloid Malignancies Reveals Expression of Multiple Molecular Targets.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1381-1381
Author(s):  
Stefan Florian ◽  
Karoline Sonneck ◽  
Alexander W. Hauswirth ◽  
Maria-Theresa Krauth ◽  
Wolfgang R. Sperr ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Systemic Mastocytosis ◽  
Target Antigen ◽  
Normal Bone Marrow ◽  
Normal Bone ◽  
Myeloid Neoplasms ◽  
Neoplastic Stem Cells

Abstract Recent data suggest that myeloid neoplasms are organized hierarchically in terms of self renewal and maturation of early progenitor cells, similar to normal myelopoiesis. In acute myeloid leukemia (AML), the NOD/SCID mouse-repopulating leukemic stem cells usually co-express CD123 with CD34, but lack CD38. So far, however, little is known about expression of other markers and targets on these progenitors. In the present study, expression of target antigens on CD34+/CD38− cells was analyzed by multicolor flow cytometry in patients with AML (n=18), myelodysplastic syndromes (MDS, n=6), chronic myeloid leukemia (CML, n=8), systemic mastocytosis (SM, n=9), and normal bone marrow (n=5). The IL-3Ra chain (CD123) was found to be expressed on CD34+/CD38− cells in a majority of all patients in all disease-categories. Independent of the type of disease, the vast majority of these stem cells also co-expressed aminopeptidase-N (CD13) and the target receptor CD44 in all patients. CD34+/CD38− progenitor cells expressed variable amounts of the Mylotarg® receptor CD33, KIT (CD117), HLA-DR, and AC133 (CD133). With regard to AC133, two distinct subpopulations of progenitor cells were detected in many cases, namely a CD133+ and a clearly CD133- cell-fraction. In patients with AML, the levels of CD33 varied from patient to patient with a broad range of reactivity, whereas in most patients with MDS, CML, and SM, CD33 was found to be consistently expressed on most progenitors. In most patients, neoplastic stem cells did not express substantial amounts of the GM-CSF receptor alpha chain (CD116), Thy-1 (CD90), E-NPP3 (CD203c), MDR-1 (CD243), or PAR-2. In the normal bone marrow, CD34+/CD38− cells co-expressed CD13, CD44 and CD45, but did not express CD33, CD116, or CD123. In conclusion, neoplastic stem cells in various myeloid neoplasms appear to express a similar phenotype including target receptors such as CD13, CD33, and CD44. These antigens may thus be attractive targets of therapy in AML. However, since many of these targets are not expressed on all stem cells in all patients, the elimination of the entire clone may require combinations of targeted antibodies or use of additional drugs. In other cases (CD13, CD44, CD45), the target antigen is also expressed on normal stem cells, so that targeted therapy is likely to be an ablative maneuver and thus would require a combined stem cell transplantation approach.

Late Development of Cytogenetic Abnormalities in Ph Negative Cells of Chronic Myeloid Leukemia Patients Treated with Imatinib.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1108-1108
Author(s):  
Michael Deininger ◽  
François-Xavier Mahon ◽  
Francois Guilhot ◽  
Giuseppe Saglio ◽  
Philipp le Coutre ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Acute Leukemia ◽  
Cytogenetic Analysis ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Imatinib Treatment ◽  
Trisomy 8 ◽  
Monosomy 7 ◽  
Late Event

Abstract Abstract 1108 Poster Board I-130 Clonal cytogenetics abnormalities in Ph negative metaphases (CCA/Ph-) are observed in a variable fraction of Chronic Myeloid Leukemia (CML) patients (pts) after they obtain a Complete Cytogenetic Remission (CCyR). It is not known whether such abnormalities develop soon after CCyR or if they can appear as a late event. Cytogenetic analysis remains the only methodology able to detect such abnormalities and its use in pts in CCyR after several years of imatinib therapy is being questioned. The Imatinib Long Term Effect (ILTE) study enrolled 948 CML pts in 24 centers around the world (Europe, North/South America, Africa, Middle East and Asia); in order to be eligible, pts had to achieve a CCyR within 2 years after starting imatinib. These pts are being followed for long term side effects such as loss of CCyR, toxicities including second cancers, and survival. Within the ILTE cohort, 384 eligible pts received imatinib for > 5 years and remained in CCyR at 5 years. In 309 cases, at least one standard routine cytogenetic analysis after 5 years of treatment was available. The median duration of imatinib treatment is 6.5 years in this group of pts. A cytogenetic abnormality in the Ph negative metaphases was detected in 18 cases (5.8%; 99% Confidence Interval: 0-10.1%); the number of available cytogenetics analyses positive for CCA/Ph- varied from 1 to 12 per patient. The percentages of pts positive for CCA/Ph- in the the different participating centers ranged between 0 and 28.6%. Of the 18 cases positive for CCA/Ph-, 10 were diagnosed within the first 5 years of treatment, and 8 cases afterwards. Three pts (17%) developed abnormalities during the first 2 years of treatment, 5 (28%) during the third or fourth year, 4 (22%) during the fifth or sixth year, and 6 (33%) during year 7, 8 or 9. Abnormalities were: deletion of Y chromosome (7 cases), trisomy 8, del 7q (2 cases each), monosomy 7, trisomy 6, del 9q, Y duplication, del 13, del 18. With a median follow up of 4.5 years after first detection, none of the patients have developed acute leukemia or myelodysplasia. In addition none of these 18 pts lost his/her CCyR status. CCA/Ph-are detectable in a low but consistent proportion of CML pts in CCyR; their occurrence is not limited to the first 5 years of treatment. Our study supports the notion that patients with CCA/Ph- have a favorable prognosis, despite the similarity of the abnormalities to those observed in acute leukemia and myelodysplasia, suggesting CCA/Ph- to be quite slow in their evolution. These data suggest that the search for CCA/Ph- should not be limited to the first years of imatinib treatment. Disclosures No relevant conflicts of interest to declare.

KLF4 Regulates Self-Renewal of Leukemic Stem Cells in Chronic Myeloid Leukemia By Repressing Gbl Expression and Altering mTORC2 Activity

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1789-1789
Author(s):  
Chun Shik Park ◽  
Ye Shen ◽  
Takeshi Yamada ◽  
Koramit Suppipat ◽  
Monica Puppi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Chronic Phase ◽  
Leukemic Stem Cells ◽  
Self Renewal ◽  
Hematopoietic Stem

Abstract Tyrosine kinase inhibitors (TKIs) are the standard treatment for eradicating BCR-ABL-positive progenitor cells in chronic myeloid leukemia (CML); however, disease often relapses upon drug discontinuation because TKIs do not effectively eliminate leukemic stem cells (LSC). The development of novel strategies aimed at eradicating LSC without harming normal hematopoietic stem cells (HSC) is essential for the cure of CML patients. The generation of LSC-directed therapy relies on the identification of novel molecular pathways that selectively regulate LSC function independent of BCR-ABL. The Krüppel-like factor 4(KLF4) is a transcription factor that can either activate or repress gene transcription acting as an oncogene or a tumor suppressor depending on the cellular context. Analysis of a published dataset from chronic phase CML patients revealed elevated levels of KLF4 in LSC compared to progenitor cells indicating that KLF4 is likely implicated in LSC regulation. To study the role of KLF4 in LSC function, we used a CML mouse model combining somatic deletion of the Klf4 gene and retroviral transduction and transplantation of HSC. In contrast to mice receiving BCR-ABL-transduced Klf4fl/fl HSC that developed and succumbed to CML, mice transplanted with BCR-ABL-transduced Klf4Δ/Δ (Klf4fl/fl Vav-iCre+) HSC showed a progressive loss of leukemia despite an initial expansion of myeloid leukemic cells, which led to increased overall survival. This inability to sustain CML in the absence of KLF4 was caused by attrition of LSC in bone marrow and the spleen. Furthermore, deletion of KLF4 impaired the ability of LSC to recapitulate leukemia in secondary recipients suggesting a loss of self-renewal capacity. In contrast to LSC, KLF4 deletion led to increased self-renewal of normal HSC assessed by serial competitive transplantation. To identify KLF4 target genes involved in LSC self-renewal, we performed a global gene expression analysis using Klf4Δ/Δ LSC purified by cell sorting from leukemic mice. Analysis of gene expression in Klf4Δ/Δ LSC revealed significant upregulation of GβL, a component of mTOR complexes. Finally, we identified that KLF4 binds to GβL promoter by Chip-Seq analysis and that silencing resulted in inhibition of mTORC2 but not mTORC1 activity in 32D-BCR-ABL-positive CML cells. Our findings suggest that KLF4 transcriptionally represses GβL expression in LSC and that mTORC2 inhibition has the potential to completely eradicate LSC and induce treatment-free remission. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characterization of CD34+ Hematopoietic Progenitor Cells in JAK2V617F and Calr-mutated Myeloproliferative Neoplasms

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4572-4572
Author(s):  
Anna Angona ◽  
Alberto Alvarez ◽  
Raquel Longarón ◽  
Laura Camacho ◽  
Concepción Fernández ◽  
...  
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Mutant Allele ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Differentiation Potential ◽  
Allele Burden ◽  
Cd34 Cells

Abstract Introduction: The dominance of the JAK2V617F-positive clone at the CD34+ compartment is an important modifier of the disease phenotype in myeloproliferative neoplasms (MPN). Recently, mutations in the calreticulin gene (CALR) have been described in around 40-70% of JAK2V617F and MPL wild-type essential thrombocythemia (ET) and myelofibrosis (MF) patients. However, there is limited information regarding the role of CALR mutant clone in hematopoietic progenitor cells. Objective: To study the mutant allele burden at progenitor level in JAK2V617F-positive and CALR-mutated MPN. Methods: Sixty-five patients with MPN including 36 with polycythemia vera (PV) all JAK2V617F-positive, 13 with ET (7 JAK2V617F-positive and 6 CALR-mutated) and 16 with MF (9 JAK2V617F-positive post-PV MF, 4 CALR-mutated primary MF and 3 CALR-mutated post-ET MF) were included in the study. Granulocytes were isolated from peripheral blood by density gradient, whereas CD34+ cells were purified by immunomagnetic positive selection. Stem cells (CD34+CD38-) and progenitors (CD34+CD38+) populations were further separated by fluorescence-activated cell sorting. JAK2V617F and CALR allele burden was measured by quantitative PCR and PCR followed by fragment analysis, respectively, in stem cells, progenitor cells and granulocytes. The study was approved by the local Ethics Committee and informed consent was obtained according to the Declaration of Helsinki. Results: CALR-mutated ET patients harbored a higher mutant load in CD34+CD38- than JAK2V617F-positive ET patients (30.6 vs 6.3%, p=0.01), whereas no significant differences were observed in CD34+CD38+ and in granulocytes allele burdens. Moreover, CALR-mutated ET patients showed a higher mutational load in CD34+CD38- than JAK2V617F-positive PV (30.6% vs 15.7%, p=0.04) but the mutant load in granulocytes was lower (29.6% vs 63.3%, p<0.001). The mutant allele burden in granulocytes and CD34+ cells was higher in patients with JAK2V617F-positive MF than in those with CALR-mutated MF (CD34+CD38-: 71% vs 47.2% p=0.05, CD34+CD38+: 68.4% vs 40.6% p=0.018, granulocytes: 76.9% vs 53.7% p=0.05). Finally, we could demonstrate that the mutant load was lower in CALR-mutated ET patients than in CALR-mutated MF at progenitor level and in granulocytes (CD34+CD38-: 30.6% vs 47.1% p=0.08, CD34+CD38+: 17.8% vs 40.6% p=0.03, granulocytes: 29.6% vs 53.7% p=0.004). Conclusion: CALR-mutated ET patients have a higher mutant load in CD34+CD38- than JAK2V617F-positive ET and PV patients, whereas the JAK2V617F-positive hematopoietic progenitor cells have more differentiation potential than those CALR-mutated. Moreover, in the MF phase of MPN, the expansion of the mutated clone at the progenitor level is greater in JAK2V617F-positive than in CALR-mutated patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Identification of BCR/ABL-negative primitive hematopoietic progenitor cells within chronic myeloid leukemia marrow

Blood ◽  
1993 ◽  
Vol 81 (3) ◽  
pp. 801-807 ◽  
Author(s):  
T Leemhuis ◽  
D Leibowitz ◽  
G Cox ◽  
R Silver ◽  
EF Srour ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Polymerase Chain Reaction Analysis ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Hematopoietic Stem

Chronic myeloid leukemia (CML) is a malignant disorder of the hematopoietic stem cell. It has been shown that normal stem cells coexist with malignant stem cells in the bone marrow of patients with chronic-phase CML. To characterize the primitive hematopoietic progenitor cells within CML marrow, CD34+DR- and CD34+DR+ cells were isolated using centrifugal elutriation, monoclonal antibody labeling, and flow cytometric cell sorting. Polymerase chain reaction analysis of RNA samples from these CD34+ subpopulations was used to detect the presence of the BCR/ABL translocation characteristic of CML. The CD34+DR+ subpopulation contained BCR/ABL(+) cells in 11 of 12 marrow samples studied, whereas the CD34+DR- subpopulation contained BCR/ABL(+) cells in 6 of 9 CML marrow specimens. These cell populations were assayed for hematopoietic progenitor cells, and individual hematopoietic colonies were analyzed by PCR for their BCR/ABL status. Results from six patients showed that nearly half of the myeloid colonies cloned from CD34+DR- cells were BCR/ABL(+), although the CD34+DR- subpopulation contained significantly fewer BCR/ABL(+) progenitor cells than either low-density bone marrow (LDBM) or the CD34+DR+ fraction. These CD34+ cells were also used to establish stromal cell-free long-term bone marrow cultures to assess the BCR/ABL status of hematopoietic stem cells within these CML marrow populations. After 28 days in culture, three of five cultures initiated with CD34+DR- cells produced BCR/ABL(-) cells. By contrast, only one of eight cultures initiated with CD34+DR+ cells were BCR/ABL(-) after 28 days. These results indicate that the CD34+DR- subpopulation of CML marrow still contains leukemic progenitor cells, although to a lesser extent than either LDBM or CD34+DR+ cells.

scholarly journals Mesenchymal Stem Cells (MSCs) Intensify the Impact of KIR Ligand-Mismatching on Acute Graft-Versus-Host Disease Post HSCT in Patients with Acute Myeloid Leukemia but Not with Acute Lymphocytic Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 42-42
Author(s):  
Yu Zhang ◽  
Shaozhen Chen ◽  
Jinhua Ren ◽  
Xiaofeng Luo ◽  
Zhizhe Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Mesenchymal Stem Cells ◽  
Graft Versus Host Disease ◽  
Myeloid Leukemia ◽  
Acute Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Graft Versus Host ◽  
Gvhd Prophylaxis ◽  
Acute Myeloid

Objectives: Mesenchymal stem cells (MSCs) and killer cell immunoglobulin-like receptor (KIR) ligand-mismatch, which can trigger the alloreactivity of natural killer (NK) cells, have been shown to be protective for severe acute and chronic graft-versus-host disease (aGVHD, cGVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, there are no prospective or retrospective studies exploring their relationship. Here, we investigated the potential influence of KIR matching, MSCs and their coaction on GVHD prophylaxis, overall survival (OS) and relapse rate (RR) of allo-HSCT. Methods: Data from 154 patients with acute myeloid and lymphocytic leukemia treated with allo-HSCT between May 2015 and May 2020 in the transplantation unit of the Fujian Medical University Union Hospital were retrospectively analyzed. The cohort included 93 male patients (60.3%) and 61 female (39.7%), with a median age of 24 years (1-59 years), 104 cases of acute myeloid leukemia (AML; 67.5%) and 50 cases with acute lymphocytic leukemia (ALL; 32.5%). Eighty-one patients (52.6%) underwent MSCs infusion on day+1. The sources of MSCs were human placenta or human bone marrow. MSCs infusion dose ranged from 0.5 to 3x106/kg of recipient weight. KIR genotyping was performed by the PCR-SSO method. The amplicons were quantified on the Luminex 200 flow analyzer and analyzed using the Quick-Type for Lifecodes software for generating KIR data. Cox proportional hazards model and Kaplan-Meier survival curves were used for analysis. Results: At the time of transplantation, 65 cases (42.2%) were in remission, while 89 (57.8%) had active disease. aGVHD occurred in 31 patients (20.1%) and recurrence arose in 21 patients (13.6%), but no significant cGVHD was observed. After adjusting for age, disease-risk, HLA-match, donor gender, conditioning regimen intensity and type of post-grafting GVHD prophylaxis, Cox regression analysis revealed that KIR ligand-matching was associated with an increased risk of aGVHD compared to KIR ligand-mismatching (p=0.023) in AML patients, but KIR ligand-mismatching had no significant effect on aGVHD in ALL patients, and on OS and RR in both AML and ALL patients. MSCs was associated with much lower recurrence rate (RR) (p=0.049), even when the recipients were not in remission at the time of HSCT. Furthermore, MSCs reduced the incidence of aGVHD in both AML and ALL patients, although it did not reach statistical significance (p=0.19). The combination of KIR ligand-mismatching and MSCs infusion significantly suppressed aGVHD occurrence in AML patients (p=0.033). More importantly, MSCs infusion intensified the suppression effect of KIR ligand-mismatching on aGVHD in AML patients (p=0.047). In the KIR ligand-mismatch group, the incidence of aGVHD was 10.3% when patients received MSCs, compared to 25.6% in those who did not. However, combining KIR ligand-mismatch and MSCs injection had no significant effect on aGVHD in ALL patients, or on OS and RR in both AML and ALL patients. Conclusions: KIR ligand-mismatch, MSCs infusion and their combination significantly reduced the risk of aGVHD after allo-HSCT in AML patients. It confirms the relationship between MSCs injection and lower RR. These data provide a clinically applicable strategy where co-transplantation with MSCs and triggering of allo-NK cells by KIR ligand-mismatching can ameliorate aGVHD, thus improving allo-HSCT outcome in AML patients. Disclosures No relevant conflicts of interest to declare.

Minimal Residual Disease (MRD) Data in Hematologic Malignancy Drug Applications and Prescribing Information: FDA Analysis

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4928-4928
Author(s):  
Maryam Sarraf Yazdy ◽  
Andrea C. Baines ◽  
Theresa Carioti ◽  
Rachel Ershler ◽  
Emily Y. Jen ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Clinical Response ◽  
Myeloid Leukemia ◽  
Conflicts Of Interest ◽  
Residual Disease ◽  
Hematologic Malignancy ◽  
Lymphocytic Leukemia ◽  
Test Validation ◽  
Period 2 ◽  
Prescribing Information

Abstract Introduction: In the past decade, multiple studies have reported the prognostic and predictive value of MRD status in specific hematologic malignancies (HM). Because clinical trials are increasingly incorporating MRD status as a biomarker and efficacy endpoint, the adequacy of the MRD data to inform the prescribing information (PI) is relevant for the design and conduct of pivotal clinical trials. We present an analysis of the trends in inclusion of MRD data in pivotal trials in HMs and regulatory decisions made by the U.S. Food and Drug Administration (FDA). Methods: We reviewed FDA internal databases for original and supplemental new drug applications (NDAs) and biologics licensing applications (BLAs) submitted 1/2014-12/2020 to support approval of therapies (drugs, biologics, and cellular therapies) for HM. MRD data were evaluated for two time periods to inform potential trends: 1/2014-6/2017 (period 1) and 7/2017-12/2020 (period 2). Clinical study reports, selected datasets, FDA clinical reviews, and the proposed and approved PIs were examined for inclusion of MRD data, and FDA assessments of the adequacy of the MRD data for inclusion in the PI were reviewed. Results: Of 196 NDAs or BLAs involving HM submitted between 2014-2021, 53 (27%) had MRD data, including 53 pivotal trials. The trials included patients with chronic lymphocytic leukemia, chronic myeloid leukemia, acute myeloid leukemia, acute lymphocytic leukemia, and multiple myeloma. Twenty-one applications and pivotal trials with MRD data were submitted in period 1, and 32 applications and 35 trials were submitted in period 2. Three trials were resubmitted in period 2. MRD evaluation was specified as a secondary and exploratory endpoint in 35 (66%) and 19 (36%) of the trials, respectively. Of the 53 trials, MRD data was proposed by the Applicant for inclusion in the PI in 41 (77%) but was ultimately included in 25 (47%). Of the trials for which MRD data was proposed in labeling, MRD data were deemed adequate by FDA in 81% of studies in period 1 (13/16) and 48% of studies in period 2 (12/25). MRD assays in the PI included polymerase chain reaction, flow cytometry, and next-generation sequencing in 18 (72%), 5 (20%) and 4 (16%) of the trials, respectively, with the clinical threshold for test positivity ranging from 10 -3 to 10 -5. For 11 trials with MRD data in the PI (44%), the MRD was evaluated regardless of clinical response, and in 14 trials (56%) MRD was evaluated in patients achieving a specific clinical response. The leading reasons for excluding MRD data from the PI were analytical and test validation deficiencies (e.g., incomplete test characteristics data, lack of test validation overall or in that disease) followed by performance issues (e.g., high amount of test failure, inability to identify a clone) and issues with trial conduct or design (e.g., inadequate data collection, statistical issues). Conclusion: A quarter of HM drug applications, including 53 pivotal trials, submitted to the FDA between 2014-2020 included MRD data. Characterization of regulatory actions showed that despite the increasing number of submissions proposing MRD data for inclusion in the PI, rates of inclusion of MRD data in the PI did not reflect this increase. Improvements in assay validation and performance characteristics, robust collection of MRD data, and appropriate statistical planning can enable greater representation of MRD data in prescription drug labeling. Disclosures No relevant conflicts of interest to declare.

scholarly journals Altered NFE2 activity predisposes to leukemic transformation and myelosarcoma with AML-specific aberrations

Blood ◽  
2019 ◽  
Vol 133 (16) ◽  
pp. 1766-1777 ◽  
Author(s):  
Jonas Samuel Jutzi ◽  
Titiksha Basu ◽  
Maximilian Pellmann ◽  
Sandra Kaiser ◽  
Doris Steinemann ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Myeloproliferative Neoplasms ◽  
Functional Characterization ◽  
Trisomy 8 ◽  
Chromosome 5Q ◽  
Therapeutic Decisions ◽  
Prognostic Implications ◽  
Clinical Algorithms

Abstract In acute myeloid leukemia (AML), acquired genetic aberrations carry prognostic implications and guide therapeutic decisions. Clinical algorithms have been improved by the incorporation of novel aberrations. Here, we report the presence and functional characterization of mutations in the transcription factor NFE2 in patients with AML and in a patient with myelosarcoma. We previously described NFE2 mutations in patients with myeloproliferative neoplasms and demonstrated that expression of mutant NFE2 in mice causes a myeloproliferative phenotype. Now, we show that, during follow-up, 34% of these mice transform to leukemia presenting with or without concomitant myelosarcomas, or develop isolated myelosarcomas. These myelosarcomas and leukemias acquired AML-specific alterations, including the murine equivalent of trisomy 8, loss of the AML commonly deleted region on chromosome 5q, and mutations in the tumor suppressor Trp53. Our data show that mutations in NFE2 predispose to the acquisition of secondary changes promoting the development of myelosarcoma and/or AML.

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