scholarly journals UTX mutations in Myeloid Neoplasms

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3148-3148
Author(s):  
Yasunobu Nagata ◽  
Tomas Radivoyevitch ◽  
Hideki Makishima ◽  
Cassandra M. Hirsch ◽  
Bartlomiej P Przychodzen ◽  
...  

Abstract Genetic studies in myeloid neoplasms have revealed that somatic mutations and deletions frequently affect epigenetic regulation via DNA methylation and histone modification. One frequently affected epigenetic complex is polycomb repressive complex 2 (PRC2), which trimethylate Histone3Lysine27 (H3K27) to create a repression mark for the expression of a variety of genes that includes essential homeobox genes. Members of this complex include EZH2, EED and SUZ12, which exert methyltransferase activity, and perhaps indirectly also DNTM3A and ASXL1. The histone demethylase ubiquitously transcribed X (UTX) counters the enzymatic activity of PRC2 by removing di- and trimethyl groups from H3K27. It thus removes repressive marks. We were the first to report UTX mutations in a small portion of CMML and MDS cases. In another cohort, frequent somatic loss-of-function mutations in UTX were found in ALL. The goal of the present study was to understand the functional role of UTX and the consequences of its mutations on H3K27 methylation status, specifically with respect to their relevance to myeloid neoplasia. A total of 1,979 patients with various myeloid neoplasms (n = 1,686) and other hematologic disorders (n = 293) were screened for gene mutations in UTXand other reported driver genes relevant to myeloid neoplasms using whole exome sequencing and/or targeted deep-sequencing. Expression array analyses were performed on 200 samples. In addition, we also used sequencing and expression data from the de novo AML TCGA repository. UTXwas mutated in 55 (2.8%) cases out of 1,979 cases. The mutations were found in 2.5% of MDS, 3.1% de novo AML (including 8.3% CBF AML), 4.8% MDS/MPN, and 1.4% secondary AML (sAML). Of those, 77% were missense mutations and 23% nonsense, splice site and frameshift mutations, without an evident hot spot. The male-to-female ratio was 1.2 (55% vs. 45%). UTX gene expression was significantly higher in females than in males (p<.001). After gender adjustment and dichotomized using a threshold of expression of 2 standard deviations from the mean, low UTX expression levels were identified in 13/183 (7%) individuals. When we focused on clonal burden using variant allele frequencies (VAFs) to investigate clonal architecture within the tumor population, in 37 cases UTX constituted subclonal events and in 18 they were dominant. We then examined the molecular context of UTX lesions. Average mutation burden in patients with UTX mutations was higher than in WT UTX carriers (4 vs. 1.5, p<.001). UTX mutations co-occurred with other driver genetic mutations such as ASXL1, ZRSR2, CUX1, NF1. Surprisingly, EZH2 mutations are also enriched in UTX mutated cases although they function in the opposite direction of H3K27 trimethylation. Focusing on dominant clone and subclonal events in cases with these two mutations, EZH2mutations were enriched in cases with dominant UTX clone. This suggests that they play important roles in the cancer's pathogenesis. To clarify the role of UTX in the maintenance of leukemia, genomic knockouts of UTX were developed in human leukemic cell lines using the CRISPR-Cas9 system. RNA sequencing revealed that knockout cell enrichment for developmental regulators such as Hox genes. In addition, we made knockdowns of human CD34+ cells using short hairpin RNAs against UTX. The cells showed enhanced colony formation and increased replating efficiency consistent with retained clonogenicity. The truncating pattern of UTX mutations in myeloid neoplasms suggests that they are loss-of-function hits. Missense mutations thus need to be confirmed. Functional analysis in vitro shows that low expression of UTX may have functionally equivalent consequences. If so, an additional 7% of patients may have low UTX expression, and may thus phenocopy patients with UTX mutations. Combined, a total of ~10% out of myeloid neoplasm patients may harbor UTX deficiency. Epigenetic modifying drugs related to H3K27 such as inhibitors of EZH2and histone deacetylases are in development. It is controversial to which patients they should be applied. Our findings could be key to a deeper understanding of epigenetic alterations, drug function, and response. Disclosures Makishima: The Yasuda Medical Foundation: Research Funding. Mukherjee:Novartis: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Carraway:Celgene: Research Funding, Speakers Bureau; Baxalta: Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Sekeres:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 955-955 ◽  
Author(s):  
Ryunosuke Saiki ◽  
Yusuke Shiozawa ◽  
Tetsuichi Yoshizato ◽  
Kenichi Yoshida ◽  
Yuichi Shiraishi ◽  
...  

Abstract Background Copy number alteration (CNA) is a hallmark of cancer genomes and has been implicated in the development of human cancers, including myeloid neoplasms. We developed a novel, next-generation sequencing-based platform for highly sensitive detection of CNAs with a single exon resolution, which was applied to sequencing data from 1,185 patients to delineate a comprehensive landscape of CNAs in myeloid neoplasms. Materials and Methods We enrolled 1,185 patients with different myeloid neoplasms including myelodysplastic syndromes (n = 607), myelodysplastic/myeloproliferative neoplasms (n = 80), de novo acute myeloid leukemia (AML) (n = 136), secondary AML (sAML) (n = 226), and unknown myeloid malignancies (n = 136). Whole-exome sequencing (WES) was performed on samples from 260 patients, while samples from 925 patients including pre-transplantation peripheral blood samples provided by Japan Marrow Donor Program were subjected to targeted deep sequencing. Eight cases were serially evaluated before and after progression tosAML. RNA baits for targeted deep sequencing were designed to cover 69 driver genes in myeloid neoplasms and 1,158 single-nucleotide polymorphisms (SNPs)for assessment of allelic imbalance. In WES, allelic imbalance was examined using allele frequencies of SNPs within coding regions. Focal CNAs were defined as CNAs whose lengths relative to the chromosomal arms were below 10%. Results To obtain a landscape of CNAs in coding regions, a comprehensive copy number analysis was performed on 260 patients including 136 with de novo AML and 124 with myeloid neoplasms with myelodysplasia, all of whom were studied by WES. A total of 755 CNAs (502 deletions and 253 amplifications) were identified, where 52% of the patients harbored at least one alteration. Using GISTIC 2.0 algorism, we identified 21 significantly altered regions involving known or putative driver genes (Figure 1): losses of 7q22.1 (CUX1), 12p13.2 (ETV6), 13q14 (RB1),17p13.1(TP53), and 17q11.2 (NF1), and gains of 3q26-27 (EVI1), 8q24.21 (MYC), 11q13.5-14.1(PAK1), 11q23.3 (MLL),11q24-25 (ETS1), 13q12.2 (FLT3),21q22.2 (ETS2 and ERG). We next compared the frequencies of CNAs between de novo AML and myeloid neoplasms with myelodysplasia. While chromosomes 7, 12, and 17 were commonly affected, deletions of 13q14 were significantly enriched in myeloid neoplasms with myelodysplasia (Odds ratio [OR]: 5.07, P = 0.040), and amplifications of 11q24-25 (OR: 5.54, P = 0.028), and 21q22.2 (OR: 6.10, P = 0.020) in de novo AML, suggesting a specific role of these events in each disease entity. In addition, serial sampling revealed trisomy8, deletions of 7q and 12p were recurrently acquired during leukemic transformation in patients withmyelodysplasia. Taken together, many driver genes in myeloid neoplasms were frequently targeted by CNAs includingmicrodeletions. Based on these finding, we sought to obtain a more detailed landscape of CNAs in a larger cohort. We combined copy number profiles of patients studied by targeted deep sequencing and those by WES. Of total, 1,691 CNAs (1,096 deletions and 595 amplifications) were detected, where 39% of the cases harbored at least one alteration. Microdeletionsor focal amplifications were frequently found in the significantly altered regions revealed by WES: microdeletionsof ETV6 (n = 10), NF1 (n = 8), CUX1 (n = 5), TP53 (n = 5), and amplifications of FLT3 (n = 7), ETS1 (n = 3), ETS2 (n = 3), and ERG (n = 3), validating the result obtained from a cohort studied by WES. We also identified known driver genes in myeloid neoplasms were recurrently affected with focal CNAs: microdeletions of RUNX1, BCOR, ASXL2, DNMT3A, and ZRSR2, and amplifications of GNAS, RIT1, CSF3R, and BCL11A. Among them, DNMT3A and ASXL2, located within 500 kb in chromosome 2, tended to be co-deleted (3 out of 4 cases). Focal deletions of TP53 were often affected with homozygous deletions or were accompanied by gene mutations, implying bi-allelic inactivation. High amplifications were also observed in regions including ETS1, MLL, FLT3, MYC, and PAK1, which suggest a critical role in the pathogenesis of myeloid malignancy. Conclusion We obtained the landscape of CNAs in myeloid neoplasms based on the sequencing data of 1,185 patients. Collectively, our results indicated that CNAs targeted a specific set genes including well-known drivers of myeloid malignancies, indicating a critical role inleukemogenesis. Disclosures Kanda: Otsuka Pharmaceutical: Honoraria, Research Funding. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees. Makishima:The Yasuda Medical Foundation: Research Funding. Maciejewski:Celgene: Consultancy, Honoraria, Speakers Bureau; Alexion Pharmaceuticals Inc: Consultancy, Honoraria, Speakers Bureau; Apellis Pharmaceuticals Inc: Membership on an entity's Board of Directors or advisory committees. Ogawa:Takeda Pharmaceuticals: Consultancy, Research Funding; Kan research institute: Consultancy, Research Funding; Sumitomo Dainippon Pharma: Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2518-2518
Author(s):  
Andrew Hantel ◽  
Niloufer Khan ◽  
Richard A. Larson ◽  
Lucy A. Godley ◽  
Michael J. Thirman ◽  
...  

Abstract Introduction Improving therapy for rel/ref AML remains a challenge. Decitabine, a DNA methyl-transferase inhibitor, initially showed promise in AML as a 5-day, first-line induction regimen and more recently as a 10-day regimen in older and unfit patients (1). However, little is known about the activity of decitabine in the rel/ref patient population despite increased use. Therefore, we sought to analyze the outcomes of these pts treated at our institution. Methods To obtain data regarding decitabine efficacy in rel/ref AML, we performed a retrospective analysis of outcomes following decitabine treatment in 34 adult pts treated at The University of Chicago from January 2009 to June 2014. Permission to access patient charts was granted by the medical centerÕs Institutional Review Board. AML was defined by WHO criteria, genetic risk grouping and complete remission (CR) was according to ELN classification; PR was defined as >50% decrease in bone marrow blasts and normalization of blood counts. Rel/ref AML was defined as either having had a prior CR with recurrence of disease or having received a prior induction regimen (1-2 cycles) without CR. Results Median pt age was 62 yrs (range, 18-81) and 60% were male. Median Charlson comorbidity index (CCI) was 5 (range, 0-8); 29% had ECOG performance status 0-1 and 71% had >2. 21 pts (62%) had de novo AML (7 with myelodysplasia-related changes), 3 (9%) had therapy-related myeloid neoplasm (t-MN), and 10 (29%) had secondary AML after myelodysplastic syndrome. 6% were in the ELN favorable genetic group, 3% intermediate-I, 18% intermediate-II, and 67% adverse; 2 cases were unevaluable. The median number of prior treatment regimens was three. 9% had received prior azacitidine, 85% had received prior HiDAC, and 38% had a prior allogeneic stem cell transplant (SCT). 34 pts received a total of 71 cycles of decitabine, 20 mg/m2 daily, in 5 or 10-day cycles every 28 days. All patients received 10-day courses, 91% had an initial 10-day course, and 74% had only 10-day courses. The median number of cycles per pt was 2; 59% received >1 cycle. 7 (21%) achieved CR and 4 (12%) had a partial response (PR), for an overall response rate (OR) of 33%. Responses occurred in 24% of pts with de novo AML, 66% with t-MN, and 50% with secondary AML. Intermediate and adverse group pts had OR of 14% and 39%, respectively. All pts achieving CR did so after 1 cycle; PR required a median of 3 cycles. Pts who achieved CR or PR had a significantly lower pretreatment WBC count (median, 9.5 vs 49.5 x 103/µL in non-responders; p=0.015) and blast percentage (44 vs 59.4; p=0.035) than those who did not. Pts with secondary AML or t-MN had a higher probability of OR compared to those with de novo AML (54 vs 23%; p=0.042). Median overall survival (OS) of all pts was 256 days; prior SCT was associated with reduced OS (p=0.017). When comparing de novo to secondary AML & t-MN, 1-year OS was not significantly different (Figure 1). Responders had a significantly longer OS (median, 622 days vs 278 days for non-responders; p=0.012). Age, race, CCI, ECOG PS, genetic risk group, prior HiDAC, dysplasia, azacitidine, and number of prior treatments did not impact OR or OS. 16 (47%) pts proceeded to SCT. During treatment, 70% had a grade 3-4 non-hematologic toxicity (based on NCI CTACE v4.0); the most common was fatigue. The median number of hospitalizations for complications per patient was 2 (range, 0-7). Causes of hospitalization were febrile neutropenia (40%), infection (22%), cytopenias (18%), rash (6%), acute kidney injury (6%), and 8% were for other causes. Conclusion Decitabine treatment of 34 adults with rel/ref AML resulted in an OR of 33% (21% CR) and allowed nearly one-half of these pts to proceed to SCT. All pts achieving CR did so after 1 cycle. Responding pts had improved OS over those without response (p=0.012). Interestingly, secondary AML or t-MN were 7.8 times more likely to achieve a response compared to de novo AML (p=0.046); lower WBC count and marrow blast percentage also correlated with higher OR. Further delineation of molecular subsets associated with response to decitabine should be evaluated in a larger prospective trial in this high-risk AML population. Citation 1. Blum KA, et al. Phase I trial of low dose decitabine targeting DNA hypermethylation in patients with chronic lymphocytic leukaemia and non-Hodgkin lymphoma: dose-limiting myelosuppression without evidence of DNA hypomethylation. Br J of Haem. Jul 2010;150(2):189-195. Figure 1. Figure 1. Disclosures Off Label Use: Decitabine is indicated for treatment of MDS but is often used to treat newly diagnosed or relapsed/refractory AML. In this study we analyzed results of patients with AML who were treated with decitabine in the relapsed/refractory setting.. Thirman:AbbVie: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Gilead: Research Funding; Merck: Research Funding; AbbVie: Research Funding; Gilead: Research Funding; Merck: Research Funding. Odenike:Sunesis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Liu:Astra Zeneca/Medimmune: Consultancy; Pfizer: Consultancy; Astra Zeneca/Medimmune: Consultancy; Pfizer: Consultancy. Stock:Gilead: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 42-42
Author(s):  
Alyssa I. Clay ◽  
Theresa Hahn ◽  
Qianqian Zhu ◽  
Li Yan ◽  
Leah Preus ◽  
...  

Abstract Both genome wide association studies (GWAS) of common variation and exome wide association studies (EXWAS) of rare variation have successfully identified disease susceptibility variants for a variety of diseases. One GWAS of inherited susceptibility to Acute Myeloid Leukemia (AML) has been conducted, but no EXWAS have been performed to measure risk of AML attributable to low-frequency constitutional genetic variation. We performed the first EXWAS of risk of AML as a nested case-control study in the DISCOVeRY-BMT (Determining the Influence of Susceptibility Conveying Variants Related to one-Year mortality after BMT) cohorts. The DISCOVeRY-BMT parent study examined transplant-related mortality in leukemia patients undergoing unrelated donor allogeneic BMT. To identify low frequency variants and genes contributing to increased susceptibility to AML we used genotype data from the Illumina HumanExome BeadChip typed in the DISCOVeRY-BMT cohorts; the HumanExome BeadChip contains 242,901 variants, which are mainly protein-coding variants. The optimal sequence kernel association test (SKAT-O) was used to analyze gene-level associations with risk of AML. These gene-based tests evaluate the cumulative effects of multiple single gene variants on risk of AML. Analyses were performed in all European American AML cases and two subtypes: 1) de novo AML, 2) de novo AML with normal cytogenetics. Models were adjusted for age at transplant and principal components to control for population stratification. For gene-based tests at least 2 variants with minor allele frequency (MAF) ≤ 5%, were required to be present in the gene. This yielded a total of 13,687 genes tested, and a Bonferroni corrected significance level of P<3.65 x 10-6. Association tests were performed in 1,189 AML cases reported to CIBMTR 2000-08 (Cohort 1) and 327 AML cases reported to CIBMTR from 2009-11 (Cohort 2). Controls in Cohorts 1 (n=1,986) and 2 (n= 515) were 10/10 HLA-matched unrelated donors who passed a comprehensive medical exam and deemed healthy. We used metaSKAT to combine Cohorts 1 and 2 and obtain p-values of association with AML. We present the results of gene-level tests significant in both cohorts. The likely pathogenicity of these variants was determined in silico using SIFT, PolyPhen and MutationTaster. Patient characteristics are in Table 1. DNMT3A, on chromosome 2, was associated in the gene-based test with risk of AML (Pmeta=1.70x10-9, Table 2). Three missense variants at MAF <1% comprise both overall AML and de novo AML gene-based association: exm177559 (Asn->Ser), exm177507 (Arg->His), and exm177543 (Arg->Trp). Normal cytogenetics de novo AML gene-based assocations consisted of only 2 of these variants: exm177559 and exm177507 (Table 2). While prevalence of exm177507 is <1% for all AML cases, in de novo AML with normal cytogenetics the MAF was higher at 3%. The other 2 variants had a MAF<1% irrespective of subtype. Somatically, DNMT3A is most frequently mutated in hematologic malignancies, with >30% of de novo AML cases with a normal karyotype and >10% of MDS patients having DNMT3A mutations. Although these are germline gene associations all three of the variants found have been reported somatically in hematologic malignancies. In 200 AML cases from The Cancer Genome Atlas (TCGA) p.R882H (represented as exm177507 on the exome chip) was a frequent somatic mutation (25%). Exm177543 (p.R635W) and exm177559 (p.N501S) are reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) as somatic mutations involved in hematopoietic and lymphoid tissue in both cell lines and humans. Exm177507 and exm177543 show evidence of pathogenicity in all three in silico tools, while exm177559 was reported as deleterious and disease causing by Sift and MutationTaster, respectively. Our results show that multiple potentially pathogenic missense germline variants in DNMT3A comprise the gene-based association with AML, specifically de novo AML with normal cytogenetics. Given the functional nature of these variants it is possible germline risk stratification could be informative in determining AML risk, and subsequently development of AML harboring DNMT3A mutations. Confirmation of these findings in additional cohorts could have implications for individualized risk screening, prediction and prognosis. Additional cytogenetic subgroup analyses, including treatment-related AML, are underway. Disclosures Hahn: Novartis: Equity Ownership; NIH: Research Funding. McCarthy:Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; The Binding Site: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gamida Cell: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sucheston-Campbell:NIH/NCI: Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1487-1487
Author(s):  
Tatjana Meyer ◽  
Nikolaus Jahn ◽  
Anna Dolnik ◽  
Peter Paschka ◽  
Verena I. Gaidzik ◽  
...  

Abstract Introduction BRCA1/BRCA2-containing complex 3 (BRCC36) is a Lys63-specific deubiquitinating enzyme (DUB) involved in DNA damage repair. Mutations in BRCC36 have been identified in 2-3% of patients with myelodysplastic syndromes (MDS) and secondary AML (sAML). The role of BRCC36 mutations in de novo AML and their impact on DNA damage-inducing cytotoxic chemotherapy sensitivity is not clear. Aim We aimed to determine the incidence of BRCC36 mutations in AML and their impact on outcome and drug sensitivity in vitro. Methods We analyzed the entire coding region of BRCC36 for mutations in 191 AML cases with t(8;21) (q22;q22.1) and 95 cases with inv(16) (p13.1q22) using a customized targeted sequencing panel. Data for de novo AML was derived from The Cancer Genome Atlas Research Network (TCGA) data set (NEJM 2013). Lentiviral CRISPR/Cas9 was used to inactivate BRCC36 in t(8;21)-positive AML cell lines - Kasumi-1 and SKNO-1 - and murine hematopoietic stem and progenitor cells (LSKs). Knockout was confirmed by a cleavage assay as well as Western blot. AML1-ETO-9a was expressed by a retroviral vector. Cell lines and LSK cells were treated with different concentrations of doxorubicin or cytarabine and their viability was assessed seven days post treatment. DNA damage was assessed through phospho-γH2AX staining using flow-cytometry. Results BRCC36 mutations were identified in 7 out of 191 patients (3.7%) with t(8;21) AML and none of 95 patients with inv(16). In the TCGA data set one out of 200 patients (0.5%) with de novo AML had a BRCC36 mutation. This patient had a complex karyotype and would be considered as secondary AML with myelodysplastic-associated changes according to the 2016 WHO classification. Six of the 7 mutations were missense or nonsense mutations that were predicted to be deleterious to BRCC36 function. One mutation affected a splice site at exon 6, resulting in an impaired splicing capability. With intensive standard chemotherapy all patients with BRCC36 mutations achieved a complete remission and had an estimated relapse-free and overall survival of 100% after a median follow up of 4.2 years. Given its role in DNA damage repair, we hypothesized that BRCC36 inactivation sensitizes AML cells to DNA-damage inducing drugs. In order to test this, we generated BRCC36 knockout Kasumi-1 and SKNO-1 cell lines using CRISPR-Cas9. BRCC36 inactivation had no impact on cell growth on either of the cell lines. However, we found that BRCC36 knockout cells were significantly more sensitive to doxorubicin as compared to the parental cells with normal BRCC36. This was accompanied by a significant increase in DNA damage as assessed by phospho-γH2AX in BRCC36 knockout vs control cells after doxorubicin treatment. In contrast, BRCC36 inactivation had no impact on cytarabine sensitivity. We next assessed drug sensitivity in primary murine leukemic cells expressing AML1-ETO-9a. Again, inactivation of BRCC36 resulted in a significant higher sensitivity to doxorubicin but not cytarabine. Conclusion We found BRCC36 to be recurrently mutated in t(8;21)-positive AML Inactivation of BRCC36 was associated with impairment of the DNA damage repair pathway and thus higher sensitivity to DNA damage-inducing chemotherapy. This might be also reflected by the favorable clinical outcome of patients with BRCC36 mutated t(8;21)-positive AML, a finding which has to be confirmed in a large patient cohort. Disclosures Paschka: Pfizer: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Travel support; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Otsuka: Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees; Jazz: Speakers Bureau; Amgen: Other: Travel support; Janssen: Other: Travel support; Bristol-Meyers Squibb: Other: Travel support, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees, Travel support; Astex: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees. Bullinger:Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Speakers Bureau; Bayer Oncology: Research Funding; Sanofi: Research Funding, Speakers Bureau; Janssen: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau; Amgen: Honoraria, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Döhner:Novartis: Consultancy, Honoraria, Research Funding; Jazz: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Janssen: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Pfizer: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria; AROG Pharmaceuticals: Research Funding; Janssen: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria; Astex Pharmaceuticals: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Pfizer: Research Funding; Agios: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Agios: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celator: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Bristol Myers Squibb: Research Funding; Seattle Genetics: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Sunesis: Consultancy, Honoraria, Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2629-2629
Author(s):  
Yuki Nishida ◽  
Jo Ishizawa ◽  
Vivian Ruvolo ◽  
Michael Andreeff

Abstract Background TP73 is one of the TP53 family transcription factors and generates two isoforms, the transactivation p73 (TAp73) and the N-terminally truncated ΔNp73. TAp73 shares a homologous N-terminal activation domain with p53 and has similar pro-apoptotic function to p53. ΔNp73 lacks an activation domain and has activities distinct from TAp73. ΔNp73 has a dominant negative effect on the DNA binding of TAp73 and more importantly, of p53, since the DNA binding domain is homologous with that of TAp73 and highly similar to that of p53. In acute myeloid leukemias (AML), TP73 has been reported to be expressed except in acute promyelocytic leukemias. However, the association of TP73 isoforms with clinical and genetic characteristics and the regulation of the isoforms in AML have not been explored. Results We determined copy numbers of ΔNp73 and TAp73 mRNA levels in 78 AML samples including 31 de novo AML using droplet digital PCR (ddPCR), which allows to determine the absolute quantity of the isoforms expressed, and investigated their clinical and biological relevance. ΔNp73 and TAp73 expression was detected in 93.6% and 98.7% of AML samples at variable levels (mean ± SEM, 10.6 ± 5.0, and 106.6 ± 33.7 copies/µL, for ΔNp73 and TAp73, respectively). ΔNp73 and TAp73 mRNA levels were highly correlated (R2 = 0.72, P < 0.0001). Normal peripheral blood mononuclear cells and CD34+ hematopoietic cells showed little or no ΔNp73 and TAp73 expression (0.09 ± 0.09 and 0.42 ± 0.35 copies/µL, respectively), demonstrating that expression of ΔNp73 and TAp73 is 100 - 1,000 fold higher in AML as compared to normal hematopoietic cells. These data collectively suggests that transcriptional systems of both isoforms in AML cells are abnormally activated. Disease status (de novo or relapsed/refractory) and cytogenetic abnormalities did not correlate with ΔNp73 and TAp73 levels. However, AML with IDH1/2 mutations had 8.5-fold lower ΔNp73 expression than those with wild-type IDH1/2 (1.8 ± 0.8 vs 15.4 ± 7.7 copies/µL, P = 0.0069), with a similar trend for TAp73 (49.0 ± 20.3 vs 138.6 ± 51.4 copies/µL, P = 0.056). For de novo AML samples, those with DNMT3a and NRAS mutations had significantly higher ΔNp73, but not TAp73, than those without these mutations (21.6 ± 18.2 vs 2.5 ± 1.2 copies/µL, P = 0.017 and 5.6 ± 2.5 vs 9.7 ± 8.0 copies/µL, P = 0.047, respectively). These findings suggest that ΔNp73 and TAp73 can be differentially regulated in AML based on mutation status. To further explore the regulation of TP73 isoforms, we used MDM2 inhibitor Nutlin-3a to induce p53 which is a transcriptional inducer of ΔNp73. Indeed, MDM2 inhibition increased p73 protein levels, and knockdown of both TAp73 and ΔNp73 in AML cells enhanced apoptosis induction by Nutlin-3a (specific annexin V induction by 5 uM Nutlin-3a, 21.9 ± 1.3% vs 61.3 ± 5.2%, P = 0.0084 in OCI-AML3 cells with vector control vs Shp73, respectively), possibly due to the silencing of ΔNp73. AML cells with IDH1/2 mutations are more dependent on Bcl-2 than those without (Chan, Nat Med 2015). Intriguingly, (R)-2HG, the oncometabolite of mutant IDH1/2, reduced both TAp73 and ΔNp73 in AML cells and increased susceptibility to the Bcl-2 inhibitor ABT-199. These results imply a potential mechanism that regulates p73 isoforms by histone methylation or other epigenetic modifications in AML. Conclusion Absolute quantitation of TP73 isoforms by ddPCR revealed high expression in AML cells compared to normal hematopoietic cells. The repressed expression of TP73 isoforms in AML cells with IDH1/2 mutations or by the oncometabolite (R)-2HG suggests that epigenetic modifications through (R)-2HG can regulate TP73 transcription and enhance the anti-leukemia effect by Bcl-2 inhibition. Finally, downregulation of TP73 isoforms enhances the efficacy of MDM2 inhibitor in AML, suggesting a potential therapeutic strategy to enhance MDM2 inhibitor-mediated p53 activation. Disclosures Andreeff: Amgen: Consultancy, Research Funding; Oncolyze: Equity Ownership; Oncoceutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Astra Zeneca: Research Funding; Aptose: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; United Therapeutics: Patents & Royalties: GD2 inhibition in breast cancer ; SentiBio: Equity Ownership; Reata: Equity Ownership; Eutropics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Consultancy; Daiichi-Sankyo: Consultancy, Patents & Royalties: MDM2 inhibitor activity patent, Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2800-2800
Author(s):  
Sara Farshchi Zarabi ◽  
Steven M. Chan ◽  
Vikas Gupta ◽  
Dina Khalaf ◽  
Andrzej Lutynski ◽  
...  

Abstract The outcome of adult patients with AML who are primary non-responders to two courses of induction chemotherapy is poor. However, the utility of a 3rd induction for a select subgroup of these patients is uncertain. Here, we evaluated the rates of response and survival after a 3rd course of induction chemotherapy for primary non-responders with AML. We identified 98 patients from the Princess Margaret Cancer Centre between May 1999 and March 2015 who were non-responders to induction and reinduction chemotherapy. No-response to re-induction chemotherapy was defined according to the Revised Recommendations of the International Working Group for AML (JCO, 2003) as patients who survived > 7 days post re-induction and had persistent AML in blood or bone marrow (>5%). Median age was 58.3 years [range: 20-76.6]. 50 (51%) were male. 2% had favorable, 18% normal, 18% intermediate, and 48% adverse cytogenetics. 50% had de novo AML, 23% had AML secondary to MDS or MPN, and 17% had therapy-related AML. Induction chemotherapy consisted of "7+3" (n =88), Nove-HiDAC (n=1), Flag-Ida (n= 2), or similar variants (n=7). Reinduction chemotherapy consisted of Nove-HiDAC (n=70), Flag-Ida (n=7), "7+3" (n=1) or other similar variants (n =20). No patients received the same regimen for both induction and reinduction. Of the 98 primary non-responders, 15 received a 3rd induction regimen, while the others received supportive/palliative care ± low-dose chemotherapy (57 pts), or a non-induction clinical trial (26 pts). Average age was 56.4 (sd: 12.9) for patients who received supportive/palliative care and 47.0 (sd: 17.5) for patients who received a 3rd induction (p=0.008). Other baseline characteristics including gender, cytogenetic risk, marrow blast count post 2nd induction, and time between 1st and 2nd induction, did not differ between patients who did and did not receive a 3rd induction. Time to 3rd induction was a median of 54 days [range:36-126] from the start of the 2nd induction. Of the 15 third inductions, 7 were clinical trials evaluating novel agents in combination with induction chemotherapy, while the other 8 were combinations of standard chemotherapeutics (Flag-Ida n=1), AMSA+HiDAC (n=2), Daunorubicin+ HiDAC (n=1), Nove-HiDAC (n=4). Of the 15 patients who received a 3rd induction, 3 (20%) achieved a CR following Nove-HiDAC and Flag-Ida or AMSA+HiDAC chemotherapy, where the Ara-C was given as continuous infusion. 1 patient underwent allogeneic stem cell transplant (SCT) approximately 3.7 months after 3rd induction and remains alive 4.6 years post CR. 2 patients relapsed 2.3 and 4.7 months post CR without having received alloSCT. None of the 12 other patients responded to the 3rd induction and none had prolonged aplasia. 2 of 15 (13%) died during 3rd induction. Among the 83 patients who did not receive a 3rdinduction, 1 achieved a CR after a phase 1 clinical trial (MDM2 inhibitor) and remains in CR 3.6 years following an alloSCT. For patients who survived the immediate post induction period and were discharged from hospital median overall survival from the start of the 2nd induction did not differ between patients who did and did not receive a 3rd induction (276 days [range: 78-1304] vs 181.5 days [range: 47-1855] respectively p= 0.14). Median duration of hospital stay (including subsequent admissions) was longer for patients receiving a 3rd induction compared to those who did not (94 days following start of the 2nd induction [range: 47-169] vs 57 days [range: 51-181], respectively;(p= 0.003)). In summary, remissions after 3rd inductions for primary non-responders are uncommon, and short-lived, suggesting that 3rd inductions should be considered with caution and only when an SCT strategy is in place. Disclosures Gupta: Incyte Corporation: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Research Funding. Schuh:Amgen: Membership on an entity's Board of Directors or advisory committees. Yee:Novartis Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding. Schimmer:Novartis: Honoraria.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5176-5176
Author(s):  
Frieda Kontsioti ◽  
Eirini Maratou ◽  
Anthi Bouhla ◽  
Vassiliki Mpakou ◽  
Konstantinos Gkodopoulos ◽  
...  

INTRODUCTION AML is the most common malignant myeloid disorder in adults. Relapses are initiated by chemoresistant leukemic cells. DNA damage and repair mechanisms influence not only the genetic predisposition to leukemia but are also very important for refractoriness to treatment. The aim of this study was to investigate the possible alterations in the gene expression profile in DNA damage signaling pathways in two leukemic cell lines following their exposure to chemotherapeutic agents and verify the findings in AML patients. METHODS Kasumi-1 and MV4-11 AML cells were treated with either idarubicin (0.1μΜ) for 6h or cytarabine (1μΜ) for 48h. Dead cells were eliminated from drug-treated cells using the appropriate commercial kit. Gene expression profiling through PCR arrays analysis (RT2Profiler, Qiagen) was performed after RNA extraction from untreated, drug-treated and chemoresistant (live) cells following their exposure to cytotoxic agents. Human DNA Damage Signaling pathway related genes' expression was evaluated and analyzed through RT2Profiler PCR Array data analysis tool. Following our initial results, two genes were selected for further analysis: PPP1R15A and HUS-1 genes' relative expression was evaluated by qRT-PCR analysis with QuantiTect Primer Assays kit (Qiagen) using the 2^-∆∆Ct method. The analysis included 28 de novo AML patients before the onset of the 7+3 combination chemotherapy and 16 healthy donors. Eighteen cases had normal karyotype including 7 with flt3 mutation, 1 case had inv(16) and 9 cases intermediate risk karyotype. Statistics were performed through One Way Anova analysis. RESULTS PCR Array analysis after idarubicin and cytarabine treatment of Kasumi-1 cells revealed a significant up-regulation of genes involved in apoptosis, cell cycle, DNA damage and repair, and ATM/ATR signaling. Significant differences in their gene expression patterns were observed between cytarabine-treated Kasumi-1 cells and chemoresistant ones. HUS-1 gene (DSB) was 3x fold up-regulated in cytarabine-treated cells and 0.7x fold down-regulated in chemoresistant cells compared to untreated cells. Cytarabine and idarubicin treatment of MV4-11 cells led to an up-regulation of genes involved in cell cycle, DNA damage repair, including DSB repair and NER mechanisms. Most importantly, PPP1R15A gene's expression in both cytarabine and idarubicin chemoresistant MV4-11 cells was significantly 4.2x and 2.7x fold up-regulated compared to drug treated cells. Following these results the expression level of genes PPP1R15A and HUS1 was examined in the bone marrow cells of AML patients in order to verify their association with chemoresistance. PPP1R15A gene's relative expression was significantly up-regulated in non-responding to induction chemotherapy AML patients compared to responding (median: 2.705 vs. 0.73, p<0.05) and in non-responding to chemotherapy AML patients compared to controls (median: 2.705 vs. 0.577, p<0.01). HUS1 gene's relative expression was remarkably down-regulated in AML patients compared to controls (median: 1.585 vs. 7.74, p<0.001). This was also observed comparing responding and refractory to chemotherapy AML patients to controls (median: 1.09 vs. 7.74, p<0.001 and 1.585 vs. 7.74, p<0.05, respectively). CONCLUSIONS The up-regulation of PPP1R15A gene in chemoresistant MV4-11 cells after treatment with cytotoxic agents is justified since this gene participates in growth arrest and apoptosis in response to DNA damage, negative growth signals and protein malfolding by binding to protein phosphatase PP1, and attenuating the translational elongation of key transcription factors through dephoshorylation of eukaryotic initiation factor 2a(eIF2a). Most importantly the significant increased baseline expression of PPP1R15A in AML chemoresistant patients indicates its involvement in chemoresistance mechanisms and paves the way for targeted treatment. HUS1 gene's expression was remarkably depressed in de novo AML samples. This gene is required for the optimal ATM/ATR signaling response to DSBs and replication stress forming part of the RAD9A-RAD1-HUS1 (9-1-1) complex functioning as a damage sensor in checkpoint pathway. Therefore the described above reduced expression in AML samples indicates reduced ATM-ATR response to DSBs associated with genetic instability and offers new options for synthetic lethality treatment strategies Disclosures Symeonidis: Tekeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; MSD: 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, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding. Pappa:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Celgene / GenesisPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 698-698 ◽  
Author(s):  
Nathan Singh ◽  
Olga Shestova ◽  
Katharina Hayer ◽  
Albert Hong ◽  
Pranali Ravikumar ◽  
...  

Abstract Background: T cells engineered to express chimeric antigen receptors targeting the B-cell antigen CD19 (CART19) have demonstrated impressive results in the treatment of lymphoid cancers. Despite these promising outcomes, a significant subset of patients relapse after initial response. To investigate the molecular pathways that drive relapse, we performed an unbiased, CRISPR/Cas9-mediated genome-wide knockout screen in the acute lymphoblastic leukemia (ALL) cell line Nalm6, and found that loss of CD19 was the primary driver of relapse after initial response. This finding is consistent with clinical observations that antigen loss is a primary driver of late disease recurrence, however it fails to address the molecular etiology of intrinsic resistance, which affects ~50% of patients with non-Hodgkin lymphoma and ~20% of patients with ALL, or of late antigen-independent relapse, which accounts for ~40% of relapses in ALL. Identification of the mechanisms regulating CART19 susceptibility is an essential first step in overcoming resistance to this powerful therapy. We hypothesized that genetic alteration in ALL cells were responsible for mediating intrinsic, CD19-independent resistance. To investigate this, we conducted a genome-wide loss of function screen in a model designed to evaluate intrinsic resistance to CART19. Methods: Using a lentiviral guide RNA (gRNA) library containing four distinct gRNAs targeting each human gene (~80,000 gRNAs total), we enabled genome-wide knockout in Nalm6, whereby each target cell lost function of only one gene. This gene-modified cell pool was then exposed to either CART19 or control T cells at a low effector:target ratio (0.25:1) to model the expected in vivo E:T ratio. At 24h, surviving Nalm6 cells were collected and gRNA from these cells underwent next-generation sequencing. Sequenced samples were processed using three distinct genome-scale knockout screen algorithms (MAGeCK, permutation-based non-parametric analysis and ScreenBeam). This pipeline allowed identification of (i) significantly enriched gRNA, postulated to mediate loss of gene function that confers resistance to CART19, and (ii) significantly depleted guides, postulated to mediate loss of gene function that confers sensitivity to CART19. The role of identified genes was then validated in in vitro and in vivo studies. Results: Analysis of gRNA sequencing data from our screen (Figure 1) revealed that the three genes whose loss of function most significantly promoted resistance to CART19 were BID, FADD and CASP8, all of which are key regulators of death receptor-driven apoptosis. TNFRSF10B, encoding the death receptor TRAIL-R2, was also significantly enriched. Interestingly, amongst the 10 genes whose loss most significantly sensitized to CART19 were TRAF2, BIRC2 and CFLAR, all negative regulators of death receptor activity. Pathway analysis of the top 50 genes (25 enriched, 25 depleted) demonstrated significant enrichment in the death receptor pathway, with a false discovery rate of 3.79x10-7. We proceeded to functionally validate the role of BID and FADD in mediating resistance to CART19 by deleting these genes in Nalm6 using de novo designed gRNAs. Strikingly, BIDKO and FADDKO cells were highly resistant to CART19 cytotoxicity in vitro as compared to wild-type Nalm6. Resistance was evident as early as 6 hours after co-culture and was maintained for at least 7 days. Observed resistance to CART19 directly correlated to fraction of KO cells present, suggesting that gene loss was mechanistically responsible for failed CART19 cytotoxicity. We further evaluated the impact of BID or FADD loss on anti-leukemic activity of CART19 in our Nalm6 xenograft model. We observed that BIDKO or FADDKO significantly impaired the anti-leukemic activity of CART19 in vivo. Conclusions: CART19 can cure select patients with B-cell cancers, while others experience transient or no clinical benefit. Using a genome-wide loss of function screen, we identified that death receptor-associated proteins are centrally involved in regulating CART19 cytotoxicity, and that loss of these molecules leads to intrinsic resistance to CART19. These findings are, to our knowledge, the first to characterize the role of death receptors as critical regulators of CART19 cytotoxicity, and suggest that tumor cell modulation of death receptor signaling may drive both inherent resistance and antigen-independent relapse. Disclosures June: Celldex: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Immune Design: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Immune Design: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Gill:Novartis: Research Funding; Carisma Therapeutics: Equity Ownership; Extellia: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ruella:University of Pennsylvania: Patents & Royalties.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2291-2291
Author(s):  
Hari S. Raman ◽  
Yael Flamand ◽  
Marlise R. Luskin ◽  
Daniel J. DeAngelo ◽  
Richard M. Stone ◽  
...  

Abstract Introduction The COVID-19 pandemic disrupted non-urgent and preventive medical care. During the early peak of the pandemic, an estimated 41% of US adults delayed or avoided medical care (Czeisler et al, CDC, 2020). While there were documented declines in the number of emergency department visits for myocardial infarction, stroke and hyperglycemia, similar data is not available related to acute myeloid leukemia (AML) (Lange et al, CDC, 2020). A delay in the diagnosis of AML could lead to presentation when patients are less able to withstand chemotherapy or have a higher disease burden which could compromise overall survival (OS). In this retrospective analysis, we aim to elucidate if there was a difference in clinical, cytogenetic, or molecular presentations and if there was an effect on early mortality as determined by overall survival at 1 and 6 months. Methods We compared the clinical, cytogenetic, and baseline molecular genetics of consecutive adult patients diagnosed with de novo AML at Dana-Farber Cancer Institute/Brigham and Women's (DFCI/BWH) Hospital from March 23, 2020, the date of the Massachusetts COVID State of Emergency, to August 23, 2020 to a historical cohort of similar patients between presenting between March 23, 2017 and August 23, 2020. Data was obtained from the Hematological Malignancy Data Repository and via review of the medical record. Patients were excluded from this cohort if they were diagnosed with acute promyelocytic leukemia, had known antecedent myeloid malignancy, or if they did not have DFCI/BWH 96-gene next-generation sequencing panel (RHP) performed at the time of diagnosis. Baseline clinical, laboratory, cytogenetic, and molecular characteristics and outcomes were compared between the pre-pandemic and pandemic cohorts using chi-squared, Fisher's exact, and Wilcoxon rank sum analyses (where appropriate) at a significance of p&lt;0.05. Results Thirty-eight AML patients presented during the COVID-19 pandemic (PAN) and 308 in the pre-pandemic (PREPAN) period. There was no statistically significant difference in the monthly rate of new patients presenting in PREPAN and PAN cohorts (8 vs. 6 new patients/month, p=0.73). The median age at presentation (64 PREPAN vs. 65 PAN, p=0.77), sex, and therapeutic approach (intensive, non-intensive, supportive care, other) were not statistically different between cohorts. Presenting white blood cell count, platelet count, and fibrinogen were not different between cohorts, while hematocrit was significantly lower in the PAN cohort (23.8% vs. 26.0%, p=0.001). There was a trend for a higher median blast percentage (28.5% vs. 13%, p=0.09) in the PAN cohort. There were no differences between the cohorts in the median number of cytogenetic abnormalities, nor in the incidence of complex karyotype, (25.3% vs. 23.7%) across PREPAN and PAN respectively. There were also no significant differences in the European LeukemiaNet (ELN) risk classification scores across the PREPAN and PAN time periods, with 57.8% vs. 52.6% of total patients presenting with adverse risk disease respectively. When specific mutations of TP53, NPM1, and FLT3 were evaluated, only FLT3 demonstrated a statistical difference with a higher proportion in the pandemic group (p=0.04). OS at 1-month (97.4% and 93.2%, p=0.15) and 6-months (71.1% and 75.0%, p-0.87) were not statistically different in the PREPAN and PAN cohorts, respectively. Conclusion These data represent a novel analysis of the presenting clinical, cytogenetic and molecular characteristics of de novo AML during the COVID-19 pandemic. In contrast to other diseases, we did not see fewer de novo AML presentations during the peak of the COVID pandemic. While the reasons are unknown and require validation in large cohorts, the symptoms of leukemia including symptomatic anemia (low hematocrit) and higher WBC and blast count possibly driven by FLT3 mutations may drive patients to seek emergent clinical evaluation despite COVID pandemic barriers. The lack of difference in cytogenetic or other prognostic entities may demonstrate a lack of symptom correlation causing patients to present for care. The higher incidence of FLT3 mutations and lower hematocrit could reflect more symptomatic presentation of AML during the COVID pandemic. Since these differences may be a surrogate for a higher disease burden, it will be important to compare outcomes at longer time points. Figure 1 Figure 1. Disclosures DeAngelo: Pfizer: Consultancy; Novartis: Consultancy, Research Funding; Jazz: Consultancy; Incyte: Consultancy; Forty-Seven: Consultancy; Autolus: Consultancy; Amgen: Consultancy; Agios: Consultancy; Takeda: Consultancy; Glycomimetrics: Research Funding; Blueprint: Research Funding; Abbvie: Research Funding; Servier: Consultancy. Stone: Bristol Meyers Squibb: Consultancy; Astellas: Membership on an entity's Board of Directors or advisory committees; BerGen Bio: Membership on an entity's Board of Directors or advisory committees; Boston Pharmaceuticals: Consultancy; Innate: Consultancy; Foghorn Therapeutics: Consultancy; Gemoab: Membership on an entity's Board of Directors or advisory committees; Glaxo Smith Kline: Consultancy; Celgene: Consultancy; Elevate Bio: Membership on an entity's Board of Directors or advisory committees; OncoNova: Consultancy; Syntrix/ACI: Membership on an entity's Board of Directors or advisory committees; Syndax: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Agios: Consultancy, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Aprea: Consultancy; Arog: Consultancy, Research Funding; Jazz: Consultancy; Macrogenics: Consultancy; Novartis: Consultancy, Research Funding; Actinium: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Syros: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy. Garcia: AstraZeneca: Research Funding; Prelude: Research Funding; Pfizer: Research Funding; Genentech: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Winer: Abbvie: Consultancy; Takeda: Consultancy; Novartis: Consultancy.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1469-1469
Author(s):  
Alexey Aleshin ◽  
Robert Durruthy-Durruthy ◽  
M. Ryan Corces ◽  
Melissa Stafford ◽  
Michaela Liedtke ◽  
...  

Abstract Background: De novo acute myeloid leukemia (AML) is a molecularly heterogeneous disorder with clinically variable outcomes. Recent studies on the mutational landscape of AML have been informative in better stratifying risk of relapse. However, bulk sequencing techniques have been limited in their ability to delineate the true complexity of tumoral molecular heterogeneity and allow for efficient identification of drug resistant subclones. Here, we applied high-throughput single cell sequencing technique to identify patterns of clonal heterogeneity and evolution in longitudinal samples from patients with AML undergoing induction chemotherapy. Methods: Matched diagnosis, remission, and relapse samples were examined for 20 de novo AML cases including 15 relapsed and 5 non-relapsed controls. Mutational bulk sequencing was performed by NGS panel sequencing and exome sequencing was available in select cases. Single cell processing was performed using the Tapestri (Mission Bio) platform. Briefly, individual cells were isolated using a microfluidic approach, followed by barcoding and genomic DNA amplification for individual cancer cells confined to droplets. Barcodes were then used to reassemble the genetic profiles of cells from next generation sequencing data. We applied this approach to individual AML samples, genotyping the most clinically relevant loci across upwards of 10,000 individual cells. Results: Targeted single-cell sequencing was able to recapitulate bulk sequencing data from both peripheral blood and bone marrow aspirate samples. We observed high concordance between bulk VAFs and sample level VAFs derived from single cell sequencing data. Additionally, single cell analysis allowed for resolution of subclonal architecture and tumor phylogenetic evolution beyond what was predicted from bulk sequencing alone. Rare subclones associated with disease relapse, were identified in initial diagnostic samples that were frequently under the limit of detection of bulk NGS. Conclusions:Taken together, our results suggest a greater degree of heterogeneity in de novo AML samples than suggested with bulk sequencing methods alone and shows the utility of single-cell sequencing for longitudinal monitoring and identification of resistant clones prior to therapy initiation in select patients. We show here that this approach is a feasible and effective way to identify and track heterogeneous populations of cells in AML and may be valuable for MRD identification. Disclosures Aleshin: Mission Bio, Inc.: Consultancy; Natera, Inc.: Employment. Durruthy-Durruthy:Mission Bio, Inc.: Employment, Equity Ownership. Liedtke:Prothena: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech/Roche: Research Funding; Caelum: Membership on an entity's Board of Directors or advisory committees; Amgen/Onyx: Consultancy, Honoraria, Research Funding; BlueBirdBio: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; celgene: Research Funding. Medeiros:Celgene: Consultancy, Research Funding; Genentech: Employment. Eastburn:Mission Bio, Inc.: Employment, Equity Ownership.


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