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In: Blood, American Society of Hematology, Vol. 136, No. Supplement 1 ( 2020-11-5), p. 30-31

Abstract: Introduction. Mutations in genes encoding the metabolic enzymes isocitrate dehydrogenase (IDH) 1 and 2 are found in 10-20% of patients with acute myeloid leukemia (AML). Recently, IDH inhibitors have shown good clinical response in patient's refractory to standard treatments, providing evidence for a new treatment paradigm. Comprehensive real-world studies are needed to explore genotype-to-phenotype correlations and prognosis of IDH mutated AML, which may influence targeted treatment strategies. Patients. From a retrospective, European, real-word population (ClinicalTrials.gov Identifier: NCT04369287) we studied 477 IDH mutated patients and 954 IDH wild type patients matched for age, sex and type of treatment with a 1:2 ratio. Results. Median age of IDH mutated patients was 67 years; IDH1 mutations were found in 202 patients (89% carried R132 mutation), while IDH2 mutations were found in 275 cases (51% and 28% carried R140 and R172 mutations, respectively). At diagnosis, IDH mutated patients had lower neutrophil and higher platelet count and higher percentage of marrow blasts (P & lt;0.001). IDH mutations were more frequently observed in de novo AML vs. AML from previous myeloid malignancy (P=0.043). Considering cytogenetic risk according to ELN criteria, the great majority of IDH1 and IDH2 mutated patients had an intermediate cytogenetic risk (84% and 86%, respectively, P & lt;.001, most of them showing a normal karyotype). Considering IDH1 vs. IDH2 mutated population, deletion of chromosome 7 was more frequently reported in IDH2 mutated patients (P=.001). We then analysed the most common co-mutational patterns in IDH mutated patients. A total of 53% of IDH1 mutated patients carried NPM1 mutations (without FLT3 mutations), while the majority of IDH2 mutated patients had wild type NPM1 gene (P & lt;.001). IDH2 mutated patients more frequently presented with co-mutation in FLT3 gene (P & lt;.001); among IDH2/FLT3 co-mutated patients, the great majority of cases carried the R140 mutation (P & lt;.001). ASXL1 mutations were also more frequently associated with IDH2 mutations (P=.029). Most patients with CEBPA biallelic mutations carried IDH1 or 2 mutations (66%, P=.01), while core binding factor translocations, and mutations in TP53 and RUNX1 were rarely associated with IDH1 or 2 mutations. Median overall survival from diagnosis (OS) was 14 months for IDH1 mutated patients, 23 for IDH2 mutated patients and 19 for IDH wild type patients (P & lt;.001, figure 1); the independent negative effect on OS for IDH1 mutations was confirmed in a multivariable analysis on the whole study population including age, sex, ELN risk group, and type of treatment as covariates (HR was 1.65 vs. wild type population and 1.36 vs. IDH2 mutated patients, P & lt;.001), as well as in a specific analysis focused on patients belonging to intermediate ELN risk category (HR 1.75 vs. wild type population, P & lt;.001). Focusing on different mutational hotspots, survival analysis confirmed that IDH1 R132 mutation was associated with worse prognosis among IDH mutated patients (P & lt;.001). Moreover, we observed a reduced relapse-free survival (RFS) for both IDH1 and 2 mutated patients vs. wild type patients (P & lt;.001, figure 1). Multivariable analysis confirmed worse RFS for IDH1 and 2 patients vs. wild type patients (HR 3.8 and 1.4, respectively, P & lt;.001), as well as for IDH1 vs. IDH2 mutated patients (HR 1.5, P & lt;.001). IDH mutated patients receiving hypomethylating agents (n=211) had a lower response rate vs. wild type patients (56% vs. 36% of treatment failure, respectively, P=.04), while no significant different probability of response to intensive chemotherapy was noticed. In patients who received allogeneic transplantation (n=345), IDH1 mutated patients shower higher relapse rate vs. wild type and IDH2 mutated patients (53% vs. 34%, P & lt;.001). Conclusion. In a real world context, AML patients with IDH1 and 2 mutations have high marrow blasts percentage, frequently present normal karyotype and show specific co-mutational patterns with respect to NPM1, FLT3 and ASXL1 genes. IDH1 mutations were an independent predictor of unfavorable outcome with high rate of disease recurrence under currently available treatment options, and could be considered as an additional marker to improve personalized prognostic assessment within ELN risk groups. Dissection of prognosis of IDH mutated AML may influence targeted treatment strategies in clinical practice. Disclosures Voso: Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Heibl:Takeda: Honoraria; AOP orphan: Consultancy, Honoraria, Research Funding; BMS/celgene: Consultancy, Honoraria, Research Funding; novartis: Consultancy, Honoraria. Metzeler:Astellas: Honoraria; Daiichi Sankyo: Honoraria; Otsuka Pharma: Consultancy; Pfizer: Consultancy; Jazz Pharmaceuticals: Consultancy; Novartis: Consultancy; Celgene: Consultancy, Honoraria, Research Funding. Thiede:AgenDix GmbH: Other: Co-owner and CEO. Fracchiolla:ABBVIE: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, expenses, Speakers Bureau. Todisco:Jannsen, Abbvie, Jazz: Membership on an entity's Board of Directors or advisory committees. Passamonti:Novartis: Speakers Bureau; BMS: Speakers Bureau; Roche: Other: Support of parent study and funding of editorial support.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2020-140494

Language: English

Publisher: American Society of Hematology

Publication Date: 2020

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 140, No. Supplement 1 ( 2022-11-15), p. 3408-3409

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2022-167022

Language: English

Publisher: American Society of Hematology

Publication Date: 2022

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 136, No. Supplement 1 ( 2020-11-5), p. 4-5

Abstract: Background: Mutations in the protein tyrosine phosphatase gene PTPN11 (also known as SHP2) are found in approximately 10% of adult patients with acute myeloid leukemia (AML). A recent study reported that mutated PTPN11 associates with inferior response rates and shorter survival among intensively treated AML patients, independently of the ELN prognostic groups (Alfayez et al., Leukemia 2020). Earlier analyses of the genomic landscape of AML did not uncover a similar prognostic relevance of PTPN11 mutations. Therefore, our aim was to clarify the prognostic relevance of mutated PTPN11 variants in AML patients receiving intensive front-line therapy. Patients and Methods: We studied 1116 AML patients enrolled on two subsequent multicenter phase III trials of the German AML Cooperative Group (AML-CG 1999, NCT00266136; and AML-CG 2008, NCT01382147) who were genetically characterized by amplicon-based targeted next-generation sequencing (Herold et al., Leukemia 2020). All patients had received induction chemotherapy containing cytarabine and daunorubicin or mitoxantrone. Results: We identified 146 PTPN11 mutations in 114 of 1116 patients (10%). Mutations clustered in two hotspot regions (5': codons 52-79; n=108 and 3': codons 491-512, n=38) as previously reported. Associations of PTPN11 mutations with baseline clinical and genetic patient characteristics are shown in Figure A. PTPN11 mutations were most frequent in the European LeukemiaNet (ELN) "favorable" genetic risk group, and associated with higher leukocyte counts. Patients with mutated PTPN11more commonly had mutated NPM1, IDH1 and DNMT3A, and less frequently had FLT3-ITD, IDH2 and TP53 mutations, compared to patients with wild-type PTPN11. With regard to treatment outcomes, the rate of complete remission was similar among patients with mutated and wild-type PTPN11 (65% vs. 59%, P=.25). In univariate analyses, PTPN11-mutated patients had significantly longer relapse-free survival (RFS; 5-year estimate, 55% vs 33% for PTPN11-wild type patients; P=.001; Figure B) and tended to have longer overall survival (OS; 5-year estimate, 43% vs 32%; P=.06; Figure C). However, in multivariable models adjusting for age, sex, leukocyte count, AML type (de novo/sAML/tAML) and ELN-2017 genetic risk group, mutated PTPN11 no longer associated with RFS (hazard ratio [HR], 0.89, 95% confidence interval [CI] , 0.63 - 1.27; P=0.53) or OS (HR, 1.03; 95% CI, 0.80 - 1.33; P=.79). Moreover, PTPN11 mutations did not significantly associate with RFS or OS within any of the ELN genetic risk groups. Finally, we detected no significant differences in baseline characteristics or outcomes between patients with PTPN11 mutations affecting the 5' hotspot region (n=82), the 3' hotspot region (n=21), or mutations at both hotspots (n=11). Conclusion: In our cohort of newly diagnosed and intensively treated AML patients, mutations in PTPN11 occurred in 10% and associated with prognostically favorable genetic characteristics such as mutated NPM1 and absence of FLT3-ITD and TP53mutations. Consequently, PTPN11 mutations were most commonly found within the ELN-2017 favorable risk category. While patients with PTPN11 mutations had relatively favorable survival outcomes, multivariable models suggest this observation is confounded by the frequent co-occurrence of known favorable genetic markers. Our data are in disagreement with a recently published study on 880 newly diagnosed patients that found an unfavourable prognostic impact of mutated PTPN11, particularly among the 410 patients who received intensive treatment. Possible explanations for these discrepant results include differences in treatment regimens between the two cohorts, as well as the play of chance when studying a relatively rare gene mutation in medium-sized cohorts. In summary, our data do not support a role of PTPN11 mutations as an adverse prognostic biomarker in newly diagnosed, intensively treated adult AML patients. Figure Disclosures Metzeler: Daiichi Sankyo: Honoraria; Otsuka Pharma: Consultancy; Pfizer: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy; Astellas: Honoraria. Subklewe:AMGEN: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Novartis: Consultancy, Research Funding; Janssen: Consultancy; Morphosys: Research Funding; Seattle Genetics: Research Funding; Roche AG: Consultancy, Research Funding; Gilead Sciences: Consultancy, Honoraria, Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2020-137487

Language: English

Publisher: American Society of Hematology

Publication Date: 2020

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 140, No. Supplement 1 ( 2022-11-15), p. 936-939

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2022-165395

Language: English

Publisher: American Society of Hematology

Publication Date: 2022

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 3815-3815

Abstract: Background: Mutations in DNA methyltransferase 3A (DNMT3A) are common in acute myeloid leukemia (AML), affecting ~20% of patients (pts) and 30-40% of those with cytogenetically normal (CN-) AML. Although several groups have investigated their prognostic relevance, most studies focused on younger adults ( 〈 60 years [y]), and their results were inconsistent. Moreover, there is conflicting data regarding possible differences between mutations affecting the 'hotspot' codon R882 and other variants. We therefore performed comprehensive mutational analyses in 660 younger and older ( 〉 =60 y) AML pts treated on German AML Cooperative Group (AMLCG) protocols, and studied the association between DNMT3A mutations and outcomes. Patients and Methods: We analyzed pretreatment blood or bone marrow specimens from 660 adult AML pts who received intensive induction chemotherapy on two consecutive phase III trials (AMLCG-1999, n=388, and AMLCG-2008, n=272; median age, 57y, range, 18-86y). Sequence variants in DNMT3A exons 7-23 and other genes known to be mutated in myeloid neoplasms were analyzed by multiplexed amplicon resequencing (Agilent Haloplex). Sequencing was performed on an Illumina MiSeq instrument using 2x250bp paired-end reads. Variants were classified as known/putative driver mutations, variants of unknown significance, or known germline polymorphisms based on published data including dbSNP, the Catalogue Of Somatic Mutations In Cancer (COSMIC) and The Cancer Genome Atlas (TCGA). Cytogenetic analyses were performed centrally. Results: We identified 223 DNMT3A mutations in 207/660 pts (31%), including 180/449 pts (40%) with intermediate-risk cytogenetics according to the MRC classification (P 〈 .001). Missense mutations affecting codon R882 were found in 114 pts, other missense mutations in 59, and truncating mutations (nonsense SNVs or frame shift variants) in 43. Nine pts had 〉 1 type of DNMT3A mutation. DNMT3A mutations tended to be more frequent in older compared to younger pts (35% vs. 28%, P =.08) and were associated with female sex (38% vs 26% in males; P 〈 .001), higher leukocyte counts (P =.008) and higher marrow blast percentages (P =.005). In the entire cohort, mutated DNMT3A associated with shorter relapse-free survival (RFS, hazard ratio [HR], 1.64, P 〈 .001) and shorter overall survival (OS; HR, 1.26; P =.02). Outcomes were similar for pts with DNMT3A codon R882 mutations, other missense mutations, or truncating mutations. Shorter RFS and OS of DNMT3A -mutated pts was also observedin the subgroup with intermediate-risk cytogenetics (RFS: HR, 1.62; P =.002 and OS: HR, 1.34; P =.02). DNMT3A mutations associated with inferior outcomes in younger pts (RFS: HR, 1.58; P =.02 and OS: HR, 1.55; P =.005), while in older pts, no significant impact of mutated DNMT3A as a single marker on RFS or OS was observed. Due to the strong association of DNMT3A mutations (which appear to be prognostically unfavorable) with mutated NPM1 (an established favorable risk marker), we studied the four subgroups defined by the combination of both mutations. DNMT3A mutations associated with shorter RFS (Fig. A) in pts with mutated NPM1 as well as in those with wild-type NPM1, and with shorter OS in NPM1-mutated pts (Fig. B). When we considered the prognostically favorable 'molecular low risk' genotype (i.e., CN-AML with mutated NPM1 without FLT3 internal tandem duplication [ITD]), DNMT3A mutations associated with shorter RFS (Fig. C) and a trend for shorter OS (Fig. D) in pts with this combination, and with significantly shorter RFS and OS in the remaining ('high molecular risk') CN-AML pts. Finally, in a multivariate model adjusting for other clinical and genetic risk factors, mutated DNMT3A remained a significant risk factor for shorter RFS (HR, 1.44; P =.01) and OS (HR, 1.26; P =.04). Conclusion: In our cohort of intensively treated AML pts covering a broad age range, we found that DNMT3A mutations associate with inferior survival and modulate the prognostic impact of mutated NPM1, confirming data recently reported by the MRC group (Gale et al., J Clin Oncol 33:2072). In contrast to this and other published reports, we observed no outcome differences between different types of DNMT3A mutations. Information on DNMT3A mutation status further refined the risk stratification of CN-AML based on the NPM1 mutated / FLT3-ITD negative genotype, supporting a role for DNMT3A mutations as a prognostic marker. Figure 1. Figure 1. Disclosures Subklewe: AMGEN Research (Munich): Research Funding. Krug:Boehringer Ingelheim: Research Funding; Novartis; BMS; Roche; Boehringer Ingelheim; Bayer: Honoraria; Sunesis: Speakers Bureau; Sunesis; Clavis Pharma; usa Pharma, Catapult Cell Therapy, Gilead, Roche: Membership on an entity's Board of Directors or advisory committees.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V126.23.3815.3815

Language: English

Publisher: American Society of Hematology

Publication Date: 2015

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In: Blood, American Society of Hematology, Vol. 140, No. Supplement 1 ( 2022-11-15), p. 4882-4883

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2022-167299

Language: English

Publisher: American Society of Hematology

Publication Date: 2022

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 1486-1486

Abstract: Background: Mutations in the NPM1 gene are among the most common genetic alterations in patients with acute myeloid leukemia (AML). NPM1 mutations predominantly occur in patients with normal or intermediate-risk abnormal cytogenetics, and define a distinct subgroup of AML patients recognized in the 2016 WHO classification. Overall, mutated NPM1 associates with favorable response to induction chemotherapy and relatively favorable overall survival. However, this prognostic impact is modulated by the presence of other gene mutations including FLT3 internal tandem duplications (ITD) and DNMT3A mutations. Recently, Patel and colleagues reported that a high variant allele frequency (VAF) of mutated NPM1 at the time of initial diagnosis associates with unfavorable outcomes in de novo AML (Blood 131:2816-25). This interesting and unexpected observation prompted us to investigate the association between NPM1 VAF and outcomes in a large AML patient cohort. Patients and Methods: We studied NPM1 mutated AML patients who had been enrolled on two successive multicenter phase III trials of the German AML Cooperative Group (AML-CG 1999, NCT00266136; AML-CG 2008, NCT01382147) and genetically characterized by amplicon-based targeted next-generation sequencing (NGS, Agilent Haloplex; Metzeler et al., Blood 128:686-98 and unpublished data). All patients had received induction chemotherapy containing cytarabine with either daunorubicin plus thioguanine or mitoxantrone. The minimum VAF for calling of insertion/deletion variants was 0.05, and samples with NPM1 coverage 〈 100-fold (n=17) were excluded. FLT3 internal tandem duplication (ITD) status and FLT3 ITD-to-wild type allelic ratio were determined by PCR and fragment analysis from gDNA. Results: We identified 417 NPM1-mutated patients (type A mutations, 316; type B, 28; type D, 35; and other types, 38). Median patient age was 56 years (range, 19 - 86 years), and 31/414 patients (7.5%) with cytogenetic data had abnormal karyotypes. The median NPM1 VAF was 0.43 (range, 0.05 to 1.0). Type A NPM1 mutations had significantly higher VAFs than non-type A mutations (median, 0.43 vs. 0.41; P=.0002), while type B mutations had lower VAFs than non-type B mutations (median, 0.34 vs. 0.43; P=.0025) (Figure A). Age or karyotype did not associate with NPM1 VAF. NPM1 VAF, as a continuous variable, did not associate with response to induction chemotherapy (P=.6) or relapse-free survival (P=.22). A higher NPM1 VAF did, however, associate with shorter OS (hazard ratio for an increase in NPM1 VAF equal to the interquartile range, 1.14; 95% confidence interval, 1.00-1.30; P=.049). In particular, patients in the lowest quartile of NPM1 allele burden ('low NPM1 VAF') had longer OS than patients with allele burdens above the 25th percentile ('high NPM1 VAF') (median OS, 63.7 vs. 27.0 months; 5-year OS, 51% vs 42%; P=.05; Figure B). Patients with high NPM1 VAF had higher leukocyte counts (median, 46000/µl vs. 9300/µl; P 〈 .0001) and bone marrow blast percentages (median, 85% vs. 80%; P=.0004) than patients with low NPM1 VAF. On the genetic level, patients with high NPM1 VAF more frequently had concomitant FLT3-ITD (47% vs. 37%; P=.07), and particularly FLT3-ITD with a high (≥0.5) mutant-to-wild type ratio (33% vs. 17%; P=.007), compared to patients with low NPM1 VAF. DNMT3A co-mutation was also more frequent in patients with high vs. low NPM1 VAF (63% vs. 46%; P=.002). In multivariable analyses adjusting for FLT3-ITD allelic ratio and/or DNMT3A mutation status, only the latter genetic alterations but not NPM1 VAF remained associated with OS. Conclusion: Our study confirms the recent report that adult AML patients with high NPM1 mutant allele burden have shorter survival. In our cohort, however, higher NPM1 VAF also associated with higher leukocyte counts and marrow blast percentage, and with prognostically adverse FLT3-ITD and DNMT3A mutations. After adjusting for these confounders, NPM1 allelic burden did not independently predict survival in our analysis. We therefore suspect that high NPM1 VAF may be a surrogate marker of highly proliferative AML subsets, for example those with high allelic ratio FLT3-ITD, rather than a novel independent prognostic factor. Figure. Figure. Disclosures Prassek: Jannsen: Other: Travel support; Celgene: Other: Travel support. Subklewe:Roche: Consultancy, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Hiddemann:Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; F. Hoffman-La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Metzeler:Celgene: Consultancy, Research Funding; Novartis: Consultancy.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2018-99-112549

Language: English

Publisher: American Society of Hematology

Publication Date: 2018

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 128, No. 22 ( 2016-12-02), p. 1682-1682

Abstract: Introduction In Acute Myeloid Leukemia (AML) internal tandem duplications (ITD) in the fms-related tyrosine kinase 3 (FLT3) are a frequent event associated with an unfavorable prognosis. At diagnosis, the FLT3-ITD status is routinely assessed by fragment analysis of PCR-amplified cDNA. However, this assay only provides information on the length but not on the position and sequence of the insertion. Therefore, it is attractive to overcome this limitation by the use of high-throughput amplicon sequencing (HTAS) as an alternative strategy for FLT3-ITD detection. To proof the feasibility and accuracy of this approach we performed HTAS on 260 AML patients, of which 250 were FLT3-ITD positive according to routine diagnostics. Patients and Methods All samples were obtained from patients treated on the German Acute Myeloid Leukemia Cooperative Group (AMLCG) trials 1999, 2004 and 2008. All patients received intensive induction therapy with curative intent. At diagnosis, patients had a median age of 60 years (range, 18-80 years). Additional molecular marker were screened routinely: NPM1 mutation (62%), KMT2A-PTD (8%), CEBPA mutations (8%). According to the ELN-classification patients clustered into the following groups: ELN intermediate I (70%), intermediate II (21%) or adverse (9%). A normal karyotype was observed in 71%, while 29% had an aberrant karyotpye. All patient samples were analyzed routinely by FLT3 fragment analysis. For HTAS of FLT3 we used custom FLT3 cDNA primers including barcode and adapter-sequences enabling a one-step PCR-protocol. Sequencing was performed (2x250bp paired end) on a MiSeq (Illumina). Per run, up to 96 samples were sequenced, yielding a median of 79,110 reads per amplicon (range: 31,996 - 259,783). As controls, cDNA from FLT3-ITD positive (Molm-13) and negative (HL60) cell lines were used. Sequencing data were aligned to the FLT3 cDNA reference (NM_004119.2) and FLT3-ITDs were called using Pindel software (version 0.2.5a7). Results Based on the HTAS results obtained from the FLT3 wild-type control HL60, we set the cut-off for ITD detection at a variant allele frequency (VAF) of 0.5%. Using this threshold, all patients which were assessed to be FLT3-ITD negative in diagnostic routine, were also negative in HTAS. FLT3-ITDs were detected by HTAS in 242 out of 250 (97%) patients who were FLT3-ITD positive patients according to routine fragment analysis. For six out of the 8 remaining patients, no valid ITD was detected by HTAS possibly due to one of the following reasons: a low mutational burden resulting in a VAF below the cut-off level (n=4) or a deletion near the ITD (n=2) potentially interfering with ITD-detection. In total, 308 ITDs were detected in 242 patients by HTAS while in these patients 282 ITDs were detected by routine diagnostics. Of note, HTAS missed 13 subclonal ITDs reported in routine, while 39 additional subclonal ITDs were detected by HTAS only. Overall, HTAS detected a higher number of ITDs per patient (mean: 1.27; range: 1-4) compared to fragment analysis (mean: 1.17; range: 1-3). Patients with more than one ITD according to HTAS showed a trend towards shorter overall and relapse free survival (p=0.105, p=0.104 respectively; Figure 1A). The ITD position (i.e. affected FLT3 domain) based on HTAS did not impact on clinical outcome. There was a significant correlation between the FLT3-ITD levels detected by fragment analysis and HTAS (Pearson, R=0.801, p=0.01; Figure 1B). High FLT3-ITD levels measured by fragment analysis had a significant impact on RFS, whereas this effect was not observed for FLT3-ITD levels measured by HTAS. The quantification of FLT3-ITD by HTAS might be hampered by underestimation of the VAFs of long ITDs that are less likely to be mapped correctly compared to shorter ITDs. Conclusion In summary, our study demonstrates the feasibility of HTAS for FLT3-ITD detection in AML. In particular, the identification of subclonal ITDs with high sensitivity provides additional information with potential prognostic value. Thus, HTAS may serve as a robust tool that could be implemented in future diagnostic routines. However, bioinformatic algorithms for ITD detection may need further improvement, e.g. to optimize ITD quantification and to facilitate the detection of ITDs in combination with deletions. Disclosures Hiddemann: Roche: Other: Grants; Genentech: Other: Grants; Roche: Membership on an entity's Board of Directors or advisory committees.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V128.22.1682.1682

Language: English

Publisher: American Society of Hematology

Publication Date: 2016

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In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 2753-2753

Abstract: The prognosis of patients with AML is determined by a multitude of recurrent genetic alterations, and treatment algorithms heavily rely on risk stratification by genetic characterization of the disease at the time of diagnosis. However, this a priori risk stratification does not integrate information on treatment susceptibility of the individual patient. Assessment of Minimal Residual Disease (MRD) aims to implement this information in the patient-specific treatment management. AML cells with aberrant phenotypes can be detected at sensitivities below 1:104 by flow cytometry in the majority of patients. Therefore, flow cytometry MRD assessment (flow MRD) enables determination of MRD status in patients without suitable molecular markers (e.g. NPM1, CBFß-MYH11, and RUNX1-RUNX1T1). Here, we validate the role of flow MRD in AML patients receiving intensive chemotherapy with and without available molecular markers. Flow MRD was analyzed in patients with AML (excluding APL) diagnosed between 2012 and 2017 receiving intensive induction chemotherapy (sHAM or 7+3). Flow MRD analysis was performed during aplasia (on day 16 after treatment initiation) as well as post induction. Presence of ≥0.1% Leukemia-associated immunophenotype (LAIP)-positive cells was defined as flow MRD positivity. Molecular MRD was analyzed post induction for NPM1 and CBF, and post consolidation for RUNX1-RUNX1T1. Kaplan-Meier estimators and log-rank tests were used to analyze survival data. Cox's proportional hazards regression model was used to determine the influence of individual factors in multivariate analyses. A total of 161 patients were included. In 5 cases (3.1% of all cases), no LAIP could be identified, and these patients were excluded from further analyses. Flow MRD assessment during aplasia was available in 145 cases. 122 patients had flow MRD assessments available post induction. 114 patients achieving CR or CRi after induction therapy had flow MRD assessments available at both time points. Flow MRD positivity during aplasia was associated with shorter event free survival (EFS, 6.1 months vs. 19.1 months, p 〈 0.001). Similarly, flow MRD positivity post induction was associated with shorter EFS (11.9 months vs. median not reached, p=0.007). For both timepoints, flow MRD was an independent risk factor in multivariate analysis compared to known risk factors such as age, genetic/molecular risk profile as determined by the ELN2017 risk categories as well as early blast clearance by morphology. Persistent flow MRD positivity at both timepoints (combined flow MRD) identified patients with particularly short EFS (8.2 months), whereas patients with flow MRD negativity at both time points had the best outcome in our cohort (median not reached, p=0.002). Combined flow MRD status was an independent predictor of EFS and RFS (HR 1.9 and 1.8, p=0.001 and p=0.007, respectively), whereas blast clearance by morphology had no significant prognostic impact (p 〉 0.05 for all endpoints). 64/161 patients (39%) had molecular MRD assessment available for analysis. In these patients, molecular MRD positivity predicted a significantly shorter EFS (9.3 months vs. median not reached, p=0.01). Indeed, molecular MRD positivity was an independent risk factor for adverse EFS and RFS (HR 1.7 and 1.6, p=0.008 and p=0.018, respectively). In this subgroup, flow MRD was not an independent prognostic factor. However, for patients without available molecular MRD marker (97/161 patients), flow MRD positivity at aplasia (p=0.004), post induction (p=0.015) or as combined status (p=0.004) was associated with a significantly shorter EFS and remained an independent risk factor in multivariate analysis (HR 2.5 and 2.6, p=0.016 and p=0.012 for EFS and RFS, respectively). Taken together, we demonstrate that both flow MRD as well as molecular MRD strongly correlate with survival. While molecular MRD assessment was only available in 39% of patients, MRD assessment by flow cytometry was feasible in 〉 95% of AML patients. Flow MRD positivity both during aplasia and post induction was an independent risk factor, confirming the superiority of flow MRD compared to early morphologic response assessment. In conclusion, molecular and flow cytometric MRD assessment are complementing methods for the estimation of treatment response, and will be integrated in clinical trials to validate their significance for patient-specific treatment management. Disclosures Metzeler: Celgene: Consultancy, Research Funding; Novartis: Consultancy. Hiddemann:F. Hoffman-La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Subklewe:Gilead Sciences: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Roche AG: Research Funding; AMGEN: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2018-99-119065

Language: English

Publisher: American Society of Hematology

Publication Date: 2018

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: HemaSphere, Ovid Technologies (Wolters Kluwer Health), Vol. 7, No. S3 ( 2023-08), p. e03586b2-

Type of Medium: Online Resource

ISSN: 2572-9241

URL: Article

DOI: 10.1097/01.HS9.0000968692.03586.b2

Language: English

Publisher: Ovid Technologies (Wolters Kluwer Health)

Publication Date: 2023

detail.hit.zdb_id: 2922183-3