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  • 1
    In: Blood, American Society of Hematology, Vol. 119, No. 14 ( 2012-04-05), p. 3211-3218
    Abstract: A cohort of MDS patients was examined for mutations affecting 4 splice genes (SF3B1, SRSF2, ZRSR2, and U2AF35) and evaluated in the context of clinical and molecular markers. Splice gene mutations were detected in 95 of 221 patients. These mutations were mutually exclusive and less likely to occur in patients with complex cytogenetics or TP53 mutations. SF3B1mut patients presented with lower hemoglobin levels, increased WBC and platelet counts, and were more likely to have DNMT3A mutations. SRSF2mut patients clustered in RAEB-1 and RAEB-2 subtypes and exhibited pronounced thrombocytopenias. ZRSR2mut patients clustered in International Prognostic Scoring System intermediate-1 and intermediate-2 risk groups, had higher percentages of bone marrow blasts, and more often displayed isolated neutropenias. SRSF2 and ZRSR2 mutations were more common in TET2mut patients. U2AF35mut patients had an increased prevalence of chromosome 20 deletions and ASXL1 mutations. Multivariate analysis revealed an inferior overall survival and a higher AML transformation rate for the genotype ZRSR2mut/TET2wt (overall survival: hazard ratio = 3.3; 95% CI, 1.4-7.7; P = .006; AML transformation: hazard ratio = 3.6; 95% CI, 2-4.2; P = .026). Our results demonstrate that splice gene mutations are among the most frequent molecular aberrations in myelodysplastic syndrome, define distinct clinical phenotypes, and show preferential associations with mutations targeting transcriptional regulation.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2012
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 2
    In: Leukemia, Springer Science and Business Media LLC, Vol. 32, No. 8 ( 2018-8), p. 1856-1860
    Type of Medium: Online Resource
    ISSN: 0887-6924 , 1476-5551
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    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2018
    detail.hit.zdb_id: 2008023-2
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  • 3
    In: Medicine, Ovid Technologies (Wolters Kluwer Health), Vol. 92, No. 5 ( 2013-09), p. e1-e9
    Type of Medium: Online Resource
    ISSN: 0025-7974
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2013
    detail.hit.zdb_id: 2049818-4
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  • 4
    In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 1697-1697
    Abstract: Abstract 1697 Background Abnormal and clonal hematopoiesis resulting in peripheral blood cytopenias, and risk of progression to acute myeloid leukemia (AML) are the main characteristics of myelodysplastic syndromes (MDS) which present a high diversity of somatically mutated genes. Recently, mutations targeting genes whose products participate to the early steps of RNA splicing (SF3B1, SRSF2, ZRSR2, and U2AF35) have been reported. Mutations in ASXL1, DNMT3, EZH2, IDH1/2 and TET2, suggest deregulation of the epigenetic control of transcription. Additional genes known to be mutated in MDS include RUNX1, TEL/ETV6, TP53 and NRAS The alteration of some of these genes may carry prognostic value. Next-generation sequencing analyses of AML and related disorders recently identified mutations in two chromosome X genes, BCOR and BCORL1, that code for related transcriptional co-repressors interacting with histone deacetylases and presenting specific properties. BCOR interacts with BCL6 and constitutional inactivating mutations have been described in the Oculo-Facial-Cardio-Dental syndrome. BCOR is also affected by mutations or translocations in retinoblastoma and sarcoma. BCORL1 has been implicated in chromosomal rearrangements in hepatocellular carcinoma. In this study, we have investigated BCOR and BCORL1 gene by Sanger sequencing in a cohort of 221 MDS samples. Methods The 221 MDS samples were collected at diagnosis in multicenter clinical trials in France between 1999 and 2011. The coding sequences of BCOR (ENST00000378444) and BCORL1 (ENST00000218147) were analyzed by Sanger sequencing. Mutational analyses of ASXL1, CBL, DNMT3A, ETV6, EZH2 IDH1/2, JAK2, NRAS, RUNX1, SF3B1, SRSF2, TET2, TP53, U2AF35, and ZRSR2 were previously reported. Non tumoral material (buccal swab or CD3+ cells) was analyzed for the presence of the identified variations of BCOR or BCORL1 when available (n=9). The prognostic impact of BCOR mutations was evaluated in MDS patients with available follow-up information (n=203). Results BCOR and BCORL1 coding sequences were analyzed in the cohort of 221 MDS patients and we found mutations in 8.6% (n=19) and 2.3% (n=5) respectively. Alterations were distributed all over the coding regions. Strikingly, two patients presented concomitant inactivating mutations of BCOR and BCORL1. Among the 19 BCOR alterations, 9 were missense, 3 nonsense, 5 frameshift and 2 splice site mutations. No significant difference in age, sex, karyotype, blood counts or bone marrow blasts between BCORmut and BCORwt patients was observed. Mutations were found in patients of all IPSS risk-groups and WHO subtypes. Comparison of cytological bone marrow reports revealed a trend for a higher rate of dysgranulopoiesis in BCORmut patients (P=0.06). Because only truncating mutations (splice, frameshift and nonsense mutations) are unambiguously expected to affect BCOR function, statistical analyses were restricted to truncating BCOR mutations (n=10/221, 4.5%). Truncating BCOR mutations were frequent in RUNX1mut patients (19% versus 3% in RUNX1wt patients; P=0.027). They were by trend associated with SRSF2 and DNMT3A mutations (P=0.09) and were exclusive with IDH1/2, JAK2, NRAS, TP53, and ZRSR2 mutations. In univariate analysis, Overall Survival (OS) and AML transformation rate did not differ between patients with either missense or truncating BCOR mutations and BCORwt patients (Figure A & B). However, inferior OS (P=0.034) and higher AML transformation rate by trend (P=0.051) were observed for patients with truncating BCOR mutations (Figure C & D). Multivariate analysis demonstrated that a truncating BCOR mutation was an independent unfavourable prognostic factor for OS (HR 3.3; 95%CI 1.4 – 8.1; P=.008). The low number of BCORL1 mutated patients precludes any statistical analyses but clinical follow-up was available for 4 out of 5 patients. Three patients died 7, 17 and 27 months after MDS diagnosis. The fourth patient received allogeneic bone marrow transplantation after AML transformation and is in complete remission 5 years after transplantation. Conclusion In summary, truncating mutations of BCOR were independently associated with a worse OS in MDS. These data support the idea that BCOR mutations appear as associated with RUNX1 and DNMT3A mutations as reported in AML. Moreover, and despite a relatively low mutation frequency in MDS, BCOR might be considered as a key gene in risk stratification. Disclosures: No relevant conflicts of interest to declare.
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    ISSN: 0006-4971 , 1528-0020
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    Publisher: American Society of Hematology
    Publication Date: 2012
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  • 5
    In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 2568-2568
    Abstract: Introduction: AML with multilineage dysplasia (MLD) are included in the WHO subset of "AML with myelodysplasia-related changes" (AML-MRC), together with AML arising from previous MDS or AML with MDS-related cytogenetic abnormalities. In the WHO classification, MLD is defined by dysplasia in at least 50% of the cells in at least two bone marrow (BM) myeloid cell lines. On the other hand, some genetically defined AML subgroups are specifically associated with morphologic changes, but close correlations do not exist for most of these entities. We searched for correlations between BM dysplasia and molecular aberrations in de novo AML patients included in 2 ALFA clinical trials Methods: BM cytomorphology was retrospectively reassessed in 192 patients with de novo AML (excluding CBF-AML), aged 18 to 70 enrolled in ALFA-0702 (n=123) and ALFA-0701 (n=69) clinical trials in 5 centers. 4 distinct morphologists performed the analysis from BM smears. Dysmegakaryopoiesis (DM), dyserythropoiesis (DE) and dysgranulopoiesis (DG) were quantified (respectively on 30, 200 and 200 cells) using 22 criteria designed by GFHC, which allow better evaluation of cytoplasmic and nuclear dysplasia in all BM lineages. Dysplasia was also evaluated using WHO criteria. NPM1, FLT3, MLL, CEBPA, IDH1, IDH2, WT1, DNMT3A, RUNX1, TET2 and ASXL1 gene mutations and EVI1 gene overexpression were detected by standard methods, as previously published (Renneville et al. Oncotarget 2014). Results: In the 192 patients analyzed, the incidence of molecular abnormalities was: MLL-PTD 5% (8/155), NPM1 31% (52/170), FLT3-TKD 9% (15/171), FLT3-ITD 19% (34/171), CEBPA double mutated (CEBPA-dm)11% (17/152), EVI1 overexpression 11% (17/152), IDH1 R132 9% (14/146), IDH2 R140 6% (10/159), IDH2 R172 2% (2/92), RUNX1 8% (6/67), DNMT3A 26% (11/43), TET2 12% (5/43) and ASXL1 7% (4/62). DG, DE and DM was evaluable in 59%, 83% and 85% of the patients, respectively. WHO-MLD was identified in 43/192 (22%) patients, and was not significantly associated with any genetic marker, even in AML with normal karyotype (Table 1). On the other hand, when using GFHC criteria, we observed in NPM1 mutated patients a higher % of bi-tri or multi nucleated megakaryocytes (25% vs 10%, p=0.03), of cytoplasmic DG (74% vs 58%, p=0.03); and more dysplasia in other cell lines including eosinophils, basophils, mastocytes, monocytes (p=0.008). In CEBPA-dm patients, lower % of global DG (21% vs 54%, p=0.04) was seen. In EVI1 overexpressing patients, we found a higher % of global DM, of micromegacaryocytes and of hypolobulated megacaryocytes (80% vs 31%, p=0.01; 18% vs 2%, p=0.01 and 19% vs 6%, p=0.001 respectively). In DNMT3A mutated patients, we observed a lower % of bi-tri or multi nucleated megakaryocytes (2% vs 28%, p=0.01) and a higher % of nuclear and cytoplasmic DG (21% vs 2%, p=0.005 and 1.2% vs 0%, p=0.03, respectively). In TET2 mutated patients, we observed less defects in nuclear segmentation and a higher % of abnormal chromatin condensation in granulocytes (1% vs 9%, p=0.02 and 6% vs 0%, p=0.008, respectively). Conclusion: Presence of WHO-MLD was not significantly correlated with any genetic subgroup. The 22 BM dysplasia parameters designed by the GFHC were evaluable in a majority of patients, and allowed us to find some specific cytomorphologic features in de novo AML with NPM1, CEBPA-DM, DNMT3A, TET2 mutation, or EVI1 overexpression. Those findings suggest that the definition of MLD may be refined by using more in depth quantification of dysplasia, especially with GFCH parameters. This study will be expanded with the inclusion of whole exome sequencing data (ongoing). Table 1. Correlation between MLD, normal karyotype and molecular abnormalities % AML-MLD % AML-MLD in AML with normal karyotype MLL-PTD 37,5% 29% NPM1 25% 28% FLT3-TKD 27% 33% FLT3-ITD 27% 25% CEBPA-dm 0% 0% IDH1 R132 21% 18% IDH2 R140 10% 0% IDH2 R172 0% 0% RUNX1 40% 40% DNMT3A 0% 0% TET2 0% 0% ASXL1 25% 50% EVI1 24% 0% Disclosures Fenaux: Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Novartis: Honoraria, Research Funding.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2015
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  • 6
    In: Blood, American Society of Hematology, Vol. 110, No. 11 ( 2007-11-16), p. 2847-2847
    Abstract: Mutations in exon 12 of the nucleophosmin (NPM1) gene occur in approximately 50% of adult acute myeloid leukemia (AML) with normal karyotype. More than 40 mutant variants have been identified. Most of these mutations consist of a 4-bp insertion, which can be used as a target for minimal residual disease (MRD) monitoring. We previously checked the stability of NPM1 mutations at relapse in 21 NPM1-mutated patients at initial diagnosis. In this prospective study, we evaluated MRD by real-time quantitative PCR (RQ-PCR) in 36 NPM1-mutated AML patients corresponding to 33 adult and 3 pediatric cases, treated according to the French ALFA9801 or ALFA9802 and ELAM02 protocols, respectively. Out of these patients, 31/34 (91%) had normal karyotype, 13/33 (39%) had a high initial white blood cell count, and 10/36 (28%) were FLT3-Intern Tandem Duplication (FLT3-ITD) positive. 28 (78%) patients carry NPM mutation A, 3 (8%) mutation B and 5 (14%) other rare variants. RQ-PCR assays using a mutation-specific primer were performed on cDNA for mutation A and B and on genomic DNA for other NPM1 mutants. In our experiments, the maximal reproductible sensitivity of NPM1-based MRD detection is about 10−4 on genomic DNA and 10−5 to 10−6 on cDNA. The median follow-up was 260 days [40–791]. 2 to 9 follow-up samples from bone marrow and/or peripheral blood were analysed per patient. No correlation was found between leukocytosis at diagnosis and initial expression ratio of NPM1 mutation. The study of MRD log reduction after induction therapy shows that molecular responses are very heterogeneous (from 4.10−2 to more than 1.10−5), but 50% of patients reach at least a 4 log reduction in NPM1 levels. Patients with FLT3-ITD tend to have lower log reduction after induction than patients without FLT3-ITD, although not statistically significant (P=0.07). The analysis of NPM1-MRD in bone marrow and in peripheral blood at the same follow-up time-points shows that NPM1 levels can be until 1 log higher in bone marrow. This indicates that the evaluation of NPM1-MRD in bone marrow is more informative than in peripheral blood. We found all relapses had NPM1-MRD levels comparable to those observed at diagnosis. Among the 5 patients who relapsed so far, 2 were predictable by increasing MRD levels 1 to 4 months before hematological relapse. In 29 out of 36 cases, we could monitor MRD by both NPM1 mutation and WT1 gene expression. The comparison of the MRD profiles obtained by these two approaches reveals some discordant results, which can be, at least in part, explained by difference in the sensitivity of the RQ-PCR techniques, since the sensitivity of WT1 expression as MRD target is generally not higher than 10−3. In conclusion, NPM1 mutations are very specific and sensitive markers for MRD monitoring in AML. Further studies are required to determine if NPM1-MRD provides an independent prognostic factor and may be useful for therapeutic stratification in AML patients with intermediate risk cytogenetics.
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    ISSN: 0006-4971 , 1528-0020
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    Publisher: American Society of Hematology
    Publication Date: 2007
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  • 7
    In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 2881-2881
    Abstract: Introduction Isolated trisomy 8 is a frequent cytogenetic abnormality in MDS, but hematological characteristics of MDS with isolated trisomy 8 have not been reported in detail. Patients and Methods This was a retrospective analysis of cases of MDS with isolated trisomy 8 diagnosed in 6 French centers of the Groupe Francophone des Myélodysplasies (GFM) between 2003 and 2013. Only patients with isolated trisomy 8 diagnosed as MDS or MPN/MDS (other than CMML) according to WHO were eligible, excluding AML, well characterized MPN (PV, ET) and CMML. Myeloproliferative (MP) features were defined by repeated presence (in the absence of infection) of one of the following: WBC 〉 10G/L, circulating immature granulocytes (myelemia ) 〉 2%, or palpable splenomegaly. Results 103 patients with isolated trisomy 8 were identified, with a median age of 75 years, and M/F 1.7. At diagnosis, median WBC count was 4.1 G/L, with WBC ≥ 10 G/L in 13 patients (12.6 %), myelemia ≥ 2% in 27 patients (26.2 %), palpable splenomegaly in 9 patients (8.7 %). WHO diagnosis included 20 RA, 2 RARS, 22 RCMD, 1 RCMD-RS, 1 RCUD, 21 RAEB-1, 18 RAEB-2, 7 MDS-U, 10 MDS/MPN, 1 hypoplastic MDS. IPSS was intermediate 1 (72.2 %), intermediate 2 (19.6 %), high (8.2 %) ; IPSS-R was low (37.1 %), intermediate (29.9 %), high (22.7 %), very high (10.6 %). MP features were found in 50 patients (48.5 %): 31 at diagnosis, 19 during evolution (in patients without MP features at diagnosis). Bone marrow morphological features could be reviewed in 15 MP cases, showing hypercellular marrow in 60 % cases, granulocytic hyperplasia (E/G 〈 0.25) in 53%, marked neutrophil hypogranularity in 87% and abnormal chromatin clumping in neutrophils in 53 %. Somatic mutations were studied in 31 patients on diagnostic samples (16 MP and 15 non MP) for 27 most frequently mutated genes in MDS and MPN: ASXL1, CBL, DNMT3A, ETV6, EZH2, IDH1, IDH2, JAK2, cKIT, KRAS, NRAS, MPL, PHF6, PTPN11, RIT, RUNX1, SETBP1, SF3B1, SRSF2, TET2, TP53, U2AF1, WT1, ZRSR2, FLT3-TKD, FLT3-ITD, NPM1 (FLT3-TKD, FLT3-ITD and NPM1 were studied in only 15 patients). Mutations were seen, for MP cases, in ASXL1 (64%), EZH2 (50%), TET2 (40%), RUNX1 (33%), SRSF2 (27%), DNMT3A (15%), JAK2 (14%), IDH2 (14%), NRAS (8%), SF3B1 (9%), U2AF1 (8%); for non MP cases in ASXL1 (33%), SRSF2 (27%), SF3B1 (27%), TET2 (20%), DNMT3A (13%), JAK2 (13%), RUNX1 (13%), EZH2 (7%), IDH2 (7%), ZRSR2 (7%), NRAS (0%). In spite of a trend for more mutations of ASXL1 (p=0.128), and EZH2 (p=0.053) in MP forms, the difference with non MP forms was not significant, possibly due to small patient numbers. 40 patients received an HMA (AZA in 36, DAC in 4) and 27.3% responded (4 CR, 1 PR, 1 marrow CR, 3 HI), including 11.7% of MP cases and 43.8% of non MP cases (p=0.057). 5 patients received intensive chemotherapy (with 2 CR). 42 (40.8%) received an ESA, with 60% responses, including 50% in MP and 73% in non MP patients (p= NS).10 (9.7%) received hydroxyurea. With a median follow up of 30 months, progression to AML was seen in 26% and 18.9% in MP and non MP patients, respectively (p= NS). Median survival was 35 months in the whole cohort, without difference between patients who, at diagnosis had MP features and no MP features (35 months for both). Conclusion Myeloproliferative (MP) features were found at diagnosis or during evolution in our experience in about 50% of MDS with isolated trisomy 8, a finding not previously reported, to our knowledge, and suggesting that some of those patients may have to be reclassified among MDS/MPN. The subset of patients with MP features tended to have a higher frequency of ASXL1 and EZH2 mutations (findings that will have to be confirmed on larger patient numbers), and seemed to respond poorly to HMA, although its survival was not lower than that of non MP forms in our experience. Disclosures Park: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Hospira: Research Funding; Celgene: Research Funding. Fenaux:AMGEN: Honoraria, Research Funding; CELGENE: Honoraria, Research Funding; JANSSEN: Honoraria, Research Funding; NOVARTIS: Honoraria, Research Funding.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2015
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  • 8
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4171-4171
    Abstract: Abstract 4171 NF1 acts as a tumor-suppressor gene by encoding neurofibromin1, a GTPase-activating protein (GAP) inhibiting Ras signaling pathway. Germline mutations or microdeletions of NF1 are responsible for neurofibromatosis type 1, and the somatic loss of the remained wild-type allele lead to malignant tumors or juvenile myelomonocytic leukemia (JMML). Furthermore, several studies revealed heterozygous somatic deletions of the 17q11.2 region including NF1 in adult myeloid malignancies. The reported frequencies of this abnormality varied between 2.6% and 11% in AML and this variation can be attributable to heterogeneity or size of the analysed cohorts. Previously, we analyzed 131 de novo AML cases (AML3 excluded) by Agilent™ 105K microarrays. 6/131 cases (4.6%) showed somatic deletions in 17q11.2, including a small minimal deleted region of 300 kb comprising the entire NF1 gene. To further investigate the incidence of NF1 deletion in de novo AML, 354 additional patients were therefore screened for the deletion by quantitative real-time PCR (Primers and TaqMan-based probe Hs 01778367_cn from Applied Biosystems), and FISH (NF1/MPO probe KBI-40144 from Kreatech) was performed to confirm the loss of NF1 copy number. Altogether, heterozygous NF1 deletion was observed in 17/485 (3.5%) de novo AML. Clinico-biological data were available from 14 NF1 deleted patients and 380 non-deleted patients included in the ALFA-9801 and 9802 French Trials. There were no significant differences between the 2 groups in age, sex ratio, leukocytosis, FAB classification of AML, mutational status of FLT3, NPM1, CEBPα and IDH. Interestingly, NF1 deletion was significantly correlated with unfavourable cytogenetic (50% vs 18%, p=0.008) and especially with monosomal karyotype (29% vs 9%, p=0.03). However, no statistical significant differences were observed for complete remission rate, relapse risk 3 years after diagnosis and 3-years overall survival. Screening for bi-allelic inactivation by sequencing the remained allele in NF1 deleted patients is in progress. We next evaluated NF1 gene expression for 93 patients of our cohort (3 with NF1 deletion and 90 without) by Affymetrix U133 Plus 2.0 microarrays. The 3 NF1 deleted patients revealed a significant reduced mean of NF1 expression level. Interestingly, about 10% of the NF1 non-deleted patients presented a similar decrease in NF1 expression rate. This suggests that mechanisms for transcriptional regulation (such as mutations or epigenetic silencing of NF1) may also contribute to AML pathogenesis. In conclusion, NF1 deletions occur in only 3.5% of de novo AML and are associated with unfavourable cytogenetic. This relatively low frequency of NF1 deletion can however be counterbalanced by others alterations acting at the transcriptional level and this remains to be investigated. Disclosures: No relevant conflicts of interest to declare.
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    ISSN: 0006-4971 , 1528-0020
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    Publisher: American Society of Hematology
    Publication Date: 2010
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  • 9
    In: Blood, American Society of Hematology, Vol. 118, No. 21 ( 2011-11-18), p. 2608-2608
    Abstract: Abstract 2608 Aim. CBF-AML is a favorable AML subset cytogenetically defined by t(8;21) or inv(16)/t(16;16) rearrangements, respectively responsible for RUNX1-RUNX1T1 (CBFα) or CBFB-MYH11 (CBFβ) gene fusion. Nonetheless, relapse incidence may reach 30–40% in these patients. The tyrosine kinase (TK) receptor KIT is expressed in the vast majority of CBF-AML and activating KIT gene mutations, including exon 8 del/ins and exon 17 point mutations, have been reported in both CBF-AML subtypes. These mutations have been retrospectively associated with a higher risk of relapse. Dasatinib is a TK inhibitor active on both wild-type and mutant KIT isoforms. These observations led several groups to initiate prospective trials testing dasatinib/chemotherapy combinations in newly diagnosed CBF-AML patients. The aim of the present Phase 2 DASA-CBF trial (EudracCT 2006-00655-12) was to search for a positive signal by treating CBF-AML patients in first complete remission (CR), but with persistent or re-appearing molecular minimal residual disease (MRD), by the single-agent dasatinib. Prevention of further hematological relapse was the primary endpoint. Methods. Eligible patients (18–60y) had to have been previously enrolled and treated in the CBF-2006 study (Jourdan et al. this meeting). MRD was quantified by RQ-PCR and results were expressed as 100 × CBF fusion gene/cABL ratios. Patients in first CR were eligible if: 1) MRD ratio reduction less than 3-Log before the second consolidation cycle (refractory Mol-REF patients); or 2) MRD ratio re-increase more than 1-Log on two successive evaluations (relapsing Mol-REL patients). Patients with a sibling or unrelated donor and no contra-indication to allogeneic stem cell transplantation (SCT) were not eligible. Dasatinib was administered orally at 140 mg once daily for a total duration of 12 months. In case of grade 3 adverse event (AE), treatment was discontinuated until AE resolution to grade 0–1. In case of grade 4 AE or AE reappearance, dose reduction to 100 mg/d was allowed. Dose escalation to 90 mg bid was allowed in case of stable or increasing MRD after 2 months of therapy without toxicity. Results. Between June 2008 and June 2011, 26 CBF-AML patients (median age, 44y) were included. They were 12 CBFα patients (6 Mol-REF, 6 Mol-REL) and 14 CBFβ patients (12 Mol-REF, 2 Mol-REL). Seven patients had a KIT mutation (4 exon 8 and 3 exon 17; 3 CBFα and 4 CBFβ). The median time between CR achievement and DASA-CBF enrollment was 161 days (106–406) in Mol-REF patients and 413 days (167–530) in Mol-REL patients. Overall, dasatinib was well tolerated. Two grade 3 AEs (hypertension, headache) led to dasatinib dose reduction without further reoccurrence. Dose escalation was performed in two patients. With the exception of one patient (without KIT mutation) still alive in CR1 at 929 days, 7 of the 8 Mol-REL patients had rapid hematological relapse under dasatinib treatment after a median time of 60 days (52–120). In the 18 Mol-REF patients, the probability of persistent hematological remission was 65% (95% CI, 38–82) at 12 months and 45% (95% CI, 20–67) at 24 months, with a trend for shorter remission duration in the 6 patients with KIT mutation (P=0.07). These 18 Mol-REF patients were compared to the 37 other Mol-REF patients from the CBF-2006 trial not enrolled in the DASA-CBF trial (9 SCT in CR1, 28 without further therapy). Both series were comparable in terms of age, WBC, baseline fusion transcript ratio, MRD ratio Log-reduction after induction and first HDAC consolidation, as well as additional cytogenetic anomalies and KIT, FLT3 and RAS gene mutations. Despite dasatinib treatment, the probability of persistent hematological remission was not higher in the 18 DASA-CBF patients than in the 28 patients who received no further therapy (45% versus 53% at 24 months, P=0.91). Conversely, only one hematological relapse was observed in the 9 patients who received SCT in CR1, the remaining 8 patients being alive in continuous CR. Conclusion. This Phase 2 trial failed to show a significant effect of single-agent dasatinib in the prevention of hematological relapse in CBF-AML patients in first CR after standard therapy, but at high risk of relapse because of persistent or re-appearing MRD. Moreover, no trend towards a preferential effect was observed in KIT mutated patients. This observation does not preclude any dasatinib activity in CBF-AML patients when combined with conventional chemotherapy. Disclosures: Off Label Use: Dasatinib is not approved for AML patients. Mohamed:Bristol-Myers Squibb: Employment.
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    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2011
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  • 10
    In: Blood, American Society of Hematology, Vol. 121, No. 22 ( 2013-05-30), p. 4504-4511
    Abstract: The MYD88 locus is altered in 91% of patients with WM. MYD88 might be new target for therapeutic in WM.
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    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2013
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