Favorable Cytogenetic Risk Groups Research Articles

Impact of Spliceosome Mutations on the Prognosis of Myelodysplastic Syndrome (MDS)

Introduction: More than half of patients with myelodysplastic syndrome (MDS) have spliceosome mutations (SM) including ZRSR2, U2AF1, SF3B1 and SRSF2. Splicing is fundamental for proper mRNA processing. Mechanistic descriptions of the after-effects of SM remain elusive as improperly formed mRNA quickly decays or changes are subtle and may lack observable effects. These mutations have been implicated in multiple biological alterations including myeloid proliferation through aberrant NF-kB signaling. SRSF2P95* has been consistently shown to provide the highest fitness advantage in the bone marrow environment. This study reports the characteristics, treatment outcomes, leukemia free and overall survival of MDS with spliceosome mutations. Patients and Methods: A retrospective review of patients diagnosed with MDS older than 18 for whom genomic data was available were included at a single institution. Patient characteristics and bone marrow data, including cytogenetic and next generation sequencing (NGS) information were assessed. Genomic DNA was extracted from whole bone marrow aspirate samples and subject to 81-gene target PCR-based sequencing using a NGS platform. The IWG 2006 response assessment criteria were used. Overall and leukemia-free survival were calculated, the latter as a composite of acute myeloid leukemia diagnosis or death from any cause, using the log-rank test for group comparison. Results: First, we compared patients with SM vs no SM. We identified 427 patients with SM and 658 patients with no SM from 2017 to 2022 (Table 1). Among patients with SM, 71% were male, median age was 71. SM patients had higher incidence of IPSS Low (33.3% vs 10.3%) and IPSS Int- 1 (35.6% vs 32.2%), and a higher incidence of diploid karyotype (45% vs 21%), compared to patients with no SM. There was no difference in treatment regimens, and 66.9% of patients with SM received hypomethylating agents (HMA) alone or in combination vs 60.3% in the group without SM. MDS with SM had a lower CR/CRi rate (27% vs 36%); however, they had higher hematologic improvement (HI) (23% vs 14%) and lower chance of disease progression or death at the time of response assessment (39% vs 31% (p = 0.01)). Leukemia-free survival was longer in patients with SM vs no SM (median 4.1 years vs 1.9 years (p<0.0001), this was independent of SF3B1 mutations. Median OS was 4.5 years vs 1.9 years in patients with SM and no SM, respectively (p <0.0001). We then compared outcomes between patients with specific SM mutations. These included SF3B1 (34%), SRSF2 (26%), U2AF1 (25%), and ZRSR2 (14%). Thirty-six percent were female. Median age was 71 (range 28-93). Median percentage of blasts was 3 (range 0-19). Most frequent diagnoses were MDS-EB (35%), MDS-RS (25%) and MDS-MLD (23%). IPSS was Low, Intermediate 1, Intermediate 2 and High in 33.3%, 35.6%, 17.1% and 4.2%, respectively. Fifty-seven percent were in the favorable cytogenetic risk group, 44% with diploid karyotype. Patients with a SM mutation did not share any other SM mutation (Table 2). There were no differences in therapy selected or response rate among SM mutations. Median LFS was not reached (NR), 5.7 years, 3.4 years, and 2.7 years for patients with SF3B1, ZRSR2, U2AF1, and SRSF2 mutations, respectively. Median OS was NR, 5.7 years, 3.6 years, and 2.7 years (p = 0.005) for the same groups, respectively. Conclusions: In our study, patients with SM had a lower rate of CR/CRi with HMA-based therapy, however, leukemia free and overall survival were markedly different for each mutated gene. SM mutations were significantly more prevalent in males. Compared to MDS with diploid cytogenetics, ZRSR2 and SF3B1 mutations have a similar median LFS and OS, but SRSF2 and U2AF1 mutations carry a significantly worse median LFS and OS. While it is convenient to group these mutations together, prognostication should be individualized to specific mutations and co-mutations. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Non-Age-Related Neoplastic Loss of Sex Chromosomecorrelated to Prolonged Survival in CBF-AML Patients in Real-World Clinical Setting

IntroductionSince Core-binding factor acute myeloid leukemia (CBF-AML) is categorized as a favorable cytogenetic risk group, allogenic hematopoietic stem cell transplantation (HSCT) is generally not recommended during the first complete remission (CR1). However, approximately 30-50% of CBF-AML patients relapse, and about 50% of relapsed patients remain incurable. Therefore, in real-world clinical setting, the indication of HSCT even in CR1 is considered based on prognosis prediction and minimal residual disease (MRD) status. With respect to prognosis prediction by chromosomal abnormalities, the prognostic impact of loss of sex chromosome (LOS) in the patients with CBF-AML is still controversial. Previous studies suggest that the impact of LOS in predicting the prognosis of CBF-AML may depend on treatment strategies including HSCT. In addition, although CBF-AML develops LOS at a high rate of 20-40%, it is still unclear whether LOS is age-related or neoplastic.MethodsHokkaido Leukemia Net (HLN) is prospective cohort study collecting AML samples from hospitals of North Japan Hematology Study Group (NJHSG).Cases of CBF-AML that were registered in HLN from January 2010 to December 2019 were used for analysis in the present study. All the patients received either intensive or low-intensity chemotherapy. HSCT was performed at the discretion of the attending physicians even in CR1. Conventional cytogenetic analysis was performed at the time of diagnosis and after each treatment. FLT3-ITD and KIT exon17 mutations were analyzed using genome DNA template at the central laboratory. The results of genetic analysis were returned to physicians so that they could reflect the genetic result in their treatment choice. We evaluated the impacts of several factors including advanced age, poor response to chemotherapy, LOS, and KIT exon17 mutation on overall survival (OS) and relapse-free survival (RFS) in these patients. This study was conducted in compliance with ethical principles based on the Declaration of Helsinki and was approved by the institutional review board of Hokkaido University Hospital.ResultsA total 96 CBF-AML patients including 62 patients with RUNX1/RUNX1T1 and 34 patients with CBFβ/MYH11 were enrolled in the present study. Intensive induction chemotherapy using '7+3' cytarabine plus anthracycline and low-intensity induction chemotherapy were performed in 90 patients and 6 patients, respectively. In 90 patients who underwent intensive induction chemotherapy, the CR rate after one cycle of induction therapy was 73.3%. Total CR rate as the best response was 91.7% for all CBF-AML patients. HSCT in CR1 was performed in 15 patients (15.6%) at the discretion of the attending physician based on genetic alterations, poor response to chemotherapy, and sustained detection of MRD after chemotherapy. There was no significant difference in 5-year OS (RUNX1/RUNX1T1 64.9% vs CBFβ/MYH11 52.9%; P=0.546) or 5-year RFS (63.6% vs 53.3%; P=0.364) between the CBF subtypes. LOS was significantly more frequent in patients with RUNX1/RUNX1T1 than in patients with CBFβ/MYH11 (35.5% vs 5.9%; P=0.001). Multivariate analyses for 5-year OS in CBF-AML patients revealed that age of 50 years or older (HR: 3.46, 95% CI: 1.47-8.11, P=0.004) and receiving 2 or more induction cycles (HR: 3.55, 95% CI: 1.57-8.05, P=0.002) were independently associated with worse OS and that LOS was independently associated with better OS (HR: 0.09, 95% CI: 0.01-0.71, P=0.022). We next sought to clarify whether LOS was age-related or neoplastic based on the transition of chromosome results. All the 24 patients with LOS achieved CR, and chromosome analysis at CR showed a normal karyotype in all of the 21 patients for whom chromosome analysis was performed. In the remaining 3 patients, only FISH analysis for RUNX1/RUNX1T1 or CBFβ/MYH11 was performed. Furthermore, chromosome analysis showed mosaics of metaphase cells with and without t(8;21) in 9 patients at diagnosis. In all of those patients, metaphase cells without t(8;21) showed a normal karyotype.ConclusionIn our real-world clinical setting in which '7+3' induction was performed and the indication of HSCT was determined by prognostic factors and MRD status, LOS correlated to prolonged survival in CBF-AML patients. Furthermore, the transition of chromosome results revealed that LOS was not age-related physiological loss but part of neoplastic chromosomal abnormalities. [Display omitted] DisclosuresTeshima: CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; Janssen Pharmaceutical K.K.: Other; Novartis International AG: Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Gentium/Jazz Pharmaceuticals: Consultancy; Takeda Pharmaceutical Company: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin Co.,Ltd.: Honoraria, Research Funding; Astellas Pharma Inc.: Research Funding; Merck Sharp & Dohme: Membership on an entity's Board of Directors or advisory committees; TEIJIN PHARMA Limited: Research Funding; Nippon Shinyaku Co., Ltd.: Research Funding; Bristol Myers Squibb: Honoraria; Fuji pharma CO.,Ltd: Research Funding; Pfizer Inc.: Honoraria; Sanofi S.A.: Research Funding. Kondo: Astellas Pharma Inc.: Consultancy, Honoraria; Otsuka Pharmaceutical: Honoraria, Research Funding; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb Company: Honoraria; Sumitomo Dainippon Pharma: Honoraria; Sanwa Kagaku Kenkyusho CO.,LTD: Consultancy.

Survival Trends Among Patients with Acute Myeloid Leukemia with Favorable Cytogenetics in the United States

Background:Cytogenetics remains the single most important prognostic factor in patients with acute myeloid leukemia (AML). t(8; 21), inv(16) and t(16;16) are the favorable cytogenetic risk groups. Karyotyping not only predicts outcome but also provides an important guidance for therapy. A Southwest Oncology Group (SWOG)/ Eastern Cooperative Oncology Group (ECOG) intergroup study revealed an estimated 5-year survival rates of 55% in this subset of patients [1]. Population based study to estimate survival pattern in this subset of patients is lacking. We conducted this study to evaluate survival rates in AML patients with favorable cytogenetics over 15 years in the United States.Methodology:Surveillance, Epidemiology and End Result (SEER-18) database was utilized to identify adult patients (≥ 18 years) with AML (as first primary) with favorable cytogenetics from 2000 to 2014. 1-year relative survival rates (RS) with 95% Confidence Interval (CI) were calculated using SEER stat at different time intervals (2000-2004, 2005-2009 and 2010-2014) and compared utilizing Z-test among different cohorts categorized by race, age and sex. Also, a Kaplan Meier Curve and log rank test were used to compare overall survival (OS) in months between AML patients with and without favorable cytogenetics.Results:The database identified 30,618 AML patients. Among them, only 984 patients (3.2%) were found to have favorable risk cytogenetics. Out of these, 554 were males. Median age at diagnosis was 51 years. 785 of them were Caucasian, 82 were African Americans and 113 were from other races.In all the time periods, younger age at diagnosis was associated with better survival rate (RS for 18- 59 years: 84.8%, CI 79.6-88.7% vs. RS for 60-79 years: 49.6%, CI 39.0-59.3% vs. RS for ≥ 80 years was 14.9%, CI 5.4-28.8% in 2010-2014).Races other than Caucasian and African American (AA) had better survival than Caucasian or AA. The RS for Caucasian were better than AA for the time period 2000-2004 and 2005-2009. However, AA had better RS compared to Caucasian in the recent years (RS: 80.3%, CI 62.1-90.4% vs. 66.1%, CI 60.4-71.2%).The survival was significantly better for those with favorable cytogenetics as compared to those without favorable cytogenetics (RS: 69.7%, CI 64.8-74.1% vs. 41.1%, CI 40.1-42.2%; 3-year OS: 47.5±1.7 vs. 19.2±0.2, 2-year OS: 52.8±1.7 vs. 23.5±0.3, 1-year OS: 65.2±1.6 vs. 35.4±0.3 in 2010-2014). And the median OS was 28 months vs. 6 months, p<0.001.Conclusion:Most AML patients with favorable cytogenetics achieve a complete response after induction therapy. They continue to remain in long-term remission after consolidation or autologous transplant. Our study demonstrated a significant survival benefit in AML patients with favorable cytogenetics at a population level. Also, the survival rates have increased significantly in recent years. Improved supportive care and increased rate of transplant likely have contributed to this improvement in survival.

Impact of Race/Ethnicity on Pediatric Core Binding Factor AML Outcomes and Response to Gemtuzumab Ozogamicin

Introduction: Racial disparities in pediatric acute myeloid leukemia (AML) outcomes have consistently demonstrated inferior event-free survival (EFS) and overall survival (OS) in minority populations with the worst outcomes in Black children. However, AML is a heterogenous disease classified by recurrent genetic aberrations, and these disparities have not been thoroughly investigated within specific cytogenetic groups. In addition, race-based response to individual chemotherapy agents in AML has not been explored. Here, we use data from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database to describe the effects of race on outcomes and response to gemtuzumab ozogamicin (GO) therapy in core binding factor (CBF) AML, a favorable risk AML subtype. Methods: CBF AML patient data was extracted from the online TARGET database. Race and ethnicity were self-reported. Estimates of 2-year OS and EFS were calculated using the Kaplan-Meier method and analyzed via log-rank statistic. Pearson's Chi-squared test and Fisher's exact test were used to analyze patient variables. Results: The OS in CBF AML differed significantly based on race/ethnicity at 87% (95% CI, 82-93%) for White non-Hispanic (WNH), 77% (95% CI, 67-89%) for Hispanic, and 71% (95% CI, 58-88%) for Black children (p=0.005). EFS was also significantly lower in Black (46%; 95% CI, 32-66%) compared to non-Black children (66%; 95% CI, 60-73%)(p=0.023). When assessed by CBF AML subtype, EFS and OS in t(8;21) AML varied significantly based on ethnicity at 50% (95% CI, 34-75%) and 67% (95% CI, 50-88%) in Black patients, 63% (95% CI, 49-82%) and 69% (95% CI, 55-87%) in Hispanic patients, and 82% (95% CI, 72-92%)(p=0.01) and 90% (95% CI, 93-98%)(p=0.006) in WNH patients. In inv(16) AML, Hispanic patients experienced the highest EFS (71%; 95% CI, 55-92%) followed by WNH (54%; 95% CI, 43-66%) and Black (36%; 95% CI, 17-79%) patients though this did not reach statistical significance (p=0.12). There was no impact of race/ethnicity on OS in inv(16) AML. The use of GO did not alter OS in any subset of CBF AML. EFS appeared to be slightly improved but was not statistically significant. However, Black children with any type of CBF AML had preferential improvement with GO with significantly higher EFS (69% v. 26%, p=0.03) and a trend toward improved OS (81% v. 63%, p=0.19) with GO therapy. These improvements were primarily driven by a significant increase in EFS in inv(16) AML when treated with GO (80% v. 50%, p=0.01) and a similar but non-significant improvement in OS in this group. In Hispanic children there was a trend toward inferior EFS with the use of GO (63% v. 73%, p=0.37) in CBF AML, particularly in t(8;21) patients with a 1-year EFS of 56% (95% CI, 37-87%) compared to 81% (95% CI, 64-100%)(p=0.23). WNH children were more likely to achieve Complete Remission (CR) after course 1 (OR 2.36, 95% CI 1.09-5.10, p=0.03), and Black children were more likely to have persistent Minimal Residual Disease (MRD) after course 2 (OR 9.64, 95% CI 2.48-37.43, p&amp;lt;0.001). No differences were detected in other patient variables. Conclusion: Children with CBF AML represent a favorable cytogenetic risk group with an EFS of 70% and OS of 85%. However, the impact of race/ethnicity on outcome is significant with Black children experiencing the lowest EFS and OS at 46% and 71%, respectively, with this trend persisting across cytogenetic subtypes. Black children were also more likely to remain MRD positive after Induction II and less likely than WNH patients to achieve CR. However, while the addition of GO to standard therapy did not improve outcomes in CBF AML overall, Black children selectively benefited from GO therapy. Black children trended toward improved EFS and OS with GO with the most pronounced effect on EFS in inv(16) which was improved from 50% to 80% at 1 year. These results demonstrate that Black children with CBF AML are disproportionately at risk for poor outcomes compared to other ethnicities, but these risks may be mitigated by the use of GO which increase EFS and OS primarily in this group. Conversely, Hispanic patients trended toward worse EFS with GO, particularly in t(8;21) AML, possibly due to treatment-related toxicity. As CD33 expression and certain ABCB1 SNPs are known to predict response to GO therapy, our ongoing work investigates racial differences in these variables as a potential explanation for the differing responses to GO. Disclosures Rau: Jazz Pharmaceuticals, Inc.: Consultancy, Other: Travel Fees.

Dual Targeting of ALDH1 and ALDH3: A Promising Therapeutic Approach in Acute Myeloid Leukemia

Background. The aldehyde dehydrogenasesfamily(ALDHs) play a major cytoprotective role in cells via detoxification of a wide range of aldehydes. Their functional activity also extends to modulation of cell proliferation, differentiation and survival of cancer cells. Nevertheless, the identity of the specific isoforms contributing to this in acute myeloid leukemia (AML), the underlying mechanisms and the therapeutic value of ALDH inhibitors remain elusive. Methods. We conducted a meta-analysis to investigate the impact of ALDHs on clinicopathological parameters and survival in AML patients. The expression of ALDHs and their corresponding enzymatic activities were monitored in AML patient-derived cells (n=83) and pharmacologically inhibited with DIMATE, an irreversible suicide inhibitor of ALDH1 and ALDH3. Targeting of ALDH was evaluated both, in vitro and in orthotopic xenograft tumor models and the molecular mechanisms associated were studied in loss-of-function experiments, luciferase reporter assays and combination-index for DIMATE-drug interactions. Results. We detected gene amplification or mRNA upregulation of ALDH1 and ALDH3 subfamilies in about 45% of AML (n = 200). The expression of these isoenzymes revealed shorter survival times in patients and strong impact on chemotherapy resistance. Lower enzymatic activity of ALDH was noted in AML patients in the favorable cytogenetic risk group. Consistently, the ALDH activity was significantly higher in patients with refractory AML (&gt;5% blasts after first line treatment) compared to non-refractory patients (p&lt;0,005). Simultaneous inhibition of ALDH1 and 3 activates JNK signaling, compromises glutathione homeostasis and induces a redox state imbalance that is amplified by the accumulation of malondialdehyde and 4-hydroxynonenal-protein adducts. This condition ultimately results in severe oxidative damage and cell death. In AML xenografts with high to moderate resistance to cytarabine, combination with DIMATE promoted strong synergistic responses. Conclusion. These results provide a proof of concept that AML with increased expression of ALDH1 and 3 may benefit from strategies including inhibitors of these isoenzymes, as single agents or in combination with chemotherapy to overcome patient-specific drug resistance. For these patients, who often have poor responses and no alternative therapeutic plan, DIMATE could be a promising option. Disclosures Perez-Alea: Advanced Biodesign: Employment, Membership on an entity's Board of Directors or advisory committees, Patents &amp; Royalties: MPA reports patent WO/2017/064247. Guillaume:Advanced Biodesign: Patents &amp; Royalties: GM reports patent WO/2017/064247. Ceylan:Advanced Biodesign: Patents &amp; Royalties: IC reports patent WO/2017/064247.

Prospective Evaluation of Prognostic Relevance of Gene Mutations and Minimal Residual Disease in Acute Myeloid Leukaemia with RUNX1-RUNX1T1 or CBFB-MYH11

Background: Although acute myeloid leukaemia (AML) with RUNX1-RUNX1T1 and CBFB-MYH11 is categorized into a favorable cytogenetic risk group, several prognostic factors are suggested. However, those clinical significance remains controversial. We aimed to evaluate the prognostic relevance of gene mutations and minimal residual disease (MRD) in AML with RUNX1-RUNX1T1 and CBFB-MYH11. Methods: In this phase 4 trial, we enrolled AML with RUNX1-RUNX1T1 or CBFB-MYH11 patients aged 16 to 64 years old who achieved complete remission. Patients received three courses of high-dose cytarabine therapy, but no further treatment until haematological relapse. We analyzed mutations in exons 8, 10-11, and 17 of the KIT gene, and 55 genes that are frequently identified in myeloid malignancies, and also evaluated MRD. The primary endpoint was relapse-free survival (RFS) according to KIT mutation. This study is registered with UMIN Clinical Trials Registry, number UMI03434. Findings: Between May 25, 2010, and September 10, 2014, 203 patients were enrolled, and 199 patients were eligible. Median follow-up was 52·2 months (IQR 39·2-62·2). The primary endpoint RFS in KIT-mutated patients was inferior to that in unmutated patients (hazard ratio [HR] 1·92; 95% CI 1·23-3·00; p=0·003). Subgroup analysis showed a prognostic impact of KIT mutation in patients with RUNX1-RUNX1T1 (HR 3·27; 95% CI 1·90-5·64; p<0·001), but not in those with CBFB-MYH11, and only exon 17 mutation had such a notable impact. MRD was evaluated in 112 patients, and its presence was associated with a lower RFS in patients with CBFB-MYH11 (HR 4·55; 95% CI 1·20-17·2; p=0·03), but not in those with RUNX1-RUNX1T1. Interpretation: KIT exon 17 mutation was an unfavorable prognostic factor for RFS in AML patients with RUNX1-RUNX1T1. In contrast, the positivity of MRD was an unfavorable prognostic factor for RFS in AML patients with CBFB-MYH11. Trial Registration Number: This study is registered with UMIN Clinical Trials Registry, number UMI03434. Funding: Japan Agency for Medical Research and Development (AMED). Conflict of Interest: HKi received research funding from Chugai Pharmaceutical Co., Ltd., Kyowa Hakko Kirin Co., Ltd., Zenyaku Kogyo Co., Ltd., FUJIFILM Corporation, Astellas Pharma Inc., Otsuka Pharmaceutical Co., Ltd., Nippon Shinyaku Co., Ltd., Eisai Co., Ltd., Pfizer Japan Inc., Takeda Pharmaceutical Co., Ltd., Novartis Pharma K.K., Sumitomo Dainippon Pharma Co., Ltd., Sanofi K.K., and Celgene Corporation, consulting fees from Astellas Pharma Inc., Amgen Astellas BioPharma K.K., and Daiichi Sankyo Co., Ltd., and honoraria from Bristol-Myers Squibb. NDob received research funding from Pfizer Japan Inc., Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Kyowa Hakko Kirin Co., Ltd., Zenyaku Kogyo Co., Ltd., Eisai Co., Ltd., Otsuka Pharmaceutical Co., Ltd., Celgene Co., and Sysmex Co. NA received research funding from Chugai Pharmaceutical Co., Ltd., and Toyama Chemical Co., Ltd., and consulting fee from SRL Inc. No other potential conflict of interest relevant to this article was reported. Ethical Approval: The protocol was approved by the Ethics Committees of all participating institutions.

THE EFFICACY OF HIGH-DOSE CONSOLIDATION AND AUTOLOGOUS BONE MARROW TRANSPLANTATION IN FIRST REMISSION OF ACUTE MYELOID LEUKEMIA

Introduction. The question of the most adequate treatment strategy of AML in cases when it is impossible to perform allogeneic HSCT because of any reason still remains open. The aim of this study was to assess the long-term survival of patients with AML who received chemotherapy (CT) or autologous HSCT as consolidation in the first remission of the disease. It was included 135 patients aged 18 to 67 years, with a verified diagnosis of AML (except FAB M3) in the study. Of these, 100 patients received only CT, 35 patients received consolidation with autologous bone marrow transplantation. Patients who achieved remission after completion of induction CT courses received one of three treatment options as consolidation: 1) chemotherapy of standard-intensity (sCT), 2) high-dose chemotherapy (HDCT), 3) autologous HSCT (autoHSCT) conducted after 1–2 courses of high-dose CT. Adverse prognostic factors were identified as: age over 40 years, hyperleucocytosis more than 50,0 × 10 9/L and unfavorable cytogenetic and molecular-biological risk group. Materials and methods. Depending on the number of prognostic factors at the onset of disease relapse-free survival (RFS) was 47 % in their absence, 45 % in the presence of 1 factor, in the presence of 2 factors – 14 % (p = 0,000), regardless of the variant of consolidation therapy (sCT, HDCT, autoHSCT). A high level of white blood cells adversely affects OS (38 % vs. 22 %) and increases the frequency of relapse (52 % vs. 69 %) when performing only CT (sCT and HDCT). At initial white blood cells level more than 50,0 × 10 9/L the 5-year OS was 60 % when performing both autoHSCT and HDCT. Performance of autoHSCT at failure to achieve remission after the 1st induction course CT is associated with the best 2-year OS (62 % vs. 35 %, p = 0,05), EFS (50 % vs. 22 %, p = 0,05) and RFS (50 % vs. 37 %, p = 0,05) in comparison with HDCT and sCT. In favorable cytogenetic risk group 5-year RFS was 80 % when performing autoHSCT and 67 % when performing HDCT; the 5-year OS was 80 % regardless of consolidation therapy option. Conclusion. AutoHSCT is the preferred consolidation option in favorable risk group patients, and after failure to achieve remission after the 1st CT course.

The Preclinical Efficacy of a Novel Telomerase Inhibitor, Imetelstat, in AML - a Randomized Trial in Patient-Derived Xenografts

Replicative immortality depends on telomerase activation in the majority of cancers including acute myeloid leukemia (AML). Imetelstat is a covalently lipidated 13-mer oligonucleotide that competitively inhibits telomerase activity. Clinical efficacy of imetelstat has recently been reported in essential thrombocythemia and myelofibrosis. We investigated the efficacy of imetelstat in AML using a randomized trial in patient-derived xenografts (PDX).To establish an AML PDX cohort, primary bone marrow (BM) or peripheral blood (PB) samples from 31 AML patients were transplanted into NOD.Cg Prkdcscid Il2rgtm1Wjl Tg (CMV-IL3,CSF2,KITLG)1Eav/Mlo (NSGS). Engraftment was defined by reconstitution of BM and spleen with CD33+ donor cells, PB circulating blasts, anemia or thrombocytopenia. The success rate for engraftment was 70.4% and was independent of cytogenetics.Fifteen independent AML patient samples (n=12 recipients/sample) were tested for efficacy of imetelstat. After engraftment, mice were randomized and treated with imetelstat (15 mg/kg body weight) or control phosphate-buffered saline (PBS) intraperitoneally every 48-72h. Across the entire cohort, survival was improved for imetelstat- vs. PBS-treated PDX (Hazard ratio PBS: 5.299; 3.379 ± 8.312; p < 0.0001; Cox proportional hazards model). Imetelstat delayed the expansion of human AML cells in 14 PDX (93.3%). AML patient samples were divided into 2 groups based on survival outcomes, "Sustained responders" (imetelstat extended survival > 2-fold or > 4 weeks; 9 AML patient samples; 60%) or "Poor responders" (6 AML patient samples, 40%). European LeukemiaNet (ELN)-karyotypic subtypes differed trend-wise between groups: favourable (100% sustained, 0% poor response to imetelstat); intermediate-1, intermediate-2 and poor (45.5% sustained, 54.5% poor response to imetelstat; p = 0.1, Fisher’s exact test). Next generation sequencing revealed baseline AML PDX genetic profiles. FLT3, NRAS, TET2, RAD21 as well as 15 genes annotated in DNA damage, cell cycle regulation and apoptosis were mutated exclusively in the sustained responders group. Poor responders revealed mutations in ETV6, FANCM, MKI67, WT1 and 16 additional genes regulating growth factor independence and evasion of apoptosis. Imetelstat response was associated with reduced quiescence and induction of γ-H2AX levels in AML populations (n=4-6 / group / 3 individual AML patient samples): γ-H2AX (MFI normalized to PBS; PBS: 1.0 ± 0.02; imetelstat: 1.24 ± 0.02; p < 0.0001, Student’s t test), quiescence (%Ki67-diploid AML cells; PBS: 11.62% ± 0.87; imetelstat: 6.9% ± 0.68; p < 0.001, Student’s t test). The presence of spliceosome mutations (SRSF2, U2AF1) was not correlated with response (p = 0.5; Fisher’s exact test).To investigate the effects on normal human hematopoiesis, CD34-enriched cord blood was transplanted into NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG, n=5-6/group/donor in 2 replicate experiments). Engraftment was confirmed at 4 weeks post-transplant by PB chimerism (>=1%). Mice were treated with imetelstat or vehicle control from 4 weeks. After 10 weeks treatment, BM cellularity and donor engraftment were significantly reduced whereas the frequency of the CD34+CD38low HSC-enriched population was unchanged (donor 1 PBS: 0.35% ± 0.03%, imetelstat: 0.23% ± 0.06%, p = 0.1; donor 2 PBS: 0.45% ± 0.05%, imetelstat: 0.92% ± 0.35%, p = 0.2, Student’s t test). HSC cell cycle and γ-H2AX levels were unchanged. PB and spleen B-cell engraftment were reduced (donor 1 spleen PBS: 77.74% ± 4.66%, imetelstat: 45.48% ± 9.03%, p < 0.05; donor 2 spleen PBS: 93.95% ± 0.40%, imetelstat: 89.1% ± 2.52%, p = 0.09, Student’s t test), whereas the myeloid lineage was elevated or relatively preserved (donor 1 spleen PBS: 3.29% ± 0.71%, imetelstat: 7.53% ± 1.6%, p < 0.05; donor 2 spleen PBS: 1.20% ± 0.12%, imetelstat: 4.49% ± 1.60%, p = 0.07, Student’s t test).In summary, imetelstat demonstrates efficacy in a significant proportion of AML PDX (60%, 9 out of 15 individual AML patient samples). Robust responses to imetelstat were associated with favourable cytogenetic risk groups and mutations in pathways controlling DNA damage. The effects on normal human hematopoiesis were modest and predominantly seen in the B-lymphocyte lineage with relative preservation of myeloid and stem cell populations. Further study is warranted to understand the preclinical and clinical efficacy of imetelstat in AML. DisclosuresLane:Janssen: Other: i have done consulting (once) for janssen..

Analysis of Genetic Mutation of the Elderly Patients with Acute Myeloid Leukemia

Backgrounds: Acute myeloid leukemia (AML) is a heterogeneous disease whose onset involves a variety of chromosomal abnormalities and genetic mutations. To improve the outcome of AML treatment, it is very important to establish a prognosis from cytogenetic and genetic analysis and provide accordingly differentiated treatment. However, the treatment strategy has not been clear in elderly patients with AML due to intolerance of treatment and its adverse characteristics such as concomitant comorbidity and poor performance status. To clarify the prognostic impact of genetic abnormalities in elderly AML, we conducted a comprehensive analysis of recurrently mutated 28 genes in AML.Method: We retrospectively analyzed newly diagnosed 128 AML patients excluding M3 who were more than 65 years old at Nippon Medical School Hospital or its associated facilities between 1990 and 2014. Mutation analyses were performed by direct sequence analysis, Mutation Biased PCR, direct sequence analysis, and the next-generation sequencer Ion PGMTM.Results: Average age was 70.5 years (65-91years). The patients from 65 years old to 74 years old (early elderly) were 92 (71.9%)cases, the patients 75 years or older (late elderly) were 36 (28.1%)cases. Chromosomal analysis according to the prognostic risk classification of the Eastern Cooperative Oncology Group (ECOG) classified into 14 of the favorable cytogenetic risk group (10.9%), 80 of the intermediate cytogenetic risk group (62.5%), and 24 of the poor cytogenetic risk group (18.8%). Gene mutations were observed in 112 cases (87.5%). The most frequent gene mutations were NPM1 (89 cases/28.9%), FLT3/ITD (25 cases/19.5%), TET2 (20 cases/15.6%), and DNMT3A (19 cases/14.8%). CEBPA double mutation was detected at low frequency in elderly patients (younger patients: 15/311 (4.8%) vs elderly patients: 1/128 (0.8%)). There were no significant differences in gene mutations between early elderly and late elderly patients). Of 102 patients who received induction therapy, 52 patients (51.0%) achieved first hematological complete remission (CR), but primary refractory and early death were observed in 50 patients (49.0%). There was no significant difference in CR rate between the two groups in the early elderly patients and late elderly patients (early elderly: 53.8% vs late elderly: 41.7%. p= 0.354). In addition, there was no difference in CR rate in the standard chemotherapy and low dose chemotherapy group (standard chemotherapy: 48.7% vs low dose chemotherapy: 38.9%. p= 0.601). Median overall survival (OS) was 287days, OS at 3years was 35.9%. Prognostic stratification was possible for CR rate on the chromosomal classification (favorable cytogenetic risk 92.9%, intermediate cytogenetic risk 50.0%, poor cytogenetic risk 12.5%, p< 0.001). For total cohort of patients, rates of relapse free survival (RFS) at 3 years are significantly lower in patients with FLT3ITD (p=0.006) and TP53 abnormality (p< 0.001) compared to without it. Rates of overall survival (OS) at 3 years are significantly lower in patients with DNMT3A mutation (p=0.004), FLT3ITD (p=0.003), and TP53 abnormality compared to without it. Also late elderly patients (p=0.010) and high white blood cell count (≥ 20,000/μl) (p=0.023) were powerful factors for unfavorable prognosis. In stratified analysis of FLT3ITD-negative cases aged below 75 years with intermediate cytogenetic prognosis, TP53 abnormality was associated with unfavorable prognosis (RFS: p=0.062, OS: p< 0.001). Finally multivariate analysis demonstrated that FLT3ITD (p=0.014) and TP53 abnormality (p=0.015) were an independent poor prognostic factor for RFS, and poor cytogenetic risk (p=0.002), Flt3ITD (p=0.014), TP53 abnormality (p=0.015), and DNMT3A mutation (p=0.001) were an independent poor prognostic factor for OS.Conclusions: Our results suggest that the genetic abnormalities have a prognostic importance in elderly patients, as well as younger patients with AML. FLT3ITD mutation is an important factor for unfavorable prognosis, but going forward TP53 mutation may also serve as a clinically important gene mutation marker in elderly patients with AML. DisclosuresNo relevant conflicts of interest to declare.

Acute myeloid leukaemia: expression of MYC protein and its association with cytogenetic risk profile and overall survival.

Acute myeloid leukaemia (AML) is a clinically aggressive disease with marked genetic heterogeneity. Cytogenetic abnormalities provide the basis for risk stratification into clinically favourable, intermediate, and unfavourable groups. There are additional genetic mutations, which further influence the prognosis of patients with AML. Most of these result in molecular aberrations whose downstream target is MYC. It is therefore logical to study the relationship between MYC protein expression and cytogenetic risk groups. We studied MYC expression by immunohistochemistry in a large cohort (n = 199) of AML patients and correlated these results with cytogenetic risk profile and overall survival (OS). We illustrated differential expression of MYC protein across various cytogenetic risk groups (p = 0.03). Highest expression of MYC was noted in AML patients with favourable cytogenetic risk group. In univariate analysis, MYC expression showed significant negative influence of OS in favourable and intermediate cytogenetic risk group (p = 0.001). Interestingly, MYC expression had a protective effect in the unfavourable cytogenetic risk group. In multivariate analysis, while age and cytogenetic risk group were significant factors influencing survival, MYC expression by immunohistochemistry methods also showed some marginal impact (p = 0.069). In conclusion, we have identified differential expression of MYC protein in relation to cytogenetic risk groups in AML patients and documented its possible impact on OS in favourable and intermediate cytogenetic risk groups. These preliminary observations mandate additional studies to further investigate the routine clinical use of MYC protein expression in AML risk stratification. Copyright © 2016 John Wiley & Sons, Ltd.

A randomized comparison of 4 courses of standard-dose multiagent chemotherapy versus 3 courses of high-dose cytarabine alone in postremission therapy for acute myeloid leukemia in adults: the JALSG AML201 Study

AbstractWe conducted a prospective randomized study to assess the optimal postremission therapy for adult acute myeloid leukemia in patients younger than 65 years in the first complete remission. A total of 781 patients in complete remission were randomly assigned to receive consolidation chemotherapy of either 3 courses of high-dose cytarabine (HiDAC, 2 g/m2 twice daily for 5 days) alone or 4 courses of conventional standard-dose multiagent chemotherapy (CT) established in the previous JALSG AML97 study. Five-year disease-free survival was 43% for the HiDAC group and 39% for the multiagent CT group (P = .724), and 5-year overall survival was 58% and 56%, respectively (P = .954). Among the favorable cytogenetic risk group (n = 218), 5-year disease-free survival was 57% for HiDAC and 39% for multiagent CT (P = .050), and 5-year overall survival was 75% and 66%, respectively (P = .174). In the HiDAC group, the nadir of leukocyte counts was lower, and the duration of leukocyte less than 1.0 × 109/L longer, and the frequency of documented infections higher. The present study demonstrated that the multiagent CT regimen is as effective as our HiDAC regimen for consolidation. Our HiDAC regimen resulted in a beneficial effect on disease-free survival only in the favorable cytogenetic leukemia group. This trial was registered at www.umin.ac.jp/ctr/ as #C000000157.

Aberrant Methylation of Death-Associated Protein Kinase 1 CpG Islands in Myelodysplastic Syndromes

Death-associated protein kinase 1 (DAPK1), a proapoptotic serine/threonine kinase, is a candidate tumor suppressor gene. We studied the methylation status of the promoter region of the DAPK1 gene and the expression of the DAPK1 protein in 78 bone marrow samples from untreated patients with myelodysplastic syndrome (MDS) by PCR and Western blot analysis. Hypermethylation of DAPK1 was present in 42.3% (33 of 78) of MDS specimens and was significantly correlated with the loss of DAPK1 mRNA and protein expression (p < 0.01). There were no significant differences in methylation frequency among subgroup of MDS. DAPK1 hypermethylation in MDS was associated with the presence of cytogenetic abnormalities in the bone marrow at the time of the initial diagnosis. A higher frequency of DAPK1 hypermethylation was found in the unfavorable cytogenetic risk group (12 of 21 cases; 57.1%) compared to the favorable cytogenetic risk group (5 of 20 cases; 25.0%, p = 0.0368). These findings suggest that suppression of DAPK1 expression by DNA methylation may play a substantial role in the development of MDS.

Secondary Acute Myeloid Leukemia (AML), Including Therapy-Related AML, Associates with Worse Treatment Outcomes, Than De Novo AML Even After Hematopoietic Stem Cell Transplantation, and Its Unfavorable Behavior Does Not Associated with Functional Activity of p-Glycoprotein, MDR1

AbstractAbstract 2157 Background:Secondary acute myeloid leukmia (AML; sAML) is a distinct disease entity among AMLs. It usually includes AMLs with previous history of myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN), and therapy-related AMLs (tAMLs) developed after exposure to leukemogenic chemotherapy or radiation therapy. It has been known that its prognosis is very poor with median survival of less than 1 year, and that allogeniec hematopoietic stem cell transplantation (HSCT) is the only curative treatment modality with improving clinical outcomes. The current study evaluated clinical characteristics, treatment outcomes in patients with sAML, the impact of cytogenetic risk group or functional activity of p-glycoprotein, related to multidrug resistance 1 (MDR1), on the treatment outcomes in sAML compared to those in de novo AML (dAML). Methods:A total of 441 consecutive AML patients diagnosed at the Samsung Medical Center, Seoul, Korea between Jan 2002 and Jun 2010 were included in this retrospective study. Out of them, 76 patients (17.2%) were sAML, among whom 39 patients (8.8%) had previous history of MDS or MPN and 37 patients (8.4%) were tAML. The overall survival (OS) and event free survival (EFS) were evaluated according to the cytogenetic risk group and the performance of HSCT, in addition to other clinical risk factors. Furthermore, P-glycoprotein assay for multidrug resistance 1 (MDR1) functional activity was performed. MDR1 functional activity was calculated by verapamil-inhibited rhodamine-123 efflux activity minus uninhibited rhodamine-123 efflux activity, and positivity was determined as equal to or over 5% MDR activity. Results:In sAML, a trend of higher frequency of unfavorable cytogenetic group was noted (23.7% in sAML vs 13.7% in dAML). The OS and EFS were significantly shorter in sAML than in dAML. Median OS duration was 12.8 months in sAML, but not reached in dAML (p<0.001), while that of EFS was 8.5 months in sAML, vs. 28.1 months in dAML (p<0.001).Confined to intermediate cytogenetic risk group, sAML group showed shorter OS than dAML group (8.0 months vs 55.1 months; p<0.001). However, no difference of OS was noted between sAML vs dAML in favorable (not reached vs not reached; p=0.4) or unfavorable cytogenetic risk groups (16.5 months vs 11.2 months; p=0.7), respectively. With respect to EFS, when confined to intermediate cytogenetic risk group, sAML group showed shorter EFS than dAML group (5.7 months vs 19.9 months; p<0.001). No difference of EFS was noted between sAML vs dAML in unfavorable cytogenetic risk groups (12.6 months vs 7.9 months; p=0.9). Of interest, in favorable cytogenetic risk group, adverse impact of sAML over dAML on EFS was suggested (15.4 months vs not reached, p=0.1).The patients receiving HSCT for sAML showed better survival compared to those not receiving HSCT for sAML (p<0.001). Among patients receiving HSCTs, OS of sAML patients was still shorter than that of dAML patients (28.3 months vs not reached, p=0.01). Even more, among patients without receiving HSCT, OS of sAML patients was significantly shorter than that of dAML patients (4.4 month vs 28.3month, p<0.001), thus still requiring further improvement of HSCT outcomes in sAML.In terms of MDR1 activity, no difference of MDR1 positivity was noted between sAML (60.6% [n=20/33]) and dAML (61.9% [n=117/189]; p=0.8). Also, mean MDR1 activity was indifferent between in sAML and dAML groups (12.5±2.9% in sAML, 13.4±1.8% in dAML, p=0.8). This finding suggested that MDR1 may not be resopnsbile for drug resistance in patients with sAML, thus other mechanism needs to be investigated for unfavorable characteristics of sAML. Conclusion:The current study suggested that 1) the patients with sAML showed a poorer outcome especially in intermediate cytogenetic risk group; 2) HSCT could improve treatment outcomes of sAML patients, but transplant outcome in sAML patients is still inferior to that in dAML patients receiving HSCT; 3) MDR1, one of important resistance mechanism of AML, may not be the case for resistance in sAML. Disclosures:No relevant conflicts of interest to declare.

DNA repair polymorphisms associated with cytogenetic subgroups in B‐cell chronic lymphocytic leukemia

Genetic polymorphisms in DNA repair genes can affect the risk of developing different forms of cancer. Therefore, we have studied the putative association of seven single nucleotide polymorphisms (SNPs) in five DNA repair genes with the incidence of chronic lymphocytic leukemia (CLL). We included 461 CLL patients and the same number of age- and sex-matched controls. As chromosomal aberrations are important prognostic markers in CLL, we additionally correlated the SNPs with the occurrence of favorable and unfavorable cytogenetic aberrations in CLL patients. Patients with del(13q) as a sole aberration were allocated to the favorable cytogenetic risk group, and patients with del(17p) and/or del(11q) to the unfavorable cytogenetic risk group. All investigated SNPs were equally distributed between patients with the favorable cytogenetic aberration and controls. However, differences were observed in the distribution of rs13181 in ERCC2 between all CLL patients and controls. Moreover, the clearest differences were found for rs13181 in ERCC2 and rs25487 in XRCC1 between CLL patients with unfavorable cytogenetic aberrations and controls. These data suggest that inborn genetic polymorphisms may predict the outcome of CLL.

Isolated Extramedullary Relapse in the Breast of a Patient with Acute Myeloid Leukemia following Allogeneic Stem Cell Transplantation: Case Report and Review of the Literature

We report an unsual case of a woman with acute myeloid leukemia who showed an isolated extramedullary relapse (IEMR) in the breast following allogeneic stem cell transplantation and review the related literature. Eighty cases of IEMR following allogeneic stem cell transplantation, including our case, were identified. The review suggests that an M2 or M4 phenotype in the French-American-British classification and a favorable cytogenetic risk group are more frequently associated with the occurrence of IEMR. Combined treatment with radiation and high-dose chemotherapy may be effective.

Efficacy of allogeneic hematopoietic stem cell transplantation depends on cytogenetic risk for acute myeloid leukemia in first disease remission

The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from a human leukocyte antigen-identical sibling donor remains controversial for patients with acute myeloid leukemia (AML) in first complete disease remission (CR1). Because the karyotype identified at diagnosis is the most relevant prognostic factor for AML, it should be possible to assess the efficacy more accurately on the basis of cytogenetic risk. The authors performed a metaanalysis of five studies, which employed both natural randomization based on donor availability and intention-to-treat analysis, with overall survival as an outcome of interest. Metaregression analysis was then performed to identify the efficacy for patients stratified into the favorable, intermediate, and poor cytogenetic risk groups. For the entire cohort, there was a statistically significant advantage with allo-HSCT in terms of overall survival with a summary hazard ratio of 1.15 (95% confidence interval, 1.01-1.32, P = 0.037) for the random-effect model. Metaregression analysis showed a significant coefficient of +0.24 for the poor cytogenetic risk group, and -0.25 for the favorable cytogenetic risk group, indicating that the benefit of allo-HSCT was further increased for the former, and lost for the latter. The coefficient for the intermediate cytogenetic risk group was +0.09, and was not statistically significant. These findings suggested that the efficacy of allo-HSCT for patients with AML in CR1 depended on cytogenetic risk. The beneficial effect of allo-HSCT was yielded for the poor risk group, and probably for the intermediate risk groups, but was absent for the favorable risk group.