Secondary Adult Acute Myeloid Leukemia Research Articles

DELE1 haploinsufficiency causes resistance to mitochondrial stress-induced apoptosis in monosomy 5/del(5q) AML

Monosomy 5 and deletions of the chromosome 5q (−5/del(5q)) are recurrent events in de novo adult acute myeloid leukemia (AML), reaching up to 40% of cases in secondary AML. These chromosome anomalies are associated with TP53 mutations and with very poor prognosis. Using the large Leucegene genomic and transcriptomic dataset composed of 48 −5/del(5q) patient specimens and 367 control AML, we identified DELE1 – located in the common deleted region – as the most consistently downregulated gene in these leukemias. DELE1 encodes a mitochondrial protein recently characterized as the relay of mitochondrial stress to the cytosol through a newly defined OMA1-DELE1-HRI pathway which ultimately leads to the activation of ATF4, the master transcription factor of the integrated stress response. Here, we showed that the partial loss of DELE1 expression observed in −5/del(5q) patients was sufficient to significantly reduce the sensitivity to mitochondrial stress in AML cells. Overall, our results suggest that DELE1 haploinsufficiency could represent a new driver mechanism in −5/del(5q) AML.

Proteomic Profiling Identifies Unique IDH Mutant Signatures and Novel Therapeutic Opportunities in Adult Acute Myeloid Leukemia Patients

CONCLUSION Patients with IDH mutations are common in adult Acute Myeloid Leukemia (AML), with selective IDH inhibitors (IDHi) being recommended, but they do not always respond. We evaluated the proteome of IDH mutant AML patients to identify prognostic signatures and therapeutic targets. The expression of 429 proteins (339 total, 90 post-translational modified) were measured by Reverse Phase Protein Array in fresh samples from 805 newly diagnosed AML patients, and normalized to normal CD34+ cells. We analyzed 151 patients with IDH mutations (IDH1 = 56, IDH2 = 76, both = 19), treated with AraC-based combination therapy (N=71, including 5 with IDHi, 11 with Venetoclax (VTX)) or Hypomethylating agent based (HMA, N=65, + IDHi=5, +VTX=11, or both=2) and 3 received IDHi monotherapy, Proteins prognostic for Overall Survival (OS) were identified using pairwise LogRank tests (p<0.05) adjusted for False Discovery Rate (FDR), followed by unbiased hierarchical clustering. Continuous and categorial variables were compared with Wilcoxon, Kruskal-Wallis (KS) or Fisher's Exact test with simulated p-values (10000 replicates). Cox proportional hazards models (CoxPH) were developed for Uni-(UV) and Multi-variate (MV) analysis. Differentially expression (DE) analysis was performed using the KS test and pairwise Dunn's tests with p-values adjusted with FDR (p<0.01). Deep neural network analysis using random forest models identified proteins most predictive of cluster assignment. 97 proteins were individually prognostic for OS, and formed 3 patient clusters (Fig. 1: C1=red, C2=blue, C3=green). Most clinical and molecular features were not biased between clusters, however C2 had more cases with primary AML, diploid karyotype (kar.), intermed. cytogenetic (cyto.) risk, and IDH+FLT3_ITD or NPM1 mutants, while C3 has more cases with unfavorable cyto. risk, complex kar., and mutations in IDH+EZH2 or TP53, and ASLX1+IDH combination were more frequent in C1. Of note, C1 has the largest proportion of VTX-treated patients, while C3 has the largest proportion of IDHi-treated ones. The OS (Fig. 2) of C1 patients was better (Median: C1=42.2mo, C2=18.3mo, C3=10.7mo; p=0.0021), but no difference was noted for Complete Remission Duration (CRD) (Median: C1=72.3mo, C2=21.6mo, C3=33.4mo; p=0.7). The OS was similar when patients were filtered by specific mutations or combinations, e.g. IDH1, IDH2, and IDH combined with ASLX1, RUNX1 or TET2, or by other features, e.g. 56-70 age group, males, primary AML, intermed. cyto. risk, diploid kar., VTX or HMA without IDHi and/or VTX (HMA-TX) therapies. CoxPH models showed only C1 and C3 predictive for OS in the UV analysis (HR=1, 1.5, 2.3; p=ref., 0.22, <0.001), along with age, secondary AML, complex, diploid and del12 kar., HMA-TX, and IDH1, IDH2, NPM1, TP53, DNMT3a and JAK2 mutations. In the MV analysis, C1, C2 and C3 (HR=1, 2.6, 3.4; p=ref., 0.019, <0.001), age, secondary AML, complex and diploid kar., HMA-TX and IDH1 mutation predicted OS. Regarding CRD, no cluster was predictive in the UV model (HR=1, 1.2, 1.4; p=ref., 0.65, 0.41), but age, secondary AML, complex kar., HMA-TX, and ASLX1, EZH2 and IDH2 mutants were. In contrast, C1 and C3 (HR=1, 2.3, 2.6; p=ref., 0.13, 0.046) predicted CRD in the MV model, as well as secondary AML, HMA-TX and IDH2 mutation. epigenetics, DNA damage response, cell cycle and metabolism, with 23, 12, 12, and 11 proteins. DE analysis identified 133 proteins among 429, including: ADM, LCK and BTK up-, and TP53BP1 and PRMT1 down-regulated in C1; ANXA1 up-, and PTK2 and SRC down-regulated in C2. In C3, TGM2 is higher than normal, although lower than in C1. Inhibitors for upregulated proteins are in clinical development, potentially working as synergistic agents. Furthermore, a set of 5 proteins (SMARCB1, SMARCA2, WTAP, PIK3CB and RAD50) predicted cluster membership with 97% of accuracy, useful for quickly identifying patients and personalizing therapy. Proteomics identified unique protein profiles that were independently prognostic for outcome in IDH mutant AML patients. We identified upregulated proteins for which inhibitors are in development, suggesting potential therapeutic synergies to improve outcomes. Finally, we defined 5 proteins that accurately stratifies IDH patients for novel treatment recommendations.

Optimizing FLT3 Inhibitor Use in Adult Acute Myeloid Leukemia with FLT3 Mutations Using Proteomics

CONCLUSION FLT3 mutations are the most frequent genetic alteration in adult Acute Myeloid Leukemia (AML). The use of FLT3 inhibitors (FLT3I) has improved outcome among FLT3 mutant patients, but not all benefit. We developed a proteomic-based approach to stratify patients according to their response to FLT3I therapy. The expression of 429 proteins (339 total, 90 post-translational modified) was measured by Reverse Phase Protein Arrays (RPPA) in fresh samples from 805 newly diagnosed AML patients, with levels normalized to normal CD34+ cells. Of 137 with FLT3 ITD or D835 mutations, 54 who were treated with FLT3I (Sorafenib=22, Quizartinib=11, Midostaurine=6, Gilteritinib=4 and Crenolanib=1) combined with other agents (Hypomethylating agents (HMA)=23, HMA+Venetoclax (VTX)=5, Idarrubicin+Cytarabine (AraC)+Purine Analogs (IA+Pur)=19, IA+Pur+VTX=2, AraC=3, Fludarabine+AraC (FA)=1, none=1) were selected for analyses. Proteins prognostic for Overall Survival (OS) and Complete Remission Duration (CRD) were identified using pairwise LogRank tests (p < 0.05) adjusted for False Discovery Rate, followed by unbiased hierarchical clustering. Continuous and categorial variables were compared with Wilcoxon, Kruskal-Wallis or Fisher's Exact test with simulated p-values (10000 replicates). Cox proportional hazards models (CoxPH) were developed for Uni-(UV) and Multi-variate (MV) analysis. Deep neural network analysis using random forest models identified proteins most predictive of cluster assignment. 28 proteins were individually prognostic for both OS and CRD and divided patients into 3 clusters (Fig. 1: C1=red, C2=blue, C3=green). The distribution of nearly all other clinical and molecular features did not differ between clusters, including: age, gender, race, cytogenetic risk and AML group. Co-occurrence with other mutations was not biased, except for FLT3+TET2 and FLT3+TET2+NPM1 mutants, more frequent in C1. OS was significantly longer (Fig. 2), in C1 (Median: C1>84mo, C2=14.8mo, C3=11.4mo; p<0.001) as was CRD (Median: C1>84mo, C2=8.6mo, C3=5.7mo; p<0.05). A similar OS pattern was observed for mutation combos, including with NPM1 or DNMT3a but not if IDH, CEBPa, TET2, or ASXL1 mutation were present. It was also seen when patients were divided by gender, age groups (except >70yo), primary, but not secondary AML, diploid karyotype and intermediary cytogenetic risk, and with Sorafenib or IA+PR therapies. In the UV CoxPH model for OS, C1, C2 and C3 were predictive (HR=1, 4.1, 7.5; p=ref., 0.037, 0.009), along with age, secondary AML, complex karyotype, Trisomy 6 and IDH1 mutation. In the MV model for OS, only C1, C2 and C3 (HR=1, 3.3, 4.8; p=ref., 0.011, <0.001), and age were predictive. In the CRD UV model, C1 and C3 (HR=1, 3.3, 4.8; p=ref., 0.072, 0.022), age, secondary AML, and mutations in ASLX1, PTPN11, RAS, TP53 and WT1 were predictive. Only C1 and C3 were predictive in the MV model for CRD (HR=1, 2.9, 6.3; p=ref., 0.16, 0.04). The predictive proteins, are biased towards specific cellular processes, mainly: proliferation and metabolism (RHEB, GSKA_B, SDHA, AKT1, AKT2 and TYRO3), cell cycle and DNA damage response (CDKN2A, DDB1, SIRT6, SLFN11 and WEE1), cellular adhesion and cytoskeleton organization (MYH9.pS1943, PAK4 and PXN), and apoptosis (AIFM1, BBC3 and BCL2L11). Key differences between clusters included: higher FOS in C1, and higher CDKN2A, MYH9.pS1943, PXN, PAK4, SDHA, BBC3 in both C2 and C3, with higher levels of these in C3. Since PAK4, PXN and MYH9 are connected to cellular motility/migration and inhibitors for those proteins are available, there is a therapeutic opportunity to overcome FLT3I resistance in C2/C3 patients. Moreover, we identified a set of 6 proteins (FOS, AKT1, PXN, SMARCA2, CDKN2A and DPF2) that predicted cluster assignment with 97.5% accuracy, making rapid patient stratification possible in the clinical setting. Protein profiling identified cohorts of FLT3 mutant patients that achieved the highest benefit from FLT3I addition, regardless of all other clinical or molecular characteristics. We identified targetable proteins that are elevated in adverse signatures, and hypothesized that these may be targets for modulation to improve FLT3I response. Moreover, a small set of 6 proteins accurately classifies patients and could be used clinically to triage patients for treatment recommendation.

Proteomics-Based Strategy for the Recommendation of Conventional Chemotherapy Vs Venetoclax Plus Hypomethylating Agents in Adult Acute Myeloid Leukemia (AML)

INTRODUCTION: Newer AML therapies with Hypomethylating Agents & Venetoclax (HV) provide an alternative to Conventional Chemotherapy (CC), with anthracycline and cytosine arabinoside, but criteria to select which to use are lacking. We investigated whether proteomic classification could provide guidance. METHODS: Using Reverse Phase Protein Array (RPPA) methodology, the level of 405 proteins (327 total; 78 post-translational modified) were measured in 818 samples from newly diagnosed adult AML patients and normalized to normal CD34+ cells. Patients treated with HV (N=85) or CC (N=335) were analyzed. Overall Survival (OS) and Complete Remission Duration (RD) analysis was performed with pairwise LogRank tests (p < 0.05), adjusted for False Discovery Rate (FDR), to identify individual proteins predictive of outcome. Patients were clustered based on protein expression. Categorical clinical variables were compared with Fisher's Exact test with simulated p-values (10000 replicates), and continuous ones with Kruskal-Wallis test. Univariate (UV) and Multivariate (MV) models were built with Cox proportional hazards model (CoxPH). Deep neural network analysis using random forest was performed to create a Protein Classifier for treatment recommendation. RESULTS: Individual protein analysis found 55 prognostic proteins (Protein Selector 1 - PS1), which clustered patients into 3 groups. A preferred therapy for cluster 2 was not identified with PS1, so a second Protein Selector 2 (PS2) was generated, identifying 45 predictive proteins in this subset. From the PS1/2 analysis, the 95 proteins formed 4 distinct expression profiles (C1=red, C2=gold, C3=magenta, C4=green) which were stratified by treatment (HV or CC), as shown in Fig. 1. Patients in C2 were enriched for secondary AML (57% vs C1=41%, C3=33%, C4=32%; p<0.001) and unfavorable cytogenetics (41% vs C1=32%, C3=39%, C4=35%; p<0.001), and were older (60yo vs C1=61yo, C3=54yo, C4=56yo; p<0.001). Mutations in CEBPA, GATA2, FLT3 and NPM1 were more common in C4 (22%, 13%, 35%, 35% vs C1=12%, 1.7%, 5.7%, 6%; C2=7.8%, 6.2%, 18%, 15%; C3=9.3%; 1.4%, 29%, 21%; p=0.037, p=0.013, p<0.001, p<0.001, respectively), highlighting the heterogeneity between groups. We evaluated OS and RD (Fig. 2) in each cluster (C1=red, C2=gold, C3=magenta, C4=green), considering each treatment (HV= solid line, CC=dashed line). Patients in C1 and C2 treated with HV had a diametrically different and superior response compared to those treated with CC (C1-HV: Median OS (MS)>65mo, Median RD (MRD)>60mo; C2-HV: MS=15mo, MRD=24mo vs C1-CC: MS=20mo, MRD=39mo; C2-CC: MS=10mo, MRD=17mo). C3 showed the opposite, with CC outperforming HV (MS=19mo, MRD>102mo vs MS=7mo, MRD=9mo). Similarly, in C4, CC patients did dramatically better, (MS=40mo, MRD>96mo vs MS=9mo, MRD=7mo). In the UV CoxPH model, we included variables for PS cluster and treatment and all groups predicted OS, except for C3-CC and C4-CC, as did age, secondary AML, complex karyotype, and CEBPA, FLT3, KIT, MLL, NPM1, PTPN11 and TP53 mutations. In the MV model, all clusters were predictive for OS, together with age, secondary AML, complex karyotype and NPM1 mutation. Regarding RD, in the UV model, only C2-HV, C2-CC, and C4-HV predicted RD, as did age, secondary AML, complex karyotype, unfavorable cytogenetics, and FLT3, RUNX1 and TP53 mutations. In the MV model of RD, all clusters, except for C3-HV were predictors, together with age. Importantly, optimized treatment triaging based on PS1/2 would have reassigned 52% (218/420) of cases, and is estimated to increase the 3yrs OS of the whole cohort from 35.6% to 48.8%, a 37.2% increase. Moreover, the 2yrs Relapse Free Survival would increase from 57,9% to 63,9%, a 10.39% increment. Furthermore, our Protein Classifier identified a set of 3 proteins (SPI1, NOTCH1.cle, and TGM2) whose expression can be used to rapidly classify patients and recommend either HV or CC. This classifier has a very high c-index (a measure of individual patient discriminatory power) of 0.93 (>0.7 is considered predictive, 1 would indicate perfection) demonstrating that it robustly predicts optimal therapy choice. CONCLUSION: Protein profiling identified protein expression patterns which had diametrically different responses according to treatment (HV or CC). Given the US annual incidence of 20000 newly diagnosed AML cases, proteomic triaging could result in ~2600 more cures using existing therapy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Comparison of Frontline Induction Therapy Using Idarubicin in Combination with High-Dose (HDAC3) Versus Intermediate-Dose Cytarabine (IDAC3) in Adult Acute Myeloid Leukemia

BackgroundThe utility of high-dose cytarabine during induction chemotherapy for adult acute myeloid leukemia (AML) remains contentious. Intermediate-dose cytarabine may maintain a high first-cycle complete remission (CR) rate, whilst reducing treatment-related toxicity.AimWe examined the outcomes of adult AML patients treated with idarubicin (12 mg/m2 days 1-3) in combination with high-dose (3 g/m2; HDAC3) or intermediate-dose cytarabine (1.5 g/m2; IDAC3) given twice daily on days 1, 3, 5, and 7.MethodsConsecutive AML patients aged ≤60 years at 2 major tertiary referral centers, the Alfred and Austin Hospitals, were treated with sequential protocols of HDAC3 (n=52; 2010-2014) and then IDAC3 (n=58; 2014-2017). Planned consolidation chemotherapy consisted of up to 2 cycles of idarubicin 9 mg/m2 days 1-2, cytarabine 100 mg/m2 days 1-5, and etoposide 75 mg/m2 days 1-5 (IcE). Favorable-risk karyotype was excluded from this analysis. We assessed treatment responses (2017 European LeukaemiaNet recommendations), 30 and 60-day mortality, ability to deliver consolidation therapy (number of cycles and days from induction to first consolidation chemotherapy), rates of allogeneic hematopoietic stem cell transplant (allo-HSCT) in first remission (CR1), rates of total parenteral nutrition (TPN) usage, haematologic toxicities (days to platelet and neutrophil recovery), and relapse-free (RFS) and overall survival (OS) censored for allo-HSCT or loss to follow-up. Statistical analysis was performed using R version 3.3.2.ResultsIDAC3-treated patients were younger than those receiving HDAC3 (median 44 vs 48 years) but had a higher frequency of secondary AML (16% vs 4%); (Table 1). Other baseline characteristics were balanced between both groups. No significant differences were observed for any outcome (Table 2), except the use of TPN which is most likely a result of change in practice over time rather than a true reflection of mucositis. Response rates including CR or CR with incomplete haematologic recovery (CRi) were similar: 79% (HDAC3) vs 83% (IDAC3) after 1 cycle of induction. There was no death at 30 days and only 1 death at 60 days. Allo-HSCT in CR1 was similar; among patients with adverse-risk karyotype, allo-HSCT in CR1 was performed for 9/15 (60%) after IDAC3 and 7/11 (64%) after HDAC3. Days to neutrophil and platelet recovery were also similar.Delivery of consolidation chemotherapy was similar between both groups. After excluding treatment failure and partial remission (PR), 94 patients were eligible for first consolidation chemotherapy (3 patients with PR were considered near CR), of which 14 (15%) did not receive further consolidation therapy with the following reasons: allo-HSCT in CR1 (n=10); prolonged cytopenias (n=3); and maintenance clinical trial (n=1). Twenty-nine patients (31%) received only 1 consolidation therapy due to the following reasons: allo-HSCT in CR1 (n=14); prolonged cytopenias (n=10); non-hematologic toxicities (n=2); relapse (n=2); and unknown (n=1). IcE chemotherapy was administered in all except 2 cases: one received high-dose cytarabine for 1 cycle, and another had reduced idarubicin dose for 1 cycle.Survivors were followed up for a median of 8 (IDAC3) and 37 months (HDAC3), respectively. Median OS were 11.5 and 18.6 months for IDAC3 and HDAC3 (p=0.3), respectively (Figure 1A), and the corresponding median RFS were 8.4 and 9.4 months (p=0.5), respectively (Figure 1B). Overall, the median OS for adverse-risk karyotype remained significantly inferior compared to intermediate-risk (5.6 vs 20.9 months, p=0.009 by log-rank test); among adverse-risk karyotype, this was 5.1 vs 6.5 months for IDAC3 and HDAC3, respectively. Similarly, patients with FLT3 -ITDpos/ NPM1WT had inferior median OS (n=7, 6.1 months) when compared with FLT3 -ITDneg/ NPM1WT (n=55, 15.9 months), FLT3 -ITDpos/ NPM1MUT (n=14, 20.9 months), and FLT3 -ITDneg/ NPM1MUT (n=16, 40.6 months, p=0.06 by log-rank test).ConclusionIDAC3 and HDAC3 were both well tolerated in adult patients with AML with high first-cycle CR/CRi rates observed and low early mortality. No significant differences in hematopoietic recovery or delivery of post-remission therapy was apparent. With the caveat of limited sample size and follow-up duration, survival outcomes appeared equivalent. [Display omitted] DisclosuresGrigg:Amgen: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Merck Sharpe Dohme: Membership on an entity's Board of Directors or advisory committees. Wei:AbbVie, Celgene, Servier: Research Funding; AbbVie, Celgene, Novartis, Amgen, Servier: Membership on an entity's Board of Directors or advisory committees; AbbVie, Celgene, Novartis, Amgen, Servier: Honoraria.

Identification of Relapse Risk Using a Multiparameter Flow Cytometry-Based Detection of Minimal Residual Disease in Adult Patients with Acute Myeloid Leukemia at ELN Intermediate-Risk

Background: Minimal Residual Disease (MRD) measurement is a useful tool to refine prognosis in adult Acute Myeloid Leukemia (AML) patients in morphological complete remission (CR). Multiparametric flow cytometry (MFC) may provide independent prognostic information particularly in intermediate (Int)-I and Int-II ELN 2010 risk groups.Patients and methods: Analysis was performed on bone marrow (BM) aspirates of 120 ELN Int-I/II patients (pts) from 2 independent institutions, separately analyzed in two MFC labs. Treatment consisted of one-two idarubicin-based induction courses followed by High-dose-Ara-C consolidation and by allogeneic transplantation (NILG, n: 18/51; GIMEMA, n: 20/69). The median age was 49yr (18-73yr), F/M ratio was 49/71; de-novo and secondary AML cases were 94.2% and 5.8%, respectively. FLT3 gene was mutated in 41.7% of the patients (50/120), being wild type in 56.6% of the cases (68/120). FLT3-ITD was detected in 35.0% of the patients (42/120) and FLT3-D835 was detected in 7.5% of the patients (9/120). NPM1 gene was mutated in 31.6% of the patients (38/120) being wild type in 65.8% of the cases (79/120). ELN 2010 int risk groups were distributed as follows: 79.2% Int-I (n: 95) and 20.8% Int-II (n: 25). At diagnosis, a panel of 22 monoclonal antibodies, combined in four 8-color tubes, was employed to detect leukemia-associated immunophenotypes (LAIPs). MRD was measured after the first cycle (TP1) and after the second cycle (TP2). MRD was considered positive if residual leukemic cells were equal or higher than 0.1% and 0.035% at TP1, and than 0.035% at TP2, respectively. Relapse-free survival (RFS) and overall survival (OS) were analyzed using Kaplan-Meier curves and the log-rank test.Results: One-hundred-eighteen and 116 patients were tested at TP1 and TP2, respectively. At TP1, MRD-positivity was detected in 72.9% (86/118) at a threshold of 0.1% and 83.9% pts (99/118) at a threshold of 0.035%. Both thresholds were significant in predicting relapse (P=0.0002 and P=0.0158 for the 0.1% and the 0.035% threshold, respectively). We observed a shorter RFS in MRD-positive versus MRD-negative patients: median RFS was 10.8 months (0.1% threshold) and 11.3 months (0.035% threshold) in MRD-positive pts as compared to 28.5 months (0.1% threshold) and 19.5 months (0.035% threshold) in MRD-negative patients. Furthermore, MRD-positive pts presented with a significantly shorter OS as compared to MRD-negative patients (0.1% threshold, P=0.0185), with a median OS of 18.2 months as compared to 33.7 months for MRD-negative pts. When the 0.035% threshold was used, OS was not different between the two groups of pts. At TP2, MRD-positivity was detected in 75.8% of the pts (88/116) and significantly predicted relapse (P=0.0023, 0.035% threshold): the median RFS was 10.8 months in MRD-positive pts vs 26.3 months in MRD-negative. Moreover, we observed a significant improvement in terms of OS in MRD-negative vs MRD-positive pts (P=0.0411), the median OS being 37.0 and 18.2 months, respectively. Notably, the proportion of MRD-positive and MRD-negative patients did not differ in terms of age, sex, ELN risk classification, FLT3 mutational status, and number of allogeneic transplanted patients.Conclusions: Overall, our findings demonstrate a correlation between MRD levels by MFC and relapse risk in ELN-intermediate risk patients. The use of an allogeneic transplantation approach rather than other consolidation strategies in ELN-intermediate risk AML patients is often debated. MFC-based MRD potentially allows for a more appropriate and tailored post-remission therapeutic strategy in these AML patients. Furthermore, harmonization of MRD analysis between different labs and different protocols sharing a common technical approach seems to be feasible. Future prospective studies are warranted for prospective evaluation of MRD in ELN-intermediate AML patients. DisclosuresRossi:AbbVie: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees.

A Descriptive Study on Healthcare Utilization and Costs in Secondary Acute Myeloid Leukemia Patients Treated with CPX-351 Versus Those Treated with 7+3

Introduction: The 7 + 3 regimen, consisting of cytarabine treatment continuously for 7 days, and short infusions of an anthracycline on each of the first 3 days, has been the mainstay for adult acute myeloid leukemia (AML) therapy. However, in older adults and patients with secondary AML, 7+3 is associated with lower remission rates, shorter overall survival, and higher relapse rates than in younger adults and older patients with de novo AML (Kayser et al, Blood 117:2137-2145, 2011; Schoch et al, Leukemia 18: 120-125, 2004). CPX-351 (VYXEOS®) CPX-351 was approved by the FDA in the US in August 2017 and EU in August 2018 for the treatment of adults with newly diagnosed therapy-related AML (t-AML) or AML with myelodysplasia-related changes (AML-MRC). It is a fixed combination of daunorubicin and cytarabine at a synergistic 1:5 molar ratio, encapsulated in a liposome to provide optimal delivery of the two drugs. The Phase III pivotal trial demonstrated that CPX-351 significantly improved overall survival (OS; 9.56 vs 5.95 months; hazard ratio [HR] = 0.69; 1-sided P = 0.003) and complete remission rates versus 7+3, and was associated with shorter per patient year (PPY) hospital length of stay (LOS) without an increase in PPY non-drug costs (Chung, et al. AMCP HCRU Abstract JOV-62933; 2018). This study characterized the patients treated with CPX-351 and 7+3 and compared healthcare utilization and costs associated with the treatments using a large U.S.-based hospital administrative database. Methods: A retrospective, observational study was conducted using data from the Premier Healthcare Database. The study included patients aged 18+ years with any inpatient hospitalization or hospital-based outpatient visit with a diagnosis of AML, who received treatment of 7+3 or CPX-351 between 8/1/2017 and 2/28/2019. Variable-length follow-up was used. Patients were excluded if their length of follow-up was shorter than 30 days, or they had received treatment with gemtuzumab, midostaurin, sorafenib, venetoclax, quizartinib, or gilteritinib. Patients were assigned into two cohorts: 1) patients treated with CPX-351; 2) 7+3 treated patients with newly diagnosed t-AML or AML-MRC who were never treated with CPX-351 (CPX-351 eligible 7+3). Outcomes included total inpatient LOS, total costs, drug and non-drug costs. The outcomes were converted to per patient year (PPY) values, which was the original value divided by the length of follow-up and multiplied by 365. Unadjusted descriptive statistics were reported, and bivariate analysis was performed using Wilcoxon rank sum tests to examine the difference in outcomes between 7+3 treated patients and those treated with CPX-351. Results: The study included 195 qualifying patients treated with CPX-351, and 160 CPX-351 eligible 7+3 patients. The median age was 68 years (Q1-Q3: 61-71) in the CPX-351 patients and 61 years (Q1-Q3: 52.5-69) in CPX-351 eligible 7+3 patients. Male patients accounted for 62.6% of the CPX-351 patients and 55.0% of the CPX-351 eligible 7+3 patients. Among the CPX-351 patients, 72.3% were White, while the proportion of White is 75.0% in CPX-351 eligible patients. The median length of follow up was 136 days (Q1-Q3: 68-232) in the CPX-351 patients, and 126 days (Q1-Q3: 54.5-241.5) in the CPX-351 eligible 7+3 patients. The median total inpatient LOS per patient year (PPY) was shorter in CPX-351 patients compared to the CPX-351 eligible 7+3 patients (nominal p=0.068, Table). Although the median total hospital cost PPY of the CPX-351 patients was higher (nominal p&lt;0.001), the non-drug medical cost PPY was not higher than the CPX-351 eligible 7+3 patients (nominal p=0.785, Table). Conclusions: In this inferential analysis, patients treated with CPX-351 appeared to be older than those treated with 7+3. CPX-351 treated patients spent fewer days as inpatients, and the non-drug medical cost incurred was not higher compared to the 7+3 patients eligible for CPX-351, although the drug costs for the CPX-351 treated patients were higher than the 7+3 treated patients. Further adjusted analysis is warranted to control for the differences in baseline characteristics such as age, clinical conditions, and other characteristics in this real-world data. Disclosures Price: Jazz Pharmaceuticals: Employment, Equity Ownership. Cao:Jazz Pharmaceuticals: Other: Zhun Cao is an employee of Premier Inc, which receives payments from Jazz Pharmaceuticals for this research project.; Premier Inc.: Employment, Other: Premier received funding from Jazz Parmaceuticals to perform the study and analysis. Lipkin:Jazz Pharmaceuticals: Other: Craig Lipkin is an employee of Premier Inc, which receives payments from Jazz Pharmaceuticals for this research project.; Premier Inc: Employment. Robinson:Premier Inc.: Employment, Other: Premier received funding from Jazz Pharmaceuticals to perform the study and analysis; Jazz Pharmaceuticals: Other: Scott Robinson is an employee of Premier Inc, which receives payments from Jazz Pharmaceuticals for this research project.. Profant:Jazz Pharmaceuticals: Employment, Equity Ownership.

Fractionated Gemtuzumab Ozogamicin Combined with Intermediate-Dose Cytarabine and Daunorubicin As Salvage Therapy in Very High Risk AML Patients: A Bridge to Reduced Intensity Conditioning Transplant?

Introduction: Despite recent improvements in the treatment of adult acute myeloid leukemia (AML), many patients still fail to achieve complete remission (CR) or relapse early after response to initial induction chemotherapy. Outcome of patients with primary refractory/relapsed (R/R) acute myeloid leukemia (AML) remains dismal. Nevertheless, most of these patients undergo salvage chemotherapy. Gemtuzumab ozogamicin (GO) is an antibody-targeted chemotherapy agent consisting of a humanized murine anti-CD33 monoclonal antibody linked to calicheamicinϒ1, a potent antitumor antibiotic. Binding of GO induces cell death in CD33-positive cells by internalization of the calicheamicin drug and toxin release intracellulary leading then to then cleavage of double-stranded DNA. In relapsed AML, GO used alone with an unfractionated dose of 9 mg/m² on days 1 and 14 resulted in 13% of CR and a median OS of 5 months. Combined with intermediate-dose cytarabine and mitoxantrone, unfractionated dose of GO gave 50% of CR in patients with R/R AML, and a 2-year OS of 41%. However, early toxic deaths were reported related to sinusoidal obstruction syndrome (SOS). These results were confirmed by subsequent studies evaluating unfractionated GO combined with various agents in patients with R/R AML. The main objective of the present retrospective study was to evaluate the efficacy of the combination of fractionated GO with intermediate-dose cytarabine and daunorubicin in very high-risk patients with AML, and its potential use as bridge to transplant in this patient population.Methods: Herein we present a retrospective monocentric study of 24 very high-risk AML patients who received a combination of fractionated gemtuzumab ozogamicin (GO) with intermediate-dose cytarabine and daunorubicin as salvage therapy.Results: Median age was 55.3 years. Diagnoses were secondary AML for 33% of them. Seven patients had favorable, 8 had intermediate-1 or intermediate-2 and 6 unfavorable-risk AML according to the European LeukemiaNet prognostic index. Complete remission rate was achievied in 50% of cases (46% in refractory and 55% in relapsed AML) without excessive toxicity. Only allogeneic hematopoietic stem cell transplantation provided a benefit in this patient cohort with a one-year overall survival of 50.7% versus 18.1% in the absence of transplantation. Patients treated with reduced intensity conditioning (RIC) showed a higher survival as compared to those undergoing myeloablative conditioning regimen. CD33 expression was not associated with survival. In multivariate analysis in a model including the age older than 60 years, allo-HSCT, refractory AML and achievement of CR after GO, only the performance of allo-HSCT predicts patients' outcome with a Hazard Ratio (HR) of 0.25 (95% CI 0.07-0.86), p=0.02.Conclusions: Our data suggest that salvage therapy with fractionated GO combined with intermediate-dose cytarabine and daunorubicin in very high-risk patients may serve as a potential bridge therapy to RIC transplant. Data from studies published after withdraw of GO from the market, of which our present study, suggest that the licence status of GO might be reviewed, at least for certain subtypes of patients and certain situations of which R/R AML patients. [Display omitted] [Display omitted] DisclosuresNicolini:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria; Ariad pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Salles:Gilead: Honoraria, Research Funding; Roche/Genentech: Consultancy, Honoraria, Research Funding; Mundipharma: Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Thomas:Pfizer: Consultancy.

Minimal Residual Disease (MRD) As Exploratory Endpoint in a Phase 1 Study of the Anti-CD123 Mab CSL362 Given As Post-Remission Therapy in Adult Acute Myeloid Leukemia (AML)

BackgroundAML patients (pts) who achieve a morphologic complete remission (CR) may have MRD in bone marrow (BM) and/or peripheral blood detected as patient-specific leukemia-aberrant immunophenotype by multiparameter flow cytometry (MFC) or as abnormal transcripts of AML gene mutations/translocations by quantitative RT-PCR. Presence of MRDafter induction and/or consolidation therapy identifies pts at high risk of relapse, with increasing MRD levels indicating impendingrelapse in individual pts. Although standardized testing and validated endpoints for MRD determination across institutions are lacking, major cancer treatment centers can diagnose and track MRD reliablywhen assessed in serial BM samples.CD123 (IL3-Rα) is overexpressed by AML blasts and leukemia stem cells (LSC), suggesting that agents designed to target and kill CD123+ AML LSC and blasts may eliminate MRD and delay or prevent relapse. Retrospective clinical data suggest that conversion of AML pts from MRD + to MRD negative (-) status may confer clinical benefit; however this has not been fully characterized in prospective clinical trials.MethodsCSL362 is a fully humanized, anti-CD123 monoclonal antibody, Fc domain-engineered to bind with high affinity to CD16 on natural killer (NK) cells. CSL362 activates antibody-dependent cell-mediated cytotoxicity (ADCC) of CD123+ cells. The first-in-human Phase 1 study of CSL362 assessed safety, PK and targeted bioactivity. An exploratory objective was to track changes in MRD and to correlate changes with maintenance of CR.Eligible pts had CD123+ de novo or secondary AML in 1st or 2nd CR or CRp who recovered from induction with or without consolidation therapy, had risk factors prognostic for early relapse, and were not candidates for hematopoietic stem cell transplantation. CSL362 was infused IV over 3 hours once every 14 days for up to 6 doses. Sequential pt cohorts were treated at ascending dose levels from 0.3 to 12.0 mg/kg. The final safety evaluation visit was at week (wk) 16, and each center reported remission status at wk 24 from first dose. BMwas assayed for MRD at baseline as well as in wk 5 and wk 12 during therapy according to individual site's laboratory standards using MFC and/or PCR. Changes in MRD were compared to the baseline result for each pt.ResultsEnrollment completed with 30 pts total, in 6 dose level cohorts, treated at 4 hospitals. Safety, PK and biomarker results showing an acceptable safety profile, and targeted bioactivity of CSL362 were reported at the ASH 2014 Annual Meeting [Blood 124 (21); 120]. At baseline, 12 pts were MRD+ (5 by MFC only, 4 by PCR only and 3 by both methods); 11 of 12 had a follow up evaluation. Molecular mutations in post-remission BM identified by PCR were FLT3 (3 pts), NPM1 (3 pts) and MLL (1 pt).Of 4 pts MRD+ by MFC only, 1 converted to MFC- and maintained CR at wk 24. Of 4 pts MRD+ by PCR only, 1 converted to PCR- and maintained CR at wk 24; a 2nd pt, who remained PCR+ on study also maintained CR at wk 24. Of 3 pts MRD+ by both MFC and PCR, 1 converted to MFC-, PCR follow-up was not done but the pt maintained CR at wk 24. The 7 pts MRD+ who did not convert to MRD- relapsed prior to wk 24. [See table].Table 1MRD+ at baselineConverted to MRD - at Wk 5Converted to/Maintained MRD - at Wk 12Maintained CR at Wk 244 + by MFC only1214 + by PCR only (1 FLT3, 1 MLL, 2 NPM1)01 (NPM1)2(NPM1; MLL)3 + by MFC & PCR (2 FLT3, 1 NPM1)by MFC 3by PCR 0by MFC 1by PCR 01 (Flt3)DiscussionConversion from MRD + to MRD - in 4 of 11 pts, with CR maintained at wk 24, is hypothesis generating; MRD conversion suggests possible eradication of residual leukemia cells while on study. Maintenance of morphologic CR was more likely for patients who converted to a MRD-state than those who remained MRD+ during therapy. Multiple factors may affect AML response to CSL362 immunotherapy, including cytogenetic abnormalities, specific molecular mutations, and each pt's immune system status. Preclinical data suggest the activity of CSL362 requires adequate numbers and function of NK cells and expression of the target receptor (CD123) on LSC and MRD cells. This observation would provide validation for the use of MRD response as efficacy endpoint and indicator of benefit for CSL362 and, perhaps, other AML therapies. With further efforts to standardize AML MRD assessments across laboratories, MRD response may become useful as a surrogate endpoint for clinical drug development in AML. DisclosuresDeWitte:CSL Behring: Employment. Dasen:CSL Behring: Employment. Bensen-Kennedy:CSL Behring: Employment. Walter:AstraZeneca, Inc.: Consultancy; Pfizer, Inc.: Consultancy; Amphivena Therapeutics, Inc.: Consultancy, Research Funding; Covagen AG: Consultancy; Seattle Genetics, Inc.: Research Funding; Amgen, Inc.: Research Funding.

Secondary Adult Acute Myeloid Leukemia: a Review of Our Evolving Understanding of a Complex Disease Process.

Secondary AML (s-AML) encompasses AML evolving from myelodysplasia (AML-MDS) and treatment-related AML (t-AML) after exposure to chemotherapy, radiation, or environmental toxins. S-AML has traditionally been considered a devastating disease, affecting a vulnerable population of heavily pretreated, older adults. A limited understanding of disease pathogenesis/heterogeneity and lack of effective treatments have hampered overall improvements in patient outcomes. With the recent understanding that the secondary nature of sAML does not by itself incur a poor prognosis and incorporation of cytogenetics and molecular genetics into patient care and the advancement of treatment, including improved supportive care, novel chemotherapeutics agents, and nonmyeloablative conditioning regimens as part of allogeneic hematopoietic cell transplantation (HCT), modest gains in survival and quality of life are beginning to be seen among patients with s-AML.

BCOR and BCORL1 mutations in pediatric acute myeloid leukemia

BCOR and BCORL1 mutations in pediatric acute myeloid leukemia

Association of prior epidemiologic exposures with cytogenetic risk in adult acute myeloid leukemia (AML).

7047 Background: In addition to secondary AML (sAML), important lifestyle and environmental exposures associated with increased risk of AML development have been identified in recent case-control studies including obesity (BMI&gt;30kg/m2), smoking, regular acetaminophen use, and rural/farm habitat. The association of these exposures with AML cytogenetic risk groups is unknown. We therefore evaluated relevant exposures in a cohort of 301 AML patients with confirmed central cytogenetics analysis diagnosed and treated at Mayo Clinic FL and AZ since 1995. Methods: Documented patient exposures were extracted from central electronic medical records, including: prior chemotherapy/radiation or hematologic malignancy, occupation, select medications, “toxins” (esp. benzene) and solid organ transplantation (SOT). Standard cytogenetic risk categories (including intermediate abnormal) were applied. The association of epidemiologic exposures with cytogenetic risk was evaluated on multivariable analysis using logistic regression models. Results: sAML was significantly associated with cytogenetic risk groups, as was prior SOT, healthcare occupation, farm habitat and toxin exposures [see Odds Ratios (OR), Table). In contrast, prior radiation for epithelial malignancies, smoking and BMI were not independently associated with specific cytogenetic risk categories. Conclusions: Specific epidemiologic exposures are significantly associated with AML cytogenetic risk categories suggesting a unique clinical phenotype. This supports a link to leukemogenesis and requires validation in a controlled prospective therapeutic study. [Table: see text]

The Impact of Obesity on the Presentation & Outcome of Adult Acute Myeloid Leukemia (AML) - ECOG Studies E1900 & E3999

Abstract 2568 Background:Obesity is associated with an increased risk of development of adult AML (Relative Risk approx. 2-fold) (Ross J, Cancer Epidemiol Biomarkers Prev 2004;13:1810) and significantly higher mortality in pediatric AML (Lange B, JAMA 2005;293:203). We therefore examined the association of obesity with presenting characteristics in 2 recent large ECOG phase III adult AML trials to determine whether there was a unique clinical and genetic phenotype, and also the impact of obesity on clinical outcomes (complete remission - CR; early death - ED; overall survival - OS) in association with other known risk factors. The impact of obesity on receiving full-dose daunorubicin (D) was also evaluated in these studies. We included patients (pts) from E1900 receiving standard infusional cytarabine with intensified D (45 vs. 90mg/m2) in adults age ≤60 yrs (NEJM 2009;361:1249), and from E3999 receiving conventional intensive chemotherapy +/− the MDR-inhibitor zosuquidar in adults age >60 yrs (Blood 2010;116:4077). Obesity was defined as Body Mass Index (BMI) >30kg/m2. Methods:Pt baseline characteristics were compared using Fisher’s exact (categories variables) or Wilcoxon rank sum tests (continuous variables). Logistic regression models were used to examine the association between obesity and CR or ED; Cox models stratified on induction treatment arms were used to examine the association between obesity and OS. Multivariate models to examine the effect of Obesity controlled for known prognostic factors (including cytogenetics & secondary AML - sAML). Results:A total of 1089 pts (E1900, n=651; E3999, n=438) with available BMI data were included, the median follow-up of living pts is 4.7 yrs. Obesity was prevalent, with n=359 (33%) of pts with a BMI>30 at presentation. For all patients, median BMI was 27.1 (range 16.7–93.0); for non-obese patients median BMI was 25.0 (range 16.7–29.96) while for obese patients the median BMI was 34.0 (range 30.0–93.0).Obese pts were older (p=0.06), and significantly more likely female gender (p=0.05), ECOG PS>0 (p=0.01), & Intermediate Risk cytogenetics (p=0.006) but not sAML (14% overall, p=ns). Genotyping for FLT3 & MLL was performed in E1900 pts (age ≤60yrs): there was no difference in incidence of FLT3-ITD, but lower incidence of MLL-PTD was observed (p=0.08) in obese pts (not performed in E3999) (See Table).Obese (BMI>30)Non-ObeseP-valueMedian Age59yrs56yrs0.06Female gender51%44.5%0.05Intermediate Cytogenetics42.3%35.5%0.006PS>064.1%57.6%0.01MLL-PTD1.7%3.6%0.08FLT3-ITD14.8%12.5%0.31Overall, only 3.7% of pts received <90% of intended D dose. However obesity was significantly associated with receiving <90% intended D dose: in E1900, 11% of obese pts received <90% intended D (45mg/m2 cohort, p<0.001; 90mg/m2 cohort p=0.002), while in E3999 4% obese pts received <90% intended D (45mg/m2, p=0.07). There was no clear difference in toxicity/adverse events during initial induction therapy reported in obese vs. non-obese pts.On multivariate analysis obesity was not significantly associated with achieving CR (p=0.09), and had no direct independent association with ED (p=0.38).Kaplan-Meier plots of OS are shown in Figure. On multivariate analysis, age (p<0.001); ECOG PS (p<0.001); cytogenetic risk group (p<0.001); sAML (p=0.03); gender (p=0.05); and peripheral blasts (p=0.003) but not obesity were significantly associated with OS. Receiving <90% intended D dose was marginally associated with increased hazard ratio for OS (HR 1.50, 95%CI 0.98–2.28, p=0.06). Conclusion:Obesity is associated with specific presenting clinical characteristics in adult AML (female, older, PS>0, Int. risk cytogenetics, less frequent MLL-PTD), but has no direct impact on CR, ED or OS in the setting of a controlled therapeutic trial. Obese pts are at risk of receiving <90% intended D dose, which may impact OS. This analysis suggests that factors that predispose to adult AML may present with a unique clinical phenotype. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Subnormal Vitamin D Levels Are Associated with Adverse Outcome In Newly-Diagnosed Similarly-Treated Adult Acute Myeloid Leukemia (AML) Patients.

AbstractAbstract 1041Several studies suggest that subnormal vitamin D levels may be prognostic in a number of malignancies, including non Hodgkin lymphoma, prostate, breast, colon and lung cancer. However, no studies have evaluated the impact of subnormal vitamin D levels on treatment outcome in AML. Vitamin D levels were evaluated in 97 consecutive newly diagnosed similarly treated patients with AML (excluding AML M3). There were 50 (52%) males and 47 (48%) females with a median age of 60 years (range 19–91). The median white blood cell (WBC) count at diagnosis was 18×109/L (range 0.57–555.23). Karyotype was favorable in 11%, intermediate in 50%, adverse in 23%, of unknown significance in 11% and not available in 5%. A total of 74 patients (76%) had de novo AML. Albumin levels were subnormal (<3.5g/dl) in 33 (34%) patients and normal (≥3.5g/dl) in 64 (66%) patients. Body mass index (BMI) was calculated on all patients, normal weight (BMI 18–24.9) 33 (32%) patients, overweight (BMI 25–29.9) 34 (35%) patients, obese (BMI 30–34.9) 16 (16%) and very obese (BMI ≥35) 15 (15%) patients. Induction consisted of cytarabine (100mg/m2 × 7 days), daunorubicin (90mg/m2 for <60 and 60mg/m2, for ≥60 × 3 days) and etoposide (100mg/m2 × 3 days) (ADE 7+3+3).Consolidation therapy consisted of either high-dose cytarabine (47%), ADE (5+2+2) (15%), allogeneic (8%) transplantation, or other/no further treatment (30%). The median follow-up was 8.1(range, <1-66) months. Serum samples were obtained at diagnosis and studied for 25-(OH)-Vitamin D levels using radioimmunoassay. Thirty-four (35%) patients had normal vitamin D levels (32-100 ng/mL), and 63 (65%) patients had levels <32ng/ml.; 34 (35%) patients had levels considered insufficient (20-31.9ng/ml) and 29 (30%) patients were deficient (<20ng/ml). We have studied vitamin D concentrations in a cohort of 100 healthy volunteers from Western New York and found a similar frequency of vitamin D serum concentrations subnormal. Complete remission rate was similar in those with normal and subnormal vitamin D levels (50% vs. 57%; P=0.53). In univariate analysis, WBC count ≥100×109/L was associated with worse progression-free survival (PFS) and overall survival (OS) [14.3 vs. 2.2 months; 95% confidence interval (CI) 8.9 to 21.9 vs. 0.49 to 5.9 for PFS (P=<0.0001) and 17.3 vs. 2.2 months; 95% CI 13.6 to 24.6 vs. 0.49 to 6.7 for OS (P=<0.0001). Similarly, secondary AML was associated with worse PFS and OS [14.9 vs. 6.3 months; 95% CI 9 to 26.7 vs. 4.1 to 10.1 for PFS (P=0.028) and 18.9 vs. 6.7; 95% CI 13.6 to NA vs. 5.6 to 16.7 for OS (P=0.048)]. In addition, unfavorable karyotype, when compared with intermediate and favorable karyotypes, was associated with worse OS [6.6 vs. 18.9 vs. 21.2 months; 95% CI 4.8 to 16.7 vs. 11.5 to NA vs. 14.2 to NA for OS (P=0.04)]. Interestingly, in this cohort, age affected neither PFS nor OS and karyotype had no effect on PFS. Subnormal vitamin D levels were associated with worse PFS and OS [7.9 vs. 16.5 months; 95% CI 5.0 to 12.8 vs. 14.3 to NA for PFS (P=0.007) and 9.2 vs. 21.2 months; 95% CI 6.6 to 18.9 vs. 16.5 to NA for OS (P=0.01)] (Figure 1A and B). Nutritional status, assessed by albumin and BMI, did not affect PFS and OS. In multivariate analyses, only vitamin D (P=0.03 and P=0.049) and WBC count (P=0.02 and P=0.02) retained their statistical significance for PFS and OS. In summary, AML patients with subnormal vitamin D levels had significantly inferior PFS and OS compared to patients with normal vitamin D levels. Additional investigations to validate this observation and determine the mechanisms by which vitamin D levels are associated with inferior survival in AML are warranted. If confirmed, studies of the role of vitamin D supplementation in AML patients would be valuable. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

EVI1 overexpression in distinct subtypes of pediatric acute myeloid leukemia

Overexpression of the ecotropic virus integration-1 (EVI1) gene (EVI1+), localized at chromosome 3q26, is associated with adverse outcome in adult acute myeloid leukemia (AML). In pediatric AML, 3q26 abnormalities are rare, and the role of EVI1 is unknown. We studied 228 pediatric AML samples for EVI1+ using gene expression profiling and RQ-PCR. EVI1+ was found in 20/213 (9%) of children with de novo AML, and in 4/8 with secondary AML. It was predominantly found in MLL-rearranged AML (13/47), monosomy 7 (2/3), or FAB M6/7 (6/10), and mutually exclusive with core-binding factor AML, t(15;17), and NPM1 mutations. Fluorescent in situ hybridization (FISH) was performed to detect cryptic 3q26 abnormalities. However, none of the EVI1+ patients harbored structural 3q26 alterations. Although significant differences in 4 years pEFS for EVI1+ and EVI1- pediatric AML were observed (28%+/-11 vs 44%+/-4, P=0.04), multivariate analysis did not identify EVI1+ as an independent prognostic factor. We conclude that EVI1+ can be found in approximately 10% of pediatric AML. Although EVI1+ was not an independent prognostic factor, it was predominantly found in subtypes of pediatric AML that are related with an intermediate to unfavorable prognosis. Further research should explain the role of EVI1+ in disease biology in these cases. Remarkably, no 3q26 abnormalities were identified in EVI1+ pediatric AML.

Prognostic Value of Cytogenetics in Patients with Acute Myeloid Leukemia Aged More Than 60 Years at Diagnosis: Identification of Subgroups Taking Benefit from Intensive Chemotherapy. Results from a Large Single Center Retrospective Study.

Cytogenetic analysis performed at diagnosis is known as the most important independent prognostic factor in adult acute myeloid leukemia (AML) treated with intensive chemotherapy. This major predictor of outcome has been mostly identified in younger patients who are categorized into three risk groups: favorable, intermediate and adverse. However, the prognostic value of chromosome abnormalities in elderly patients with AML aged 60 years or older has been evaluated in much fewer studies and overall prognosis remains very poor in this population with a very small number of long-term survivors using current standard chemotherapy. To further investigate the prognostic relevance of cytogenetic abnormalities in older patients, we reviewed 376 patients with de novo or secondary AML aged 60 years or more and available cytogenetic data at diagnosis. APL were excluded and no patient received allogeneic bone marrow transplantation. Of 376 patients, 280 (74%) received induction chemotherapy based on association with cytarabine (ara-C) and anthracyclins according to GOELAMS SA2, SA3, SA4 and SA2002 prospective trials between 1988 and 2005. Patients who were not treated with induction regimen received best supportive care or low dose ara-C. Overall complete remission rate was 42%, induction failure 38% and induction death 20%. With a median follow-up of 11.5 years for survivors, overall survival (OS) was 4.5% at 5 years (95% confidence interval [CI], 3.8%–5.8%) and disease free survival (DFS) was 4.3% at 5 years (95% CI, 3.7%–5.9%). Using a proportional hazards model with normal cytogenetics as reference group, 3 prognostic subgroups were identified for OS: low-risk (t(8;21) and inv(16)) in 20 of 280 patients (7%), standard-risk (+8, +11, −13/del(13q), t(11q23), +22, all in no complex karyotypes) in 175 of 280 patients (63%) and high-risk (−5/del(5q), −7/del(7q), −17/del(17p), −20/del(20q), +21, rare aberrations, complex≥3 and complex≥5) in 85 of 280 patients (30%). In multivariate analyses using a Cox model with backward selection procedure, high-risk cytogenetics (p<0.001), age>65 years (p=0.01), multilineage dysplasia on marrow at diagnosis (p=0.008) and white blood cell count (WBC) (p=0.03) appeared as independent prognostic factors on OS and DFS. Secondary AML did not appear as prognostic factor in multivariate analysis (p=0.18) but in a log-rank test, AML secondary to hematologic malignancy did significantly worse than AML secondary to solid tumors in both OS and DFS (p=0.01 and p=0.04, respectively). OS distribution between treated and untreated patients was compared using a log-rank test with homogeneous subgroups based on cytogenetic risk group and age. Three-years OS was significantly better in patients <70 years with standard-risk cytogenetics (p=0.008 if age<65years and p=0.02 if age <70 years). For high-risk cytogenetic group, 3-years OS was improved only in patients <65 years with WBC<30G/L (p=0.03). These results confirm the independent prognostic value of pretreatment karyotype, age >65 years, WBC and associated multilineage dysplasia in elderly patients with AML. Overall prognosis remains very poor and intensive chemotherapy does not improve OS in patients aged >70 years and high-risk cytogenetic groups.

Absence of JAK2 V617F Activating Mutations in Children with Acute Megakaryoblastic Leukemia with and without Down Syndrome.

Activating mutations at codon 617 of the Janus-2 tyrosine kinase (JAK2 V617F) have recently been described in hematological malignancies. In adult acute myeloid leukemia (AML), the reported frequencies vary, and JAK2 V617F mutations have mainly been detected in secondary AML following a myeloproliferative disorder. In adult de novo AML, the mutation was less frequent, and detected in 2/11 (18%) acute megakaryoblastic leukemia (FAB M7) samples (Jelinek et al., Blood 2005), and occasionally in other FAB-types.This prompted us to analyze a cohort of pediatric AML FAB M7 samples for this particular mutation. In children, at least 3 different subsets of AML M7 can be identified: infants with AML M7 characterized by t(1;22)(p13;q13), older children with random cytogenetic aberrations, and myeloid leukemia of Down syndrome (DS ML). DS ML is often preceded by transient myeloproliferative disease (TMD), hence we also screened TMD samples to detect whether JAK2 V617F mutations would be involved in clonal evolution from TMD to DS ML. To exclude germ-line mutations in DS, we tested normal mononuclear bone marrow cells (NBMC) from children with DS. These NBMC were obtained from a sternal aspirate from children undergoing cardiac surgery, after informed consent was obtained. Genomic DNA was harvested from leukemic cells, and JAK2 exon 12, including the intron-flanking regions, was amplified and sequenced to screen for the JAK2 V617F mutation. As a positive control for the JAK2 V617F mutation, we used HEL 92.1.7 cells (an erythroleukemic cell line). In a dilution experiment we could still detect the mutation, using direct sequencing, if 10% HEL/JAK2 mutated cells were mixed with 90% wild-type control cells. We tested 49 samples, comprising of 9 NBMC, 11 TMD, 14 DS-ML M7, 11 non-DS AML M7 and 4 relapsed non-DS AML M7 samples (including 2 initial diagnosis-relapse pairs). The median age of the TMD cohort was 3 days, for DS-ML children 1.9 years (range 0.9–3.8 yrs), and for non-DS AML 1.5 years (range 1.2–13.7 yrs). The median white blood cell count for TMD was 25.8x109/l, for DS-ML 13.8x109/l, and for non-DS AML 12.4x109/l. Cytogenetic data were available in 5/11 non-DS AML cases only, which showed no cases with a t(1;22). No JAK2 V617F mutations were detected in any of the clinical samples. We conclude that the role of JAK2 V617F mutations in pediatric DS and non-DS acute megakaryoblastic leukemia is limited at best. However, we were not able to screen the subgroup of non-DS AML cases with t(1;22).

High Dose Cytosine Arabinoside, Idarubicin and G-CSF Therapy forDe Novoand Secondary Adult Acute Myeloid Leukemia

High Dose Cytosine Arabinoside, Idarubicin and G-CSF Therapy for<i>De Novo</i>and Secondary Adult Acute Myeloid Leukemia