Cytogenetic Lesions Research Articles

Epigenetic alterations in AML: Deregulated functions leading to new therapeutic options.

Acute myeloid leukemia (AML) results in disruption of the hematopoietic differentiation process. Crucial progress has been made, and new therapeutic strategies for AML have been developed. Induction chemotherapy, however, remains the main option for the majority of AML patients. Epigenetic dysregulation plays a central role in AML pathogenesis, supporting leukemogenesis and maintenance of leukemic stem cells. Here, we provide an overview of the intricate interplay of altered epigenetic mechanisms, including DNA methylation, histone modifications, and chromatin remodeling, in AML development. We explore the role of epigenetic regulators, such as DNMTs, HMTs, KDMs, and HDACs, in mediating gene expression patterns pushing towards leukemic cell transformation. Additionally, we discuss the impact of cytogenetic lesions on epigenomic remodeling and the potential of targeting epigenetic vulnerabilities as a therapeutic strategy. Understanding the epigenetic landscape of AML offers insights into novel therapeutic avenues, including epigenetic modifiers and particularly their use in combination therapies, to improve treatment outcomes and overcome drug resistance.

Combining Gene Mutation with Transcriptomic Data Improves Outcome Prediction in Myelodysplastic Syndromes

Background and Aim. Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by peripheral blood cytopenias and risk of progression to acute myeloid leukemia (AML). Disease management is challenged by heterogeneity in clinical courses and survival probability. Recently, the genomic screening integration (by Molecular International Prognostic Scoring System, IPSS-M) into patient's assessment has resulted into a significant improvement in predicting clinical outcomes compared to the conventional prognostic score (Revised IPSS, IPSS-R). Many of the consequences of genetic and cytogenetic alterations will affect gene expression by means of transcriptional and epigenetic instability and altered microenviromental signaling. The aim of this project conducted by GenoMed4All and Synthema EU consortia is to link genomic information with transcriptomic data for possibly improving the prediction of clinical outcomes in MDS patients. Patients and Methods.Clinical, cytogenetic, genomic (somatic mutations screening of 31 target genes) and transcriptomic (bulk RNA-seq of CD34 + bone marrow cells) data were collected at diagnosis in 389 MDS patients. Transcriptomic and genomic profiles were processed and the former were normalized before Principal Component Analysis (PCA) dimensionality reduction to mine the interdependency of expression-wide perturbation and recurrent genomic alterations. The prognostic impacts of genetic, cytogenetic, transcriptomic, clinical and demographic features were assessed with a penalized Cox's proportional hazards model [Gerstung M et al, Nat Commun. 2015. 6, 5901] considering the Overall Survival (OS) as primary end point. A 5-fold cross-validating (CV) scheme was exploited to control bias in risk estimation. Model accuracy was assessed using Harrell's concordance index (C-index). An independent validation of the results on 202 patients was planned. Results.We first processed each data layer assessing data robustness, removed not informative variables and scaled quantitative ones. We considered recurrent genomic and cytogenetic lesions (present in ≥5 patients), platelets, hemoglobin and bone marrow blasts (%), age and sex as covariates. To explore the main patterns of expression changes, PCA was performed to reduce multidimensional correlated expression features (20 PCs was selected, explaining 42% of the total transcriptomic variability). To evaluate the prognostic power of each data layer we grouped all available features into five groups: gene mutations (n=15), cytogenetic alterations (n=7), expression data (n=20), blood counts (n=3) and demographic variables (n=2). Within a 5-fold CV we combined these variables in our integrative model to calculate MDS patients risk. The obtained predictive accuracy (C-index) for OS was 0.83, underlying that transcriptomic data significantly improved the current standard prognostic scoring systems. Accordingly, in our patient population, the C-index of the conventional IPSS-R score and the new IPSS-M were 0.68 and 0.76, respectively. A similar improvement by adding transcriptomic data was observed in prediction of the risk of AML evolution. Moreover, by analyzing the contribution of each feature category to the OS probability ( Figure 1), in term of explained variance, the relative impact of transcriptomic is 40%, with the remaining prognostic information distributed among genomic features (somatic gene mutations and cytogenetics lesions, 24%), demographics (20%) and clinical features (15%). An independent validation of these results on 202 patients is currently ongoing. Figure 2 shows an example of personalized survival prediction using patients from the study population. In two subjects with same clinical phenotype and mutations leading to a similar IPSS-M prognosis, the integrative model captures additional prognostic information and efficiently predicts clinical outcome. Given the complexity of our model, specific technological support is needed to combine data at individual patient level and to translate it into a personalized outcome prediction. To this aim, we created a prototype web portal based on our dataset for user-defined genomic/transcriptomic and clinical features. Conclusion. In predicting survival of MDS patients, genomic, transcriptomic and diagnostic clinical variables all have utility, with a significant contribution from the transcriptome.

Excellent PFS and OS of Newly Diagnosed Multiple Myeloma Patients Receiving Carfilzomib, Bendamustine, and Dexamethasone (KBD): A 6.5 Year Follow-up

INTRODUCTION While quadruplet regimens including PIs, IMiDs, and anti-CD38 mAb are now standard in the US for multiple myeloma (MM), the alkylating agent bendamustine has proven safe and effective in the first-line setting. 1 IMIDs can thus be preserved until relapse or replaced after adverse events. Carfilzomib has demonstrated efficacy in newly diagnosed MM. 2 We previously published the results of a phase I/II study of carfilzomib, bendamustine, and dexamethasone (KBD) in newly diagnosed MM during the pre-daratumumab era. 3 We report long-term survival outcomes. METHODS Patients enrolled in NCT02002598 with newly diagnosed MM and adequate renal function received IV carfilzomib, IV bendamustine, and IV/PO dexamethasone at prespecified doses for 8 cycles, each 28 days. 3 Stem cell collection for autologous stem cell transplant (ASCT) was performed after cycle 4. ASCT was performed after cycle 8 for transplant eligible patients. Maintenance was carfilzomib 36 mg/m 2 every 2 weeks or investigator's choice. Trial cessation occurred 12/2018. Here we provide an updated analysis of the outcome of patients with a median follow up of 77.5 months. RESULTS Data from 2/2014 to 7/2023 were reviewed. 19 patients received ≥2 cycles of KBD and were eligible for analysis. 5/19 (26.3%) had ≥1 high- or ultra-high-risk cytogenetic lesion (gain 1q, amplification 1q, 17p deletion/TP53 mutation, t(4;14), t(14;16), t(14;20)). 4 7/19 (36.8%) were R-ISS stage 1. 5/19 (26.2%) were R-ISS stage 3. ORR was 100.0% with 12/19 patients (63.2%) achieving a complete remission (CR) and 7/12 (58.3%) minimal residual disease (MRD) negativity. Median time to response was 1 cycle and to best response 7 cycles. 12/19 patients (63.2%) underwent ASCT. Times to neutrophil and platelet engraftment occurred in the expected timeframe. 16/19 patients completed median 19 maintenance cycles (IQR: 1-24). 10/19 patients (52.6%) received carfilzomib 36 mg/m 2 every 2 weeks; 5 patients received lenalidomide d1-21 every 28 days; 1 patient received KRd. 2 patients declined maintenance; 1 patient died prior to maintenance due to septic shock. After median follow up of 77.5 months (95% CI: 52.2-82.2), 7/19 (36.8%) patients suffered PD, including 3/12 (25.0%) who achieved CR. 1/19 died due to PD; 1/19 died due to septic shock. Median PFS was 77 months (34.5-NR); median time to next treatment (TTNT) was 77.0 months (36.1-NR). Median OS was not reached. 4/5 patients with high-risk cytogenetics suffered PD at median 48.6 months (14.6-NR); 1 without PD survived 17.2 months before loss to follow up. 1/5 high-risk cytogenetics patients died from PD at 37.2 months. For the 7/19 (36.8%) without ASCT, median PFS, TTNT, and OS were 41.8 months (9.8-NR), 45.2 months (9.8-NR), and not reached, respectively. 2/19 (10.5%) patients developed a second primary malignancy: melanoma in situ, fully resected; and localized prostate cancer at age 73, on active observation. No MDS occurred. CONCLUSIONS and DISCUSSION Patients with newly diagnosed MM who received KBD and, if eligible, ASCT had an excellent outcome with a median PFS of 77 months and a median OS that has not yet been reached at a median follow up of over 6 years. These findings equal or surpass the results achieved with RVD induction with a median PFS of 50 months for RVd + ASCT and 36 months for RVd only. 5 No adverse effects due to bendamustine were apparent, including development of MDS. KBD with anti-CD38 mAb should be explored as a viable IMID-sparing first-line regimen, regardless of ASCT eligibility. REFERENCES 1. Mateos MV, Oriol A, Rosinol L, et al: Bendamustine, bortezomib and prednisone for the treatment of patients with newly diagnosed multiple myeloma: results of a prospective phase 2 Spanish/PETHEMA trial. Haematologica 100:1096-102, 2015 2. Jasielec JK, Kubicki T, Raje N, et al: Carfilzomib, lenalidomide, and dexamethasone plus transplant in newly diagnosed multiple myeloma. Blood 136:2513-2523, 2020 3. Leng S, Bhutani D, Raza S, et al: Phase I/II study of carfilzomib, bendamustine, and dexamethasone (CBD) in patients with newly diagnosed multiple myeloma. Blood Cancer J 10:13, 2020 4. Perrot A, Lauwers-Cances V, Tournay E, et al: Development and Validation of a Cytogenetic Prognostic Index Predicting Survival in Multiple Myeloma. J Clin Oncol 37:1657-1665, 2019 5. Attal M, Lauwers-Cances V, Hulin C, et al: Lenalidomide, Bortezomib, and Dexamethasone with Transplantation for Myeloma. N Engl J Med 376:1311-1320, 2017

Prothrombotic Profile in Patients with Active Multiple Myeloma and the Impact of Immunomodulators: The Roadmap-MM Study

Backround: Thromboembolism occurs in about 10% of patients with multiple myeloma (MM). The incidence of VTE is higher in newly diagnosed MM patients as compared to those with relapsed or refractory disease and it is higher during the first 3 to 6 months after the initial diagnosis and treatment initiation. Some of the treatments administered to patients with MM are independent risk factors for VTE. Immunomodulatory agents (IMiDs) among anti-myeloma treatments stand out as having a considerable prothrombotic effect. Recognizing the significant risk associated with the use of immunomodulatory agents (the International Myeloma Working Group (IMWG) 2014 statement, and the European Myeloma Network Guidelines in 2015 both included guidance on the prevention of VTE in MM patients who receive IMiDs. The prospective, longitudinal observational study ROADMAP-MM CAT was designed to explore alternative strategies for the development of risk stratification tools in patients with multiple myeloma. To this target we evaluated the baseline profile of hypercoagulability in multiple myeloma patients with various disease status. Blood borne hypercoagulabity partly consisted of enhanced thrombin generation, a common phenomenon in patients with malignancies . It remains to be seen whether this phenomenon appears for multiple myeloma patients during the physical course of the disease. Aim: We conducted a study to explore the relationship between stages of MM and alterations of various thrombosis-related biomarkers in patients with MM and their relationship with MM therapy. Materials and Methods Patients with MM (n=162) were recruited and stratified to the following groups: 59 newly diagnosed treatment-naïve patients (ND), 49 patients receiving IMiDs (IM), 52 in complete remission (CR) and 12 patients in partial remission on IMiDs (PR/IM). Patients on anticoagulant treatment were excluded from the study. The control group (CG) consisted of 30 healthy age and sex-matched individuals. Samples of platelet-poor plasma (PPP) were assessed for thrombin generation (TG) with the TF 5pM PPP-Reagent® on Calibrated Automated Thrombogram (Diagnostica Stago, France). Plasminogen activator inhibitor-1 (PAI-1), soluble endothelial protein C receptor (sEPCR), and soluble vascular cell adhesion molecule-1 (sVCAM-1), Procoag-PPL were measured using antibody-based ELISA kits (Invitrogen International Inc., CA, USA, and Diagnostica Stago, France ). TF expression MPC-derived microparticles (MPC-dMPs) were detected using a Zymuphen MP-TF activity kit (Hyphen BioMed, Neuville sur Oise, France). The upper and lower normal limits (LNL and UNL) were calculated by the mean±2 SD. Results A total of 162 patients were enrolled (age 66.0±12.0 yrs; 53% male). Distribution of disease stage was as follows: 32% ISS I, 23% ISS II, 45% ISS III. Bone disease was present in 71% of patients and 19% of patients had high risk cytogenetic lesions. Patients with ongoing MM (ND, IM, PR/IM) had significantly lower Peak, ETP and MRI as compared to the CG. In contrast, patients in CR had Peak, ETP, MRI values similar to the CG. Patients with PR had lower ETP and MRI values as compared to the CR group. In ND 9% had TG >UNL and 22% had TG<LNL. In IM 10% had TG>UNL and 67% had TG<LNL. None in PR/IM had TG>UNL and 35% had TG<LNL. In CR, 23% had TG>UNL and 12% had TG<LNL. MP-TF levels and PPL were higher in untreated MM (CR) patients compared to control. MP-TF and PPL levels decreased significantly after chemotherapy in PR/IM but MP-TF remained high at CR. The plasma concentrations, PAI-1, sEPCR, and sVCAM-1 were higher in MM patients than controls. , Treatment with IMDs reduced all biomarker levels gradually from PR/IM to CR (Table 1). Conclusion Patients with active MM showed attenuated TG which was enhanced in the presence of IMiDs treatment. Complete remission was associated with normalization of TG. The plasma concentrations, TF-MP , PAI-1, sEPCR, and sVCAM-1 were increased in MM patients suggesting vascular aggression which is followed by release of these markers that could contribute to the procoagulant environment. Attention should be paid to therapy-related thrombosis indeed the effect the suggested role of IMiDs in hypercoagulability does not seem to be confirmed and requires further studies .

Pediatric-Specific Patterns of Clonal Evolution Arising from Acquired Aplastic Anemia

Introduction Acquired aplastic anemia (aAA) occurs in both children and adults, though pathophysiology and clinical outcomes differ significantly by age. While clinical testing for paroxysmal nocturnal hemoglobinuria (PNH) clones is routine, targeted next generation sequencing (NGS) for myelodysplastic syndrome (MDS) associated variants has only recently been implemented. Furthermore, single nucleotide polymorphism array (SNP-A) assessing for copy neutral loss of heterozygosity in the human leukocyte antigen (HLA) region on chromosome 6p (6p CN-LOH) and HLA NGS assessing for allele specific loss of function (LoF) mutations, which together are seen in up to 25% of aAA cases, are only now being considered for clinical use. Recent studies have reported on the frequency and overlap of these 3 types of clonal evolution (PNH, MDS-associated, HLA-targeting) in adult aAA cohorts, but none focus specifically on pediatric patients, whose MDS-associated clonal evolution patterns are distinct. Delineating patterns of clonal hematopoiesis in pediatric aAA to determine whether evolution driven by immune escape (PNH and HLA loss) affects likelihood of MDS development is critical for personalizing therapeutic options. Thus, we aimed to describe the frequency, clinical significance, and overlap of clonal evolution including PNH, HLA loss, and MDS-associated gene mutations in a pediatric cohort of aAA patients. Methods This study identified 85 pediatric aAA patients treated at Children's Hospital of Philadelphia (CHOP) and enrolled on the IRB-approved CHOP/Penn BMF Registry and Repository in whom clinical testing for all patterns of clonal hematopoiesis was available or could be performed with biorepository samples. PNH flow cytometry was performed clinically in all cases; subjects with PNH > 0.05% in the granulocyte fraction were considered as having a PNH clone. Peripheral blood and bone marrow samples were used for SNP-A, HLA-NGS, and an institutional somatic mutation NGS panel for hematological malignancies encompassing 118 genes. Descriptive and contingency statistical analyses along with Fisher's Exact Test were performed using SAS (Cary, NC). Results Demographic composition of the 85 pediatric subjects with aAA included a median age of 10.7 years (1.7-20.8), male/female ratio of 59%/41%, and a representative race/ethnicity distribution (Table 1). In total, 66% displayed at least one clonal event. As expected, PNH clones were most common, present in 45% (38/85) of the cohort. An additional 16 (19%) exhibited acquired HLA loss by 6p CN-LOH (n=6), allele specific LoF mutations (n=6), or both (n=4). Fifteen (18%) had clonal hematopoiesis associated with MDS, of whom 3 had cytogenetic lesions that progressed to clinical MDS (3.5%), and 12 developed no morphologic features of MDS but demonstrated a total of 14 mutations in MDS-associated genes (BCOR/BCORL1 n=6, KMT2C/KMT2D n=3, RUNX1 n=1, ASXL1 n=1, SRSF2 n=1, PRPF8 n=1, CALR n=1). Critically, pediatric subjects with aAA who developed HLA loss did not develop MDS-associated mutations, with no patient demonstrating both subtypes of clonal events (Figure 1). In contrast, PNH and MDS-associated clonal events overlapped in 11% of the overall cohort. In total, 60% of patients with MDS-associated clonal hematopoiesis also possessed PNH clones, and 23% of patients with detectable PNH clones demonstrated at least one MDS-associated clonal event. Only 3.53% (n=3) of the cohort demonstrated both PNH and HLA loss, and PNH clone size was < 1% in all 3 patients. Furthermore, patients with HLA loss were significantly less likely to have PNH clones than those without HLA somatic alterations (19% vs 51%, p = 0.026). Correlations between patterns of clonal hematopoiesis and clinical outcomes will be presented. Concalusions Pediatric aAA patients treated with IST are at risk for developing MDS and hemolytic PNH. Presence and evolution of clonal hematopoiesis influenced decisions to pursue IST versus alternative donor transplant. Importantly, our study demonstrates that occurrence of clonal hematopoiesis by HLA loss does not increase and may even decrease the risk of developing MDS-associated or PNH clones. This finding strongly suggests that treatment decisions for aAA patients whose only clonal event is HLA loss need not be considered distinctly from patients with no clonal changes. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

LSC17 Score Is Complementary with Minimal Residual Disease to Stratify NPM1-Mutated Acute Myeloid Leukemia: An ALFA Study

Context. A 17-gene Leukemic Stem Cell gene expression signature (LSC17) has been shown to be prognostic in AML (Ng et al., 2016), independently of genetic risk stratification (Bill et al., 2020; Duployez et al., 2019). Whether assessment of LSC17 adds prognostic value on top of measurable residual disease (MRD) has not been explored. Objective. We analyzed the prognostic value of LSC17 in adult AML patients prospectively treated in the intensive chemotherapy ALFA-0702 trial (NCT00932412) in the context of ELN 2017 risk stratification (ELN17) and NPM1 MRD. Methods. The LSC17 score was determined by Nanostring technology (Duployez et al., 2019). NPM1 MRD negativity was defined as a 4-log reduction in peripheral blood NPM1c expression (Balsat et al., 2017; Lesieur et al., 2021). Multiple testing was adjusted for using the Benjamini-hochberg procedure. Results. The study population included 504 AML patients (237 female, 267 male) with a median age of 48 years (range 18-60). One hundred eighty-seven (37%) patients had an NPM1 mutation. ELN17 risk was favorable in 176 (35%), intermediate in 151 (30%) and adverse in 170 (34%) patients. A higher LSC17 score was positively associated with RUNX1 (median difference [md]=0.13, corrected p-value [q]=0.0005) and negatively correlated with NPM1 mutation (md=-0.14, q<0.0001) and double-mutated CEBPA (md=-0.30, q<0.0001). Regarding recurrent cytogenetic lesions, presence of monosomy 7 or del7q (md=0.29, q<0.0001), monosomy 5 or del5q (md=0.25, q=0.0004), monosomy 17, del17p or abnormal 17p (md=0.24, q=0.01), monosomal karyotype (md=0.17, q=0.02) and complex karyotype (md=0.13, q=0.03) were each associated with higher LSC17, whereas normal karyotype was associated with a lower LSC17 score (md=-0.11, q<0.0001) (Figure 1A). In the subgroup of NPM1-mutated AML (n=187), a higher LSC17 score was only correlated with FLT3-ITD (md=0.13, q=0.0002) but not DNMT3A (md=-0.0007, q=1) mutations. Patients were dichotomized into LSC17-low (n=252) and LSC17-high (n=252) groups using the median LSC17 score as cutoff. Overall, 400 (79%) patients achieved complete response (CR) or CR with incomplete platelet recovery (CRp) after one cycle of induction and an additional 31 (6%) after a second course. LSC17-high patients had a lower rate of CR/CRp after one course of induction (69% vs 89% in LSC17-low patients) in univariate (p<0.0001) or multivariate analysis (OR=0.41, p=0.001) considering ELN17 risk, age and white blood cell (WBC) count. LSC17-high patients had lower 3-year overall survival (OS) from CR/CRp (60.6%, 95% CI, 54.2-67.8%) than LSC17-low patients (75.4%, 95% CI, 70.0-81.2%, p=0.0003). In multivariate analysis considering ELN17, age and WBC, LSC17-high population had shorter DFS (HR=1.39, p=0.038) and a trend for shorter OS from CR/CRp (HR=1.40, p=0.069). In univariate analyses, LSC17-high status was associated with a higher cumulative incidence of relapse (p=0.002) without impact on non-relapse mortality (p=0.27). Considering hematopoietic cell transplantation (allo-HCT) as a time-dependent covariate, there was no interaction on OS from CR/CRp between allo-HCT in first CR and LSC17-high status (p=0.84). In NPM1-mutated patients (n=187), the rate of CR/CRp after one induction course was 90% in LSC17-high patients versus 96% in LSC17-low patients (p=0.20). In 123 NPM1-mutated patients in CR after the first induction course and with available MRD, LSC17-high status (n=42) predicted a poorer DFS (HR:2.47, p=0.005) in multivariate analysis independently of age (p=0.55), higher WBC (p=0.84), intermediate ELN17 risk (p=0.97) and MRD positivity (p=0.0002). LSC17-high status also independently predicted poorer OS from CR/CRp (HR:2.73, p=0.007) in a similar multivariate model. Three-year OS from CR was 93.1% (95% CI, 86.8-99.9%) in the 59 (48%) NPM1-mutated LSC17-low patients achieving negative MRD compared to 60.7% (95% CI, 49.8-74.0%) in those (n=64, 52%) with LSC17-high status and/or positive MRD (p=0.0001) (Figure 1B). Conclusion. The LSC17 score complements genetic risk stratification in AML patients treated intensively. Combining LSC17 and MRD assessment identifies a subset of NPM1-mutated AML with excellent long-term prognosis. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Outcomes of Single Versus Tandem Hematopoietic Stem Cell Autologous Transplant in High-Risk Myeloma Patients: A Single-Center Experience

Introduction: Over the past decade, significant advances in the treatment strategy of newly diagnosed multiple myeloma patients (NDMM) have challenged the initial management strategy in transplant-eligible (TE) patients. The value of a single autologous stem cell transplant (ASCT) is established in standard-risk myeloma; however, the role for tandem ASCT reveals conflicting results, especially in patients with high-risk cytogenetic (HR) features. HR changes include at least one of the cytogenetic lesions: t(4;14), t(14;16), t(14;20), del17p, 1q amp +, 1q amp + del 1p. Subgroup analyses of HR patients in the EMN02 study suggest benefits with tandem ASCT.Methods: We retrospectively reviewed our single centre ASCT experience in TE NDMM patients with HR from London, Canada, from January 1, 2007, to April 30, 2021 with the primary objective to compare single versus tandem ASCT for patients with high-risk MM. Secondary objectives include progression-free survival (PFS), overall survival (OS) and the effect of maintenance therapy on survival. OS and PFS were estimated using the Kaplan-Meier method. We also applied univariate and multivariate cox regression to assess the effects of age, hemoglobin, and creatinine on survival.Results: 155 NDMM received at least one ASCT between January 1, 2007 to April 30, 2021. 61/155 (39.3%) patients had HR disease. T(4:14) was seen in 19/61 (31.1%) patients; t(14:16) in 9/61 (9.8%) patients; del 17p in 20/61 (32.7%) patients, 1q amp in 36/61 (59.0%) patients and 1p del + 1q amp in 8/61 (13.1%). Patients with more than one abnormality was seen in 22/61 (36.0%) patients. In this high-risk group, the most common induction regimen consisted of cyclophosphamide, bortezomib, and dexamethasone (CyBorD) in 58/61 patients (95.0%). 34 (55.7%) patients received single ASCT and 27 (44.2%) patients received tandem ASCT. 18/34 (52.9%) single ASCT patients and 15/27 (55.5%) tandem ASCT patients received maintenance therapy. Maintenance therapy included single-agent lenalidomide (imid) in 14/61 (22.9%); single-agent bortezomib or ixazomib (proteasome inhibitor (PI)) in 8/61 (13.1%), and; imid + PI combination in 11/61(18.0%). Baseline characteristics are summarized in Table 1.Single versus tandem ASCT in HR patients revealed no statistically significant PFS difference at 60 months (p=0.3). Maintenance therapy demonstrated a substantial improvement in PFS regardless of the number of ASCT (single ASCT HR=0.1687, 95% CI range 0.05-0.52, p<0.001) tandem ASCT (HR=0.1319, 95% CI range 0.01-0.96, p=0.019). PFS was similar in patients who did not receive maintenance in tandem ASCT (20 months) or single ASCT (19 months) (p=0.57).At the 60-month follow-up, the median PFS for high-risk patients without maintenance was 18.8 months. In contrast, the PFS for patients on maintenance was not reached (HR=0.1446, 95% CI range 0.05-0.38, p<0.001). There was no difference in OS (p=0.38) with or without maintenance therapy. When comparing single-agent vs. combination strategy with maintenance, there was no PFS (p=0.47) or OS (p=0.68) difference between strategies. All patients were progression-free in those who received any maintenance at 60 months.Conclusion: In our single centre experience, single vs. tandem ASCT in TE NDMM with HR disease did not contribute to long-term survival outcomes, but the presence of any maintenance therapy had a more considerable impact on PFS. Our data does show a longer progression-free survival compared to previous published data, which is likely due to our sample size. [Display omitted] DisclosuresLam: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Honoraria, Membership on an entity's Board of Directors or advisory committees; SeaGen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Beigene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Phua: Amgen: Honoraria; NovoNordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria. Louzada: Amgen: Honoraria; Pfizer: Honoraria; Celgene: Honoraria; Janssen: Honoraria.

Inferior Outcomes for Multiple Myeloma (MM) Patients (pts) Harbouring t(11;14) and the Promise of Venetoclax, Real-World Australian Retrospective

Introduction/ BackgroundTraditionally, MM harbouring t(11;14) is considered standard risk disease. In the era of novel therapies, however, pts with t(11;14) are reported to have inferior outcomes to other standard risk pts. Evidence of response to the BCL-2 inhibitor, Venetoclax (Ven), has further increased interest in understanding outcomes of t(11;14) pts. In this study, we aimed to describe the historical outcomes of t(11;14) MM and response to Ven in a real-world cohort of Australian pts.MethodsThis was a retrospective, multicentre study conducted by members of the Australasian Leukaemia and Lymphoma Group, Myeloma Working Party. Cases were identified by interrogation of cytogenetics/FISH database from 2010 to 2019 inclusive. Baseline patient and disease characteristics, treatment exposure and outcomes were extracted from hospital medical records. Descriptive statistics, and survival analyses were performed as appropriate.ResultsSeventy-four pts [median age 65 years (yrs), range (43-85)] were identified across seven centres. 43% pts had ISS Stage III MM with 88% harbouring additional cytogenetic abnormalities, incl. 13% with gain in 1q and 12% with del(17p). The majority (81%) of pts received proteasome inhibitor (PI)-based 1 st line therapy with 60% having an upfront autologous stem cell transplant (ASCT) and 54% having immunomodulatory drug (IMiD)-based maintenance therapy. Two patients received an allogeneic stem cell transplant after ASCT. The overall response rate (ORR) was 86% with 38% achieving very good partial response (VGPR) or better. The median progression free survival-1 (PFS-1) was 1.91 yrs (95% CI 1.73-2.56) [PI-based, n=60, PFS 1.84yrs (95% CI 1.61-2.41) vs IMiD-based, n=5, PFS 4.58yrs (95% CI 1.16-5.51), HR 0.68 p=0.45] The median overall survival (OS) was 5.35 yrs (95% CI 4.12-6.56). Second and third line therapy was predominantly IMiD-based (see Table 1) with recent introduction of anti-CD38 monoclonal antibodies (mAbs). Median PFS-2 was 0.77 yrs (95% CI 0.39-0.98) while median PFS-3 was 0.65 yrs (95% CI 0.34-1.16). Eleven pts (median 3 prior lines of therapy) were given Ven [Six pts in combination with PI, three with PI and mAbs and two with dexamethasone]. ORR to Ven was 55% with 45% achieving VGPR or better. Median PFS with Ven was 0.54 yrs (85% CI 0.05-2.17). Median PFS for patients with 1-4 lines (n=6) was 1.22 years and median PFS for patients with 5 lines or more (n=5) was 0.54 years, HR 0.56 (95% CI 0.12-2.5).ConclusionFor pts harbouring t(11;14), the duration of response to PI-based 1 st line therapy is suboptimal even with the use of ASCT consolidation in the majority of patients. Despite multiple prior lines of therapy, Venetoclax shows promising results and every effort should be made for early identification of this cytogenetic lesion. Further studies are required to examine the impact of novel triplet and quadruplet combination therapy and use of venetoclax early in the disease course of this sub-group of patients. [Display omitted] DisclosuresTalaulikar: Takeda: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Jansenn: Honoraria, Research Funding; Roche: Honoraria, Research Funding; EUSA Pharma: Honoraria, Research Funding. Gibbs: Janssen, Celgene, Amgen, Takeda, BMS and Pfizer: Consultancy, Honoraria; AbbVie: Consultancy.

Unusual CD34 positivity in acute myeloid leukaemia with myelodysplasia-related changes with megakaryoblastic differentiation.

Acute megakaryoblastic leukaemia is a rare entity with distinct immunophenotype profile and cytogenetic lesions. Herein, we report a case of acute myeloid leukaemia with myelodysplastic‐related changes with megakaryoblastic differentiation in absence of recurrent genomic lesions such as t(1;22), inv(3) and t(3;3).One of the peculiarities of this case is the positivity of CD34+ within the abnormal megakaryoblasts; CD61 immunohistochemistry highlights the heavily infiltration of bone marrow from abnormal megakaryoblasts.

P-051: Inferior outcomes for Multiple Myeloma (MM) patients (pts) harbouring t(11;14) and the promise of venetoclax, real-world Australian retrospective

<h3>Background</h3> Traditionally, MM harbouring t(11;14) is considered standard risk disease. In the era of novel therapies however, pts with t(11;14) are reported to have inferior outcomes to other standard risk pts. Evidence of response to the BCL-2 inhibitor, Venetoclax (Ven), has further increased interest in understanding outcomes of t(11;14) pts. Here we aim to describe the historical outcomes of t(11;14) MM and response to Ven in a real-world cohort of Australian pts. <h3>Methods</h3> This was a retrospective, multicentre study conducted by members of the Australasian Leukaemia and Lymphoma Group, Myeloma Working Party. Cases were identified by interrogation of cytogenetics/FISH database from 2010 to 2019 inclusive. Baseline patient and disease characteristics, treatment exposure and outcomes were extracted from hospital medical records. Descriptive statistics, and survival analyses were performed as appropriate. <h3>Results</h3> Seventy-four pts [median age 65 years (yrs), range (43-85)] were identified across seven centres. 43% pts had ISS Stage III MM with 88% harbouring additional cytogenetic abnormalities, incl. 13% with gain in 1q and 12% with del(17p). The majority (81%) of pts received proteasome inhibitor (PI)-based 1st line therapy with 60% having an upfront autologous stem cell transplant (ASCT) and 54% having immunomodulatory drug (IMiD)-based maintenance therapy. Two patients received an allogeneic stem cell transplant after ASCT. The overall response rate (ORR) was 86% with 38% achieving very good partial response (VGPR) or better. The median progression free survival-1 (PFS1) was 1.91 yrs (95% CI 1.73-2.56) [PI-based, n=60, PFS 1.84yrs (95% CI 1.61-2.41) vs IMiD-based, n=5, PFS 4.58yrs (95% CI 1.16-5.51), HR 0.68 p=0.45] The median overall survival (OS) was 5.35 yrs (95% CI 4.12-6.56). Second and third line therapy was predominantly IMiD-based with recent introduction of anti-CD38 monoclonal antibodies (mAbs). Median PFS-2 was 0.77 yrs (95% CI 0.39-0.98) while median PFS-3 was 0.65 yrs (95% CI 0.34-1.16). Eleven pts (median 3 prior lines of therapy) were given Ven [Six pts in combination with PI, three with PI and mAbs and two with dexamethasone]. ORR to Ven was 55% with 45% ≥ VGPR. Median PFS with Ven was 0.54 yrs (85% CI 0.05-2.17). Median PFS for patients with 1-4 lines (n=6) was 1.22 years and median PFS for patients with 5 lines or more (n=5) was 0.54 years, HR 0.56 (95% CI 0.12-2.5). <h3>Conclusion</h3> For pts harbouring t(11;14), the duration of response to PI-based 1st line therapy is suboptimal even with the use of ASCT consolidation in the majority of patients. Despite multiple prior lines of therapy, Venetoclax shows promising results and every effort should be made for early identification of this cytogenetic lesion. Further studies are required to examine the impact of novel triplet and quadruplet combination therapy and use of venetoclax early in the disease course of this sub-group of patients.

Factors Predicting Poor Outcomes for Myeloma Patients at Different Ages: Results from 3894 Patients in the Myeloma XI Trial

Abstract Background: Phenotypically, high-risk myeloma is characterized by early progression and death. In younger patients this is known to correlate with a number of tumour acquired genetic changes such as the cytogenetic lesions t(4;14) and del(17p). Outcomes in older patients are further nuanced by features such as age, physical function and comorbidities, which play a role in treatment tolerability, dose intensity, duration and response. In this work we studied both patient-specific and tumour acquired variables and how these were impacted by age and their effect on outcome across patients of all ages in the NCRI Myeloma XI study. Methods: Myeloma XI recruited 3894 patients and compared a triplet combination of cyclophosphamide, lenalidomide and dexamethasone to a similar combination with thalidomide (CRD vs CTD). At maximum response a maintenance randomization compared lenalidomide till disease progression vs observation. We summarise important variables by age group ( 80 n=247). A multivariate Cox regression analysis was performed within each age group to identify the variables with the greatest effect on outcome. Adverse cytogenetic lesions were defined as t(4;14), t(14;16), t(14;20), del(17p) and gain(1q). Standard risk was defined as the absence of any of these lesions, High-risk one lesion and Ultra High-risk >1 lesion. Results: Neither progression-free (PFS) nor overall survival (OS) differed between patients aged The proportion of patients with impaired performance status increased significantly with age (p 20% plasma cells on bone marrow biopsy and no significant difference in LDH. There was a significant increase in B2M with age (p The biological and genetic features of disease changed significantly across age groups. The youngest patient group ( Using multivariate Cox regression analysis of factors affecting PFS and OS we show that with advancing age cytogenetic based risk stratification has a lesser influence on outcome compared to other factors. Performance status had a clear impact on outcomes at all ages suggesting that physical frailty might be a more important driver of outcome that age itself. Conclusions: The spectrum and relative importance of patient-specific and tumour acquired biological and genetic features change significantly across age-groups of myeloma patients. This is important to understand as we design disease segmentation strategies to deliver personalized treatment approaches to improve patient outcomes. Whereas the focus in younger patients should be on targeting high-risk disease biology, approaches to improve outcomes for older patients will require a focus on clinical variables and treatment modification strategies. Download : Download high-res image (139KB) Download : Download full-size image Disclosures Pawlyn: Janssen: Other: Travel support; Takeda: Honoraria, Other: Travel support; Celgene: Honoraria, Other: Travel support. Kaiser: Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Takeda: Consultancy; Amgen: Consultancy, Honoraria; BMS: Consultancy, Other: Travel expenses; Chugai: Consultancy. Jones: Celgene: Honoraria, Other: Travel Support, Research Funding. Jenner: Chugai: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Support , Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Drayson: Abingdon Health: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Owen: Janssen: Consultancy, Other: travel support; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Other: travel support. Gregory: Janssen: Honoraria; Celgene: Consultancy, Honoraria. Cook: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Research Funding, Speakers Bureau; Glycomimetcs: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Jackson: Celgene: Honoraria; Amgen: Honoraria; JJ Chugai: Honoraria; Takeda: Honoraria. Morgan: Celgene: Consultancy, Honoraria, Research Funding; Bristol Myers: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Davies: Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria.

Lenalidomide Maintenance Significantly Improves Outcomes Compared to Observation Irrespective of Cytogenetic Risk: Results of the Myeloma XI Trial

Lenalidomide Maintenance Significantly Improves Outcomes Compared to Observation Irrespective of Cytogenetic Risk: Results of the Myeloma XI Trial

Prospective Study of Acute Myeloid Leukemia (AML) Clinical Epidemiology and Cytogenetic Risk Group in Older Adults in the ECOG-ACRIN E2906 Clinical Trial: The Acute Leukemia Epidemiology, Survival and Endpoints (ALESE) Study

Prospective Study of Acute Myeloid Leukemia (AML) Clinical Epidemiology and Cytogenetic Risk Group in Older Adults in the ECOG-ACRIN E2906 Clinical Trial: The Acute Leukemia Epidemiology, Survival and Endpoints (ALESE) Study

DNA Methylation Clusters and Their Relation to Cytogenetic Features in Pediatric AML.

Simple SummaryAcute myeloid leukemia is a heterogenous disease with dismal outcome. In order to improve currently used therapeutic strategies it is important to get a in depth understanding of the molecular and genomic landscape of AML. Adult AML studies have established the significant of mutational profile of epigenetic genes as well as epigenetic deregulation DNA methylation signatures. In the current study we focused on establishing the DNA methylation profile in pediatric AML. Our result show that in pediatric AML patients the risk group and cytogenetic features have distinctive epigenetic signatures. Additionally, we observed that distinctive epigenetic hotspots co-occur complementary to the known genomic lesions and contribute towards leukemogenesis.Acute Myeloid Leukemia (AML) is characterized by recurrent genetic and cytogenetic lesions that are utilized for risk stratification and for making treatment decisions. In recent years, methylation dysregulation has been extensively studied and associated with risk groups and prognosis in adult AML, however, such studies in pediatric AML are limited. Moreover, the mutations in epigenetic genes such as DNMT3A, IDH1 or IDH2 are almost absent or rare in pediatric patients as compared to their abundance in adult AML. In the current study, we evaluated methylation patterns that occur with or independent of the well-defined cytogenetic features in pediatric AML patients enrolled on multi-site AML02 clinical trial (NCT00136084). Our results demonstrate that unlike adult AML, cytosine DNA methylation does not result in significant unique clusters in pediatric AML, however, DNA methylation signatures correlated significantly with the most common and recurrent cytogenetic features. Paired evaluation of DNA methylation and expression identified genes and pathways of biological relevance that hold promise for novel therapeutic strategies. Our results further demonstrate that epigenetic signatures occur complimentary to the well-established chromosomal/mutational landscape, implying that dysregulation of oncogenes or tumor suppressors might be leveraging both genetic and epigenetic mechanisms to impact biological pathways critical for leukemogenesis.

Common Fragile Sites Are Characterized by Faulty Condensin Loading after Replication Stress

SummaryCells coordinate interphase-to-mitosis transition, but recurrent cytogenetic lesions appear at common fragile sites (CFSs), termed CFS expression, in a tissue-specific manner after replication stress, marking regions of instability in cancer. Despite such a distinct defect, no model fully provides a molecular explanation for CFSs. We show that CFSs are characterized by impaired chromatin folding, manifesting as disrupted mitotic structures visible with molecular fluorescence in situ hybridization (FISH) probes in the presence and absence of replication stress. Chromosome condensation assays reveal that compaction-resistant chromatin lesions persist at CFSs throughout the cell cycle and mitosis. Cytogenetic and molecular lesions are marked by faulty condensin loading at CFSs, a defect in condensin-I-mediated compaction, and are coincident with mitotic DNA synthesis (MIDAS). This model suggests that, in conditions of exogenous replication stress, aberrant condensin loading leads to molecular defects and CFS expression, concomitantly providing an environment for MIDAS, which, if not resolved, results in chromosome instability.

Uncommon cytogenetic abnormalities identifying high-risk acute myeloid leukemia in children.

Pediatric acute myeloid leukemia (AML) represents an aggressive disease and is the leading cause of childhood leukemic mortality. The genomic landscape of pediatric AML has been recently mapped and redefined thanks to large-scale sequencing efforts. Today, understanding how to incorporate the growing list of genetic lesions into a risk stratification algorithm for pediatric AML is increasingly challenging given the uncertainty regarding the prognostic impact of rare lesions. Here we review some uncommon cytogenetic lesions to be considered for inclusion in the high-risk groups of the next pediatric AML treatment protocols. We describe their main clinical characteristics, biological background and outcome. We also provide some suggestions for the management of these rare but challenging patients and some novel targeted therapeutic options.

Micronuclei in blood lumphocytes of existing and former coal miners: evaluation of the effect of anthracosilicosis

Background. The purpose of this study was to investigate the genotoxic risk in anthracosilicosis patients and in those with occupational exposure to coal dust.&#x0D; Materials and methods. We studied micronuclei (MN) and other cytogenetic lesions in blood lymphocytes in three groups of men comparable in age: 74 coal miners suffering from anthracosilicosis (AS), 41 healthy miners, and 70 control donors.&#x0D; Results. A significant increase in the frequency of MN was revealed with a simultaneous decrease in proliferative activity in samples of healthy and sick miners compared with the control. The level of MN in the lymphocytes of patients with AS significantly exceeded the corresponding indicator in the sample of healthy miners (1.22 0.05% versus 1.03 0.07%; p 0.01). The age of the subjects and the status of smoking did not have a significant effect on the frequency of cytogenetic parameters.&#x0D; Conclusion. AS in miners makes an additional contribution to the formation of DNA damage in lymphocytes. This contribution is probably due to oxidative stress accompanying inflammatory processes in pulmonary fibrosis. The results of the study also indicate the absence of differences in the frequency of MN when comparing subgroups of current and former miners. This means that the genotoxic effects in the lymphocytes of miners are able to persist for a long time after the termination of exposure by adverse factors in coal mining.

Sex Differences in Multiple Myeloma Biology and Clinical Outcomes: Results from 3894 Patients in the Myeloma XI Trial

Sex Differences in Multiple Myeloma Biology and Clinical Outcomes: Results from 3894 Patients in the Myeloma XI Trial

MPO as a Novel Susceptibility Gene in Myeloid Malignancies

Myeloperoxidase (MPO) on chromosome 17q22 codes for a heme-containing protein produced following commitment and during myeloid differentiation. Ultimately, mature neutrophil azurophilic granules have MPO as their major component. Consistently, high MPO expression, suggestive of a more differentiated type, has been associated with favorable outcomes in acute myeloid leukemia (AML). MPO deficiency is an extremely rare autosomal recessive disorder caused by any of a number of known germline variants, though the propensity to develop myeloid malignancy has not been reported for affected individuals. Somatic MPO mutations have not be identified in myeloid neoplasia (MN). In an effort to identify novel susceptibility genes and variants, we analyzed whole-exome sequence data from the germlines of 690 MN patients. Among all genes examined, MPO carried the highest burden of variants deemed pathogenic or likely pathogenic under the American College of Medical Genetics (ACMG) criteria; 19/690 MN patients (2.7%) carried a pathogenic/likely pathogenic MPO variant. Carriers of pathogenic MPO variants had higher rates of cytogenetic lesions, particularly -5 and complex karyotypes (Fig. A). The pathogenic variants found in our cohort are dominated by two substitutions: a splice site variant (c.2031-2A&gt;C; eleven patients), and a missense variant (c.C1705T, p.R569W; seven patients) (Fig. B). Multi-species alignment shows that both of the corresponding wild-type alleles are highly conserved. Furthermore, both variants have significantly higher frequencies in our cohort (0.8% and 0.51%, respectively), as well as in the recently-published Beat AML patient cohort (0.8% and 0.6%), as compared to control populations (0.38% and 0.13% in gnomAD; OR 1.9, 95% CI 1.1-3.5, P&lt;0.05 for c.2031-2A&gt;C and OR 3.6, 95% CI 1.9-8.0, P&lt;.0005 for p.R569W) (Fig. C). Of note is that the c.2031-2A&gt;C variant has previously been reported in a family with hereditary MPO deficiency, with a splice variant-induced retention of intron 11 in MPO messenger RNA, inducing a premature stop codon. Another study showed that the R569W variant results in maturation arrest in the processing of MPO precursors. Analysis of the 3D structure of MPO shows that the R569W variant will abrogate heme binding (Fig. D). We next sought to validate our findings in an independent cohort. To this end, we queried next-generation DNA and RNA sequence from 1,119 myeloid malignancy patients from the Munich Leukemia Laboratory (MLL). Similar to our discovery cohort and the Beat AML group, the c.2031-2A&gt;C variant had significantly higher allele frequency in confirmatory cohort (0.8%) than in population controls (0.38%), though the R569W did not (Fig. C). We found that MPO expression is significantly lower in carriers of the c.2031-2A&gt;C allele (P = 0.024), as expected since the variant affects mRNA processing. There have been no prior reports of MPO as a MN susceptibility gene, but it is an appealing candidate. Taken together with evidence from earlier studies characterizing the impact of the variants highlighted here, our results support the hypothesis that inherited disruption of MPO confers myeloid malignancy susceptibility. Disclosures Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Maciejewski:Alexion: Consultancy; Novartis: Consultancy.

Cytogenetic Characteristics and Outcomes of Patients Receiving CTL019 CAR T Cell Therapy

Background: CTL019 is a therapy derived from autologous T cells expressing a CD19-specific chimeric antigen receptor (CAR) that was approved by the FDA in August 2017 (tisagenlecleucel). Complete and durable remissions have been seen in the setting of pediatric and young adult patients with relapsed and refractory B cell acute lymphoblastic leukemia (ALL) (Maude NEJM 2018). Initial case reports suggested that there may be differential outcomes mediated by cytogenetic characteristics of the leukemia at CAR T cell infusion. Here, we report results from a single institution experience of 112 patients. Methods: Patients with relapsed/refractory ALL were identified as having received CTL019 either in the context of a clinical trial (NCT02906371) or commercial product (tisagenlecleucel) at Children's Hospital of Philadelphia from October 2016 to April 2019. Patients who received prior CAR T therapy were excluded. Demographic, cytogenetic, and outcome data were manually abstracted from the medical record or clinical trial datasets. High risk lesions were defined as MLL(KMT2A) rearrangements, Philadelphia-chromosome (Ph+), Ph-like, hypodiploidy, and TCF3/HLF fusion. Favorable cytogenetics were defined as the presence of hyperdiploidy or ETV6/RUNX1fusion and intermediate were defined as iAMP21, IKZF1deletion, or TCF3/PBX1. Patients were classified according to their highest risk cytogenetic characteristic and stratified by cytogenetic risk category present at CAR T cell infusion. Relapse-free survival (RFS) and overall survival (OS) was described for cohorts with more than 10 patients. Results: One hundred and twelve patients were included in the analysis, with a median age of 11 years (range 1-29) at infusion, of which 32% had had a previous allogeneic hematopoietic stem cell transplant (alloHSCT). Disease burden at the time of CTL019 infusion was heterogenous, with 61% having detectable disease in the bone marrow and 21% having more than 25% blasts by flow cytometry. Thirty-six patients (32%) had leukemias with high-risk genetic lesions at infusion, including 12 with MLL rearrangements and 18 with Ph+ or Ph-like lesions (Table 2). Thirty-one patients (28%) had hyperdiploidy or ETV6/RUNX1; 3 additional were in conjunction with high-risk cytogenetics (t(17;19) and 2 with Ph+), and 3 in the setting of intermediate-risk cytogenetics (iAmp21, TCF3/PBX1, IKZF1deletion). Figure 1 demonstrates RFS for those patients in remission at day 28 following infusion, stratified by cytogenetic risk category. Complete remission (CR) rate in the high-risk cytogenetics group was 94%. RFS at 12 months was 69% (0.50-0.82), 69% (0.40-0.86), and 67% (0.48-0.80) for non-informative, favorable, and high-risk cytogenetic groups, respectively. Figure 2 shows OS of patients infused with CTL019, again stratified by cytogenetic categories of interest, with a maximum follow-up time of 30 months. OS at 12 months was 84% (0.68-0.93) and 76% (0.56-0.88) for the non-informative and high-risk cytogenetic groups, respectively. There were no deaths in that time period for the favorable risk category. There was no statistically significant difference in RFS or OS for patients with high-risk cytogenetics. The intermediate-risk cytogenetics group (n&amp;lt;10) was excluded from these analyses. Conclusion: Durable remissions can be achieved with CTL019 across several high-risk cytogenetic subtypes of B-ALL. Stratifying outcomes by cytogenetic risk category in this unadjusted analysis does not show a statistically significant difference in either RFS nor OS. Further investigation is needed to parse out the contribution of individual cytogenetic lesions as well as the effects of other relapse and survival risk factors at play. Figure Disclosures Rheingold: Novartis: Consultancy; Pfizer: Research Funding. Callahan:Novartis: Consultancy. Hunger:Bristol Myers Squibb: Consultancy; Amgen: Consultancy, Equity Ownership; Jazz: Honoraria; Novartis: Consultancy. Grupp:Novartis: Consultancy, Research Funding; Roche: Consultancy; GSK: Consultancy; Cure Genetics: Consultancy; Humanigen: Consultancy; CBMG: Consultancy; Novartis: Research Funding; Kite: Research Funding; Servier: Research Funding; Jazz: Other: study steering committees or scientific advisory boards; Adaptimmune: Other: study steering committees or scientific advisory boards. Maude:Kite: Consultancy; Novartis: Consultancy.