Excess Blasts Research Articles

Evaluating Complete Remission with Incomplete Hematologic Recovery (CRh) As a Response Criterion in Myelodysplastic Syndromes (MDS)

Evaluating Complete Remission with Incomplete Hematologic Recovery (CRh) As a Response Criterion in Myelodysplastic Syndromes (MDS)

Germline and Somatic Variants Co-Ocurrence Profile in Early Onset Adult Myelodysplastic Syndromes without a Preexisting Disorder

Germline and Somatic Variants Co-Ocurrence Profile in Early Onset Adult Myelodysplastic Syndromes without a Preexisting Disorder

Modeling Clonal Progression in SF3B1-Mutant Myelodysplastic Syndrome

SF3B1-mutant myelodysplastic syndrome (MDS) has recently been proposed as a distinct disorder characterized by ring sideroblasts, ineffective erythropoiesis and good prognosis. Selected co-occurring genetic abnormalities were reported associated with significantly worse outcome and suggested as exclusion criteria for the proposed entity. However, it remains unclear how a limited spectrum of co-occurring drivers affects SF3B1-mutant MDS biology to determine evolution from a relatively indolent condition to high risk malignancy.To gain a better insight into the clonal progression of SF3B1-mutant MDS, we analyzed SF3B1 co-mutations in a cohort of 176 SF3B1-mutated patients diagnosed with a myeloid neoplasm. RUNX1 and STAG2 were the only co-mutated genes found significantly associated with advanced disease phenotype (i.e. MDS with excess blasts and secondary acute myeloid leukemia) (OR=18.36 (2.18-862.91), P=0.001, and OR= Inf (3.57-Inf), P<.001, respectively), and reduced overall survival (P<.001). Based on these data, we hypothesized that acquisition of RUNX1 or STAG2 co-mutations in patients with SF3B1-mutant MDS drives progression to high-risk neoplasms.RUNX1 and STAG2 control hematopoietic stem and progenitor cell self-renewal and differentiation by regulation of gene expression. To explore the biological impact of RUNX1 or STAG2 loss in the context of SF3B1-mutant MDS, we disrupted RUNX1 or STAG2 using CRISPR/Cas9 in an induced pluripotent stem cell (iPSC) model of MDS-RS that we previously established by reprogramming of bone marrow cells from SF3B1-mutant individuals. This patient-derived system allows hematopoietic progenitor expansion through doxycycline-mediated expression of 5 transcription factors (5F-HPC) and multilineage differentiation upon doxycycline withdrawal. We asked how RUNX1 or STAG2 disruption affected SF3B1-mutant HPCs self-renewal and differentiation in our model of MDS-RS, and sought to define the underlying transcriptional changes.RUNX1-edited cells maintained significantly higher proportion of CD34 + HPCs, suggesting that RUNX1 mutation increases self-renewal capacity of SF3B1-mutant progenitors. Consistently, SF3B1/RUNX1 double-mutant 5F-HPCs showed positive enrichment of HSC-specific gene signatures. This was accompanied by broad upregulation of inflammatory programs, recapitulating the activated gene signatures we identified in SF3B1/RUNX1 co-mutated patients in our cohort. RUNX1 disruption promoted myeloid skewing at the expense of erythroid differentiation in SF3B1-mutant cells. Consistent with this, granulocyte-monocyte progenitors (GMP) and myelo-erythroid transcriptional programs were positively and negatively enriched, respectively. By contrast, in SF3B1/STAG2 double-mutant 5F-HPCs, both erythroid and myeloid populations were reduced compared to SF3B1 single mutant controls, suggesting a block in both myeloid and erythroid differentiation, despite the presence of pro-differentiation signals. This was supported by a profound down-regulation of genes involved in the response to external stimulus and suppression of GMP specific transcriptional signature.In summary, we identified RUNX1 and STAG2 mutations as main drivers of disease progression in SF3B1-mutant patients, and generated extensive cell line panels to interrogate their functional interaction with mutant SF3B1. By applying CRISPR/Cas9 editing to our MDS-RS model, we could overcome limited availability of primary MDS samples to show that RUNX1 or STAG2 co-mutations drive progression through distinct biological mechanisms in SF3B1-mutant HPCs. DisclosuresNo relevant conflicts of interest to declare.

Clinical, Cytogenetic, and Molecular Characteristics Analysis in Myelodysplastic Syndromes with Elevated Ferritin Levels

IntroductionMyelodysplastic syndromes (MDS), a heterogeneous group of acquired clonal hematopoietic stem cell disorders, is characterized by peripheral cytopenia and has a high tendency to progress to acute myeloid leukemia (AML). Serum ferritin (SF) level is a well-known indicator of iron stores and inflammation. Elevated SF levels is common in patients with MDS and appear to be largely related to regular red blood cell (RBC) transfusions. However, some patients with MDS showed high SF levels at the time of diagnosis, even before receiving RBC transfusions, although the exact mechanisms is unclear. The impact of SF elevation without RBC transfusion has not been well characterized. In this study, we assessed cytogenetic, molecular, and clinical characteristics of patients with MDS and SF elevation.MethodsPatients with newly diagnosed MDS who visited our hospital between Jan 2011 and Jan 2020 were included in this study. Patients were defined as high-SF-MDS when SF values were >350 ng/mL (patients with <350 ng/mL were defined as low-SF-MDS). Patients with autoimmune diseases, active infections, hemophagocytic syndromes, and RBC transfusion were excluded. Baseline characteristics were compared using Fisher's exact test for categorical variables and the Mann-Whitney test for continuous variables. The log-rank test was used for the overall survival (OS) analysis. The cumulative incidence of AML progression was estimated and compared using Gray's method. In next-generation sequencing (NGS) analysis, 68 genes associated with myeloid malignancy were analyzed using DNA extracted from bone marrow samples.ResultsAmong the 112 patients with MDS, SF value were available for 87 patients. This study analyzed 28 women and 59 men with a median age of 69 years (range: 28-87 years). The median follow-up period was 540 days (range: 3-3618 days). A total of 17 patients died during the observational period (until Apr 2021). Patients were diagnosed with MDS with single lineage dysplasia (MDS-SLD, n = 9), MDS with multilineage dysplasia (MDS-MLD, n = 26), MDS with ring sideroblasts with SLD (MDS-RS-SLD, n = 5), MDS-RS-MLD (n = 6), MDS with excess blasts 1 (MDS-EB1, n = 25), MDS-EB2 (n = 13), MDS with isolated del(5q) (n=1), and MDS, unclassifiable (MDS-U, n = 2). The median SF value was 263 ng/mL (range: 3-1,245 ng/mL); 31 patients were classified as high-SF-MDS and 56 were classified as low-SF-MDS. The Proportion of MDS subtypes differed significantly between the groups (P=0.004, Table1). Compared to low-SF-MDS, MDS-EB1/2 (51.6% vs. 39.3%) and MDS-RS-SLD/MLD (22.6% vs. 1.8%) was more common in high-SF-MDS. In the laboratory data analysis, high-SF-MDS patients showed low Hb levels, high RBC distribution width values, and high bone marrow RS percentages. In patients with high-SF-MDS, as well as MDS-RS, the presence of bone marrow RS was also observed in seven out of 11 patients with MDS-EB1/2 (median 8%, range 2-19%). Complex karyotype ( was more common in patients with high-SF-MDS (46.4% vs. 16.0%, P=0.007) than those with low-SF-MDS. Trisomy 8 and del (5q) were also frequently detected among those with high-SF-MDS. Patients with high-SF-MDS had worse 2-year overall survival (OS) than those with low-SF-MDS. To clarify the molecular characteristics of high-SF-MDS in more detail, NGS analysis was performed on 11 patients with high-SF-MDS whose samples were available. Ten gene mutations were detected in eight patients. Interestingly, five among 11 patients harbored TP53 mutation; the median variant allele frequency was 53.9% (range, 39.7-64.1%). Subsequently, SF3B1 gene mutation was detected in three patients; and two of them also harbored TP53 mutation. Other gene mutations, RUNX1, STAG2, SRSF2, ASXL1, ATM, DNMT3A, BCOR, and DDX41 were detected in one patient each. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Endothelial Cell Dysfunction Is Involved in the Progression of Myelodysplastic Syndromes

Background:Myelodysplastic syndromes (MDS) are a group of heterogeneous myeloid clonal disorders characterized by ineffective hematopoiesis, refractory anemia, and a tendency to transform to acute myeloid leukemia (AML). Ineffective hematopoiesis progression and immune deregulation are dominating pathophysiological process of MDS. Emerging evidences showed the role of bone marrow (BM) microenvironment in MDS. In MDS murine model, integral BM microenvironment contributes to inferior hematopoietic function and disease progression. As an important component of BM microenvironment, the relationship between endothelial cells (ECs) and MDS progression remains largely unknown. Although ECs from MDS patients have been identified to have decreased supporting ability to normal hematopoietic stem cells (HSCs), the supporting ability of ECs in different clinical stages of MDS remains to be elucidated. In addition, the role of BM ECs from MDS patients in supporting leukemia cells and their immunomodulatory ability remains unclear.Aims:To determine the number and functions of BM ECs in different subtypes of MDS patients. Moreover, to explore the correlation between BM ECs and MDS progression, which may represent a potential therapeutic target for MDS patients.Methods:In the prospective cohort study, patients with multilineage dysplasia (MDS-MLD, N=15), MDS with excess blasts (MDS-EB, N=15), or AML(N=15) and healthy donors (HD, N=15) were enrolled. BM ECs were analyzed in HD and patients by flow cytometry and in situ histological analyses. The functions of BM ECs were analyzed by migration, angiogenesis capacities, levels of apoptosis and reactive oxygen species (ROS). To evaluate the supporting abilities of BM ECs on HSCs, leukemia cells and T cells, in vitro co-culture strategies were used. The levels of apoptosis, ROS and colony-forming unit-plating (CFU) efficiency of CD34+ and HL-60 cells were investigated. T cell subsets were analyzed by flow cytometry as previously reported. To further investigate the underlying mechanism of dysfunctional ECs, RNA sequencing (RNA-Seq) analyses and real time-PCR (qRT-PCR) were performed in BM ECs from HD and MDS patients with different subtypes.Results:In the current study, gradually increased BM ECs were observed from MDS-MLD, MDS-EB to AML patients. Furthermore, dysfunctional BM ECs were found with MDS progression, characterized by increased levels of migration, angiogenesis capacities, apoptosis and ROS. More importantly, BM ECs from MDS patients exhibited decreased supporting ability of HSCs whereas increased supporting ability of leukemia cells in vitro with MDS progression. After coculture with ECs, levels of apoptosis and ROS in CD34+ cells were increased whereas their CFU efficiency reduced. On the other hand, levels of apoptosis and ROS of HL-60 cells were decreased. The proliferation capacity and leukemia CFU efficiency of HL-60 cells after co-cultured with ECs were enhanced with MDS progression. Furthermore, following coculture with BM ECs, deregulated differentiation was demonstrated in T cell subsets, characterized by elevating proportion of Th2 and Treg and decreasing proportion of Th1 and Th17 with MDS progression. RNA-Seq showed that the expression profile of BM ECs from MDS-EB was closer to MDS-MLD, whereas that of MDS-EB was closer to AML. Different gene expression profiles indicated the expression of hematopoiesis and immune related genes increased in BM ECs with MDS progression. Mechanistically, the mRNA levels of CX CL12, SCF and NFKB of ECs were increased with MDS progression.Summary/Conclusion:In summary, the number of BM ECs gradually increased, BM EC dysfunction more and more severe, and the supporting abilities of BM ECs on HSCs decreased, whereas on leukemia cells increased with MDS progression. Moreover, ECs regulated the differentiation of T cells into immune tolerant cells with MDS progression. Although further validation is required, these findings indicated that the improvement of BM ECs may represent a potential therapeutic approach for MDS patients.Keywords: Myelodysplastic syndromes, endothelial cells, disease progression, ineffective hematopoiesis, immune deregulation DisclosuresNo relevant conflicts of interest to declare.

Treatment Utilization and Characteristics Among Patients with Higher-Risk Myelodysplastic Syndromes According to Hypomethylating Agent Use

Introduction: Hypomethylating agents (HMAs) are standard of care treatment for patients with higher-risk myelodysplastic syndromes (HR-MDS) who are ineligible for stem-cell transplantation or intensive chemotherapy. Until recently, approved HMAs included intravenous or subcutaneous azacitidine and decitabine, which should be administered for a minimum of 4-6 cycles to elicit response in the absence of progression or unacceptable toxicity. In real-world clinical practice, underutilization of HMA therapy has been documented; however, prior estimates have utilized data preceding 2016. The study objectives were to understand recent treatment utilization and characteristics among patients newly diagnosed with HR-MDS in the United States (US).Methods: This retrospective observational study utilized the IQVIA PharMetrics ® Plus database which comprises adjudicated claims for more than 190 million unique patients across the US. Adult patients newly diagnosed with HR-MDS from July 1, 2016 through December 31, 2019 were included. Patients had ≥1 inpatient claim or ≥2 outpatient claims >60 days apart with diagnosis codes for high grade MDS lesions and/or refractory anemia with excess blasts (RAEB), and continuous enrollment for 6 months prior to and ≥180 days following the index date (index date = first diagnosis claim). Patients had a variable follow-up period up to 1 year post-index, and were followed through June 30, 2020. Patient characteristics at baseline, and treatment utilization based on observed MDS-related therapy (HMAs and supportive care), over the variable follow-up period were evaluated.Results: A total of 371 patients were included; the mean age of patients at baseline was 69.2 years and 57.7% were male. Of these, 61 (16.4%) patients received no HMA and no supportive care over the variable follow-up period following diagnosis. Half (n=182, 49.1%) received no HMA but received supportive care, and the remainder (n=128, 34.5%) received HMA therapy over the variable follow-up period; 45 (12.1%) received decitabine as the first HMA in a mean of 89.2 days from diagnosis, and 83 (22.4%) received azacitidine as the first HMA in a mean of 51.1 days from diagnosis (Table). Patients receiving no HMA therapy but with supportive care were older (mean age 70.6 years; 45.6% aged ≥75 years) and had higher comorbidity burden (mean Charlson Comorbidity Index [CCI] 2.5) than the other cohorts (mean age 66.6-68.8 years; 24.4-37.7% aged ≥75 years; CCI 1.2-2.0). For example, a higher proportion of patients receiving no HMA therapy but with supportive care had baseline renal disease (21.4%) compared to the other cohorts (4.9-15.6%). Patients receiving no HMA or supportive care in this study had a similar mean age compared to those who received HMAs (68.8 vs 66.6-68.0 years), but tended to have lower comorbidity burden (CCI 1.2 vs 1.9-2.0).Conclusions: In this real-world study using contemporary data, utilization of HMA therapy among patients with HR-MDS in the US was low, with only around one-third of patients receiving HMAs. Patients who did not receive HMAs but received supportive care tended to be older and have higher comorbidity burden than those who received HMAs, suggesting potential barriers for physicians in prescribing HMAs to older, frailer patients. [Display omitted] DisclosuresZeidan: Pfizer: Other: Travel support, Research Funding; Jazz: Consultancy; Jasper: Consultancy; AstraZeneca: Consultancy; Janssen: Consultancy; Novartis: Consultancy, Other: Clinical Trial Committees, Travel support, Research Funding; Loxo Oncology: Consultancy, Other: Clinical Trial Committees; Ionis: Consultancy; Kura: Consultancy, Other: Clinical Trial Committees; Incyte: Consultancy, Research Funding; Gilead: Consultancy, Other: Clinical Trial Committees; Genentech: Consultancy; Epizyme: Consultancy; Daiichi Sankyo: Consultancy; Geron: Other: Clinical Trial Committees; BMS: Consultancy, Other: Clinical Trial Committees, Research Funding; Cardiff Oncology: Consultancy, Other: Travel support, Research Funding; Boehringer Ingelheim: Consultancy, Research Funding; BioCryst: Other: Clinical Trial Committees; BeyondSpring: Consultancy; Astex: Research Funding; Astellas: Consultancy; Aprea: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Agios: Consultancy; ADC Therapeutics: Research Funding; Acceleron: Consultancy, Research Funding; AbbVie: Consultancy, Other: Clinical Trial Committees, Research Funding. Divino: IQVIA: Current Employment, Other: IQVIA received funding for this study from Epstein Health in connection with this study. DeKoven: IQVIA: Current Employment, Other: IQVIA received funding for this study from Epstein Health in connection with this study. Shah: IQVIA: Current Employment, Other: IQVIA received funding for this study from Epstein Health in connection with this study. Wang: IQVIA: Current Employment, Other: IQVIA received funding for this study from Epstein Health in connection with this study. Bey: Taiho Oncology: Current Employment. Salimi: Taiho Oncology: Current Employment. Epstein: Epstein Health: Current Employment; Fate Therapeutics: Other: Holds leadership position; Veracyte: Other: Holds leadership position; Illumina: Other: Holds leadership position; Merck: Consultancy; Radius Health: Consultancy; Halozyme: Consultancy; Intra-Cellular Therapies: Consultancy; Taiho Oncology: Consultancy; Otsuka: Consultancy.

Molecular Responses Are Observed across Mutational Spectrum in Treatment-Naïve Higher-Risk Myelodysplastic Syndrome Patients Treated with Venetoclax Plus Azacitidine

Molecular Responses Are Observed across Mutational Spectrum in Treatment-Naïve Higher-Risk Myelodysplastic Syndrome Patients Treated with Venetoclax Plus Azacitidine

Initial Results of Phase I/II Study of Azacitidine in Combination with Quizartinib for Patients with Myelodysplastic Syndrome and Myelodysplastic/Myeloproliferative Neoplasm with FLT3 or CBL Mutations

Initial Results of Phase I/II Study of Azacitidine in Combination with Quizartinib for Patients with Myelodysplastic Syndrome and Myelodysplastic/Myeloproliferative Neoplasm with FLT3 or CBL Mutations

Finding the best haematopoietic stem cell transplant regimen for GATA2 haploinsufficiency: how close are we?

Finding the best haematopoietic stem cell transplant regimen for GATA2 haploinsufficiency: how close are we?

Low-affinity immunoglobulin gamma Fc region receptor III-B (FcγRIIIB, CD16B) deficiency in patients with blood and immune system disorders.

Low-affinity immunoglobulin gamma Fc region receptor III-B (FcγRIIIB) deficiency is present in ˜0·05% of the general population. Among our patients, FcγRIIIB deficiency was less frequent in those with immune-system disorders (one of 1815 patients, 0·05%) than in those with blood disorders (nine of 2147 patients, 0·42%, P = 0·023): mainly primary immune thrombocytopenia (4·34%), therapy related myeloid neoplasms (1·16%) and myelodysplastic syndrome with excess blasts (1·28%). Four of the nine (44·4%) patients with blood disorders were diagnosed with or quickly evolved to acute myeloid leukaemia (AML), suggesting that FcγRIIIB deficiency could be an adverse prognostic factor for progression to AML that should be confirmed in large multicentre studies.

Use of Oral Hypomethylating Agents for the Treatment of Myelodysplastic Syndromes

Introduction Myelodysplastic syndromes (MDS) are genomically complex clonal hematopoietic stem cell neoplasms leading to myelodysplasia and ineffective hematopoiesis.1,2 MDS is a disease of older age, clinically manifesting as symptomatic cytopenias with an added propensity for transformation to acute myeloid leukemia (AML).3 The treatment of MDS is based on a risk-adapted approach per the International Prognostic Scoring System (IPSS)4 or the modified IPSS-R.5 Allogeneic stem cell transplantation (ASCT) is the only curative strategy, but most patients are not eligible due to their age or other comorbidities.6 In these patients, hypomethylating agents (HMA, either decitabine or azacitidine) are the mainstay of therapy to either alleviate cytopenias or impede disease progression. 7 Decitabine (DEC) and azacitidine (AZA) are approved to treat patients with MDS, including previously treated and untreated, de novo, and secondary MDS of all French-American-British subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia) and intermediate-1, intermediate-2, and high-risk IPSS groups.7

MDS-029: Prevalence of VEXAS Syndrome in MDS/CMML Patients with Systemic Inflammatory and Auto-Immune Disease

Context: Systemic inflammatory and auto-immune diseases (SIAD) are observed in 25% of patients with MDS or CMML, who harbor a high frequency of mutations in TET2, IDH1/2 and SRSF2 as we previously reported (Zhao et al, Leukemia 2021). Recently, the identification of mutations in UBA1 in patients with autoinflammatory disorders, some of whom have dysplastic bone marrow, defined novel disease called VEXAS syndrome (Beck et al, NEJM 2020). Objective: To explore the prevalence of UBA1 mutations in our initial cohort of MDS/CMML patients with SIAD (n=85) (Zhao et al, Leukemia 2021). Design and Patients: All male patients for whom material was available (n=33) were analyzed for the presence of UBA1 mutations. Primary Outcome: UBA1 mutations screening with Sanger sequencing. Results: Four out of 33 (12%) patients had UBA1 mutations. All of them had MDS without excess of blasts. Cytomorphologic review of bone marrow smears showed numerous vacuoles in precursors in all 4 cases. Karyotype was normal in 3/4 patients, and one patient had deletion 9q. One patient also had somatic mutations in DNMT3A (VAF 11%) and TP53 (VAF 2%), and another patient had a mutation of TET2 (VAF 18%). Three patients in our MDS/CMML SIAD cohort had relapsing polychondritis, and 2 of them had UBA1 mutations, while 6 patients from our initial SIAD cohort had a diagnosis of Sweet syndrome, including 2 with UBA1 mutations. Three out of 4mut patients had steroid refractory SIAD and were heavily treated with other immunosuppressive therapies including methotrexate, azathioprine or cytokine targeting agents. At last follow-up, none of the 4 patients with UBA1 mutations had MDS progression, and one of them had died from a stroke, 2.4 years after MDS diagnosis. Conclusions: Our retrospective study represents the first assessment of VEXAS syndrome among patients with myeloid malignancies associated with SIAD. The low prevalence of UBA1 mutations in our cohort suggests that other pathological mechanisms may drive inflammation in the large majority of MDS/CMML patients with associated SIAD, likely in relation with mutations in epigenetic regulators TET2/IDH and SRSF2 as we previously proposed.

MDS-158: Updated Safety and Efficacy of Venetoclax in Combination with Azacitidine for the Treatment of Patients with Treatment-Naïve, Higher-Risk Myelodysplastic Syndromes: Phase 1b Results

Background: Venetoclax (Ven), a selective oral BCL-2 inhibitor, demonstrated synergy with azacitidine (Aza) in patients with higher-risk myelodysplastic syndromes (HR-MDS). Objective: We report updated safety and efficacy in an ongoing phase 1b study (NCT02942290) evaluating Ven+Aza for treatment-naïve HR-MDS patients. Methods: Patients (≥18yrs) with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, bone marrow (BM) blasts <20% at baseline, and ECOG≤2 performance status were enrolled. Aza 75 mg/m2 was administered on Days (d) 1–7 of each 28-d cycle. Initial Ven dose was 400 or 800 mg daily in 28-d cycles. Due to poor tolerance, the study was amended to examine several dose cohorts (100, 200, and 400 mg x 14-d each 28-d cycle). Main Outcomes Measures: Primary objectives were assessing Ven+Aza safety profile and establishing RP2D. Key secondary objectives included overall response rate (ORR) and overall survival (OS). Results: At data cutoff (Dec. 15, 2020), 78 patients received Ven+Aza (51 at RP2D 400 mg x 14 d), with median follow-up time of 23 mos. Median age was 70 yrs; 72% male; 90% had excess BM blasts (>5 to 10%, n=21; >10 to 20%, n=49). Grade 3/4 neutropenia (59%) or thrombocytopenia (33%) were present at baseline. All patients experienced ≥1 treatment-emergent adverse event (TEAE), the most common being neutropenia (83%), nausea (55%), and constipation (54%); 96% experienced grade 3/4 TEAEs, with neutropenia (82%), febrile neutropenia (49%), and thrombocytopenia (42%) being most common. Neutropenia (49%), including febrile neutropenia (45%), was the most common serious TEAE. The 30-d mortality rate after first dose was 1%. Intention-to-treat ORR was 80%, including complete remission (CR,40%) and marrow CR (mCR, 40%); 42% mCR had hematologic improvement; no partial remissions recorded. For 31 CR patients, median time to CR and median duration of response was 2.6 and 13.8 mos (95% CI 8.9,–), respectively. Post-baseline transfusion independence rate (defined as no transfusion ≥8 weeks), for patients transfusion-dependent for RBC and/or platelets at baseline, was 46.5%. Median OS was 28.2 mos (95% CI 17.7, –). Median OS for 31 patients achieving CR was 28.6 mos (95% CI 27.5, –). Twenty-three percent moved on to post-study allogeneic HSCT (including BM and peripheral blood stem cells). Conclusions: The combination of Ven+Aza was associated with rapid and durable response, promising efficacy, including remission rates and OS, and an acceptable safety profile for patients with HR-MDS. Additional correlation with disease risk features, including TP53 mutations, will be presented. Venetoclax (Ven), a selective oral BCL-2 inhibitor, demonstrated synergy with azacitidine (Aza) in patients with higher-risk myelodysplastic syndromes (HR-MDS). We report updated safety and efficacy in an ongoing phase 1b study (NCT02942290) evaluating Ven+Aza for treatment-naïve HR-MDS patients. Patients (≥18yrs) with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, bone marrow (BM) blasts <20% at baseline, and ECOG≤2 performance status were enrolled. Aza 75 mg/m2 was administered on Days (d) 1–7 of each 28-d cycle. Initial Ven dose was 400 or 800 mg daily in 28-d cycles. Due to poor tolerance, the study was amended to examine several dose cohorts (100, 200, and 400 mg x 14-d each 28-d cycle). Primary objectives were assessing Ven+Aza safety profile and establishing RP2D. Key secondary objectives included overall response rate (ORR) and overall survival (OS). At data cutoff (Dec. 15, 2020), 78 patients received Ven+Aza (51 at RP2D 400 mg x 14 d), with median follow-up time of 23 mos. Median age was 70 yrs; 72% male; 90% had excess BM blasts (>5 to 10%, n=21; >10 to 20%, n=49). Grade 3/4 neutropenia (59%) or thrombocytopenia (33%) were present at baseline. All patients experienced ≥1 treatment-emergent adverse event (TEAE), the most common being neutropenia (83%), nausea (55%), and constipation (54%); 96% experienced grade 3/4 TEAEs, with neutropenia (82%), febrile neutropenia (49%), and thrombocytopenia (42%) being most common. Neutropenia (49%), including febrile neutropenia (45%), was the most common serious TEAE. The 30-d mortality rate after first dose was 1%. Intention-to-treat ORR was 80%, including complete remission (CR,40%) and marrow CR (mCR, 40%); 42% mCR had hematologic improvement; no partial remissions recorded. For 31 CR patients, median time to CR and median duration of response was 2.6 and 13.8 mos (95% CI 8.9,–), respectively. Post-baseline transfusion independence rate (defined as no transfusion ≥8 weeks), for patients transfusion-dependent for RBC and/or platelets at baseline, was 46.5%. Median OS was 28.2 mos (95% CI 17.7, –). Median OS for 31 patients achieving CR was 28.6 mos (95% CI 27.5, –). Twenty-three percent moved on to post-study allogeneic HSCT (including BM and peripheral blood stem cells). The combination of Ven+Aza was associated with rapid and durable response, promising efficacy, including remission rates and OS, and an acceptable safety profile for patients with HR-MDS. Additional correlation with disease risk features, including TP53 mutations, will be presented.

AML-215: Successful Management of an Unusual Fournier’s Gangrene Secondary to Post-Transplant AML

Fournier's Gangrene is known to be one of the rarest and potentially lethal necrotizing infections of the perineum and genital region with high mortality. We report an unusual case of a 34-year-old male presenting to Saint Antoine Hospital in June 2020 after 6 months of severe pain, a mass in the anal and perineal area with blackish discoloration, and painful swelling of the scrotum and the penis. A likely diagnosis of necrotizing fasciitis associated with high-grade fever and sepsis was made. An immediate surgical debridement, colostomy, and suprapubic catheter were done, along with broad-spectrum antibiotics. Per medical history, in 1999, he had an amputation of the left foot after diagnosis with osteosarcoma and lung metastasis, followed by chemotherapy. A new evaluation was done in 2003 and showed progressive lung lesions treated with right lobectomy. In January 2010, the patient presented a blood test with pancytopenia and 14% of circulating blasts. Bone marrow aspiration (BMA) was done and showed an AML secondary to chemotherapy (t-AML) with complex karyotype of chromosome 5 and chromosome 17. Induction chemotherapy with 4 cycles of Vidaza + Revlimid from January 2010 to April 2010 led to partial response. In May 2010, bone marrow biopsy showed signs of dysmyelopoiesis with young elements of a dispersed blastic appearance of myeloid origin without excess blasts and no signs of osteosarcoma. In June 2010, the patient had a successful haploidentical allotransplant from his brother. After presenting with Fournier's Gangrene in June 2020, his blood tests showed anemia (Hb 8.6g/dL), thrombocytopenia (127g/L), and blast cells (12%). Biopsies of the genital mass showed diffuse proliferation of malignant cells, and immunohistochemistry tests came back as CD34+, CD117+, MPO-, Glycophorine +/-, CD68-/+, ACL-/+, CD163-, AE1/AE3-, Ki67%, and EBER-. BMA showed a rich marrow invaded by 50% of blasts with a cytologic aspect of AML. After controlling the Fournier's Gangrene by surgery and antibiotics, the patient was started on a new line of treatment with Vidaza/Venetoclax (July 2020). A new BMA done in September showed a complete biologic response with 1% blasts. The decision was made to continue 4 cycles of chemotherapy. The recovery phase was uneventful with satisfactory cosmetic results.

Dynamics of epigenetic regulator gene BCOR mutation and response predictive value for hypomethylating agents in patients with myelodysplastic syndrome

BackgroundBCOR (BCL6 corepressor) is an epigenetic regulator gene involved in the specification of cell differentiation and body structure development. Recurrent somatic BCOR mutations have been identified in myelodysplastic syndrome (MDS). However, the clinical impact of BCOR mutations on MDS prognosis is controversial and the response of hypomethylating agents in MDS with BCOR mutations (BCORMUT) remains unknown.ResultsAmong 676 MDS patients, 43 patients (6.4%) harbored BCOR mutations. A higher frequency of BCOR mutations (8.7%) was investigated in patients with normal chromosome, compared to 4.2% in patients with abnormal karyotype (p = 0.040). Compared to the BCORWT patients, the BCORMUT patients showed a higher ratio of refractory anemia with excess blasts subset (p = 0.008). The most common comutations with BCOR genes were ASXL1 (p = 0.002), DNMT3A (p = 0.114) and TET2 (p = 0.148). When the hierarchy of somatic mutations was analyzed, BCOR mutations were below the known initial mutations (ASXL1 or TET2) but were above U2AF1 mutations. Transformation-free survival was significantly shorter in BCORMUT patients than that in BCORWT patients (16 vs. 35 months; p = 0.035). RNA-sequencing was performed in bone marrow mononuclear cells from BCORMUT and BCORWT patients and revealed 2030 upregulated and 772 downregulated genes. Importantly, HOXA6, HOXB7, and HOXB9 were significantly over-expressed in BCORMUT patients, compared to BCORWT patients. Eight of 14 BCORMUT patients (57.1%) achieved complete remission (CR) with decitabine treatment, which was much higher than that in BCORWT patients (28.7%, p = 0.036). Paired sequencing results (before and after decitabine) showed three of 6 CR patients lost the mutated BCOR. The median survival of CR patients with a BCORMUT was 40 months, which was significantly longer than that in patients with BCORWT (20 months, p = 0.036). Notably, prolonged survival was observed in three BCORMUT CR patients even without any subsequent therapies.ConclusionsBCOR mutations occur more frequently in CN MDS patients, predicting higher risk of leukemia transformation. BCORMUT patients showed a better response to decitabine and achieved longer post-CR survival.

Allogeneic Stem Cell Transplantation for MDS

Myelodysplastic syndromes are clonal disorders with morphological dysplasia, a variable degree of cytopenia and a risk of transformation to acute myeloid leukemia. Prognosis is very variable and is defined by blast count, cytopenia, cytogenetics and more recently by somatic mutations, with IPSS or revised IPSS score being the most widely used to assess disease risk. HSCT remains the only curative treatment to date, with high-risk patients obtaining the biggest benefit. However, NRM should be carefully assessed before indicating the transplant in this usually old population, where organ toxicity and comorbid conditions are to be considered. Multi-domain assessment tools, such as CGA (comprehensive geriatric assessment) and EBMT score, are useful in this context and might guide physician decisions regarding the transplant. Indeed, with the development of reduced intensity conditioning regimens, the number of patient candidates for an HSCT has increased. Regarding pre-transplant treatment, patients with a blast excess &gt; 10% might be treated with HMAs or chemotherapy, although there are no randomized trials confirming the benefit of this approach, even when achieving a complete response. Concerning donor choice, matched sibling donors continue to be the first option, although matched unrelated donors, and more recently haploidentical donors, have proven to be valid options and should be offered in the absence of a related donor. Relapse remains the main cause of transplantation failure. MRD assessment and pre-emptive or prophylactic use of HMA or other targeted inhibitors with or without DLI are accepted strategies to reduce relapse risk, but the prognosis in this context remains dismal, and is the subject for several ongoing clinical protocols.

Quantitative analysis of myelofibrosis and its prognostic significance in patients with myelodysplastic syndrome

Objective: To quantitatively analyze the reticulin fiber intensity density (RFD) in patients with myelodysplastic syndrome (MDS) by using the computer-aided grid point method, and preliminarily explore its correlation with the prognosis of MDS patients. Methods: Bone marrow (BM) slices from 32 primary MDS patients treated in Tongren Hospital Shanghai Jiao Tong University School of Medicine from February 2017 to December 2019 were observed. Images were taken by the optical microscope imaging system after the Gomori staining. The computer grid marking software was developed according to the principle of the mesh micrometer to assess RFD, meanwhile, the artificial semi-quantitative were used to assess the fibrosis of bone marrow. The co-relation between the above two methods was evaluated, and the relationship between RFD and prognosis of MDS patients were further investigated with Cox regression analysis. Results: Of the patients, there were 17 males and 15 females with a median age of 69 years (32-91 years). The RFD quantitatively analyzed by the computer-based method was positively correlated with the myelofibrosis grade by the artificial semi-quantitative analysis (r=0.497, P=0.004). The RFD in patients diagnosed with MDS complicated with excess blasts (MDS-EB) was significantly higher than that in the non-MDS-EB group((9.55%±0.75%) vs (1.71%±0.23%), P<0.001). Cox regression model analysis showed that the RFD of MDS patients had better prognostic value when compared with the artificial semi-quantitative analysis, which was also a poor prognostic factor (RR=1.337, 95%CI: 1.085-1.648, P=0.006). The overall survival (OS) of patients with RFD>5.54% was significantly shorter than that with RFD≤5.54% (P=0.001). The OS of MDS-EB patients with RFD>9.81% was significantly shorter than that in patients with RFD≤9.81% (P=0.003). Conclusion: Abnormal proliferative fibrosis of bone marrow is a potential high-risk factor for poor prognosis of MDS patients.

Difference in outcomes following allogeneic hematopoietic cell transplantation for patients with acute myeloid leukemia and myelodysplastic syndromes

To evaluate whether outcomes following allogeneic hematopoietic cell transplantation differ according to disease type, a three-way comparison for patients with de novo acute myeloid leukemia (AML) (n = 3318), AML evolving from myelodysplastic syndromes (MDS) (n = 208), and MDS with excess blasts (MDS-EB) (n = 994) was performed. The 5-year probabilities of overall survival (OS) for de novo AML, AML evolving from MDS, and MDS-EB were 60%, 42%, and 41% (p < 0.001), respectively. Multivariate analysis revealed that, compared to de novo AML, AML evolving from MDS was associated with a higher risk of NRM (p = 0.030) and MDS-EB with a higher risk of relapse (p < 0.001), both leading to lower OS (p = 0.010 and p < 0.001, respectively). These findings demonstrate inter-disease differences in post-transplant outcomes and highlight the needs to reduce NRM for AML evolving from MDS and to reduce relapse for MDS-EB.

The ability of bone marrow progenitor cells to form colonies in ex vivo culture of MDS patients

The results of in vitro hematopoiesis studies have provided most of the knowledge about the organization, regulation, and development of the human hematopoietic system over the past three to four decades. However, due to the impossibility of an appropriate assessment of hematopoietic stem cells (HSC) in humans and because of the shortcomings of methodological approaches to determining the role of hematopoietic progenitor cells in the pathogenesis of MDS and to predicting the course of the pathological process, semiliquid agar cultures of bone marrow from patients with myelodysplastic syndrome were used. Myelodysplastic syndrome (MDS) refers to a clinically, morphologically, and genetically heterogeneous group of diseases characterized by clonalism and arising from mutations at the level of hematopoietic progenitor cells. Proliferation of such a mutated stem cell progenitors leads to ineffective maturation of myeloid lineage cells and dysplastic changes in the bone marrow (BM). The aim of the study was to establish the relationship between the functional activity of hematopoietic progenitor cells in the ex vivo culture and the activity of the pathological process in the myelodysplastic syndrome. We studied bone marrow samples from patients with the myelodysplastic syndrome, namely refractory anemia with excess blasts I (MDS RAEB I) and refractory anemia with excess blasts II (MDS RAEB II) and AML under conditions in vitro, as well as their clinical laboratory data. It was found that the percentage of blasts and myeloblasts in the samples of patients with AML and MDS RAEB II increased, compared to the samples of patients with MDS RAEB I (63.5±3.9 %, 18.05±1.01 % and 9.49±1.53 % respectively). An increase in the number of erythrocytes and hemoglobin content was noted in the group of patients with MDS RAEB I compared with MDS RAEB II (2.9±1.4×1012 / l and 105.04±3.6 g / l versus 9±0.8×1012 / l and 84.5±4.8 g / l, respectively). The analysis of the results of BM studies of patients with MDS in in vitro culture indicated a significant lag in the formation of cell aggregates during cultivation and a pronounced inhibition of the colony-forming ability of progenitor cells, compared to the control. A noticeable decrease in the colony-forming ability was observed in patients with MDS RAEB I, MDS RAEB II and AML in this sequence – 4.1±1.2 per 1×105 explanted cells, 3.2±0.9 per 1×105 explanted cells and 2.0±0.6 per 1×105 explanted cells, respectively. The analysis of hematological parameters and the results of BM cells cultivation at different stages of MDS indicates that the colony-forming ability of progenitor cells correlates with the depth of the pathological process.

Refractory Anemia With Excess Blasts In Transformation (Acute Myeloid Leukemia with 20-29% Blasts) in Older Adults is Less Aggressive Than Acute Myeloid Leukemia With ≥30% Blasts

BackgroundThe current WHO Classification defines acute myeloid leukemia (AML) in most cases as a myeloid neoplasm with ≥20% bone marrow (BM) or peripheral blood (PB) blasts. However, it is controversial whether AML cases with 20-29% BM blasts, referred to as oligoblastic AML or refractory anemia with excess blasts in transformation (RAEBT), should be considered as AML or myelodysplastic syndrome (MDS) in terms of treatment approach and prognosis. MethodsWe retrospectively studied 573 patients aged ≥50 years diagnosed after the year 2004 with de novo AML, including 142 with 20-29% BM blasts (RAEBT) and 431 with ≥30% BM blasts (AML30). Patients with t(15;17), t(8;21), inv(16)/t(16;16), or history of any prior myeloid neoplasm were excluded. Clinicopathologic and genetic features, treatments, and outcome of RAEBT were compared to AML30. The clinicopathologic and genetic features of RAEBT were also compared to 152 de novo MDS patients with 10-19% BM blasts (RAEB2) diagnosed over the same time period. Fisher's exact and Wilcoxon tests were used to compare categorical and continuous variables between groups, respectively. Overall survival (OS) was estimated using the method of Kaplan and Meier and the log-rank test was used to compare OS between groups. Univariate and multivariable Cox proportional hazards regression was used to assess the impact of the two groups along with other risk factors in OS. ResultsCompared to AML30 patients, RAEBT patients were older and had lower white blood count and BM cellularity, but had higher hemoglobin, platelet count, and UKMRC karyotype risk score and greater morphologic dysplasia (Table 1).RAEBT and RAEB2 patients were similar with respect to age, peripheral counts, BM cellularity, and karyotype risk scores. In the subsets of patients in whom they were assessed, FLT3 and NPM1 mutations and monocytic features occurred more commonly in AML30 than in RAEBT (Table 1). RAEBT patients were treated more often with hypomethylating agents and less often with intensive therapy (anthracycline/cytarabine) compared to AML30 patients, whereas allogeneic stem cell transplant frequency was similar. With 55.5 months median follow-up, OS of RAEBT patients was superior to that of AML30 patients (p=0.003)(Figure 1). Multivariable analysis showed that RAEBT (p<0.0001), hemoglobin ≥10.3 g/dL (p=0.045), intermediate UKMRC karyotype score (p<0.0001), normal bone marrow karyotype (p=0.0005), intensive therapy (p<0.0001), and stem cell transplant (p<0.0001) were associated with longer OS.Table 1Comparison of RAEBT and AML30 groupsRAEBT (n=142)AML30 (n=431)p valueMedian age in years6763<0.0001Median white blood count (x 109/L)2.389.20<0.0001Median hemoglobin (g/dL)9.809.200.0007Median platelets (x 109/L)76600.01Median BM cellularity (%)6090<0.0001Morphologic dysplasia(% with >10% erythroid / myeloid / megakaryocytic dysplasia)53 / 53 / 4631 / 25 / 27<0.0001 / <0.0001 / <0.0001Monocytic or myelomonocytic differentiation23/115 (20%)137/342 (40%)<0.0001UKMRC karyotype scores(% intermediate / adverse / missing)61 / 35 / 569 / 26 / 50.049FLT3-ITD mutation3/94 (3%)59/247 (23%)<0.0001NPM1 mutation1/55 (2%)46/151 (30%)<0.0001Supportive care only11/142 (8%)38/431 (9%)0.86Hypomethylating agent as initial therapy36/142 (25%)36/431 (8%)<0.0001Intensive therapy as initial therapy73/142 (51%)310/431 (72%)<0.0001Stem cell transplant41/142 (29%)118/431 (27%)0.7412-month OS [95% CI]60% [46-74%]51% [47-55%]0.00348-month OS [95% CI]29% [22-36%]20% [17-24%]▪ ConclusionsRAEBT is more similar to RAEB2 than to AML30 in terms of its clinicopathologic and cytogenetic features. In spite of less frequent treatment with intensive chemotherapy and higher karyotype risk, RAEBT patients had superior OS compared with AML30 patients. In a prior study (Estey E et al. Blood 1997;90:2969), RAEBT and AML30 patients treated with intensive therapy had similar outcomes; the advent of hypomethylating agent therapy may in part account for the differences found in our study. Our findings favor considering RAEBT in a disease category separate from AML with higher blast counts. Disclosures:No relevant conflicts of interest to declare.