Low Blast Research Articles

Validation of the 5th Edition of the World Health Organization Classification of Myelodysplastic Neoplasms on 852 Consecutive De Novo Patients from a Single Institute

Background: A summary of the World Health Organization (WHO) 5th edition (2022) classification of myelodysplastic neoplasms (MDS) has been published recently. As compared to the 2016 (revised 4th) WHO criteria, the newest proposal places greater emphasis on genomic and pathology features. In this study, we assess the validity of the WHO 2022 classification for MDS patients. Methods: Data from 852 consecutive subjects ≥ 18 years with newly-diagnosed MDS according to the WHO 2016 criteria in our center from August 30, 2016 to September 22, 2021 were interrogated. Subjects were re-diagnosed and re-classified according to WHO 2022 guidelines. The last follow-up was on June 4, 2022, with a median follow-up of 24 months. Results: Applying the WHO 2022 guidelines, 30 subjects with an NPM1 mutation were re-classified as acute myeloid leukemia (AML) who were previously classified as MDS with excess blast type2 (MDS-EB2; n = 13), MDS with multi-lineage dysplasia (MDS-MLD; n = 9), MDS with excess blast type1 (MDS-EB1; n = 6) and MDS unclassifiable (MDS-U; n = 2) according to WHO 2016 criteria. Nine subjects previously classified as (MDS-U) were re-classified to clonal cytopenia of undetermined significance (CCUS). Re-classification of remaining 813 subjects between the WHO 2016 to WHO 2022 classification are displayed in Figure1. Classification of the 11 subjects with MDS with low blasts and isolated del(5q) (MDS-5q) remained unchanged. In addition to prior MDS with ring sideroblasts (MDS-RS) patients (n=45), 25 subjects were reclassified as MDS with low blasts and SF3B1 mutation (MDS-SF3B1) because the new criteria have no limitation on numbers of ring sideroblasts. We re-classified 53 subjects as MDS-biTP53, most commonly those with excess blasts (34/53; 64%). Amongst subjects without the genetic abnormalities defined above, 80 previously classified as MDS with singe/multi-lineage dysplasia (MDS-SLD/MLD) or MDS-U were re-classified as hypoplastic MDS (MDS-h) and the remaining 293 as MDS with low blasts (MDS-LB). Subjects previously classified as MDS-EB1 or EB2 were re-classified as MDS with increased blasts type1 (MDS-IB1; n = 161) or MDS with increased blasts type2 (MDS-IB2; n = 103) after those with MDS with fibrosis (MDS-f; n = 42) were excluded. Survival according to WHO 2022 classification for MDS are shown in Figure2. Median survival of MDS subjects was 45 months (95% Confidence Interval [CI], [34, 56] months). There were significantly briefer median survivals of subjects with MDS-biTP53 (10 months [8, 12] months) and MDS-f (15 months [8, 23 months]) compared with other subtypes. Median survivals of MDS-h and MDS-LB cohorts were unreached but those with MDS-h had longer survival (P = 0.07). Median survivals for MDS-IB1 and MDS-IB patients were 24 months ([18, 30] months) and 26 months ([17, 35] months), respectively. Survival rate between MDS-IB1 and MDS-IB2 patients were comparable (P=0.707). We next explored the prognostic value of myelofibrosis in subjects without increased blasts. 40 subjects in our cohort had grade-2/-3 myelofibrosis. 37 were re-classified from the MDS-LB cohort and 3 from the MDS-h cohort. Median survival of subjects with low blasts and myelofibrosis (MDS-LBf) was 23 months (8, 38 months), significantly briefer compared with those with MDS-LB or MDS-h (unreached; P < 0.001) comparable to subjects with MDS-IB1 (24 months; P = 0.80) or MDS-IB2 (26 months; P = 0.79) and longer compared with subjects with MDS-f (15 months; P = 0.04). We also tested the prognostic value of dysplastic lineages in subjects with MDS-LB according to WHO 2022 classification. Based on bone marrow histology 28 subjects were considered MDS-LB with single lineage dysplasia (MDS-LB-SLD) and 228, MDS-LB with multiple lineage dysplasia (MDS-LB-MLD). Median survivals of both cohorts were unreached however MDS-LB-SLD had longer survival (P = 0.01). Based on these findings, we suggest the revised WHO 2022 classification divide subjects with low blasts in to MDS-LBf, MDS-h, MDS-LB-SLD and MDS-LB-MLD. The first supersedes other categories and MDS-h overrides the diagnosis of MDS-LB-SLD or MDS-LB-MLD. Conclusion: We validate the WHO 2022 classification of MDS as thoughtful and propose some refinements to provide more accurate prognostic information. Because our study is from 1 center, external validation is needed. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Characterization of Clinical, Molecular, and Prognostic Features of the W.H.O. 2022 Classification System for Myelodysplastic Neoplasms (MDS)

Introduction: Myelodysplastic neoplasms (MDS) are clonal disorders of relative bone marrow failure and a variable risk of progression to acute myeloid leukemia. MDS generally exhibit genetic and/or cytogenetic abnormalities, an observation that led to the reclassification of MDS in the World Health Organization (WHO) 2022 update (Khoury et al, Leukemia 2022). In parallel, studies examining the mutational landscape of MDS have shown that specific patterns of somatic gene alterations strongly impact prognosis (Bernard et al, NEJM Evidence, 2022). In this study, we characterized the mutational patterns and clinical outcomes associated with the WHO 2022 classification schema to provide a more comprehensive view of this disease framework. Methods: This is a single-center retrospective cohort study of patients (pts) with clinicopathologically-confirmed MDS between January 2018 and December 2021. We identified cases with next-generation sequencing (NGS) performed on either bone marrow (BM) aspirate or peripheral blood (PB) using a clinically validated 164 gene panel designed to detect genes recurrently mutated in both myeloid and lymphoid neoplasms. For all cases, demographic information, clinical and molecular data, WHO 2022 diagnostic class, and survival outcomes were collected. IPSS-R and IPSS-M scores were calculated. Survival was estimated using the Kaplan-Meier method. Comparisons of mutational frequencies between groups were made via Fisher's exact test. This study was approved by Stanford University's Institutional Review Board. Results: Our inclusion criteria identified 118 MDS pts with clinicopathologic and molecular review. The median age of the cohort was 72 years, 67% were male, and 70% were Caucasian. For morphologically defined pts, MDS with low blasts (MDS-LB) was the most common subtype (36% of the entire cohort), followed by MDS with increased blasts-2 (MDS-IB2; 24%) and MDS with increased blasts-1 (MDS-IB1; 16%). For genetically defined pts, MDS with low blasts and SF3B1 mutation (MDS-SF3B1) was the most common subtype (19%) while MDS with biallelic TP53 mutations (MDS-biTP53) comprised 6% pts (Table 1). Within the latter group, 86% had a complex karyotype. A co-mutation plot to visualize the distribution of mutations among the various subgroups is shown in Figure 1. Notably,TP53 mutations (either mono- or bi-allelic) occurred in 16% of the cohort, were frequent in pts with complex karyotype (17/22; 77%), and were exclusive of ASXL1, IDH2, or SF3B1 mutations. In the morphologically defined subgroups, pts with MDS-LB had the highest prevalence of TET2 mutations (12/42 pts; 29%), while pts with MDS-IB1 had none (0/19 pts). U2AF1 mutations were significantly more common in pts with MDS-LB (13/42; 31%) relative to pts with MDS-IB2 (2/28; 7%) (p = 0.04). Conversely, patients with MDS-IB2 more frequently harbored TP53 mutations compared to pts with MDS-LB (p = 0.002). Calculation of IPSS-M scores stratified 47% of pts into the lower risk categories, with the remainder in higher risk categories (Table 1). The median IPSS-M score for the entire cohort was 0.105 [min: -2.11, max: 4.59] (Moderate High, MH). Median IPSS-M scores were highest in pts with MDS-biTP53 (3.18; [-0.480, 4.59]) and MDS-IB2 (1.65; [-0.880, 3.47]) (Very High, VH), and lowest in pts with MDS-SF3B1 (-1.13; [-2.06, 0.250]). IPSS-R scores generally paralleled IPSS-M scores, with 46% of all pts falling into the lower risk groups (Table 1). Pts with MDS-biTP53 had a median IPSS-R score of 8.0 [3.0, 9.5] (VH) while pts with MDS-SF3B1 had a median score of 2.5 [1.5, 4.0] (MH). Median overall survival (mOS) from the time of diagnosis was highest for those with MDS-LB (not reached), MDS-IB1 (not reached), and MDS-SF3B1 (7.0 years). Survival for patients with MDS-IB2 and MDS-biTP53 was poor, with mOS of 1.5 years and 0.8 years, respectively (Table 1). Conclusion: Our data demonstrated the clinical and molecular characteristics of MDS pts evaluated within the WHO 2022 schema and showed that differing mutational features were prominently associated within the morphologically as well as the genetically defined subgroups. Further, OS differed substantially among the defined subgroups. Our incorporation of the IPSS-M and IPSS-R provides additive prognostic and survival components into the WHO 2022 classification, which together enhance this framework's utility for studying MDS and its natural history. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Favorable Outcomes of DDX41-Mutated MDS and Low Blast Count AML Treated with Azacitidine with or without Lenalidomide (ALLG MDS4 Trial)

Introduction. The Australasian Leukaemia and Lymphoma Group (ALLG) MDS4 phase II trial randomized 160 patients (pts) with higher risk (by IPSS) myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML) and low blast acute myeloid leukemia (AML) to either azacitidine (AZA) or combination AZA with lenalidomide (LEN, from cycle 3 onwards) (Kenealy, Haematologica 2019; ANZCTR12610000271000). Whilst the combination of LEN and AZA was tolerable, there was no improvement in clinical benefit, response rates or overall survival in patients compared to treatment with AZA alone. We performed a post-hoc genomic analysis of pts on this trial to further understand the molecular changes in this cohort and any correlation with outcomes. Methods. A unique molecular index (UMI) based QIAseq targeted DNA panel (QIAGEN) was performed as previously described (Blombery, Blood 2020). Sensitivity for variant calling was 0.5% variant allele frequency (VAF). HumanCytoSNP-12 BeadChip array (SNP-A) was previously performed and reported (Kenealy, Haematologica 2019). Primary endpoint of the study was ongoing clinical benefit at 12 months, defined as being alive and progression-free. Logistic regression and Cox proportional hazards regression were used respectively to assess the differences in response rates and overall survival between two treatment groups according to the molecular subgroups. Results. A total of 66 pts, representative of the 160 enrolled, had baseline gDNA available for targeted panel testing; 36 and 30 pts on AZA alone and AZA+LEN therapy, respectively. Median age was 71.6 years. IPSS-R risk groups were very low or low (n=20), intermediate (n=18), high or very high (n=25), and not available (n=3 due to missing karyotype). Disease subtypes were MDS (n=52), CMML (n=9), and AML (n=5). 47% of pts had an abnormal SNP-A, including 18% with complex (≥3) copy number changes. The most common gene mutations observed were ASXL1 (48.5%), TET2 (47%) and RUNX1 (30%) (Figure 1). Overall clinical benefit at 12 months was achieved in 39 pts (59%). TET2 was the only gene mutation associated with significantly improved benefit when treated with AZA alone (OR 10 [95% CI, 2 to 81]). Median follow up among survivors was 49 months and the median overall survival was 33.2 months (95% CI, 21.7 - NE). Mutations in TP53, U2AF1, EZH2 and SRSF2 were associated with inferior overall survival. Molecular subgroup analyses did not identify any significant difference between the two treatment arms. Given the recent discovery of DDX41 mutations in MDS/AML and early data supporting a favorable response to AZA/LEN, we focused on 6/66 (9%) patients with detectable DDX41 mutations. All 6 pts had a second mutation detectable in DDX41 as well as no detectable abnormalities on SNP-A. The most commonly co-mutated gene in this group was ASXL1 (in 4/6). One patient with DDX41 mutation died before receiving any therapy. Best responses achieved in DDX41 mutated patients were complete remission (CR, n=1), marrow CR (n=1), hematologic improvement (HI, n=1), and stable disease (SD, n=2). Remarkably, of the 5 patients that received treatment (4 AZA, 1 AZA+LEN), the overall survival at 52 months (range 47-58) follow up was 100% (Figure 2), despite having intermediate (n=3) and high (n=2) R-IPSS. Mutations were also serially assessed on therapy in 45 pts: ≤2 cycles in 38 pts, and ≥4 cycles in 7 pts (2 AZA+LEN). Of 166 mutations observed at baseline, majority (67%) were stable with <10% change in VAF (median +2%). Overall, 27 (60%) pts had clearance or >10% VAF reduction in ≥1 variant, including clearance in 20 (12%) variants (most commonly TET2 [n=4] and RUNX1 [n=3]), and reduction in 33 (20%) variants (ASXL1 [n=6], SF3B1, SRSF2 and TET2 [n=5 each], but no pt had complete molecular clearance. In contrast, new mutations (n=18 variants) or >10% VAF increase (n=2 variants) were observed in 14 (31%) pts, most commonly TET2 (n=6), RUNX1 (n=4), and DNMT3A and BRAF (n=3 each). Conclusions. In summary, our correlative molecular analysis of the ALLG MDS4 trial of AZA vs AZA+LEN in MDS/AML has identified, in addition to established molecular risk factors for inferior outcomes, that pts with DDX41 mutations are associated with highly favorable outcomes with either AZA or AZA+LEN. This observation and subgroup of patients warrants further study in randomized trials. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Molecular International Prognostic Scoring System (IPSS-M) in Myelodysplastic Syndromes Arising from Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria

Clonal evolution to myelodysplastic syndromes (MDS) or acute myeloid leukemia represents the most serious late complication of patients with aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH). The majority of secondary MDS (sMDS) cases present high-risk features with chromosome 7 abnormalities and mutations in ASXL1, RUNX1, SETBP1, and RAS pathway genes as the most frequent molecular lesions. Other cases tend to show more favorable outcomes with distinct genomic architecture mainly driven by generally considered low-risk cytogenetic alterations (e.g., del(13q), del(20q)). Such heterogeneity of genomic makeup, the rarity of the disease, and the scarcity of information make the prognostication of sMDS challenging for routine clinical practice. In recognition of the growing role of somatic mutations, the Molecular International Prognostic Scoring System (IPSS-M) has been conceived to improve the precision of prognostication of prior schemes by adding objective molecular markers. Whereas validated on de novo and secondary/therapy-related cases, its applicability specifically on post-AA/PNH MDS has not yet been explored. Here, we applied IPSS-M to 69 sMDS with complete clinico-genomic information from a large multicenter dataset of 1008 AA/PNH patients, using a comparator cohort of primary MDS (n=1281). The median age at MDS progression was 63 years (IQR, 34-70), and most patients were male (M:F ratio 1.65). Despite low bone marrow blast percentages (median, 2; 0-7), 71% of patients showed high-risk features according to IPSS-R (scores >3.5), chiefly due to the enrichment of poor risk cytogenetics, most frequently monosomy 7. Overall, 48% of patients received disease-modifying treatments (DMT) with either HMA (28%), HSCT (60%) or both (12%). Leukemia progression was registered in 14% of cases after a median of 5.4 months (1-14) from sMDS onset. With a median follow-up of 55.6 months (95%CI, 42.5-75.8), the 60-month overall (OS) and leukemia free-survival (LFS) achieved 44% (32-60) and 42% (31-58), respectively. The IPSS-R distribution was as follows: Very Low (6%), Low (23%), Intermediate (30%), High (23%) and Very High (18%). By applying IPSS-M, patients were redistributed in Very Low (5%), Low (19%), Moderate Low (14%), Moderate High (14%), High (29%), and Very High (19%) risk categories. When comparing five-to-five (merging together the Moderate Low/High IPSS-M categories), 55% of cases were re-stratified, of which 63% up- and 37% down-staged (Fig.1A). Indeed, 77% of sMDS patients harbored at least 1 mutation with 43% presenting >2, thereby substantiating the differences observed between the two prognostication systems. Although according to IPSS-M the majority (62%) of sMDS cases still clustered in higher-risk categories, a non-negligible fraction (38%) was assigned to lower-risk groups. To further explore whether IPSS-M could be used to predict OS/LFS also in sMDS cases, we analyzed survival outcomes by taking advantage of a cohort of de novo cases. However, approximately half of sMDS received DMT, potentially generating a bias when using survival as a surrogate for outcomes comparisons, even in cases falling into equivalent risk categories. Therefore, we applied a propensity score matching by using age, gender and DMT as relevant covariates to reduce any possible confounder. As reported for others MDS subtypes in the original IPSS-M study, OS/LFS outcomes of sMDS paralleled those observed in the de novo group within the various IPSS-M risk categories (Fig.1B). We applied for the first time IPSS-M in a real-world cohort of sMDS, showing its potential for refining the assignment of patients into risk categories prognostic of disease outcomes. The actuarial survival of sMDS cases was not distinct from de novo patients matched for basic clinical features in equivalent IPSS-M risk groups. The complexity of the genomic landscape typical of AA/PNH clonal evolution makes sMDS a prototypic model whereby the incorporation of molecular information is of paramount importance to ensure adequate clinical management. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Full Spectrum 40-Parameter Single-Tube Flow Cytometry Analysis for Longitudinal Immunophenotyping and Tracing of Clonal Heterogeneity in AML

Acute Myeloid Leukemia (AML) remains notoriously difficult to treat. AMLs manifest themselves within individual patients with remarkable heterogeneity. Heterogeneity can be observed within the tumor itself, whereby multiple genetically distinct subclones can co-exist. We have shown that such differences in genetics translate into differences at the cell biological level as well (epigenome, transcriptome, proteome, metabolome and drug sensitivities) (de Boer et al. 2018) (Erdem et al. 2022). More recently, we began to dissect the heterogeneity within the tumor immune microenvironment. For instance, we identified a subgroup of AML patients that harbor a large population of tumor supportive M2 polarized macrophages in the bone marrow and these patients have the poorest prognosis. Reversely, patients with large populations of tumor suppressive M1 polarized macrophages display a much better prognosis. We also uncovered that patients with high levels of CD4+ T cells display a relatively favorable outcome. Little is known about clonal dynamics and microenvironmental changes over time or as a consequence of treatment. With the rise of new mutation-specific treatments targeting specific genetic subclones, it is important to examine the clonal composition of residual cells, especially at Measurable Residual Disease (MRD) timepoints. This can pose challenges as patients in morphologic complete remission have relatively low blast counts and limited material is available. Full spectrum flow cytometry is a novel technique that allows the use of 40 fluorescent markers in a single panel, enabling extensive immunophenotyping requiring relatively low cell numbers. We set up two antibody panels, one for immunophenotyping based on the OMIP-069 panel (39 colors) (Park et al. 2020) and one for the detection of subclones and macrophages (37 colors). We ran both panels on AML bone marrow samples at diagnosis (n=20), after initial induction therapy (n=4) and on normal bone marrow (NBM) (n=5). Full spectrum flow cytometry showed similar results to conventional flow cytometry, although with a higher resolution. With both panels combined we could identify and quantify 105 distinct cell types. UMAP landscapes were created as a template by merging AML samples and NBM samples, on top of which activation markers and aberrant AML-specific plasma membrane (PM) protein expression profiles could be projected. Additionally, density plots of individual patient samples were generated to compare longitudinal alterations in clonal dynamics and the tumor immune microenvironment before and after treatment. Additional univariate and multivariate survival analyses were performed to link observed changes to disease progression. At diagnosis, considerable heterogeneity amongst individual patients was observed, as expected. Patients either had a tumor supportive M2 macrophage phenotype or a tumor suppressive M1 macrophage phenotype. The lymphoid compartment was overall strongly reduced in AML compared to NBM, but was highly heterogeneous between individual patients whereby the strongest heterogeneity was noted in CD4+ and TCR gamma delta (TCRγδ) T cell subsets. Low levels of either CD4+ T cells and TCRγδ showed trends towards poorer prognosis. After induction therapy, the immune landscapes recovered and started to resemble those of NBM, most notably for T cell subsets but less so for B cells that took longer to recover. AMLs with an M2 phenotype at diagnosis shifted towards an M1 phenotype and non-classical monocytes shifted to more classical monocytes. In general, AML-specific PM markers were lost upon treatment reaching complete remission, although in some cases markers remained detectable within CD45+ blast populations. One patient containing NPMcyt (VAF=0.4) and FLT3-ITD (VAF=0.04) mutations was treated with gilteritinib in addition to cytarabine, reached morphologic complete remission whereby the FLT3-ITD mutation was lost, and the immune landscape restored. However, NPM1 droplet PCR analyses revealed the presence of residual mutant cells, which corresponded with residual cell numbers expressing aberrant CKIT/IL1RAP expression. Whether these cells will give rise to relapsed disease is currently under close investigation. We conclude that full spectrum flow cytometry is a powerful approach that allows extensive longitudinal immunophenotyping and subclone detection requiring low cell numbers. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Characterize Biomarkers and Mechanisms of Resistance for MDM2 Inhibitors in AML

Acute myeloid leukemia (AML) is a molecularly and clinically heterogeneous disease with an aggressive phenotype and poor prognosis. Inactivation of the wild-type p53, through upregulation of the TP53 negative regulator MDM2, is observed in around 50% of AML patients, providing a rationale for targeting MDM2 for the treatment of AML. Small molecule inhibitors of MDM2, including Idasanutlin, have shown efficacy as monotherapy and in combinations. However, patients exhibit heterogeneous responses with frequent drug resistance. We integrated ex vivo drug sensitivity assay, clinical parameters, whole exome sequence (WES), RNAseq, cytokine stimulation, and CRISPR/Cas9 dropout screening data to identify biomarkers that predict idasanutlin response and to elucidate the underlying drug-resistant mechanisms. Surprisingly, besides TP53 itself, we did not find an essential role in losing any of the major TP53 downstream targets alone leading to Idasanutlin resistance from Idasanutlin treated resistant cell lines, CRISPR screening, or individually targeted knockout experiments. Besides TP53 mutations, other major AML mutations, including RAS pathway mutations do not drive Idasanutlin resistance indicated by the patient sample functional screening data and in vitro mutation overexpression models. We observed instead that AML with a high differentiation or mature myeloid signature: including low blast, a high percentage of monocytes/granulocytes/T cells, AML FAB M4/M5 morphology, and a high expression of a myeloid immune signature gene are relatively resistant to Idasanutlin. We further characterized that both healthy/leukemia-associated T cells, granulocytes, and monocytes are intrinsically resistant to idasnutlin due to low expression levels of MDM2 and/or TP53. To examine whether the presence of differentiated cells protects leukemia blast cells from Idasanutlin, we performed a co-culture drug treatment experiment. Strikingly, only leukemia-associated monocytes, but not healthy monocytes, healthy/leukemia T cells or granulocytes, or leukemia blast cells protected leukemia blast cells from apoptosis in the presence or absence of Idasanutlin. Similar results were obtained for the other two MDM2 inhibitors, AMG232 and DS-3032b, and a BCL2 inhibitor, venetoclax. To further uncover which cytokines secreted from the leukemia-associated monocytes confer MDM2 inhibitor resistance, we tested 11 common cytokines, including IL-1a, IL-1b, IL-3, IL-6, IL-8, M-CSF GM-CSF, FLT3, MCP-1, TNFa, and SCF. We observed that IL-1α, IL-1β, IL-3, and GM-CSF markedly induced idasanutlin treatment resistance for AML, but not ALL or CLL patient cells. Interestingly, IL-1α and IL-1β only protect leukemia blasts, but not healthy CD34 hematopoietic stem and progenitor cells from Idasanutlin-induced apoptosis. We further performed RNAseq and immunoblots on IL-1α and IL-1β treated AML, CLL, and ALL cells. We observed the major TP53 downstream pathways remain activated by idasanutlin in the presence of IL-1α and IL-1β. Interestingly, GATA2 is significantly upregulated in IL-1α and IL-1β treated AML, but not CLL or ALL cells in the presence or absence of Idasanutlin. Furthermore, overexpressing GATA2 conferred Idasanutlin resistance at high concentrations. Finally, we observed that combining a FLT3/IRAK dual inhibitor, pacritinib, or an IRAK1 /IL-1 receptor antagonist, anakinra, partially rescued IL-1α and IL-1β mediated drug resistance of MDM2 inhibitors. As such, we uncovered the role of leukemia-associated monocyte in driving intrinsic and extrinsic MDM2 inhibitor resistance and the potential underlying mechanisms.

A Novel Multi-Analytic Clinical Diagnostic Assay to Detect HLA Loss of Heterozygosity in Post-Hematopoietic Cell Transplant Relapse Patients

Genomic loss of heterozygosity in the HLA region (HLA LOH) can be an underlying driver of disease relapse in haploidentical and HLA mismatched hematopoietic cell transplantation (HCT) in which relapsing cells evade donor T-cell allorecognition by deleting non-shared HLA alleles through an acquired somatic uniparental disomy event. The presence of HLA LOH may indicate a loss of graft vs. leukemia effect, render treatments such as donor leukocyte infusion ineffective, and impact donor selection for subsequent allogeneic HCT. A major challenge in developing a clinical diagnostic assay to detect HLA LOH post-HCT is sensitive detection of a loss of genomic material against a background of multiple genomes. Cell enrichment may address this issue by isolating relapsed cells for downstream molecular analysis. However, detection of HLA LOH is most clinically useful early in relapse when the relapsed cells are likely in low abundance, the relapsed cells may not be a single clonal population, and the immunophenotypic aberrancies may be variable and/or unknown. To address these issues, we have developed a comprehensive multi-analytic approach to detect HLA LOH that includes sensitive flow cytometric enrichment of leukemic cells followed by genomic analysis. First, a "difference from normal” flow cytometry approach (ΔN:™), the approach used for determination of residual disease in Children's Oncology Group AML clinical trials, is utilized to characterize the aberrant cells for each patient and relapse episode to ensure specific enrichment of relapsed cells to high purity. Next, two complementary molecular assays are used, including detection of short tandem repeat (STR) loci throughout the HLA region and next-generation sequencing (NGS) of HLA loci to identify deleted HLA alleles. In combination, the two assays provide a sensitive and spatially resolved assessment of LOH across the entire HLA genomic region, enabling molecular characterization of LOH events ranging from an entire HLA haplotype, partial HLA haplotype, or a single HLA locus. The ability to detect a locus-specific HLA LOH event could be useful in mismatched unrelated HCT donor/recipient pairs which may differ at only one or two HLA loci. Validation of the flow cytometric methods and genomic assays were performed separately. DNA isolated from the flow sorting process was shown to be suitable for both genomic assays. The sensitivity of the molecular assays to detect HLA LOH was defined using artificial mixes of DNA from two individuals with allelic mismatching at various HLA loci. Cell lines with known HLA LOH were also used to confirm the performance of the molecular assays. As of this writing, 16 samples from post-HCT relapse patients were tested with this assay and HLA LOH was detected in 3 cases (19%), consistent with published reports on the frequency of HLA LOH detected in allogeneic HCT patients. Samples with a range of relapsed leukemic cells from <1% to 85% and cell sorting output from 800 to 250,000 cells all yielded valid results. Results were reported within an average of 7 days, allowing adequate time for integration into therapeutic decision making. Challenging and unusual patient samples such as those with extremely low blast counts will be presented. Initial results indicate this clinical diagnostic assay provides reliable and accurate detection of HLA LOH during relapse in post-HCT patients. Detection of HLA LOH using our multi-analytic diagnostic approach may also aid in optimizing therapeutic decisions to improve outcomes in allogeneic HCT patients.

Mechanical and durability properties of alkali-activated binders based paver blocks derived from secondary sources

In this research study, low calcium fly ash (FA) and Ground granulated blast furnace slag (GGBS) are used as precursors activated with the solution of sodium hydroxides (SH) and sodium silicates (SS) for the development of geopolymer(GP) paver blocks. A total of 12 FA-GGBS based GP concrete mixes are developed by varying the ratio of SS solution to SH solution (0.25,0.67 and 2.33) along with the binder variation of FA: GGBS (80:20,70:30,60:40 and 50:50) under ambient curing conditions. From the synthesised FA: GGBS and alkalinity ratio, the required GP mixes for paver blocks suitable for medium traffic (M40) and heavy traffic (M50) conditions are formulated. The properties of the GP paver blocks such as mechanical and durability properties are evaluated as per the codal recommendations. All the GP paver blocks satisfy the minimum breaking load criteria with respect to flexural strength and split tensile strength and fall within the allowable abrasion resisting limits. The research findings affirm that the FA-GGBS blend GP paver blocks perform well as per specification requirements. Hence, these GP paver blocks can be adopted for various pavement applications thereby contributing to the adoption of sustainable construction practices.

MDS-110 SELECT-MDS-1 Trial in Progress: A Phase 3 Randomized, Double-Blind, Placebo-Controlled Study of Tamibarotene/Azacitidine Versus Placebo/Azacitidine in Newly Diagnosed Adult Patients Selected for RARA-Positive Higher-Risk MDS

A novel genomically defined subset of higher-risk myelodysplastic syndrome (HR-MDS) patients with an actionable target characterized by overexpression of RARA has been identified (McKeown 2017). Approximately 30% of HR-MDS patients are RARA-positive by a blood-based biomarker test (Vigil 2017). Tamibarotene is an oral selective RARα agonist with potential for clinical benefit in RARA-positive HR-MDS patients, irrespective of mutation or cytogenetic risk. Initial clinical data in RARA-positive relapsed/refractory HR-MDS showed myeloid differentiation, improved blood counts, and reduced bone marrow blasts, including one patient who achieved marrow complete remission with hematologic improvement (Jurcic 2017). Tamibarotene/azacitidine led to a CR/CRi rate of 61% with rapid onset of response in RARA-positive newly diagnosed (ND) unfit AML patients, including those with low blast count (≤30%) AML, and a majority of patients achieved or maintained transfusion independence (de Botton 2020). Tamibarotene/azacitidine was generally well tolerated with no increase in myelosuppression compared with azacitidine alone (de Botton 2020). Historical precedent demonstrating similar clinical outcomes in HR-MDS and low blast count AML (Estey 2022) supports further development of tamibarotene/azacitidine in HR-MDS to improve clinical outcomes of standard of care treatment with hypomethylating agents (HMAs). To characterize and compare the CR rate of tamibarotene/azacitidine to placebo/azacitidine in RARA-positive ND HR-MDS patients. Secondary objectives include comparisons of overall response rate, event-free survival, overall survival, transfusion independence, and safety. Global, Phase 3, randomized, double-blind, placebo-controlled trial (NCT04797780). Approximately 190 patients will be randomized 2:1, providing 90% power to detect the difference in CR rates between the experimental and control arms. The included patients will be RARA-positive based on investigational assay and ND with HR-MDS by WHO classification (Arber 2016) with an IPSS-R risk category of very high, high, or intermediate and a blast count >5% at baseline. Patients with prior treatment for MDS with any HMA, chemotherapy, or transplant are excluded. Azacitidine will be administered at 75 mg/m2 IV/SC daily on days 1-7 (or 1-5, 8-9) followed by tamibarotene/placebo at 6 mg BID orally on days 8-28 of each 28-day cycle. Response is assessed per the modified IWG MDS criteria (Cheson 2006).

Registration of ‘Trinity’ long‐grain rice cultivar

Abstract‘Trinity’ (Reg. no. CV‐156, PI 700309), a conventional long‐grain rice (Oryza sativa L.) with high grain yield and quality, was developed by the Texas A&amp;M AgriLife Research Center at Beaumont, TX, and released in 2021. Trinity was derived from a ‘Saber’/‘Cocodrie’//‘Presidio’ cross made in 2006. It was designated as LCRA060559A2 in the observational nursery, TXEL0540 in the Beaumont and statewide yield trials, and RU1603178 in the Uniform Regional Rice Nursery. Trinity was developed for the Texas rice industry by incorporating traits important to its producers. Its main (8.75 t ha–1) and ratoon (4.60 t ha–1) crop yields are 14 and 20% greater than those of check cultivar Presidio, respectively. At 95 cm, Trinity is taller than Presidio by 6 cm and has not been observed to lodge. It heads in 87 d and is early maturing. Its percentages of chalky grain and whole milled rice are 5.3 and 60%, respectively, which are slightly higher and lower, respectively, than those of Presidio. Trinity rice grain is non‐aromatic and classified as intermediate amylose and intermediate gelatinization temperature rice types, which are typical of a U.S. long‐grain rice cultivar. It exhibits a moderately low blast disease rating even without the Piz blast resistance gene present in Presidio. Overall, Trinity shows disease ratings comparable to Presidio but with significantly better sheath blight resistance than Presidio. Surveys from rice mills indicate that it has a very high potential as an acceptable long‐grain cultivar.

PB1921: A RANDOMIZED, DOUBLE-BLIND, PHASE 3 STUDY OF TAMIBAROTENE/AZACITIDINE VERSUS PLACEBO/AZACITIDINE IN NEWLY DIAGNOSED ADULT PATIENTS SELECTED FOR RARA-POSITIVE HR-MDS (SELECT-MDS-1)

Background: A novel genomically defined subset of higher-risk MDS (HR-MDS) patients with an actionable target characterized by overexpression of RARA has been identified (McKeown 2017). Approximately 30% of HR-MDS patients are RARA-positive (RARA+) by a blood-based biomarker test (Vigil, 2017). This RARA positivity enables biologically targeted therapy with tamibarotene (formerly SY-1425), an oral selective RARα agonist with potential to provide clinical benefit for HR-MDS patients, irrespective of mutation or cytogenetic risk. Initial Phase 2 clinical data in RARA+ relapsed/refractory HR-MDS patients treated with single agent tamibarotene showed myeloid differentiation, improved blood counts, and reduced bone marrow blasts, including one patient who achieved marrow complete remission with hematologic improvement (Jurcic 2017). Tamibarotene in combination with azacitidine (aza) demonstrated high complete response rates with rapid onset of response in RARA+ newly diagnosed (ND) unfit AML patients, including those with low blast count (≤ 30%) AML, and a majority of patients achieved or maintained transfusion independence (de Botton 2020). Tamibarotene plus aza was generally well tolerated with no increase in myelosuppression compared to single agent aza (de Botton 2020). HR-MDS and AML have common cytogenetic abnormalities and gene mutations present in the blast populations in each condition. The historical precedent demonstrating similar clinical outcomes among patients with HR-MDS and AML, particularly low blast count AML (Estey 2021), supports further development of the combination of tamibarotene plus aza in the HR-MDS population, with the opportunity to improve upon the clinical outcomes of standard of care treatment with hypomethylating agents (HMAs). Aims: This is a global Phase 3, multi-center, randomized, double-blind, placebo-controlled study comparing the activity of tamibarotene plus aza, to placebo plus aza in RARA+ patients with ND HR-MDS. The primary objective is to compare the complete remission rate of tamibarotene plus aza vs. placebo plus aza, with secondary objectives to compare objective response rate, event-free survival, overall survival, transfusion independence rate, time to and duration of initial and complete responses, and safety. Methods: Patients must be RARA+ based on the investigational biomarker test, ND with HR-MDS by WHO classification (Arber 2016), classified by IPSS-R risk category as very high, high, or intermediate risk with a bone marrow blast count > 5% at study entry. Patients suitable for allogeneic HSCT at the time of screening, or who received prior treatment for MDS with any HMA, chemotherapy or allogeneic HSCT are excluded. Aza will be administered at 75 mg/m2 IV/SC daily on days 1-7 (or days 1-5, 8-9) followed by tamibarotene/placebo at 6 mg BID orally days 8-28 of each 28-day cycle. Response will be assessed per the modified IWG MDS criteria (Cheson 2006). Results: Approximately 190 patients will be randomized 2:1 and stratified by IPSS-R risk group and geographic region, providing 90% power to detect the difference in CR rates between the experimental and control arms, respectively, with one-sided alpha of 0.025. Summary/Conclusion: The SELECT-MDS-1 trial opened to enrollment in February 2021, recruitment is ongoing, with sites located in North America, Israel, and Europe (NCT04797780).

Abstract CT027: Exploration of association of leukemic molecular profile with efficacy in patients (pts) with relapsed/refractory acute lymphoblastic leukemia (ALL) treated with inotuzumab ozogamicin (InO) in the phase 3 INO-VATE trial

Abstract Background: INO-VATE (NCT01564784) demonstrated higher rates of remission, MRD-negativity, and improved overall survival (hazard ratio 0.75, one-sided P=0.01) for pts with R/R ALL who received InO vs standard chemotherapy (SC). Here we explore the potential association between leukemic molecular profiles and efficacy of InO. Methods: Pts with CD22+ ALL due to receive salvage treatment were randomized to InO or SC; clinical methods and results were published previously (Kantarjian HM, et al. N Engl J Med 2016; PMID: 27292104). Bone marrow samples collected at screening post protocol amendment 2 underwent RNA-sequencing with analysis of gene expression profile, fusions, and genomic alterations. Data cutoff: Jan 4, 2017. Results: Of 326 pts in the INO-VATE intent-to-treat (ITT) population, 91 (InO, 43; SC, 48) had samples evaluable for molecular profiling. Baseline characteristics were similar in the evaluable pts vs the ITT population. Most common (≥5%) ALL subtypes were BCR-ABL1-positive (14%), low hypodiploidy (12%), Philadelphia chromosome (Ph)-like (11%), KMT2A-rearranged (9%), and DUX4-rearranged (6%); 29% (26/91) of pts could not be subtyped due to low blast counts. Most common (≥5%) non-BCR-ABL1 oncogenic fusions detected were IGH-CRLF2 (8%), and KMT2A-AFF1 (6%). Among non-fusion genomic alterations, those involving chromatin modifying genes featured prominently (e.g. KMT2D, 18%; CREBBP, 12%; KMT2C, 11%; ARID2, 9%; ARID1A, 8%; SET2D, 7%; EP300, 6%). Other commonly altered (≥9%) genes included TP53 (14%), NOTCH1 (11%), KRAS (9%), and PAX5 (9%). Similar to the overall findings of INO-VATE, complete remission (CR)/CR with incomplete count recovery (CRi) rates were numerically higher with InO vs SC across ALL subtypes, including but not limited to, low hypodiploidy (67% [2/3] vs 13% [1/8], P=0.15), Ph-like (83% [5/6] vs 0% [0/4], P=0.02), and KMT2A (100% [2/2] vs 17% [1/6], P=0.11), although not in BCR-ABL1-positive (67% [4/6] vs 57% [4/7], P=0.59). Within pts bearing common non-BCR-ABL1 oncogenic fusions, CR/CRi was seen for InO including for IGH-CRLF2 (50% [1/2] vs 20% [1/5] for SC), KMT2A-AFF1 (100% [1/1] vs 25% [1/4] for SC), and IGH-DUX4 (100% [3/3] vs 0% [0/1] for SC). Consistent with a previous report (Yang X, et al. Blood 2019; 134 [Suppl 1]: 3888) CR/CRi rates were high for InO in pts with TP53 alterations (100% [5/5] vs 13% [1/8] for SC, P=0.0047). Conclusions: This retrospective, exploratory analysis of INO-VATE demonstrated potential for benefit with InO for ALL pts across leukemic subtypes, including Ph-like, and for those bearing diverse fusions. Further exploration of Ph-like subtype or TP53 alterations as candidate predictive biomarkers for InO in pts with R/R ALL is warranted. Citation Format: Yaqi Zhao, A Douglas Laird, Kathryn Roberts, Rolla Yafawi, Hagop Kantarjian, Daniel J. DeAngelo, Matthias Stelljes, Michaela Liedtke, Wendy Stock, Nicola Gökbuget, Susan O'Brien, Elias Jabbour, Ryan D. Cassaday, Melanie R. Loyd, Scott Olsen, Geoffrey Neale, Xueli Liu, Erik Vandendries, Charles G. Mullighan, Anjali Advani. Exploration of association of leukemic molecular profile with efficacy in patients (pts) with relapsed/refractory acute lymphoblastic leukemia (ALL) treated with inotuzumab ozogamicin (InO) in the phase 3 INO-VATE trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT027.

A randomized, double-blind, placebo-controlled study of tamibarotene/azacitidine versus placebo/azacitidine in newly diagnosed adult patients selected for RARA+ HR-MDS (SELECT-MDS-1).

TPS7075 Background: A novel genomically defined subset of higher-risk MDS (HR-MDS) patients with an actionable target characterized by overexpression of RARA has been identified (McKeown 2017). Approximately 30% of HR-MDS patients are RARA-positive (RARA+) by a blood-based biomarker test (Vigil, 2017). Biologically targeted therapy with tamibarotene, an oral selective RARα agonist, has potential to provide clinical benefit for RARA+ HR-MDS patients, irrespective of mutation or cytogenetic risk. Initial clinical data in RARA+ R/R HR-MDS patients treated with tamibarotene showed myeloid differentiation, improved blood counts, and reduced bone marrow blasts, including one patient who achieved marrow complete remission with hematologic improvement (Jurcic 2017). Tamibarotene in combination with azacitidine (aza) showed high complete response rates (CR) with rapid onset of response in RARA+ newly diagnosed (ND) unfit AML patients, including those with low blast count (≤ 30%) AML, and a majority of patients achieved or maintained transfusion independence (de Botton 2020). Tamibarotene/aza was generally well tolerated with no increase in myelosuppression compared to aza alone (de Botton 2020). Historical precedent demonstrating similar clinical outcomes in HR-MDS and AML, particularly low blast count AML (Estey 2021), supports further development of tamibarotene/aza in HR-MDS to improve clinical outcomes of standard of care treatment with hypomethylating agents (HMAs). Methods: This Phase 3, multi-center, randomized, double-blind, placebo-controlled study will compare activity of tamibarotene/aza to placebo/aza in RARA+ patients with ND HR-MDS. The primary objective is to characterize and compare the CR rate of tamibarotene/aza vs placebo/aza, with secondary objectives to characterize ORR, EFS, OS, transfusion independence rate, time to and duration of initial and complete responses, and safety. Approximately 190 patients will be randomized 2:1, providing 90% power to detect the difference in CR rates between the experimental and control arms, with a one-sided alpha of 0.025. Patients must be RARA+ based on the investigational biomarker test, ND with HR-MDS by WHO classification (Arber 2016), classified by IPSS-R risk category as very high, high, or intermediate risk with a blast count &gt; 5% at study entry. Patients suitable for transplant at screening, or with prior treatment for MDS with any HMA, chemotherapy or transplant are excluded. Aza will be administered at 75 mg/m2 IV/SC daily on days 1-7 (or 1-5, 8-9) followed by tamibarotene/placebo at 6 mg BID orally days 8-28 of each 28-day cycle. Response will be assessed per modified IWG MDS criteria (Cheson 2006). The SELECT-MDS-1 trial opened in February 2021, recruitment is ongoing, with sites located in North America, Israel, and Europe. Clinical trial information: NCT04797780.

Prognostic impact of DDX41 germline mutations in intensively treated acute myeloid leukemia patients: an ALFA-FILO study

AbstractDDX41 germline mutations (DDX41MutGL) are the most common genetic predisposition to myelodysplastic syndrome and acute myeloid leukemia (AML). Recent reports suggest that DDX41MutGL myeloid malignancies could be considered as a distinct entity, even if their specific presentation and outcome remain to be defined. We describe here the clinical and biological features of 191 patients with DDX41MutGL AML. Baseline characteristics and outcome of 86 of these patients, treated with intensive chemotherapy in 5 prospective Acute Leukemia French Association/French Innovative Leukemia Organization trials, were compared with those of 1604 patients with DDX41 wild-type (DDX41WT) AML, representing a prevalence of 5%. Patients with DDX41MutGL AML were mostly male (75%), in their seventh decade, and with low leukocyte count (median, 2 × 109/L), low bone marrow blast infiltration (median, 33%), normal cytogenetics (75%), and few additional somatic mutations (median, 2). A second somatic DDX41 mutation (DDX41MutSom) was found in 82% of patients, and clonal architecture inference suggested that it could be the main driver for AML progression. DDX41MutGL patients displayed higher complete remission rates (94% vs 69%; P < .0001) and longer restricted mean overall survival censored at hematopoietic stem cell transplantation (HSCT) than 2017 European LeukemiaNet intermediate/adverse (Int/Adv) DDX41WT patients (5-year difference in restricted mean survival times, 13.6 months; P < .001). Relapse rates censored at HSCT were lower at 1 year in DDX41MutGL patients (15% vs 44%) but later increased to be similar to Int/Adv DDX41WT patients at 3 years (82% vs 75%). HSCT in first complete remission was associated with prolonged relapse-free survival (hazard ratio, 0.43; 95% confidence interval, 0.21-0.88; P = .02) but not with longer overall survival (hazard ratio, 0.77; 95% confidence interval, 0.35-1.68; P = .5).

Exemplification of sustainable sodium silicate waste sediments as coarse aggregates in the performance evaluation of geopolymer concrete

This investigation presents the experimental studies on mechanical properties of geopolymer concrete (GPC) developed with the addition of sodium silicate waste sediments (SSW) as coarse aggregates. Conventional crushed granite coarse aggregate (CA) was replaced by SSW from the sodium silicate manufacturing plant. The GPC was developed by replacing the natural CA with SSW from 0% − 70% with a trend in exercising circular economy in the concrete. The GPC with 100% CA was used as the control specimen to compare the results of different replacement levels of SSW. A low calcium Fly ash (FA) and Ground granulated blast furnace slag (GGBS) were used as binder materials, along with sodium hydroxide and sodium silicate solutions as activator solutions. The sodium hydroxide of 4 M and sodium hydroxide to sodium silicate ratio of 1:1.5 were used in the development of the mixes. Two types of curing conditions namely, ambient and oven curing were adopted. The M30 grade design mix was used for control and CA replaced specimens. The mechanical properties such as compressive, tensile, and flexural strengths along with the elastic modulus of GPC at the ages of 7-, and 28-day were investigated. Microstructural analysis was conducted to examine the influence of SSW on the strength characteristics of GPC. The analyses were performed to evaluate the energy requirement and CO2 emission of GPC and OPCC (Ordinary Portland Cement Concrete) in the production of 1 m3 concrete based on the previous literature. The significance of the proposed research work emphasizes the utilization of waste SSW as an aggregate material for the development of GPC. Therefore, a sustainable GPC mix can be developed with lower energy requirement and CO2 emission. The results revealed that the specimens with 40% SSW cured at 60 °C produced the targeted strength of 34.6 MPa. Meanwhile, the mixes with 40% − 70% of SSW exhibited superior performance in terms of cost and eco-efficiencies.

Fabrication of alpha irradiation technique and study the impact of low alpha particles density on the lymphoblast cells of Leukemia blood samples

Fabrication of alpha irradiation technique has been fabricated using CR-39 nuclear track detector, medical injection pin, and micro capillarity tubes. Optimum alpha irradiation parameters (time of irradiation and alpha energy) were used to study the impacts of the low density of accumulated alpha particles on the percentages of lymphoblast cells (Blast cells) for 20 leukemia blood samples. The results show that the fabricated cell irradiation collimator is given significant results to irradiate whole blood samples. Low alpha particle density corresponded with the short time of irradiation at the fixed alpha energy (E=4.5 MeV). The results of the blast cell irradiation approved that the accumulated alpha particles affected the percentage of blast cells depending on the time of irradiation. 20 sec of irradiation is sufficient to reduce low blast cells percentage (≤30 %) to half, and 40 sec is enough to reduce blast cell percentage to half for the cases that have more than 30 % to 60 % of blast cells. Percentage of blast cells reduced regarded to the accumulated density of alpha particles in a power relationship.

Failure to reach hematopoietic allogenic stem cell transplantation in patients with myelodysplastic syndromes planned for transplantation: a population-based study

The only potential cure for patients with myelodysplastic syndrome (MDS) is allogeneic hematopoietic stem cell transplantation (HCT). However, a proportion of patients who are HCT candidates do not finally get transplanted. This population-based study aimed to characterize HCT candidates were attempting to reach HCT fail and to identify causes and risk factors for failure. Data were collected from (1) the national Swedish registry, enrolling 291 transplant candidates between 2009–2018, and (2) Karolinska University Hospital, enrolling 131 transplantation candidates between 2000 and 2018. Twenty-five % (nation-wide) and 22% (Karolinska) failed to reach HCT. Reasons for failure to reach HCT were progressive and refractory disease (47%), no donor identified (22%), identification of comorbidity (18%), and infectious complications (14%). Factors associated with failure to reach HCT were IPSS-R cytogenetic risk-group very poor, mixed MDS/MPN disease, low blast count (0–4.9%), and low hemoglobin levels (≤7.9 g/dL). Transplanted patients had a longer overall survival (OS) compared to patients who failed to reach transplantation (83 months versus 14 months; p < 0.001). The survival advantage was seen for the IPSS-R risk groups intermediate, high, and very high. This study demonstrated that a high proportion of HCT-candidates fail to reach HCT and underlines the difficulties associated with bridging MDS patients to HCT.

Clinical, immunophenotypic, and cytogenetic characteristics of high-grade myelodysplastic syndromes with CD41-positive progenitor cells.

Patients with myelodysplastic syndromes (MDS) with progenitors expressing CD41 (CD41+ MDS) showed a poor prognosis in a previous study but their detailed characteristics remain unclear. One hundred thirty-seven subjects at our institution were diagnosed with excess blasts (EB)-1, EB-2, and acute myeloid leukemia with a low blast count (20%-30%). The immunophenotypes of progenitor cells in their bone marrow (BM) were determined by CD45-gating flow cytometry. A false-positive reaction to CD41 was eliminated by examining the flow cytometry data of lymphocytes and monocytes in addition to progenitors and by examining CD42b in histological sections. The characteristics were compared between CD41+ and CD41- MDS patients. Forty-three patients (31%) were CD41+. Additionally, 91% of the CD41+ MDS patients were very high-risk defined by the Revised International Prognostic Score System, which was higher than in patients with CD41- MDS (p=0.015). Approximately 60% of the CD41+ MDS patients had a monosomal karyotype and very poor cytogenetics, which was higher than in CD41- MDS patients (p < 0.001). Normal cytogenetics was less common in CD41+ patients (p=0.0016). Blasts with bleb formation were more abundant in CD41+ MDS patients (p=0.026). All CD41+ MDS patients were positive for CD13 and were mostly positive for CD33. The frequency of aberrant expression of other antigens on progenitors was similar between CD41+ and CD41- MDS patients. We determined clinical, immunophenotypic, and cytogenetic characteristics of CD41+ MDS patients. Further studies are needed to improve the survival of these patients.

Hemoglobin is a key determinant of quality of life before and during azacitidine-based therapy for myelodysplasia and low blast count acute myeloid leukemia

Myelodysplastic syndromes (MDS) have a major impact on quality of life (QoL). We performed a post hoc analysis of two multicenter trials of azacitidine-based disease-modifying therapy for patients with MDS and low blast count acute myeloid leukemia (AML), to identify factors associated with QoL. 231 patients were included (median age 70 years). At baseline, higher initial hemoglobin, but not neutrophil or platelet count, was associated with better global QoL and physical function (p < 0.001 and p = 0.001, respectively). During therapy, increase in hemoglobin was associated with improvement in QoL and physical function (p = 0.005 and p < 0.001, respectively). Lower initial hemoglobin was associated with higher dyspnea and fatigue scores (p < 0.001 and p = 0.001, respectively), and hemoglobin response was associated with improvement in dyspnea and fatigue (p < 0.001 for each). In patients with MDS and low blast count AML, hemoglobin level was strongly correlated with global QoL, physical functioning, dyspnea and fatigue, both before and during azacitidine-based therapy.

Overview on Pediatric Myelodysplastic Syndrome: A Review

Myelodysplastic syndrome (MDS) is a set of clonal bone marrow diseases in children that are characterised by peripheral cytopenia, dysplastic alterations in the bone marrow, and inefficient hematopoiesis. MDS is uncommon in children, with just 1-4 occurrences per million children afflicted. Adults, particularly the elderly, are more susceptible to the disease. Some hereditary disorders, such as Fanconi's anaemia, Shwachman's, and Down's syndromes, are known to predispose children to developing MDS. JCML and monosomy 7 syndrome are the two most frequent paediatric MDS types, both of which affect children in their early years. Approximately 20% of juvenile myelodysplastic syndrome (MDS) cases are discovered by chance during normal laboratory testing or during the course of a suspected hereditary bone marrow failure (IBMF). Differentiating MDS with low blast numbers from aplastic anaemia (AA) and MDS with excess blasts from AML are the two key diagnostic issues in this condition. Bone marrow transplantation and stem cell transplantation is the treatment of choice in most cases. In this article we discuss the disease epidemiology, diagnosis, and treatment.