Expression, Regulation and Function of microRNA as Important Players in the Transition of MDS to Secondary AML and Their Cross Talk to RNA-Binding Proteins.

Myelodysplastic syndromes (MDS), heterogeneous diseases of hematopoietic stem cells, exhibit a significant risk of progression to secondary acute myeloid leukemia (sAML) that are typically accompanied by MDS-related changes and therefore significantly differ to de novo acute myeloid leukemia (AML). Within these disorders, the spectrum of cytogenetic alterations and oncogenic mutations, the extent of a predisposing defective osteohematopoietic niche, and the irregularity of the tumor microenvironment is highly diverse. However, the exact underlying pathophysiological mechanisms resulting in hematopoietic failure in patients with MDS and sAML remain elusive. There is recent evidence that the post-transcriptional control of gene expression mediated by microRNAs (miRNAs), long noncoding RNAs, and/or RNA-binding proteins (RBPs) are key components in the pathogenic events of both diseases. In addition, an interplay between RBPs and miRNAs has been postulated in MDS and sAML. Although a plethora of miRNAs is aberrantly expressed in MDS and sAML, their expression pattern significantly depends on the cell type and on the molecular make-up of the sample, including chromosomal alterations and single nucleotide polymorphisms, which also reflects their role in disease progression and prediction. Decreased expression levels of miRNAs or RBPs preventing the maturation or inhibiting translation of genes involved in pathogenesis of both diseases were found. Therefore, this review will summarize the current knowledge regarding the heterogeneity of expression, function, and clinical relevance of miRNAs, its link to molecular abnormalities in MDS and sAML with specific focus on the interplay with RBPs, and the current treatment options. This information might improve the use of miRNAs and/or RBPs as prognostic markers and therapeutic targets for both malignancies.

Concomitant and noncanonical JAK2 and MPL mutations in JAK2V617F- and MPLW515 L-positive myelofibrosis.

Sequential genotyping for phenotype-driver mutations in JAK2 (exon 14), CALR (exon 9), and MPL (exon 10) is recommended in patients with myeloproliferative neoplasms. Yet, atypical JAK2- and MPL-mutations were described in some triple-negative patients. Whether noncanonical and/or concomitant JAK2- and MPL-mutations exist in myelofibrosis (MF) regardless of phenotype-driver mutations is not yet elucidated. For this, next-generation sequencing (NGS) was performed using blood genomic DNA from 128 MF patients (primary MF, n = 93; post-ET-MF, n = 18; post-PV-MF, n = 17). While no atypical JAK2- or MPL-mutations were seen in 24 CALR-positive samples, two JAK2-mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected in two of the 21 (9.5%) triple-negative patients. Twelve of the 82 (14.6%) JAK2V617F-positive cases had coexisting germline JAK2-mutations [JAK2R1063H, n = 6; JAK2R893T, n = 1; JAK2T525A, n = 1] or at least one somatic MPL-mutation [MPLY591D, n = 3; MPLW515 L, n = 2; MPLE335K, n = 1]. Overall, MPL-mutations always coexisted with JAK2V617F and/or other MPL-mutations. None of the JAK2V617F plus a second JAK2-mutation carried a TET2-mutation but all patients with JAK2V617F plus an MPL-mutation harbored a somatic TET2-mutation. Four genomic clusters could be identified in the JAK2V617F-positive cohort. Cluster-I (10%) (noncanonical JAK2mutated (mut) + TET2wildtype (wt) ) were younger and had less proliferative disease compared with cluster-IV (5%) (TET2mut + MPLmut ). In conclusion, recurrent concomitant classical and/or noncanonical JAK2- and MPL-mutations could be detected by NGS in 15.7% of JAK2V617F- and MPLW515-positive MF patients with genotype-phenotype associations. Many of the germline and/or somatic mutations might act as "Significantly Mutated Genes" contributing to the pathogenesis and phenotypic heterogeneity. A cost-effective NGS-based approach might be an important step towards patient-tailored medicine.

Vector-based SARS-CoV-2 vaccination is associated with improved T-cell responses in hematological neoplasia.

In order to elucidate mechanisms for severe acute respiratory syndrome coronavirus 2 vaccination success in hematological neoplasia, we, herein, provide a comprehensive characterization of the spike-specific T-cell and serological immunity induced in 130 patients in comparison with 91 healthy controls. We studied 121 distinct T-cell subpopulations and the vaccination schemes as putative response predictors. In patients with lymphoid malignancies an insufficient immunoglobulin G (IgG) response was accompanied by a healthy CD4+ T-cell function. Compared with controls, a spike-specific CD4+ response was detectable in fewer patients with myeloid neoplasia whereas the seroconversion rate was normal. Vaccination-induced CD4+ responses were associated to CD8+ and IgG responses. Vector-based AZD1222 vaccine induced more frequently detectable specific CD4+ responses in study participants across all cohorts (96%; 27 of 28), whereas fully messenger RNA-based vaccination schemes resulted in measurable CD4+ cells in only 102 of 168 participants (61%; P < .0001). A similar benefit of vector-based vaccination was observed for the induction of spike-specific CD8+ T cells. Multivariable models confirmed vaccination schemes that incorporated at least 1 vector-based vaccination as key feature to mount both a spike-specific CD4+ response (odds ratio, 10.67) and CD8+ response (odds ratio, 6.56). Multivariable analyses identified a specific CD4+ response but not the vector-based immunization as beneficial for a strong, specific IgG titer. Our study reveals factors associated with a T-cell response in patients with hematological neoplasia and might pave the way toward tailored vaccination schemes for vaccinees with these diseases. The study was registered at the German Clinical Trials Register as #DRKS00027372.

Decitabine Versus Hydroxyurea for Advanced Proliferative Chronic Myelomonocytic Leukemia: Results of a Randomized Phase III Trial Within the EMSCO Network.

PURPOSE: Hydroxyurea (HY) is a reference treatment of advanced myeloproliferative neoplasms. We conducted a randomized phase III trial comparing decitabine (DAC) and HY in advanced myeloproliferative chronic myelomonocytic leukemias (CMML). PATIENTS AND METHODS: Newly diagnosed myeloproliferative CMML patients with advanced disease were randomly assigned 1:1 to intravenous DAC (20 mg/m2/d days 1-5) or HY (1-4 g/d) in 28-day cycles. The primary end point was event-free survival (EFS), events being death and acute myelomonocytic leukemia (AML) transformation or progression. RESULTS: One-hundred seventy patients received DAC (n = 84) or HY (n = 86). Median age was 72 and 74 years, and median WBC count 32.5 × 109/L and 31.2 × 109/L in the DAC and HY arms, respectively. Thirty-three percent of DAC and 31% of HY patients had CMML-2. Patients received a median of five DAC and six HY cycles. With a median follow-up of 17.5 months, median EFS was 12.1 months in the DAC arm and 10.3 months in the HY arm (hazard ratio [HR], 0.83; 95% CI, 0.59 to 1.16; P = .27). There was no significant interaction between treatment effect and blast or platelet count, anemia, CMML Prognostic Scoring System, Groupe Francophone des Myelodysplasies, or CMML Prognostic Scoring System-mol risk. Fifty-three (63%) DAC patients achieved a response compared with 30 (35%) HY patients (P = .0004). Median duration of response was similar in both arms (DAC, 16.3 months; HY, 17.4 months; P = .90). Median overall survival was 18.4 months in the DAC arm and 21.9 months in the HY arm (P = .67). Compared with HY, DAC significantly reduced the risk of CMML progression or transformation to acute myelomonocytic leukemia (cause-specific HR, 0.62; 95% CI, 0.41 to 0.94; P = .005) at the expense of death without progression or transformation (cause-specific HR, 1.55; 95% CI, 0.82 to 2.9; P = .04). CONCLUSION: Compared with HY, frontline treatment with DAC did not improve EFS in patients with advanced myeloproliferative CMML (ClinicalTrials.gov identifier: NCT02214407).

Longitudinal Humoral and Cellular Immune Responses Following SARS-CoV-2 Vaccination in Patients with Myeloid and Lymphoid Neoplasms Compared to a Reference Cohort: Results of a Prospective Trial of the East German Study Group for Hematology and Oncology (OSHO).

Purpose: To assess humoral responses longitudinally and cellular immunogenicity following SARS-CoV-2-vaccination in patients with hematologic and oncologic malignancies receiving checkpoint-inhibitors. Methods: This prospective multicenter trial of the East-German-Study-Group-for-Hematology-and-Oncology, enrolled 398 adults in a two (patients; n = 262) to one (controls; n = 136) ratio. Pre-vaccination, day 35 (d35), and day 120 (d120) blood samples were analyzed for anti-spike antibodies and d120 IL-2+IFNγ+TNFα+-CD4+- and CD8+-cells. Laboratories were blinded for patients and controls. Results: Patients belonged to the myeloid (n = 131), lymphoid (n = 104), and checkpoint-inhibitor (n = 17) cohorts. While d35 seroconversion was higher in controls (98%) compared to patients (68%) (p < 0.001), d120 seroconversion improved across all patient cohorts [checkpoint-inhibitors (81% to 100%), myeloid (82% to 97%), lymphoid (48% to 66%)]. CD4+- and CovCD8+-cells in the lymphoid (71%/31%) and control (74%/42%) cohorts were comparable but fewer in the myeloid cohort (53%, p = 0.003 /24%, p = 0.03). In patients with hematologic malignancies, no correlation between d120 humoral and cellular responses was found. A sizeable fraction of lymphoid patients demonstrated T-cell responses without detectable spike-specific-IgGs. Conclusions: Evidence of vaccine-elicited humoral and/or cellular immunogenicity in most patients is provided. Both humoral and cellular responses are crucial to determine which patients will generate/maintain immunity. The findings have implications on public health policy regarding recommendations for SARS-CoV-2 booster doses.

Altered Spatial Composition of the Immune Cell Repertoire in Association to CD34+ Blasts in Myelodysplastic Syndromes and Secondary Acute Myeloid Leukemia.

Background: Myelodysplastic syndromes (MDS) are caused by a stem cell failure and often include a dysfunction of the immune system. However, the relationship between spatial immune cell distribution within the bone marrow (BM), in relation to genetic features and the course of disease has not been analyzed in detail. Methods: Histotopography of immune cell subpopulations and their spatial distribution to CD34+ hematopoietic cells was determined by multispectral imaging (MSI) in 147 BM biopsies (BMB) from patients with MDS, secondary acute myeloid leukemia (sAML), and controls. Results: In MDS and sAML samples, a high inter-tumoral immune cell heterogeneity in spatial proximity to CD34+ blasts was found that was independent of genetic alterations, but correlated to blast counts. In controls, no CD8+ and FOXP3+ T cells and only single MUM1p+ B/plasma cells were detected in an area of ≤10 µm to CD34+ HSPC. Conclusions: CD8+ and FOXP3+ T cells are regularly seen in the 10 µm area around CD34+ blasts in MDS/sAML regardless of the course of the disease but lack in the surrounding of CD34+ HSPC in control samples. In addition, the frequencies of immune cell subsets in MDS and sAML BMB differ when compared to control BMB providing novel insights in immune deregulation.

The role of hypomethylating agents in the treatment of elderly patients with AML.

There is a major unmet medical need for treatment options in elderly patients with acute myeloid leukemia (AML) who are deemed ineligible for intensive treatment. The recent approval of decitabine in the European Union for the treatment of patients with AML≥ 65 years old highlights the potential for hypomethylating agents in this setting. Here, we review evidence to support the use of hypomethylating agents in elderly patients and emphasize the importance of tolerability and quality of life considerations. We focus on the rationale for the continued clinical development of the ribonucleoside analog azacitidine in this setting. We discuss potential differences in the activity of azacitidine and decitabine in different patient subgroups that could possibly be explained by important differences in mechanism of action. Finally, we assess practical challenges that will be faced when integrating hypomethylating agents into clinical practice, such as how to define ineligibility for intensive treatment.

Pretreatment long interspersed element (LINE)-1 methylation levels, not early hypomethylation under treatment, predict hematological response to azacitidine in elderly patients with acute myeloid leukemia.

BACKGROUND: Epigenetic modulations, including changes in DNA cytosine methylation, are implicated in the pathogenesis and progression of acute myeloid leukemia (AML). Azacitidine is a hypomethylating agent that is incorporated into RNA as well as DNA. Thus, there is a rationale to its use in patients with AML. We determined whether baseline and/or early changes in the methylation of long interspersed element (LINE)-1 or CDH13 correlate with bone marrow blast clearance, hematological response, or survival in patients with AML treated with azacitidine. METHODS: An open label, phase I/II trial was performed in 40 AML patients (median bone marrow blast count was 42%) unfit for intensive chemotherapy treated with azacitidine 75 mg/m(2)/day subcutaneously for 5 days every 4 weeks. Bone marrow mononuclear cell samples were taken on day 0 (pretreatment) and day 15 during the first treatment cycle; LINE-1 and CDH13 methylation levels were quantified by methylation-specific, semiquantitative, real-time polymerase chain reaction. RESULTS: Treatment with azacitidine significantly reduced LINE-1 but not CDH13 methylation levels over the first cycle (P < 0.0001). Absolute LINE-1 methylation levels tended to be lower on day 0 (P = 0.06) and day 15 of cycle 1 (P = 0.03) in patients who went on to achieve subsequent complete remission, partial remission or hematological improvement versus patients with stable disease. However, the decrease in LINE-1 methylation over the first treatment cycle did not correlate with subsequent response (P = 0.31). Baseline methylation levels of LINE-1 or CDH13 did not correlate with disease-related prognostic factors, including cytogenetic risk, relapsed/refractory AML, or presence of NPM1 or FLT3 mutations. No correlation was observed between LINE-1 or CDH13 methylation levels and overall survival. CONCLUSION: Analysis of baseline LINE-1 methylation levels may help identify elderly AML patients who are most likely to respond to azacitidine therapy.

Kinetics of iron removal by phlebotomy in patients with iron overload after allogeneic hematopoietic cell transplantation.

UNLABELLED: Excess body iron could persist for years after allogeneic hematopoietic cell transplantation (HCT) with possible deleterious sequels. An iron depletive therapy with phlebotomy seems rational. Kinetics of iron removal by phlebotomy without erythropoietin support in non-thalassemic adult patients with iron overload after HCT and the impact of pre- and post-HCT hemochromatosis (HFE) genotype on iron mobilization were investigated. PATIENTS AND METHODS: Phlebotomy was initiated in 61 recipients of allografts due to hematologic malignancies (median age 48 years) after a median of 18 months. The prephlebotomy median serum ferritin (SF) was 1697ng/ml and the median number of blood transfusions 28 units. Alanine aminotransferase (ALT)/aspartate aminotransferase (AST), alkaline phosphates (AP), and bilirubin were elevated in 55.7%, 64% and 11.5% patients respectively. HFE-genotype was elucidated by polymerase chain reaction using hybridization probes and melting curve analysis. RESULTS: Phlebotomy was well-tolerated irrespective of age or conditioning. A negative iron balance in 80% of patients (median SF 1086 ng/ml) and a rise in hemoglobin were observed (p<0.0001). Higher transfusional burden and SF were associated with a greater iron mobilization per session (p=0.02). In 58% of patients, a plateau after an initial steady decline in SF was followed by a second decline under further phlebotomy. The improvement in ALT (p=0.002), AST (p=0.03), AP (p=0.01), and bilirubin (p<0.0001) did not correlate with the decline in SF. Mutant HFE-gene variants were detected in 14/55 (25%) pre-HCT and 22/55 (40%) patients post-HCT. Overall, dissimilar pre- and posttransplantational HFE-genotypes were detected in 20/55 (40%) patients. Posttransplantational mutant HFE variants correlated with a slower decline in SF (p=0.007). CONCLUSIONS: Phlebotomy is a convenient therapy of iron overload in survivors of HCT. A negative iron balance and a rise in hemoglobin were observed in the majority of patients. Liver dysfunction improved irrespective of SF reduction suggesting a probable rapid decline of the deleterious labile plasma iron. In recipients of grafts with mutant HFE variants a "mixed chimerism" of HFE in body tissues might be created with a change in the set point for iron regulation. The transient plateau in SF after an initial decline might reflect iron mobilization from various tissues.

Azacitidine in patients with acute myeloid leukemia medically unfit for or resistant to chemotherapy: a multicenter phase I/II study.

The safety and efficacy of azacitidine (5-day schedule) were assessed in a multicenter study in 40 patients (median age 72 years) with acute myeloid leukemia (AML) medically unfit for (n = 20) or resistant to chemotherapy (n = 20) from April to October 2008. Median marrow blasts were 42%. After a median follow-up of 13 months, response (complete remission [CR]/partial remission [PR]/hematologic improvement [HI]) was 50% and 10% in newly diagnosed and relapsed/refractory patients, respectively (p = 0.008). Median time-to-response was 2.5 months with a median duration of 5.9 months. Median survival was not reached for responders versus 3.8 months for 15 (38%) patients with stable disease (p < 0.045). High-risk cytogenetics was associated with inferior survival (p = 0.05). Lower marrow blasts on day 15 of cycle 1, irrespective of pretreatment count, predicted subsequent response (p = 0.01). Azacitidine is active and well tolerated in elderly patients with newly diagnosed AML.