Non-catalytic Roles of Tet2 Are Essential to Regulate Hematopoietic Stem and Progenitor Cell Homeostasis

The Ten-eleven translocation (TET) enzymes regulate gene expression by promoting DNA demethylation and partnering with chromatin modifiers. TET2, a member of this family, is frequently mutated in hematological disorders. The contributions of TET2 in hematopoiesis have been attributed to its DNA demethylase activity, and the significance of its nonenzymatic functions has remained undefined. To dissect the catalytic and non-catalytic requirements of Tet2, we engineered catalytically inactive Tet2 mutant mice and conducted comparative analyses of Tet2 mutant and Tet2 knockout animals. Tet2 knockout mice exhibited expansion of hematopoietic stem and progenitor cells (HSPCs) and developed myeloid and lymphoid disorders, while Tet2 mutant mice predominantly developed myeloid malignancies reminiscent of human myelodysplastic syndromes. HSPCs from Tet2 knockout mice exhibited distinct gene expression profiles, including downregulation of Gata2. Overexpression of Gata2 in Tet2 knockout bone marrow cells ameliorated disease phenotypes. Our results reveal the non-catalytic roles of TET2 in HSPC homeostasis

Impact of baseline cytogenetic findings and cytogenetic response on outcome of high-risk myelodysplastic syndromes and low blast count AML treated with azacitidine

•Cytogenetic findings are strong predictor for survial in AZA-treated MDS patients.•Isolated del(7q) had similar survival as patients with normal karyotype.•Cytogenetic abnormalities don’t predict response to AZA.•Achieving cytogenetic response has a limited effect on outcomes in AZA-treated patients. Karyotype according to the revised IPSS is a strong independent prognostic factor for overall survival (OS) in myelodysplastic syndromes (MDS), however established in untreated patients. The prognostic impact of cytogenetics and cytogenetic response (CyR) in MDS patients receiving azacitidine (AZA) remains uncertain. We examined the prognostic value of baseline cytogenetics and CyR for overall response rate (ORR) and OS in 702 AZA-treated higher risk MDS and low blast count acute myeloid leukemia (AML), including 493 (70%) with abnormal karyotype. None of the cytogenetic abnormalities had significant impact on ORR (43.9%) or complete response (15.35%), except 3q abnormalities and complex karyotypes, which were associated with a lower ORR. OS differed significantly across all R-IPSS cytogenetic subgroups (p<10−4) but patients with non complex del(7q) had similar survival as patients with normal cytogenetics. CyR was achieved in 32% of the 281 evaluable patients with abnormal cytogenetics, was complete (CCyR) in 71 (25.3%) patients. We found no correlation between hematological response and cytogenetic response and 21% of the patients with CCyR did not achieve morphological response. In the 281 patients, we found no impact of CyR on survival, but when restricting to MDS (ie: <20% marrow blasts) achievement of CCyR was associated with better OS

Phase 2 trial of CPX-351, a fixed 5:1 molar ratio of cytarabine/daunorubicin, vs cytarabine/daunorubicin in older adults with untreated AML

CPX-351 is a liposomal formulation of cytarabine: daunorubicin designed to deliver synergistic drug ratios to leukemia cells. In this phase 2 study, newly diagnosed older acute myeloid leukemia (AML) patients were randomized 2: 1 to first-line CPX-351 or 713 treatment. The goal was to determine efficacy and identify patient subgroups that may benefit from CPX-351 treatment. Response rate (complete remission 1 incomplete remission) was the primary end point, with event-free survival (EFS) and overall survival (OS) as secondary end points. The 126 patients entered were balanced for disease and patient-specific risk factors. Overall, CPX-351 produced higher response rates (66.7% vs 51.2%, P = .07), meeting predefined criteria for success (P \u3c .1). Differences in EFS and OS were not statistically significant. A planned analysis of the secondary AML subgroup demonstrated an improved response rate (57.6% vs 31.6%, P = .06), and prolongation of EFS (hazard ratio [HR] = 0.59, P = .08) and OS (HR = 0.46, P = .01). Recovery from cytopenias was slower after CPX-351 (median days to absolute neutrophil count \u3e= 1000: 36 vs 32; platelets \u3e100 000:37 vs 28) with more grade 3-4 infections but without increase in infection-related deaths (3.5% vs 7.3%) or 60-day mortality (4.7% vs 14.6%), indicating acceptable safety. These results suggest a clinical benefit with CPX-351, particularly among patients with secondary AML, and provide the rationale for a phase 3 trial currently underway in newly diagnosed secondary AML patients. This study is registered at Clinicaltrials.gov as #NCT00788892

Severe Hypoalbuminemia at Day 90 Predicts Worse Nonrelapse Mortality and Overall Survival after Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myelogenous Leukemia and Myelodysplastic Syndrome

Because patients who undergo allogeneic hematopoietic cell transplantation (allo-HCT) remain in the vicinity of the transplant center for approximately 90 days posttransplantation, identifying prognostic factors to determine those at immediate higher risk of mortality is essential. A normal serum albumin level generally denotes healthiness. We evaluated the prognostic significance of day 90 hypoalbuminemia (and other clinical, pharmacologic, and laboratory variables) in 163 patients, median age 48 years (range, 19-69 years), who underwent allo-HCT for acute myelogenous leukemia (n = 124) or myelodysplastic syndrome (n = 39). Day 90 hypoalbuminemia (serum albumin <3.0 g/dL) was associated with worse nonrelapse mortality (NRM) and poor overall survival (OS). The estimated 1- and 2-year cumulative incidence rates of NRM were 48% and 52%, respectively, and the corresponding OS rates were 7% and 3%. Serum albumin level <3.0 g/dL and Karnofsky score <80 at day 90 were strong independent predictors of worse NRM and OS in multivariate analysis. These results support day 90 hypoalbuminemia as an adverse prognostic marker for NRM and OS after allo-HCT for acute myelogenous leukemia and myelodysplastic syndrome

Multivariate analysis of febrile neutropenia occurrence in patients with non-Hodgkin lymphoma: data from the INC-EU Prospective Observational European Neutropenia Study

Myelosuppression, particularly febrile neutropenia (FN), are serious dose-limiting toxicities that occur frequently during the first cycle of chemotherapy. Identifying patients most at risk of developing FN might help physicians to target prophylactic treatment with colony-stimulating factor (CSF), in order to decrease the incidence, or duration, of myelosuppression and facilitate delivery of chemotherapy as planned. We present a risk model for FN occurrence in the first cycle of chemotherapy, based on a subgroup of 240 patients with non-Hodgkin lymphoma (NHL) enroled in our European prospective observational study. Eligible patients had an International Prognostic Index of 0–3, and were scheduled to receive a new myelosuppressive chemotherapy regimen with at least four cycles. Clinically relevant factors significantly associated with cycle 1 FN were older age, increasing planned cyclophosphamide dose, a history of previous chemotherapy, a history of recent infection, and low baseline albumin (<35 g/l). Prophylactic CSF use and higher weight were associated with a significant protective effect. The model had high sensitivity (81%) and specificity (80%). Our model, together with treatment guidelines, may rationalise the clinical decision of whether to support patients with CSF primary prophylaxis based on their risk factor profile. Further validation is required