Loss of hematopoietic progenitors heterogeneity is an adverse prognostic factor in lower-risk myelodysplastic neoplasms.

Myelodysplastic neoplasms (MDS) are characterized by clonal evolution starting from the compartment of hematopoietic stem and progenitors cells (HSPCs), leading in some cases to leukemic transformation. We hypothesized that deciphering the diversity of the HSPCs compartment may allow for the early detection of an emergent sub-clone that drives disease progression. Deep analysis of HSPCs repartition by multiparametric flow cytometry revealed a strong disorder of the hematopoietic branching system in most patients at diagnosis with different phenotypic signatures closely related to specific MDS features. In two independent cohorts of 131 and 584 MDS, the HSPCs heterogeneity quantified through entropy calculation was decreased in 47% and 46% of cases, reflecting a more advanced state of the disease with deeper cytopenias, higher IPSS-R risk and accumulation of somatic mutations. We demonstrated that patients with lower-risk MDS and low CD34 + CD38+HSPCs entropy had an adverse outcome and that this parameter is as an independent predictive biomarker for progression free survival, leukemia free survival and overall survival. Analysis of HSPCs repartition at diagnosis represents therefore a very powerful tool to identify lower-risk MDS patients with a worse outcome and valuable for clinical decision-making, which could be fully integrated in the MDS diagnostic workflow.

Predictive Factors of Response to Immunotherapy in Lymphomas: A Multicentre Clinical Data Warehouse Study (PRONOSTIM).

Immunotherapy (IT) is a major therapeutic strategy for lymphoma, significantly improving patient prognosis. IT remains ineffective for a significant number of patients, however, and exposes them to specific toxicities. The identification predictive factors around efficacy and toxicity would allow better targeting of patients with a higher ratio of benefit to risk. PRONOSTIM is a multicenter and retrospective study using the Clinical Data Warehouse (CDW) of the Greater Paris University Hospitals network. Adult patients with Hodgkin lymphoma or diffuse large-cell B lymphoma treated with immune checkpoint inhibitors or CAR T (Chimeric antigen receptor T) cells between 2017 and 2022 were included. Analysis of covariates influencing progression-free survival (PFS) or the occurrence of grade ≥3 toxicity was performed. In total, 249 patients were included. From this study, already known predictors for response or toxicity of CAR T cells such as age, elevated lactate dehydrogenase, and elevated C-Reactive Protein at the time of infusion were confirmed. In addition, male gender, low hemoglobin, and hypo- or hyperkalemia were demonstrated to be potential predictive factors for progression after CAR T cell therapy. These findings prove the attractiveness of CDW in generating real-world data, and show its essential contribution to identifying new predictors for decision support before starting IT.

C/EBPα Confers Dependence to Fatty Acid Anabolic Pathways and Vulnerability to Lipid Oxidative Stress-Induced Ferroptosis in FLT3-Mutant Leukemia.

Although transcription factor CCAAT-enhancer binding protein α (C/EBPα) is critical for normal and leukemic differentiation, its role in cell and metabolic homeostasis is largely unknown in cancer. Here, multiomics analyses uncovered a coordinated activation of C/EBPα and Fms-like tyrosine kinase 3 (FLT3) that increased lipid anabolism in vivo and in patients with FLT3-mutant acute myeloid leukemia (AML). Mechanistically, C/EBPα regulated the fatty acid synthase (FASN)-stearoyl-CoA desaturase (SCD) axis to promote fatty acid (FA) biosynthesis and desaturation. We further demonstrated that FLT3 or C/EBPα inactivation decreased monounsaturated FA incorporation to membrane phospholipids through SCD downregulation. Consequently, SCD inhibition enhanced susceptibility to lipid redox stress that was exploited by combining FLT3 and glutathione peroxidase 4 inhibition to trigger lipid oxidative stress, enhancing ferroptotic death of FLT3-mutant AML cells. Altogether, our study reveals a C/EBPα function in lipid homeostasis and adaptation to redox stress, and a previously unreported vulnerability of FLT3-mutant AML to ferroptosis with promising therapeutic application. SIGNIFICANCE: FLT3 mutations are found in 30% of AML cases and are actionable by tyrosine kinase inhibitors. Here, we discovered that C/EBPα regulates FA biosynthesis and protection from lipid redox stress downstream mutant-FLT3 signaling, which confers a vulnerability to ferroptosis upon FLT3 inhibition with therapeutic potential in AML. This article is highlighted in the In This Issue feature, p. 1501.

Mitochondrial fusion is a therapeutic vulnerability of acute myeloid leukemia.

Mitochondrial metabolism recently emerged as a critical dependency in acute myeloid leukemia (AML). The shape of mitochondria is tightly regulated by dynamin GTPase proteins, which drive opposing fusion and fission forces to consistently adapt bioenergetics to the cellular context. Here, we showed that targeting mitochondrial fusion was a new vulnerability of AML cells, when assayed in patient-derived xenograft (PDX) models. Genetic depletion of mitofusin 2 (MFN2) or optic atrophy 1 (OPA1) or pharmacological inhibition of OPA1 (MYLS22) blocked mitochondrial fusion and had significant anti-leukemic activity, while having limited impact on normal hematopoietic cells ex vivo and in vivo. Mechanistically, inhibition of mitochondrial fusion disrupted mitochondrial respiration and reactive oxygen species production, leading to cell cycle arrest at the G0/G1 transition. These results nominate the inhibition of mitochondrial fusion as a promising therapeutic approach for AML.

Rare germline complement factor H variants in patients with paroxysmal nocturnal hemoglobinuria.

Patients with paroxysmal nocturnal hemoglobinuria (PNH) are susceptible to complement-mediated intravascular hemolysis and thrombosis. Factor H (FH) is the main regulator of the complement alternative pathway, which protects cells from unwanted complement-mediated damage. Although FH is not a glycosylphosphatidylinositol-linked molecule, it may play a role in PNH. We sought to determine if rare germline variants in complement factor H (CFH) affect the PNH course, screening 84 patients with PNH treated with eculizumab for rare variants in CFH, CFI, and C3 genes. We compared the allelic frequencies with populational data and a geographically-matched control group, looking for an association between presence of the variants and treatment response (transfusion independence by 6 months). Sixteen patients presented rare variants, 9 in CFH (10.7%). Germline CFH variants were more frequent among patients with PNH than among controls (P = .02) or public data (P < .001) and were more likely to be transfusion-dependent at 6 months after eculizumab initiation (P = .015). With a median follow-up of 5.8 years, 8 of 9 patients with the CFH variant received transfusions, and 2 developed thromboses. None of the patients with the CFH variant had severe aplastic anemia from eculizumab initiation until 6 months. We demonstrated for the first time that rare CFH variants are over-represented among patients with PNH and that germline genetic background may affect the response to eculizumab.

Patients with Hematological Malignancies Treated with T-Cell or B-Cell Immunotherapy Remain at High Risk of Severe Forms of COVID-19 in the Omicron Era.

BACKGROUND: Patients with hematological malignancies are at greater risk of severe COVID-19 and have been prioritized for COVID-19 vaccination. A significant proportion of them have an impaired vaccine response, both due to the underlying disease and to the treatments. METHODS: We conducted a prospective observational study to identify the specific risks of the outpatient population with hematological diseases. RESULT: Between 22 December 2021 to 12 February 2022, we followed 338 patients of which 16.9% (n = 57) developed SARS-CoV-2 infection despite previous vaccination (94.7%). COVID-19 patients were more likely to have received immunotherapy (85.5% vs. 41%, p < 10-4), and particularly anti-CD20 monoclonal antibodies (40% vs. 14.9%, p < 10-4) and Bruton's tyrosine kinase inhibitors (BTKi) (7.3% vs. 0.7%, p < 10-2). There was no significant difference in demographic characteristics or hematological malignancies between COVID-19-positive and non-positive patients. Patients hospitalized for COVID-19 had more frequently received immunotherapy than patients with asymptomatic or benign forms (100% vs. 77.3%, p < 0.05). Hospitalized COVID-19 patients had a higher proportion of negative or weakly positive serologies than non-hospitalized patients (92.3% vs. 61%, p < 0.05). Patients who received tixagevimab/cilgavimab prophylaxis (n = 102) were less likely to be COVID-19-positive (4.9 vs. 22%, p < 0.05) without significant difference in hospitalization rates. CONCLUSION: In the immunocompromised population of patients with hematological malignancies, the underlying treatment of blood cancer by immunotherapy appears to be a risk factor for SARS-CoV-2 infection and for developing a severe form.

Multiple Myeloma in Patients over 80: A Real World Retrospective Study of First Line Conservative Approach with Bortezomib Dexamethasone Doublet Therapy and Mini-Review of Literature.

Data on octogenarian patients with MM are scarce, and optimal management remains controversial. We report a retrospective cohort of unselected octogenarian patients with NDMM treated with bortezomib dexamethasone (Vd). Seventy-four patients were treated with an initial doublet therapy (Vd regimen, 2−3 cycles, induction). A dose escalation with an adjunction of melphalan or cyclophosphamide was proposed for patients who had an insufficient response after induction and who could tolerate it. In responders, the treatment was continued until progression or a plateau response for 6 months (consolidation). The overall response rate was 73%. After a median follow-up of 31.4 months, median progression-free survival (PFS) and overall survival (OS) were 13.2 and 26.9 months, respectively. PFS and OS of patients with ECOG PS < 3 (25.4 and 54.9 months, respectively) were better in comparison to PFS and OS of patients with ECOG PS ≥ 3 (9.3 and 11.3 months, respectively). Thirteen patients (17.6%) died during induction. Twelve patients (16.2%) died during consolidation. In conclusion, a conservative therapeutic strategy based on Vd resulted in a good response rate. However, the survival remains poor in the population of patients with an ECOG PS ≥ 3, mainly because of early mortality not related to progressive disease.

Pharmaceutical cancer care for haematology patients on oral anticancer drugs: Findings from an economic, clinical and organisational analysis.

OBJECTIVE: The clinical benefit of pharmaceutical cares in improving the quality-of-care outcomes is well demonstrated. Clinical pharmacy services are not systematically deployed in cancer units in the absence of economic data. The aim of this prospective, observational 1-year study was to evaluate the clinical, economic and organisational impacts of pharmaceutical care into a multidisciplinary day hospital for patients treated with oral cancer drugs. METHODS: All pharmacists' interventions (PI) were documented and their impact and the probability of adverse drug events were assessed using the clinical, economic and organisational tool. RESULTS: Among 360 admissions, an average of 1.81 PI per admission was accepted. Among 452 PI leading to a clinical benefit on the patient, 16.9% had a major impact, and 1.9% had an impact on survival. The large majority of PIs (87%) increased the quality-of-care organisation. The budget impact model showed a total cost savings and cost avoidance of €539,047 per year and a cost-benefit ratio of 7.07:1. The direct cost-benefit was €201,741, and the cost avoidance was €337,306. CONCLUSION: Multidisciplinary care and pharmaceutical care are key elements to improve cancer patients' outcomes and avoid evitable healthcare costs.

When refeeding is not enough: severe and prolonged pancytopenia in an adolescent with anorexia nervosa.

A 15-year-old female patient with anorexia nervosa presented an unusually prolonged and severe episode of pancytopenia with severe thrombopenia and severe leucopenia. Despite effective refeeding, active specialized interventions were necessary. Upon admission, the patient presented with severe and symptomatic thrombopenia, severe neutropenia and gelatinous marrow transformation. In addition to refeeding, active interventions such as platelet transfusion and granulocyte-colony stimulating factor were successful to manage the patient's complications. The etiological search for pancytopenia was negative. The patient's prolonged starvation was probably a key factor. Medical history, clinical presentation, evolution, and biological data including bone marrow aspiration results are presented. Management of cytopenia and of their complications in a context of severe starvation is discussed in regard of existing literature. A simple monitoring attitude may prove insufficient in cases of severe pancytopenia in anorexia nervosa.Level of evidence V, descriptive study.

Accuracy and safety of 101 consecutives neurosurgical procedures for newly diagnosed central nervous system lymphomas: a single-institution experience.

INTRODUCTION: Brain surgery is required to ascertain the diagnosis of central nervous system lymphoma. We assessed the diagnostic yield and safety of the surgical procedures, the predictors of postoperative morbidity, and of overall survival. METHODS: Observational single-institution retrospective cohort study (1992-2020) of 101 consecutive adult patients who underwent stereotactic biopsy, open biopsy, or resection for a newly diagnosed central nervous system lymphoma. RESULTS: The diagnostic yield was 100% despite preoperative steroid administration in 48/101 cases (47.5%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.006) was an independent predictor of a new postoperative focal neurological deficit (7/101 cases, 6.9%). A previous history of hematological malignancy (p = 0.049), age 65 years or more (p = 0.031), and new postoperative neurological deficit (p < 0.001) were independent predictors of a Karnofsky Performance Status score decrease 20 points or more postoperatively (13/101 cases, 12.9%). A previous history of hematological malignancy (p = 0.034), and preoperative Karnofsky Performance Status score less than 70 (p = 0.024) were independent predictors of postoperative hemorrhage (13/101 cases, 12.9%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.019), and a previous history of hematological malignancy (p = 0.014) were independent predictors of death during hospital stay (8/101 cases, 7.9%). In the 82 immunocompetent patients harboring a primary central nervous system lymphoma, age 65 years or more (p = 0.044), and time to hematological treatment more than 21 days (p = 0.008), were independent predictors of a shorter overall survival. A dedicated hematological treatment (p < 0.001) was an independent predictor of a longer overall survival. CONCLUSION: Brain biopsy is feasible with low morbidity for central nervous system lymphomas. Postoperatively, patients should be promptly referred for hematological treatment initiation.