Metformin reduces the clonal fitness of Dnmt3aR878H hematopoietic stem and progenitor cells by reversing their aberrant metabolic and epigenetic state.

Clonal hematopoiesis (CH) arises when a hematopoietic stem cell (HSC) acquires a mutation that confers a competitive advantage over wild-type (WT) HSCs, resulting in its clonal expansion. Individuals with CH are at an increased risk of developing hematologic neoplasms and a range of age-related inflammatory illnesses1-3. Therapeutic interventions that suppress the expansion of mutant HSCs have the potential to prevent these CH-related illnesses; however, such interventions have not yet been identified. The most common CH driver mutations are in the DNA methyltransferase 3 alpha (DNMT3A) gene with arginine 882 (R882) being a mutation hotspot. Here we show that murine hematopoietic stem and progenitor cells (HSPCs) carrying the Dnmt3aR878H/+ mutation, which is equivalent to human DNMT3AR882H/+, have increased mitochondrial respiration compared with WT cells and are dependent on this metabolic reprogramming for their competitive advantage. Importantly, treatment with metformin, an oral anti-diabetic drug with inhibitory activity against complex I in the electron transport chain (ETC), reduced the fitness of Dnmt3aR878H/+ HSCs. Through a multi-omics approach, we discovered that metformin acts by enhancing the methylation potential in Dnmt3aR878H/+ HSPCs and reversing their aberrant DNA CpG methylation and histone H3K27 trimethylation (H3K27me3) profiles. Metformin also reduced the fitness of human DNMT3AR882H HSPCs generated by prime editing. Our findings provide preclinical rationale for investigating metformin as a preventive intervention against illnesses associated with DNMT3AR882 mutation-driven CH in humans.

Management of Gastro-Intestinal Toxicity of the Pi3 Kinase Inhibitor: Optimizing Future Dosing Strategies.

The phosphatidylinositol 3-kinase (PI3K) pathway plays a key role in cancer progression and in host immunity. Idelalisib was the first of this class to be approved with the second-generation Pi3 kinase inhibitors copanlisib, duvelisib and umbralisib, subsequently being approved in the United States. Real-world data are lacking, however, in relation to the incidence and toxicity of Pi3 kinase inhibitor-induced colitis. We here review, in the first instance, the general landscape of the Pi3K inhibitors in the context of hematological malignancies, with a focus on the adverse gastrointestinal side effects reported by various clinical trials. We further review the available worldwide pharmacovigilance data in relation to these drugs. Finally, we describe our own real-world experience with idelalisib-induced colitis management in our center and in a national setting.

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.

Venous thromboembolism during systemic inflammatory and autoimmune diseases associated with myelodysplastic syndromes, chronic myelomonocytic leukaemia and myelodysplastic/myeloproliferative neoplasms: a French multicentre retrospective case-control study.

OBJECTIVES: Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukaemia (CMML) are associated with systemic inflammatory and autoimmune diseases (SIADs) in 10-30% of cases. The aims of this study were (i) to evaluate the prevalence of venous thromboembolism VTE in patients presenting with both MDS/CMML and SIADs, (ii) to describe risk factors associated with thrombosis, and (iii) to analyse the impact of VTE on overall survival and transformation to acute myeloid leukaemia in comparison to patients with MDS/CMML-associated SIADs without VTE. METHODS: This retrospective multicentre case-control study was conducted among patients with MDS/CMML and dysimmune disorders and featured in the French retrospective database of the French Network of Dysimmune Disorders Associated with Hemopathies (MINHEMON), diagnosed with MDS/CMML and dysimmune disorders. RESULTS: During a median follow-up of 16 months (5-48) VTE occurred in 35 patients (21.6 %) whereas 127 patients did not. Among those with VTE, 8 patients (22.9%) experienced two or more VTE. Common prothrombotic risk factors were not significantly different in patients with or without VTE. CMML was more frequent in patients without VTE (37 % vs. 14.3%, p=0.01), whereas myelodysplasic/myeloproliferative neoplasm (MDS/MPN) was higher in VTE patients (20 % vs. 5.5 %, p=0.01). In a multivariate analysis, only MDS/CMML progression at the time of VTE (odds ratio 28.82, 95 % CI (5.52-530.70) was significantly associated with VTE. When treated with an anticoagulation therapy, bleeding occurred in 19.4% of cases (6/31). Overall survival was not significantly different between patients with and without VTE (p=0.68). Leukaemia-free survival between groups was not significantly different (p=0.83). CONCLUSIONS: VTE is a common complication in MDS/CMML-associated SIADSs with an increased risk of bleeding when treated by anticoagulants. In the MDS/CMML subgroup, SIADS flares and MDS/CMML progression seem to be prothrombotic risk factors.

Antimicrobial stewardship in high-risk febrile neutropenia patients.

BACKGROUND: The 2011 4th European Conference on Infections in Leukemia (ECIL4) guidelines recommend antibiotics de-escalation/discontinuation in selected febrile neutropenia (FN) patients. We aimed to assess the impact of an antimicrobial stewardship (AMS) program based on these guidelines on antibiotics use and clinical outcomes in high-risk FN patients. METHODS: We conducted an observational study in the hematology department of Cochin University Hospital in Paris, France. An ECIL4-based antibiotics de-escalation and discontinuation strategy was implemented jointly by the hematologists and the AMS team. The pre-intervention (January-October 2018) and post-intervention (January-October 2019) periods were compared. We retrospectively collected clinical and microbiological data. We compiled antibiotics consumptions via hospital pharmacy data and standardized them by calculating defined daily doses per 1000 patient-days. We analyzed the two-monthly antibiotic consumption using an interrupted time series method and built a composite endpoint for clinical outcomes based on transfer to the intensive care unit (ICU) and/or hospital death. RESULTS: Overall, 273 hospital stays (164 patients) in the pre-intervention and 217 (148 patients) in the post-intervention periods were analyzed. Patients were mainly hospitalized for intensive chemotherapy for acute leukemia or autologous stem-cell transplant for myeloma. Patients were slightly younger in the pre-intervention compared to the post-intervention period (median age 60.4 vs 65.2 years, p = 0.049), but otherwise comparable. After implementation of the AMS program, glycopeptide and carbapenem use decreased by 85% (p = 0.03) and 72% (p = 0.04), respectively. After adjustment on confounders, the risk of transfer to the ICU/death decreased significantly after implementation of the AMS program (post-intervention period: odds-ratio = 0.29, 95% Confidence Interval: 0.15-0.53, p < 0.001). CONCLUSION: Implementation of a multidisciplinary AMS program for high-risk neutropenic patients was associated with lower carbapenem and glycopeptide use and improved clinical outcomes.

APR-246 induces early cell death by ferroptosis in acute myeloid leukemia.

APR-246 is a promising new therapeutic agent that targets p53 mutated proteins in myelodysplastic syndromes and in acute myeloid leukemia (AML). APR-246 reactivates the transcriptional activity of p53 mutants by facilitating their binding to DNA target sites. Recent studies in solid cancers have found that APR-246 can also induce p53-independent cell death. In this study, we demonstrate that AML cell death occurring early after APR-246 exposure is suppressed by iron chelators, lipophilic antioxidants and inhibitors of lipid peroxidation, and correlates with the accumulation of markers of lipid peroxidation, thus fulfilling the definition of ferroptosis, a recently described cell death process. The capacity of AML cells to detoxify lipid peroxides by increasing their cystine uptake to maintain major antioxidant molecule glutathione biosynthesis after exposure to APR-246 may be a key determinant of sensitivity to this compound. The association of APR-246 with induction of ferroptosis (either by pharmacological compounds, or genetic inactivation of SLC7A11 or GPX4) had a synergistic effect on the promotion of cell death, both in vivo and ex vivo.

[Ferroptosis and cancer: Physiopathological and therapeutic implications]. / Ferroptose et cancer - Implications physiopathologiques et thérapeutiques.

Ferroptosis is a process leading to cell death. The final event is the lethal accumulation of peroxidized lipids. Iron is at the center of the reactions leading to the formation of peroxidized lipids, while an antioxidant system is dedicated to the detoxification of these lipids to prevent cell death. Ferroptosis is involved in many human diseases, including the pathophysiology of neurodegenerative diseases, infection, and cancer. We will present the different cellular actors that control ferroptosis and propose a review of current data involving this cellular process in cancer.

TITLE: Ferroptose et cancer - Implications physiopathologiques et thérapeutiques. ABSTRACT: La ferroptose est un processus conduisant à la mort de la cellule avec, pour évènement final, l'accumulation létale de lipides peroxydés. Le fer libre intracellulaire est au centre des réactions entraînant la formation de ces lipides peroxydés. Un système antioxydant dédié à la détoxification de ces lipides permet de prévenir la mort cellulaire. Le processus de ferroptose est impliqué dans un grand nombre de maladies, notamment dans la pathogénie des maladies neurodégénératives et infectieuses et du cancer. Nous présentons dans cette revue les principaux acteurs cellulaires qui contrôlent la ferroptose et proposons une synthèse des données actuelles impliquant ce processus dans le cancer.

Relapsed, Refractory, or Advanced Hodgkin Lymphoma: A Single-Center Experience.

PURPOSE: To assess the treatment and outcomes of patients with relapsed, refractory, or advanced Hodgkin lymphoma treated with consolidation or salvage radiotherapy. PATIENTS AND METHODS: We studied all patients diagnosed with this profile treated by radiotherapy in our center between 2006 and 2019. RESULTS: A total of 33 patients who received external-beam radiotherapy for advanced (21%), relapsed (52%), or refractory (24%) Hodgkin lymphoma were studied. Median [interquartile range] age was 25 [22-38] years, with 11 women (33%). The follow-up after first-line treatment was 28 [10-53] months. Number of chemotherapy lines received before radiotherapy was 3 [1-4]. Fourteen patients (42%) had undergone autologous stem-cell transplantation before radiotherapy, and 2 patients were treated by radiotherapy alone. Nine patients (27%) were treated by involved-field radiotherapy, 17 (52%) by involved-site radiotherapy, 5 (17%) by involved-node radiotherapy, and 2 by other volumes. The acute toxicity profile was favorable, with grade 1 radiodermatitis (33%) or dysphagia (30%). Overall, 21 patients (64%) experienced prolonged complete response and 12 experienced relapse (36%) after radiotherapy. Median disease-free survival was 68.8 months. CONCLUSIONS: External-beam radiotherapy should be considered an effective treatment modality for advanced, relapsed, or refractory Hodgkin lymphoma as part of a multimodal approach.

Acute and fatal cephalosporin-induced autoimmune haemolytic anaemia.

We report the case of an 82-year old male patient admitted in our medical intensive care unit for diffuse skin lesions, 3 days after the onset of ceftriaxone for bilateral pneumonia without microbiological documentation. The patient concomitantly exhibited diffuse skin lesions compatible with livedo and neurological and haemodynamic failure. Biological analysis revealed acute haemolytic anaemia. Warming of patient, red blood-cells transfusion and high-doses corticosteroids were initiated and ceftriaxone was stopped. Despite these therapeutics, the patient exhibited multiple organ failure and died. The main suspected triggering factor of this acute and fatal haemolytic anaemia was ceftriaxone administration considering: (i) the delay between cephalosporin administration and symptoms; (ii) the worsening of livedo and acrocyanosis a few hours after meningeal ceftriaxone doses; and (iii) fatal evolution. Cephalosporin-induced autoimmune haemolytic anaemia is a rare and serious cause of livedo that should be suspected in patients exhibiting livedo and acute haemolytic anaemia within hours/days following cephalosporin administration.

From Iron Chelation to Overload as a Therapeutic Strategy to Induce Ferroptosis in Leukemic Cells.

Despite its crucial importance in numerous physiological processes, iron also causes oxidative stress and damage which can promote the growth and proliferation of leukemic cells. Iron metabolism is strictly regulated and the related therapeutic approaches to date have been to restrict iron availability to tumor cells. However, since a new form of iron-catalyzed cell death has been described, termed ferroptosis, and subsequently better understood, iron excess is thought to represent an opportunity to selectively kill leukemic cells and spare normal hematopoietic cells, based on their differential iron needs. This review summarizes the physiology of iron metabolism and its deregulation in leukemia, the known ferrotoposis pathways, and therapeutic strategies to target the altered iron metabolism in leukemia for the purposes of initiating ferroptosis in these cancer cells.

Pairing MCL-1 inhibition with venetoclax improves therapeutic efficiency of BH3-mimetics in AML.

OBJECTIVES: Venetoclax combined with hypomethylating agents is a new therapeutic strategy frequently used for treating AML patients who are not eligible for conventional chemotherapy. However, high response rates are heterogeneous due to different mechanisms mediating resistance to venetoclax such as up-regulation of MCL-1 expression. We thus tested the anti-leukemic activity of S63845, a specific MCL-1 inhibitor. METHODS: Apoptosis induces by S63845 with or without venetoclax was evaluated in primary AML samples and in AML cell lines co-cultured or not with bone marrow (BM) mesenchymal stromal cells. Sensitivity of leukemic cells to S63845 was correlated to the expression level of BCL-2, MCL-1, and BCL-XL determined by Western Blot and mass spectrometry-based proteomics. RESULTS: We observed that even if MCL-1 expression is weak compared to BCL-2, S63845 induces apoptosis of AML cells and strongly synergizes with venetoclax. Furthermore, AML cells resistant to venetoclax are highly sensitive to S63845. Interestingly, the synergistic effect of S63845 toward venetoclax-mediated apoptosis of AML cells is still observed in a context of interaction with the BM microenvironment that intrinsically mediates resistance to BCL2 inhibition. CONCLUSION: These results are therefore of great relevance for clinicians as they provide the rational for combining BCL-2 and MCL-1 inhibition in AML.

Partial response in hairy cell leukemia with vemurafenib despite early discontinuation due to agranulocytosis.

Vemurafenib is an oral BRAF kinase inhibitor approved since 2012 for the treatment of patients with unresectable or metastatic melanoma with BRAF mutations. Vemurafenib also demonstrated efficacy for patients with hairy cell leukemia genetically characterized by BRAF mutation. Here, we report the case of a 38-year-old female patient without any previous medical history who experienced agranulocytosis associated with erythrodermia after vemurafenib initiation for the treatment of hairy cell leukemia. Agranulocytosis was confirmed with bone marrow examination. Vemurafenib was considered the most probable drug responsible for this agranulocytosis and was thus stopped. We observed a full neutrophils recovery 10 days after vemurafenib cessation without any haematopoietic growth factors. A bone marrow biopsy performed 1 month after aplasia ending showed a good partial response with less than 5% of hairy cells remaining. To our knowledge, this is the first case ever described by vemurafenib-induced agranulocytosis. Thus, physicians should be warned about this risk given the growing number of patients treated with vemurafenib.

Mastocytosis onset in a patient with treated hairy cell leukemia: Just a coincidence?

Mastocytosis is a mast cell disease caused by functionally defective infiltrating mast cells and CD34+ mast cell precursors. The heterogeneous group of mast cell disorders is categorized into five variants in the updated 2017 World Health Organization (WHO) classification among those systemic mastocytosis with an associated neoplasm (SM-AHN). Except for myeloid neoplasia, lymphoproliferative disorders associated to SM-AHN are more scarce. Here, we report the second case ever described of associated mastocytosis and hairy-cell disease. A 38-year-old female patient without any specific medical history was diagnosed a hairy cell leukemia and BRAFV600E mutation was found in hairy cells. Since purine-analogs were avoided to prevent prolonged myelosuppression, she was treated with vemurafenib and rituximab. Despite early discontinuation due to vemurafenib-induced agranulocytosis, a partial response was observed. Strikingly, bone marrow biopsy performed one month after vemurafenib discontinuation revealed a nodular infiltration by 30% tumoral mastocytes. Along with elevated tryptase level, KITD816V mutation on mastocytes and clinical exam, the patient was diagnosed with systemic mastocytosis with an associated hematological neoplasm (SM-AHN). No BRAFV600E mutation was found on mastocytes. The physiopathology of this association is not known and might be only a coincidence or a common genetic driver mutation enhancing mast and hairy cells.

Autoimmune manifestations associated with myelodysplastic syndromes.

Autoimmune disorders (ADs) are encountered in 10 to 20% of patients with myelodysplastic syndromes (MDS). Available data suggest that ADs concern more often younger patients with higher risk IPSS. MDS subtypes associated with ADs are mainly MDS with single lineage dysplasia (MDS-SLD) and MDS with excess blasts (MDS-EB). Various types of ADs have been described in association with MDS, ranging from limited clinical manifestations to systemic diseases affecting multiple organs. Defined clinical entities as vasculitis, connective tissue diseases, inflammatory arthritis, and neutrophilic diseases are frequently reported; however, unclassified or isolated organ impairment can be seen. In general, ADs do not seem to confer worse survival, although certain ADs may be associated with adverse outcomes (i.e., vasculitis) or progression of MDS (Sweet syndrome). While steroids and immunosuppressive treatment (IST) remain the backbone of first-line treatment, increasing evidence suggests that MDS-specific therapy as hypomethylating agents, based on their immunomodulatory effect, may be effective in treating these complications and for sparing steroids.

The role of radiotherapy as salvage and/or consolidation treatment in relapsed/refractory and high-risk diffuse large B-cell lymphoma.

OBJECTIVE: Many salvage therapies have been proposed for relapsed/refractory (R/R) diffuse large B-cell lymphomas or for consolidation in the case of suboptimal response. Radiotherapy (RT) is one modality of salvage therapy, but its place is currently not well defined. METHOD: This study reports a retrospective review of patients receiving unplanned radiotherapy for R/R diffuse large B-cell lymphoma (DLBCL) or primary mediastinal B-cell lymphoma (PMBCL), or as consolidation therapy after second-line chemotherapy, treated in our hospital. RESULTS: Fifty-one patients with a median age of 53.5 years [19-89] were selected. The histologic type was DLBCL in 35 cases (68%), PMBCL in 8 cases (16%), and secondary transformed NHL in 8 cases (16%). Median aaIPI was 1 [0-4], and 17 patients (33%) had a high tumor burden (bulky disease). Sixteen patients (31%) were irradiated for a response considered to be insufficient, 18 patients (36%) were refractory, and 17 patients (33%) had relapsed. Patients were irradiated with a median dose of 40 Gy [15-44], 29 (57%) by a conformal 3D technique and 22 (43%) by tomotherapy. With a median follow-up of 36 months [1.0-127.8] after irradiation, 5-year progression-free survival (PFS) and overall survival (OS) were 62% and 72%, respectively. In multivariate analysis, adverse factors associated with PFS and OS in our cohort were age >70 years (HR = 5.06, P = .02) and post-RT relapse (HR = 12.24, P = .002), whereas favorable factors were number of lines of chemotherapy <3 (HR = 0.02, P = .03) and bulky disease (HR = 0.02, P = .009). CONCLUSION: Due to its low toxicity and ease of use, radiotherapy should therefore remain an available option in patients with R/R DLBCL or as consolidation therapy in patients with high-risk disease, mostly in patients with chemo-sensitive disease or bulky disease.

Autoimmune manifestations associated with lymphoma: characteristics and outcome in a multicenter retrospective cohort study.

This French multicenter retrospective cohort study aimed to describe the autoimmune manifestations (AIMs) associated with lymphoma among patients hospitalized between 2005 and 2016 in three French University Hospitals. Among 2503 patients with lymphoma, 108 (4.3%) had AIMs, mostly autoimmune cytopenias (71.3%), neurological diseases (10.2%), kidney diseases (6.5%), systemic vasculitis (5.6%) and others. As compared with the 2395 lymphoma patients without AIMs, those with AIMs were older (p = .01), more frequently had B-cell chronic lymphocytic leukemia (p < .01) and less frequently diffuse large B-cell lymphomas (p = .01) and Hodgkin lymphoma (p = .01). The 5-year overall survival with lymphoma was 65% and 79% (p = .03) with and without AIMs. This large cohort study shows that various types of AIMs, mostly cytopenias, could be associated with lymphoma and affect the overall outcome with lymphoma, in particular for B-cell non-Hodgkin lymphoma (p = .01) and T-cell non-Hodgkin lymphoma (p = .01), with no survival difference noted for other types of lymphoma (p = .2).