Abstract: Introduction: Primary mediastinal B cells lymphoma (PMBCL) is a rare subtype of aggressive non Hodgkin lymphoma (NHL). Despite therapeutic progresses, 10 to 30% of PMBCL patients are primary refractory or experience early relapses (R/R). Despite Autologous hematopoietic cell transplantation (auto-HCT) after bridging therapy or new therapies such as PD-1 inhibitors or CAR-T cells, R/R PMBL patients have a very poor outcome. Allogeneic stem cell transplantation (allo-HCT) is thus a potentially curative treatment for patients who relapsed after salvage therapies. Only limited data have been published about allo-SCT in R/R PMBCL (Herrera A. F, BBMT 2019). In the present study conducted on behalf the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) and the lymphoma study association (LYSA) group, we investigated the outcomes of allo-transplanted adult R/R PMBCL. Methods This multicenter retrospective study included all adult R/R PMBCL patients reported to the SFGM-TC and who underwent an allo-HCT between 1999 and 2018. Data have been obtained through ProMISe (internet-based system shared by all European transplantation centers) and completed by consulting the medical files of the LYSA group centers. All patients have given signed informed consent. Results Thirty-three patients with R/R PMBCL from 19 French (n=29) and 3 Belgium (n=4) centers were included. The median age at transplant was 33 y (18-61), with a predominance of female patients (58%). Majority of patients had a low HCT-CI score [0 = 9/17 (53%), data missing in 16 patients]. Seventy-six percent of patients had an IPI score between 1 and 2 and Ann Harbor score was ≥ 3 in 56.6% at diagnosis. Median number of treatment lines before allo-HCT was 3 (1-6). All patients received poly-chemotherapies with anthracyclines and anti-CD20 as first-line therapy. Most sixty-one percent of patients had previously undergone auto-HCT and one patient received CAR-T before allo-HCT. Forty one percent of patients were primary refractory. At time of transplant, 50% of patients were in complete response, 40% in partial response, and 10% had a progressive disease. Conditioning regimen was reduced intensity regimen in 63%. Stem cell source was PBSC in 88%. Donors were sibling in 42% or matched related donor in 39%. An alternative donor was chosen in 18%. GVHD prophylaxis included antithymocyte globulin in 61%, and calcineurin inhibitor in 97%. Median follow up was 78 months (3.5-157). Considering the whole cohort, 2y OS, DFS, NRM, and cumulative incidence of relapse were 48% (95%CI: 33-70), 60% (95%CI: 44-82), 18% (95%CI: 7-34), and 34% (95%CI: 18-50) respectively. Cumulative incidences of day 100 grade I-II and III-IV acute GVHD 36% and 0%, respectively. Cumulative incidence was 32% among whom 33% had an extensive cGVHD. Patients with progressive disease at transplantation had worst 2y PFS and OS (PFS: HR: 6.12, 95%CI: 1.32-28.31, p=0.02 and OS: HR: 7.04, 95%CI: 1.52-32.75, p=0.013). Conclusion: To our knowledge, this is the largest published study evaluating outcomes of allo-HCT for R/R PMBCL. Although this is a retrospective study with a limited number of patients, the outcomes suggest that allo-HCT is a therapeutic option providing durable remissions for patients with R/R PMBCL. Introduction: Primary mediastinal B cells lymphoma (PMBCL) is a rare subtype of aggressive non Hodgkin lymphoma (NHL). Despite therapeutic progresses, 10 to 30% of PMBCL patients are primary refractory or experience early relapses (R/R). Despite Autologous hematopoietic cell transplantation (auto-HCT) after bridging therapy or new therapies such as PD-1 inhibitors or CAR-T cells, R/R PMBL patients have a very poor outcome. Allogeneic stem cell transplantation (allo-HCT) is thus a potentially curative treatment for patients who relapsed after salvage therapies. Only limited data have been published about allo-SCT in R/R PMBCL (Herrera A. F, BBMT 2019). In the present study conducted on behalf the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) and the lymphoma study association (LYSA) group, we investigated the outcomes of allo-transplanted adult R/R PMBCL. Methods This multicenter retrospective study included all adult R/R PMBCL patients reported to the SFGM-TC and who underwent an allo-HCT between 1999 and 2018. Data have been obtained through ProMISe (internet-based system shared by all European transplantation centers) and completed by consulting the medical files of the LYSA group centers. All patients have given signed informed consent. Results Thirty-three patients with R/R PMBCL from 19 French (n=29) and 3 Belgium (n=4) centers were included. The median age at transplant was 33 y (18-61), with a predominance of female patients (58%). Majority of patients had a low HCT-CI score [0 = 9/17 (53%), data missing in 16 patients]. Seventy-six percent of patients had an IPI score between 1 and 2 and Ann Harbor score was ≥ 3 in 56.6% at diagnosis. Median number of treatment lines before allo-HCT was 3 (1-6). All patients received poly-chemotherapies with anthracyclines and anti-CD20 as first-line therapy. Most sixty-one percent of patients had previously undergone auto-HCT and one patient received CAR-T before allo-HCT. Forty one percent of patients were primary refractory. At time of transplant, 50% of patients were in complete response, 40% in partial response, and 10% had a progressive disease. Conditioning regimen was reduced intensity regimen in 63%. Stem cell source was PBSC in 88%. Donors were sibling in 42% or matched related donor in 39%. An alternative donor was chosen in 18%. GVHD prophylaxis included antithymocyte globulin in 61%, and calcineurin inhibitor in 97%. Median follow up was 78 months (3.5-157). Considering the whole cohort, 2y OS, DFS, NRM, and cumulative incidence of relapse were 48% (95%CI: 33-70), 60% (95%CI: 44-82), 18% (95%CI: 7-34), and 34% (95%CI: 18-50) respectively. Cumulative incidences of day 100 grade I-II and III-IV acute GVHD 36% and 0%, respectively. Cumulative incidence was 32% among whom 33% had an extensive cGVHD. Patients with progressive disease at transplantation had worst 2y PFS and OS (PFS: HR: 6.12, 95%CI: 1.32-28.31, p=0.02 and OS: HR: 7.04, 95%CI: 1.52-32.75, p=0.013). Conclusion: To our knowledge, this is the largest published study evaluating outcomes of allo-HCT for R/R PMBCL. Although this is a retrospective study with a limited number of patients, the outcomes suggest that allo-HCT is a therapeutic option providing durable remissions for patients with R/R PMBCL. Disclosures Sibon: Abbvie: Consultancy; Takeda: Consultancy; iQone: Consultancy; Roche: Consultancy; Janssen: Consultancy. Loschi: AbbVie: Ended employment in the past 24 months, Honoraria; CELGENE/BMS: Honoraria; Gilead: Ended employment in the past 24 months, Honoraria; Novartis: Ended employment in the past 24 months, Honoraria; Servier: Ended employment in the past 24 months, Honoraria; MSD: Honoraria. Dulery: Novartis: Honoraria; Takeda: Consultancy; Gilead: Other: Travel support and registration fees for scientific meetings .

Abstract: The Wigner's friend paradox concerns one of the most puzzling problems of quantum mechanics: the consistent description of multiple nested observers. Recently, a variation of Wigner's gedankenexperiment, introduced by Frauchiger and Renner, has lead to new debates about the self-consistency of quantum mechanics. At the core of the paradox lies the description of an observer and the object it measures as a closed system obeying the Schrödinger equation. We revisit this assumption to derive a necessary condition on a quantum system to behave as an observer. We then propose a simple single-photon interferometric setup implementing Frauchiger and Renner's scenario, and use the derived condition to shed a new light on the assumptions leading to their paradox. From our description, we argue that the three apparently incompatible properties used to question the consistency of quantum mechanics correspond to two logically distinct contexts: either one assumes that Wigner has full control over his friends' lab, or conversely that some parts of the labs remain unaffected by Wigner's subsequent measurements. The first context may be seen as the quantum erasure of the memory of Wigner's friend. We further show these properties are associated with observables which do not commute, and therefore cannot take well-defined values simultaneously. Consequently, the three contradictory properties never hold simultaneously.

Abstract: The Zeno effect, in which repeated observation freezes the dynamics of a quantum system, stands as an iconic oddity of quantum mechanics. When a measurement is unable to distinguish between states in a subspace, the dynamics within that subspace can be profoundly altered, leading to non-trivial behavior. Here we show that such a measurement can turn a non-interacting system with only single-qubit control into a two- or multi-qubit entangling gate, which we call a Zeno gate. The gate works by imparting a geometric phase on the system, conditioned on it lying within a particular nonlocal subspace. We derive simple closed-form expressions for the gate fidelity under a number of non-idealities and show that the gate is viable for implementation in circuit and cavity QED systems. More specifically, we illustrate the functioning of the gate via dispersive readout in both the Markovian and non-Markovian readout regimes, and derive conditions for longitudinal readout to ideally realize the gate.

Abstract: Background: Acute myeloid leukemia (AML) is a hematopoietic malignancy in which antitumor immunity is impaired. The therapeutic management of AML requires understanding the mechanisms involved in the fragility and immune dysfunction of AML T lymphocytes. Methods: In this study, T lymphocytes from healthy donors (HD) and AML patients were used. Extracellular vesicles (EVs) from leukemic cells were screened for their microRNA content and impact on T lymphocytes. Flow cytometry, transcriptomic as well as lentiviral transduction techniques were used to carry out the research. Results: We observed increased cell death of T lymphocytes from AML patients. EVs from leukemia myeloid cell lines harbored several miRNAs, including miR-21, and were able to induce T lymphocyte death. Compared to that in HD, miR-21 was overexpressed in both the bone marrow fluid and infiltrating T lymphocytes of AML patients. MiR-21 induces T lymphocyte cell death by upregulating proapoptotic gene expression. It also increases the immunosuppressive profile of T lymphocytes by upregulating the IL13, IL4, IL10, and FoxP3 genes. Conclusions: Our results demonstrate that miR-21 plays a significant role in AML T lymphocyte dysfunction and apoptosis. Targeting miR-21 may be a novel approach to restore the efficacy of the immune response against AML.

Abstract: Data on clinical use of ponatinib are limited. This prospective registry aimed to evaluate outcomes of ponatinib treatment in routine practice over 3 years (2016–2019) in Belgium (NCT03678454). Patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) were treated with ponatinib per current label. Fifty patients (33 CML and 17 Ph+ ALL) were enrolled. Fifty-five percent of CML and 29% of Ph+ ALL patients had received ≥3 prior tyrosine kinase inhibitors (TKIs). Reasons for starting ponatinib were intolerance (40%), relapse or refractoriness (28%) to previous TKIs, progression (16%), or T315I mutation (16%). Median follow-up was 15 months for CML and 4.5 months for Ph+ ALL patients. Best response was a major molecular response in 58% of CML and 41% of Ph+ ALL patients. Of 20 patients who started ponatinib due to intolerance to previous TKIs, 9 (64%) CML and 4 (67%) Ph+ ALL achieved a major molecular response. Three-year estimates of overall survival were 85.3% and 85.6%, respectively, in CML and Ph+ ALL patients; estimated progression-free survival was 81.6% and 48.9%. Adverse reactions were reported in 34 patients (68%); rash (26%) and dry skin (10%) were most common. Reported cardiovascular adverse reactions included vascular stenosis (3), arterial hypertension (2), chest pain (1), palpitations (1), and vascular occlusion (1). This Belgian registry confirms results from the PACE clinical trial and supports routine ponatinib use in CML and Ph+ ALL patients who are resistant or intolerant to previous TKIs or with the T315I mutation.

Abstract: microRNAs (miRNAs) are known as potent gene expression regulators, and several studies have revealed the prognostic value of miRNAs in acute myeloid leukemia (AML) patient survival. Recently, strong evidence has indicated that miRNAs can be transported by exosomes (EXOs) from cancer cells to recipient immune microenvironment (IME) cells. Results We found that AML blast-released EXOs enhance CD3 T-cell apoptosis in both CD4 and CD8 T cells. We hypothesized that miRNAs present in EXOs are key players in mediating the changes observed in AML T-cell survival. We found that miR-24-3p, a commonly overexpressed miRNA in AML, was present in released EXOs, suggesting that EXO-miR-24-3p was linked to the increased miR-24-3p levels detected in isolated AML T cells. These results were corroborated by ex vivo-generated miR-24-3p-enriched EXOs, which showed that miR-24-3p-EXOs increased apoptosis and miR-24-3p levels in T cells. We also demonstrated that overexpression of miR-24-3p increased T-cell apoptosis and affected T-cell proliferation by directly targeting DENN/MADD expression and indirectly altering the NF-κB, p-JAK/STAT, and p-ERK signaling pathways but promoting regulatory T-cell (Treg) development. Conclusions These results highlight a mechanism through which AML blasts indirectly impede T-cell function via transferred exosomal miR-24-3p. In conclusion, by characterizing the signaling network regulated by individual miRNAs in the leukemic IME, we aimed to discover new nonleukemic immune targets to rescue the potent antitumor function of T cells against AML blasts.

Abstract: Myomatous erythrocytosis syndrome (MES) is a rare gynaecological condition associated with the presence of a uterine fibroid and isolated polycythaemia. The main characteristic of MES is that haemoglobin returns to a normal level after removal of the myoma. MES is poorly known and still not fully understood. This case report describes the history of a patient with MES with surprising erythrocytosis resolution after myomectomy.

Abstract: Targeting non-apoptotic modalities might be therapeutically promising in diffuse large B cell lymphoma (DLBCL) patients with compromised apoptotic pathways. Thymoquinone (TQ) has been reported to promote apoptosis in cancer cells, but little is known about its effect on non-apoptotic pathways. This work investigates TQ selectivity against DLBCL cell lines and the cell death mechanisms. TQ reduces cell viability and kills cell lines with minimal toxicity on normal hematological cells. Mechanistically, TQ promotes the mitochondrial caspase pathway and increases genotoxicity. However, insensitivity of most cell lines to caspase inhibition by z-VAD-fmk (benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone) pointed to a critical role of non-apoptotic signaling. In cells dying through non-apoptotic death, TQ increases endoplasmic reticulum (ER) stress markers and substantially increases cytosolic calcium ([Ca2+]c) through ER calcium depletion and activation of store-operated calcium entry (SOCE). Chelation of [Ca2+] c, but not SOCE inhibitors, reduces TQ-induced non-apoptotic cell death, highlighting the critical role of calcium in a non-apoptotic effect of TQ. Investigations showed that TQ-induced [Ca2+]c signaling is primarily initiated by necroptosis upstream to SOCE, and inhibition necroptosis by necrostatin-1 alone or with z-VAD-fmk blocks the cell death. Finally, TQ exhibits an improved selectivity profile over standard chemotherapy agents, suggesting a therapeutic relevance of the pro-necroptotic effect of TQ as a fail-safe mechanism for DLBCL therapies targeting apoptosis.