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Ferroelectricity (Valasek, J. Phys. Rev. 1921, 17, 475) - a spontaneous formation of electric polarisation - is a solid state phenomenon, usually, associated with ionic compounds or complex materials. Here we show that, atypically for elemental solids, few-layer graphenes can host an equilibrium out-of-plane electric polarisation, switchable by sliding the constituent graphene sheets. The systems hosting such effect include mixed-stacking tetralayers and thicker (5-9 layers) rhombohedral graphitic films with a twin boundary in the middle of a flake. The predicted electric polarisation would also appear in marginally (small-angle) twisted few-layer flakes, where lattice reconstruction would give rise to networks of mesoscale domains with alternating value and sign of out-of-plane polarisation., Comment: 25 pages, 7 figures

Diverse emergent correlated electron phenomena have been observed in twisted graphene layers due to electronic interactions with the moir\'e superlattice potential. Many electronic structure predictions have been reported exploring this new field, but with few momentum-resolved electronic structure measurements to test them. Here we use angle-resolved photoemission spectroscopy (ARPES) to study the twist-dependent ($1^\circ < \theta < 8^\circ$) electronic band structure of few-layer graphenes, including twisted bilayer, monolayer-on-bilayer, and double-bilayer graphene (tDBG). Direct comparison is made between experiment and theory, using a hybrid $\textbf{k}\cdot\textbf{p}$ model for interlayer coupling and implementing photon-energy-dependent phase shifts for photo-electrons from consecutive layers to simulate ARPES spectra. Quantitative agreement between experiment and theory is found across twist angles, stacking geometries, and back-gate voltages, validating the models and revealing displacement field induced gap openings in twisted graphenes. However, for tDBG at $\theta=1.5\pm0.2^\circ$, close to the predicted magic-angle of $\theta=1.3^\circ$, a flat band is found near the Fermi-level with measured bandwidth of $E_w = 31\pm5$ meV. Analysis of the gap between the flat band and the next valence band shows significant deviations between experiment ($\Delta_h=46\pm5$meV) and the theoretical model ($\Delta_h=5$meV), indicative of the importance of lattice relaxation in this regime.

CyBorD DARA as induction is well tolerated and induces deep responses when used in conjunction with ASCT for MM.Mechanism of action studies indicate that CyBorD DARA enhances macrophage activation, which may play a role in its clinical efficacy. Daratumumab (DARA) has shown impressive activity in combination with other agents for the treatment of multiple myeloma (MM). We conducted a phase 1b study to assess the safety and preliminary efficacy, as well as potential mechanisms of action, of DARA (16 mg/kg) in combination with a weekly schedule of subcutaneous bortezomib (1.3-1.5 mg/m2), cyclophosphamide (150-300 mg/m2), and dexamethasone (40 mg) (CyBorD DARA) as initial induction before autologous stem cell transplantation (ASCT). Eligible patients were ≤70 years of age with untreated MM requiring treatment and who lacked significant comorbidities. A total of 18 patients were enrolled. Their median age was 56 years (range, 32-66 years), and all patients had Eastern Cooperative Oncology Group performance status ≤1. The International Staging System stages were I, II, and III in 78%, 17%, and 6% of patients, respectively; 28% of patients had high-risk genetic features. There was no dose-limiting toxicity, and the incidence of grade 3 or 4 infection or neutropenia was

Multiple Myeloma (MM) is a malignant disorder of plasma cells which, despite significant advances in treatment, remains incurable. Daratumumab, the first CD38 directed monoclonal antibody, has shown promising activity alone and in combination with other agents for MM treatment. Daratumumab is thought to have pleiotropic mechanisms of activity including natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). With the knowledge that CD38-expressing NK cells are depleted by daratumumab, we sought to investigate a potential mechanism of enhancing macrophage-mediated antibody-dependent cellular phagocytosis (ADCP) by combining daratumumab with cyclophosphamide (CTX). Cyclophosphamide’s immunomodulatory function was investigated by conditioning macrophages with tumor cell secretome collected from cyclophosphamide treated MM cell lines (CTX-TCS). Flow cytometry analysis revealed that CTX-TCS conditioning augmented the migratory capacity of macrophages and increased CD32 and CD64 Fcγ receptor expression on their cell surface. Daratumumab-specific tumor clearance was increased by conditioning macrophages with CTX-TCS in a dose-dependent manner. This effect was impeded by pre-incubating macrophages with Cytochalasin D (CytoD), an inhibitor of actin polymerization, indicating macrophage-mediated ADCP as the mechanism of clearance. CD64 expression on macrophages directly correlated with MM cell clearance and was essential to the observed synergy between cyclophosphamide and daratumumab, as tumor clearance was attenuated in the presence of a FcγRI/CD64 blocking agent. Cyclophosphamide independently enhances daratumumab-mediated killing of MM cells by altering the tumor microenvironment to promote macrophage recruitment, polarization to a pro-inflammatory phenotype, and directing ADCP. These findings support the addition of cyclophosphamide to existing or novel monoclonal antibody-containing MM regimens.

The anti-CD38 monoclonal antibody Daratumumab has shown impressive activity in combination with other agents for the treatment of multiple myeloma (MM), improving progression free survival and overall survival in several phase 3 studies. We conducted a phase 1b study of intravenous Daratumumab (16 mg/kg) with weekly subcutaneous bortezomib (1.3-1.5 mg/m 2 ), cyclophosphamide (150-300 mg/m 2), and dexamethasone (40 mg) (CyBorD-DARA) as induction before autologous stem cell transplantation (ASCT), followed by CyBorD-DARA consolidation (2 cycles) and monthly DARA +/- bortezomib (in high-risk disease) maintenance for 24 months. We hypothesized that the addition of cyclophosphamide could lead to enhanced antibody dependent cellular phagocytosis (ADCP). This trial was registered at www.clinicaltrials.gov as NCT02955810. We previously reported the initial results of this study. 1. In addition to a favourable safety profile we observed promising anti-MM activity with 10 of 13 patients (77%) in whom assessment was possible achieving measurable residual disease (MRD) negativity at a sensitivity of 10 -5 by next generation sequencing (NGS) after ASCT. We now report the results at EOT, with a focus on MRD. Eligible patients were ≤70 years of age with untreated transplant-eligible MM. 18 patients were enrolled. Median age was 56.5 years (range, 32-66 years), 61% were male and 94% of patients had Eastern Cooperative Oncology Group performance status ≤1. The International Staging System stages were I, II, and III in 78%, 17%, and 6% of patients, respectively. 29% of patients had high-risk genetic features by fluorescent in situ hybridisation (FISH) or gene expression profiling, including 17p deletion in 12% and t(4;14) and t(14;16) in 6% each. On an ITT basis, the rates of very good partial remission or better (≥VGPR) after ASCT, consolidation and at end of treatment (EOT) (after completion of 24 months of DARA) were 94%, 94% and 81% respectively, and rates of complete response or better (≥CR) were 50%, 63% and 63% respectively. Measurable residual disease (MRD) assessment was possible in 13 patients after induction, ASCT and consolidation, and 10 at EOT. Sustained MRD negativity (ie. MRD negativity after ASCT, consolidation and at EOT) to a level of 10 -5 by NGS was achieved in 33% (ITT). Of 13 patients who remained on study at EOT in VGPR or better, 54% were MRD negative (MRD was unavailable in 23%). 7 patients were MRD negative after both ASCT and consolidation. Of these patients, all evaluable at EOT(6/7) remained MRD negative, with 1 patient unable to undergo MRD assessment due to the COVID-19 pandemic, but remaining in CR. Nausea and diarrhoea occurred in 89% of patients, but were mostly grade 1-2 (Grade ≥3 nausea 17%; diarrhoea 6%). Neutropenia occurred in 44% (Grade ≥3 17%), anaemia in 39% (Grade ≥3 22%), and thrombocytopenia in 33% (Grade ≥3 22%). The rate of neutropenic sepsis was 11%. Infusion-related reactions occurred in 50% (Grade ≥3 6%) and peripheral neuropathy occurred in 33% (Grade ≥3 0%) The most commonly reported serious adverse event (SAE) was sepsis in 22%. One patient developed abnormal liver function tests leading to discontinuation from the trial. CyBorD-DARA induction, consolidation and DARA-maintenance is an effective and well-tolerated IMiD free regimen in transplant-eligible patients with MM. MRD negativity at a level of > 10 -5 after ASCT and consolidation may be predictive of sustained MRD negativity at EOT. References: Naicker SD, et al. Cyclophosphamide alters the tumor cell secretome to potentiate the anti-myeloma activity of daratumumab through augmentation of macrophage-mediated antibody dependent cellular phagocytosis. Oncoimmunology. 2021 Jan 25;10(1):1859263. doi: 10.1080/2162402X.2020.1859263. PMID: 33552684; PMCID: PMC7849715. O'Dwyer M, et al. CyBorD-DARA is potent initial induction for MM and enhances ADCP: initial results of the 16-BCNI-001/CTRIAL-IE 16-02 study. Blood Adv. 2019 Jun 25;3(12):1815-1825. doi: 10.1182/bloodadvances.2019000010. PMID: 31201169; PMCID: PMC6595251. Disclosures O'Dwyer: ONK Therapeutics: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Bristol Myers Squibb: Research Funding. Quinn: Takeda: Honoraria. Szegezdi: ONK Therapeutics: Research Funding.

Multiple myeloma (MM) is characterized by the clonal expansion and metastatic spread of malignant plasma cells to multiple sites in the bone marrow (BM). Recently, we implicated the sialyltransferase ST3Gal-6, an enzyme critical to the generation of E-selectin ligands, in MM BM homing and resistance to therapy. Since E-selectin is constitutively expressed in the BM microvasculature, we wished to establish the contribution of E-selectin ligands to MM biology. We report that functional E-selectin ligands are restricted to a minor subpopulation of MM cell lines which, upon expansion, demonstrate specific and robust interaction with recombinant E-selectin in vitro. Moreover, an increase in the mRNA levels of genes involved in the generation of E-selectin ligands was associated with inferior progression-free survival in the CoMMpass study. In vivo, E-selectin ligand-enriched cells induced a more aggressive disease and were completely insensitive to Bortezomib. Importantly, this resistance could be reverted by co-administration of GMI-1271, a specific glycomimetic antagonist of E-selectin. Finally, we report that E-selectin ligand-bearing cells are present in primary MM samples from BM and peripheral blood with a higher proportion seen in relapsed patients. This study provides a rationale for targeting E-selectin receptor/ligand interactions to overcome MM metastasis and chemoresistance.

Multiple myeloma is a clonal disorder of plasma cells that is currently considered incurable. CD38 is a 46 kDa type II transmembrane glycoprotein that is highly expressed on myeloma cells. Daratumumab is a first in-class human IgG1 monoclonal antibody that targets CD38, and has antimyeloma effects through several mechanisms. Single-agent trials show surprising activity in heavily pretreated myeloma patients. Trials in the relapsed setting, where daratumumab is added to lenalidomide and dexamethasone or bortezomib and dexamethasone, have demonstrated significantly improved progression-free survival with acceptable toxicity. In this review, we discuss the mechanism of action, pharmacology and pharmacokinetics of daratumumab and review the available clinical data in detail. We examine how daratumumab interferes with transfusion testing due to the expression of CD38 on the red blood cells, leading to potential difficulties releasing blood products. Daratumumab also affects disease assessments in multiple myeloma, including serum protein electrophoresis, immunofixation and flow cytometry. Strategies to mitigate these effects are discussed. The optimal use of daratumumab has yet to be decided, and several trials are ongoing in the relapsed and upfront setting. We discuss the potential upfront role of this exciting therapy, which has significant potential for increased minimal residual disease negativity and improved progression-free survival even in high-risk groups.

Introduction Myelodysplastic Syndromes are diverse group of bone marrow failure syndromes and current treatment options are guided by International Prognostic scoring systems (IPSS and IPSS-R) based on clinical phenotype and cytogenetics. Deletion of long-arm of chromosome 5 is the commonest cytogenetic abnormality and confers distinct biological and clinical implications. A specific subgroup of MDS patients with isolated Del(5q) was described as a separate entity in WHO 2008 classification owing to its unique clinical features, a low risk of leukemic transformation and a relatively good prognosis. Lenalidomide is proven to induce high erythroid response rates (frequently abolishing transfusion requirements) with a median response time of over 2 years in MDS patients with Del(5q). However, with time their anaemia worsens and most patients will become transfusion dependent with subsequent iron overload. Other treatment strategies were explored for those who failed Lenalidomide. Method This retrospective multi-centre analysis involved collecting data for MDS patients with 5q abnormalities (isolated Del(5q), Del(5q) with one additional cytogenetic abnormality, or Del(5q) within a complex karyotype) diagnosed between 2006 and 2014 in the Republic of Ireland. Six haematology units participated and the data of 47 patients were available for analysis. Results The median age of diagnosis was 72(29-91) with male-female ratio of 1:1.6. A range of WHO subgroups were identified and classic 5q Syndrome was documented in only 6.4% of patients. Cytogenetic results showed 47% isolated Del(5q), 17% Del(5q) plus one other abnormality and 36% Del(5q) in a complex karyotype. Patients with isolated Del(5q) or Del(5q) plus one other abnormality had similar haemoglobin, higher neutrophil and platelet count and lower marrow blasts than those with having a complex karyotype as previously described. IPSS-R scores were available in 37 patients as very low(7), low(8), intermediate(6), high(5) and very high(11). IPSS risks were available for 40 patients as low risk(12), intermediate-1(11), Intermediate-2(8) and high risk(9). Treatment options included red cell transfusion(85%), Recombinant Erythropoietin(45%), Lenalidomide(17%), Azacitidine(36%), Intensive chemotherapy(7%), transplantation(5%) and others(21%). All 8 patients in Lenalidomide group had either isolated Del(5q) or Del(5q) plus one other abnormality and received a median of 3 cycles (range 1-50). Responses were as follows: stable disease (3,38%), complete response (3,38%), and no response (2,25%). Three patients (38%) became transfusion independent with Lenalidomide. In 16 patients treated with Azacitidine, 50% had Del(5q) in a complex karyotype and 19% had failed Lenalidomide previously. A median of 10 cycles(range 1-18) were given. Four(25%) patients achieved a complete response, 1(6%) partial response, 1(6%) haematological improvement and 8(50%) stable disease. Response patterns were similar between the two groups with a trend towards improved survival in patients with isolated Del(5q) or Del(5q) plus one other abnormality compared to those with a complex karyotype treated with Azacitidine(23 vs. 15 months, p=0.0862). Transformation to AML was observed in 44% of patients without any difference between different cytogenetic groups. Median time to AML was 14 months. Median overall survival was 15 months(range Conclusions Irish patients with Del(5q) have similar pattern of disease with previously published data. Only a small proportion of patients were treated with Lenalidomide. Irish patients showed a good response to Azacitidine, even when Lenlalidomide failed and this is an important consideration for selected patients. A high rate of AML transformation was observed in Irish MDS patients with Del5q abnormalities. Figure 1. (a) Overall Survival of all patients (b) Overall Survival between Patients with isolated Del(5q) or Del(5q) plus one other abnormality compared to patients with complex karyotype including Del(5q) Figure 1. (a) Overall Survival of all patients (b) Overall Survival between Patients with isolated Del(5q) or Del(5q) plus one other abnormality compared to patients with complex karyotype including Del(5q) Figure 2. Figure 2. Disclosures O'Dwyer: Celgene: Honoraria, Research Funding.