bluuebunny/crossref_metadata_2025_split huggingface dataset:
PF726 TOLERABILITY OF TREATMENTS FOR RELAPSED/REFRACTORY MULTIPLE MYELOMA: A SYSTEMATIC REVIEW
Authors: Nassim M. , Nilsson J. , Zavisic S. , Malmenäs M. , Fotheringham I. , Landfeldt E. 
Published: June 2019

Background:Multiple myeloma is a fatal cancer characterized by excessive proliferation and improper function of plasma cells in the bone marrow.Aims:To conduct a systematic literature review of the tolerability of treatments for relapsed/refractory multiple myeloma.Methods:We searched MEDLINE, Embase, and the Cochrane Library for English language full‐text articles published between 2000 and 2018 reporting results from randomized controlled trials of treatments for relapsed/refractory multiple myeloma. Two independent investigators screened article titles and abstracts for eligibility and subsequently reviewed full‐text versions of selected records. For all articles included in the review, the following data were extracted: Author, year of publication, setting, sample, treatments, and tolerability results.Results:The search resulted in the identification of 3488 unique publications. Of these, 3188 were excluded following title and abstract screening and 75 after full‐text review. A total of 22 articles were included for data synthesis. Identified randomized controlled trials involved an average of 477 patients (range: 80 to 768) and covered a total of 14 interventions for relapsed/refractory multiple myeloma. Of these, 14% were monotherapies and 86% combination therapies. Across included randomized controlled trials, the most frequently occurring adverse event during treatment was neuropathy, observed in 1%–67% of patients, followed by thrombocytopenia (1%–57%), pain (1%–24%), neutropenia (1%–52%), and diarrhea (1%–68%). Treatment discontinuation (all causes) was reported at between 31% and 95%, and discontinuation due to adverse events at between 7% and 34%.Summary/Conclusion:Current therapies for relapsed/refractory multiple myeloma are associated with several serious adverse events, resulting in treatment discontinuation. Yet, tolerability profiles vary markedly between interventions and patient populations. These data should be helpful to inform therapeutic decisions in relapsed/refractory multiple myeloma to enhance patient satisfaction and treatment compliance.
PF783 TREG DOWNREGULATION IS ASSOCIATED WITH INCREASE OF T CELL RESPONSES AGAINST IMMUNOGENIC ANTIGENS AND CLINICAL RESPONSES IN PATIENTS WITH HEMATOLOGICAL MALIGNANCIES AFTER DONOR LYMPHOCYTE INFUSION
Authors: Greiner J. , Götz M. , Schmitt M. , Wiesneth M. , Bunjes D. , Hofmann S. 
Published: June 2019

Background:Cytotoxic T‐cell responses against malignant cells play a pivotal role in maintaining remission and prolonging overall‐survival after allogeneic stem cell transplantation (allo‐SCT) and donor lymphocyte infusion (DLI), however they are not well characterized so far.Aims:In this study, we focused on the detection of immune responses in patients before and after DLI. A broader epitope‐specific T cell activity is associated with clinical response of patients treated with DLI and additionally reduced regulatory T cell frequency may contribute to clinical response in patients after DLI.Methods:For a better characterization of the T cell responses, frequency and diversity of leukemia‐associated antigen (LAA)‐specific cytotoxic T cells was assessed using ELISpot and pMHC multimer assays. Furthermore, the frequency of regulatory T cells (Treg) before and after DLI was analyzed. Results were correlated to the clinical course of the patients.Results:Independently of their clinical response, over the course of DLI 7/11 patients (63.6%) showed an immunological response through an increase in the number of recognized epitopes. Comparing early screening and maximum response after DLI there was a significant increase (p = 0.02) in epitope recognition. A significant increase in the mean augmentation from 1 to 4 of the spotted epitopes in the course of DLI was detected in the cohort of clinical responders (R) compared to non‐responders (NR) who did not show any dynamics in epitope recognition with a median of 3 to 4 recognized LAA.The proportion of the CD4+CD25highFoxP3+ Treg within the CD4+CD25high T cell fraction decreased significantly in R from a median of 72.9% to 54.6% when comparing the variation at the time points before and after DLI (p = 0.04). In NR there was no significant change in the Treg fraction in the course of DLI.In general, significantly more LAA‐derived T cell epitopes (p = 0.02) were recognized in R when compared to NR. Moreover, the frequency of Treg in R decreased significantly (p = 0.008) while remaining stable in NR.Summary/Conclusion:Taken together, an increase of specific CTL responses against several LAA after DLI was detected. This study suggests that decreasing numbers of Treg as well as enhanced LAA diversity in T cell responses contribute to clinical outcome of patients treated with DLI.
PF794 DETECTION OF ANTIBODIES DIRECTED AGAINST DOMAIN 1 OF BETA 2 GLYCOPROTEIN I IN PATIENTS WITH ANTIPHOSPHOLIPID SYNDROME
Authors: Kerényi A. , Nagy G. , Antal‐Szalmás P. , Kappelmayer J. 
Published: June 2019

Background:Antiphospholipid syndrome (APS) is an acquired thrombophilia caused by antiphospholipid autoantibodies (aPL). Diagnosis of APS is based on laboratory and clinical criteria (thrombosis or pregnancy‐related complications). The detection of lupus anticoagulant (LA), IgG and/or IgM isotype anti‐cardiolipin (ACA) and anti‐β2 glycoprotein I antibodies (aβ2GPI) constitutes the laboratory tests of APS. The β2GPI protein consists of 5 domains and an association of thrombosis with the presence of antibodies directed against domain 1 (aD1β2GPI) was suggested in the literature.Aims:The aim of this study was to investigate the presence of IgG isotype aD1β2GPI and its association with thrombosis in our patient cohort.Methods:Using a chemiluminescence immunoassay (INOVA QUANTA Flash β2GPI‐Domain I, ACL Acustar) we have measured aD1β2GPI titer in 51 patients having IgG isotype aβ2GPI (APS with thrombosis: n = 21; APS with pregnancy loss: n = 7; other autoimmune disease: n = 18; aPL positive asymptomatic patients, n = 5).Results:In patient samples the concordance between the presence of IgG isotype aD1β2GPI and aβ2GPI was 67% and the correlation between these antibody titers was high (r = 0.71). We have found that the level of IgG isotype anti‐β2GPI was significantly higher in thrombotic APS patients compared to all other patient groups. The aD1β2GPI titer was the highest in thrombotic patients however, there was no significant difference in the antibody titer among the patient groups. The IgG isotype aβ2GPI and aD1β2GPI titers were significantly higher in triple positive patients (LA, ACA and aβ2GPI positive) than in double positive patients (ACA and aβ2GPI positive). In the aD1β2GPI positive group 47% of patients had thrombosis, while in the aD1β2GPI negative group this figure was only 29%, however, the association of aD1β2GPI positivity with thrombosis was non‐significant.Summary/Conclusion:This study provides further evidence that the large majority of IgG isotype aβ2GPI is directed against domain 1. Since the concordance between the two antibody positivity was not 100% and aD1β2GPI negative patients can present with thrombosis, we conclude that monitoring aD1β2GPI cannot replace detection of aβ2GPI in the laboratory diagnosis of APS.
S851 A FULLY HUMAN BISPECIFIC ANTIBODY FUNCTIONALLY RESCUES FACTOR VIII DEFICIENCY EX VIVO
Authors: Wang W. , Blackwood J. , Magliozzi R. , Moraes L. , Sinopoli A. , Chi B. , Sellick C. , Pearce C. , Theurl I. , Hollins J. , Dickson K. , Bradley A. , Lee E.‐C. 
Published: June 2019

Background:Haemophilia A is caused by deficiency of Factor VIII (F.VIII), an essential blood‐clotting cofactor. Prophylaxis or on‐demand treatment with recombinant FVIII forms the current standard of care to prevent bleeding in Haemophilia A patients in the developed world. However, approximately 30% of severe haemophilia A patients develop inhibitory antibodies against F.VIII. Moreover, FVIII treatment requires venous access which is burdensome. The recent successful clinical trials and subsequent regulatory approval of a F.VIII‐mimetic bispecific antibody, Hemlibra, in Haemophilia A patients with inhibitors have provided much needed hope for suffers and their family. However, whilst Hemilibra represents a major breakthrough in the field, there remain some concerns about balancing the risks of bleeding with those of thrombosis when using this agent.Aims:To develop a new fully human FVIII mimetic bispecific antibody that can support the assembly of a functional Factor IXa (F.IXa) and Factor X (F.X) complex, thereby replacing F.VIII function in vivo.Methods:Using Kymab's bispecific antibody platform, we developed KY1049, a fully human common light chain (CLC) bispecific antibody, to test as an effective functional mimetic of F.VIII. KY1049 bispecific heterodimer was purified using standard Protein A chromatography, followed by cation ion exchange chromatography (cIEX). The mass and heterodimer purity of the bispecific molecule was confirmed using Mass Spectrometry (MS). A combination of in vitro and ex vivo assays was used to characterize the cIEX purified bispecific antibody, including chromogenic FXase and Activated Partial Thromboplastin Time (aPTT). The affinities of the FIX arm and FX arm of KY1049 bispecific to FIX and FX, respectively, were determined using Surface Plasmon Resonance (SPR).Results:cIEX purified KY1049 molecule was confirmed as a single species by MS. After denaturing, the molecular weights of the two heavy chains and one light chain matches in silico predicted molecular weights. Purified KY1049 actively generated activated F.X (F.Xa) and functionally rescued the clotting defect in F.VIII‐depleted plasma in the aPTT assay. Importantly, ex vivo activities of KY1049 indicates its therapeutic benefit is likely to be similar in efficacy to Hemlibra. KY1049 binds F.IX and F.X simultaneously by SPR, but the affinities are different from those reported of Hemlibra.Summary/Conclusion:We have developed KY1049, a FVIII mimetic bispecific antibody, that demonstrates biological activities comparable to those reported for Hemlibra. Its therapeutic benefit is likely to be at least as effective as Hemlibra. Furthermore, initial analysis of the KY1049 molecule also showed some differences between the two molecules which could be harnessed to enhance its physical properties and activity.
S891 SUCCESSFUL TREATMENT OF INTESTINAL GRAFT‐VERSUS‐HOST DISEASE WITH FECAL MICROBIOTA TRANSPLANTATION
Authors: Van Lier Y. , Davids M. , Haverkate N. , de Groot P. , Donker M. , Heubel‐Moenen F. , Nur E. , Zeerleder S. , Nieuwdorp M. , Blom B. , Hazenberg M. 
Published: June 2019

Background:Disruption of the intestinal microbiome has a negative influence on the outcome of allogeneic hematopoietic stem cell transplantation (HSCT). Decreased gut flora diversity with loss of commensals and pathobiont domination, is associated with an increased risk to develop graft‐versus‐host disease (GvHD). Fecal microbiota transplantation (FMT) has successfully been used to treat Clostridium difficile enteritis but the safety and efficacy of FMT in immunocompromised GvHD patients remains to be elucidated.Aims:1. To assess the safety and effectiveness of FMT as treatment for GvHD patients in a prospective, single‐arm pilot study2. To analyze the microbiome dynamics of GvHD patients receiving an FMTMethods:Fifteen patients with steroid‐refractory or steroid‐dependent intestinal GvHD received a single FMT from an unrelated, healthy donor via nasoduodenal infusion. Follow‐up included collection of blood and fecal samples prior to FMT and at 1, 4, 12 and 24 weeks after FMT as well as clinical follow‐up up to 6months.Results:FMT was well tolerated by all patients, there were no serious adverse events observed that could be attributed to FMT. Response evaluation at 4 weeks after FMT identified 11 participants with a complete response (CR), defined as resolution of all GvHD, without other interventions to alleviate symptoms. In 6 CR patients, the normalization of stool frequency and consistency was sustained throughout the whole period of follow‐up, with successful taper of immunosuppressants. Five other responders initially showed improvement of GvHD after FMT but relapsed upon prednisolone taper (CR/sf; complete responders with secondary failure). A durable response to FMT was associated with a better prognosis (Figure 1). Analysis of peripheral blood immune cell subsets did not reveal significant differences. Alpha diversity of fecal samples, analyzed by 16S ribosomal RNA sequencing, was low in patients pre‐FMT but improved upon response to treatment in CR and CR/sf patients. One week after FMT, the fecal microbial composition of CR patients resembled that of the donor the most, suggesting a better engraftment of fecal donor species in patients with persistent responses.Summary/Conclusion:This pilot study shows the potential of donor FMT to safely restore microbial diversity and improve symptoms of steroid‐refractory or steroid‐dependent GvHD patients. These encouraging data promote further investigation of this therapy in larger cohorts.image
PS959 MVP COMBINED WITH FC AS LYMPHOCYTE‐DEPLETING CHEMOTHERAPY BEFORE CAR‐T TREATMENT CAN REDUCE THE INCIDENCE OF SEVERE CYTOKINE RELEASE SYNDROME FOR R/R ALL PATIENTS WITH HIGH TUMOUR BURDEN
Authors: Tang X. , Liu Q. , Li Z. , Dai H. , Yin J. , Tian X. , Xue S. , Xu Y. , Zhu X. , Wu D. 
Published: June 2019

Background:CAR‐T immunotherapy have shown remarkable promising results for relapsed/ refractory (R/R) acute lymphoblastic leukemia(ALL). However, the most common toxicity associated with CD19 CAR‐T treatment is Cytokine Release Syndrome(CRS) which can be a life threatening complication especially for high tumour burden ALL patients. How to reduce the incidence of severe CRS can be a great challenge for advanced high tumour patients.Aims:In order to evaluate the efficacy and safety of MVP+FC as lymphocyte‐depleting chemotherapy to reduce tumour burden before CAR‐T therapy.Methods:If patients’ blasts in bone marrow was more than 28%, the chemotherapy MVP(Mitoxantrone 10 mg/w once(d1)+ Vindesine 4 mg/w once(d1) + Dexamethasone 10 mg/d × 7d(d1‐d7) followed by FC(Fludarabine 30 mg/m2 × 3d (d8‐ d10)+ cyclophosphamide 300 mg/m2 × 3d(d8‐d10)) were performed. CD19 CAR‐T, CD22CAR‐T and CD19CD22 tandem CAR‐T were infused with dose escalation schedule: 10%>‐ 40%>‐ 60% (d13, d14, d15). Total dose of CAR‐T for infusion was 5–10 × 106/kg.Results:16 patients were enrolled in this study with median age of 24 (6–56) years old. 11 patients were relapse post multiple chemotherapies. Another 5 patients were relapse post allo‐HSCT including T315I and TP53 mutation patients. The median blasts in BM before and after MVP treatment were 56% (28–89%) and 34%(0–85%). Furthermore, the median blasts in BM after MVP+FC treatment were 6%(0–60.5%). Overall response of CAR‐T were 93.75% with hematological remission 93.75% and molecular remission 63.75%. Only 4 patients experienced 3 grade CRS and other patients just had 1–2 grade of CRS. Only one presented sepsis. No one experienced neurotoxicity. Treatment related mortality was 0. With the median follow up of 9(1–26)months, 6 and 12 months leukemia free survival were 56.9% and 40.6% respectively.Summary/Conclusion:MVP combined with FC was an effective and safety conditionning regimen before CAR‐T treatment with low incidence of severe CRS especially for high tumour burden ALL patients.
PS996 TCF4 IS IMPORTANT FOR MUTANT RUNX1‐MEDIATED CELL IMMORTALIZATION AND PREDICTS OUTCOME IN ACUTE MYELOID LEUKEMIA
Authors: In ’T Hout F. , Gerritsen M. , Bullinger L. , van der Reijden B. , Huls G. , Vellenga E. , Jansen J. 
Published: June 2019

Background:Aberrations of the RUNX1 transcription factor, either mutations (RUNX1
mut) or translocations t(8;21) creating a RUNX1‐RUNXT1 fusion gene, are frequently observed in AML. However, the pathomechanisms underlying RUNX1
mut AML and explaining its poor prognosis in contrast to t(8;21) cases are still poorly understood.Aims:As recent data suggested deregulation of the transcription factor 4 (TCF4) gene to play a potential role, we studied the importance of TCF4 in the context of RUNX1
mut and t(8;21).Methods:Chip‐sequencing data was analyzed to identify binding of RUNX1 on the TCF4 promoter and Luciferarse reporter assays were used to assay impact of RUNX1 on TCF4 promoter activity.CD34+ UCB cells were transduced with a pRRL construct overexpressing the RUNX1 R201Q mutant (RUNX1mut) or an empty vector (EV). Simultaneously, TCF4‐RNAi (TCF4kd) or a non‐targeting control (NT) was co‐transduced. These double transduced CD34+ UCB cells were cultured on MS5 bone marrow stromal layer and proliferation assays, colony forming unit assays and long‐term culture‐initiating cells assays were performed. TCF4 expression values were derived from a previously reported cohort of 436 AML patients of which 330 had a known RUNX1 status. Survival curves were calculated by the Kaplan‐Meier method and compared using the logrank test. Multivariate survival analysis was carried out using the Cox proportional hazards model, and covariates included were RUNX1 mutation and white blood cell count (WBC > 100 ∗109/L) with and without TCF4 expression (lowest 75% vs highest 25%).Results:While TCF4 is found upregulated in RUNX1
mut in contrast to t(8;21) AML, Chip‐seq and transactivation assays revealed that RUNX1 binds and regulates the TCF4 promoter activity. RUNX1 wild type (RUNX1wt) and the RUNX1‐RUNX1T1 fusion protein repressed TCF4 promoter activity, which was lost in RUNX1mut AML. In CD34+ cells RUNX1
mut enhanced colony‐formation and increased long‐term culture initiating cells, whereas RNA interference based TCF4 downregulation in RUNX1
mut cells abolished this effect. Being required for stem cell maintenance activity in RUNX1
mut AML, TCF4 upregulation accounted for the poor prognostic outcome of RUNX1
mut in AML patients, as RUNX1
mut lost its significance in multivariate analysis if TCF4 expression was included.Summary/Conclusion:In summary, TCF4 is an important downstream target of RUNX1mut AML contributing to leukemogenesis and poor response to standard AML therapy.
PS1012 PREDICTING A PML‐RARA FUSION GENE IN PATIENTS WITH ACUTE MYELOID LEUKEMIA BY CONVOLUTIONAL NEURAL NETWORKS
Authors: Liu C.‐J. , Liu Y.‐C. , Yuan W. , Yu K.‐H. 
Published: June 2019

Background:Acute myeloid leukemia (AML) is a prevalent hematological malignancy worldwide. The estimated incidence of AML was 2.4 per 100,000 standard population in Taiwan in 2016. Bone marrow studies are essential for the initial workup in most cases. However, these examinations require a thorough evaluation of the histopathology slides by hematopathologists. Acute promyelocytic leukemia (APL) is a subtype of AML. APL has completely different initial treatment and prognosis from the other subtypes of AML. Convolutional neural network (CNN) is the state‐of‐the‐art technology of image recognition and has been shown to successfully predict common gene mutations by using cancer pathology images (Nicolas et al. 2018 Nature Medicine).Aims:We planned to use the whole‐slide scanning images of bone marrow aspiration smears to examine the utility of CNN in predicting APL in AML patients.Methods:We collected the whole‐slide scanning images of patients with newly diagnosed AML at Taipei Veterans General Hospital between November 2009 and September 2017. The final cohort consisted of 261 AML cases. The patients’ age, sex, bone marrow blast percentage, cytogenetics and molecular studies, such as FLT3‐ITD and NPM1 and outcomes, were collected. The cohort was split into a training set (80%) and a testing set (20%). In addition, two AML cohorts from Far Eastern Memorial Hospital (n = 19) and Kaohsiung Veterans General Hospital (n = 29) were served as external validation cohorts. Inception V3 was used as the baseline model. Stochastic gradient descent was employed to refine the weights in the CNNs using the training set. The finalized model was tested on the held‐out test set. Prediction accuracy and the area under the receiver operating characteristic curves (AUCs) were analyzed to evaluate the performance of the algorithms. All CNN models were trained using Keras version 2.1.5 with Tensorflow 1.7.0, and statistical analysis was performed with R version 3.5.1.Results:The median age of the AML patients at diagnosis was 65 (range 17–96) years and 58.9% of them were male. CNN classified APL from the other subtypes of AML with high accuracy (AUC 0.92). In addition, CNN also could predict other chromosomal abnormalities, such as complex karyotypes, and molecular abnormalities, such as NPM1 mutation. Furthermore, CNN successfully predicted patients’ overall survival by using its classification.Summary/Conclusion:CNN successfully predicted genetic alterations of AML patients by using the histopathology images of the bone marrow aspiration smears. These results demonstrated the utility of convolutional neural networks in predicting common genetic mutations. Our developed methods are generalizable to other hematological malignancies or other cancers.image
PS1017 MICRO RNA SIGNATURE OF ONCOGENIC MUSASHI RNA BINDING PROTEINS MSI1 AND MSI2
Authors: Duggimpudi S. , Höll J. , Borkhardt A. 
Published: June 2019

Background:MSI1 and MSI2 are two paralogous RNA binding proteins (RBPs) which are frequently dysregulated in multiple cancers ranging from breast cancer, gliomas, medullobalstoma to acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). RBPs along with MicroRNAs are key form of regulatory molecules working post‐transcriptionally. The interplay between miRNAs and Musashi proteins on target 3’UTRs can rapidly modulate their target mRNA expression. Therefore, identification of mRNA and miRNA interactome is essential for defining the roles of these proteins. We previously identified the mRNAs that are bound and regulated by MSI proteins, next we chose to identify the microRNAs that are regulated by MSI1/2Aims:The overall objective of the study is to identify the microRNAs that are regulating and regulated by MSI1 and MSI2 to increase our understanding on the function of these oncogenic proteins.Methods:AGO2 PAR‐CLIP experiments aid in identifying the miRNAs that bind to the MSI1/2 mRNA sequence. We will also bioinformatically identify the seed sequence regions on mRNAs that are preferentially bound by miRNAs. Next, we silenced the expression of MSI1 and MSI2 and sequenced the resulting small RNAs using Truseq small RNA sequencing on Illumina platform to identify the miRNAs that are differentially expressed. We carried out functional validation of some of the most promising leukemic miRNA candidates of MSI1/2 using microRNA mimics which will help us uncover new biomarkers and potential therapeutic targets.Results:We have performed AGO2 PAR‐CLIPs on AML and CML cell lines THP‐1 and K562 along with a control and found several interesting oncogenic microRNAs binding MSI1/2. Additionally, we knocked down the expression of MSI1/2 using siRNA cocktail and isolated the microRNAs. We sequenced these microRNAs and are currently in the process of identifying the differentially regulated miRNAs.Also, miR‐143 was identified as top microRNA that bind to MSI2, therefore using miR143 mimics, we validated its binding and effect of its binding on MSI2 expression. We noted a decreased expression of MSI2 upon transfection of cells with miR143 mimics compared to controls. Other top microRNA targets like miR128, miR137, miR320 and miR181 as currently being validated.Summary/Conclusion:We identified transcriptome wide microRNAs that bind and regulate the expression of MSI1 and MSI2. We are also evaluating the miRNAs that are differentially regulated by MSI1/2. We validated the binding and regulation of miR143 on MSI2 expression. Combining the data from AGO‐CLIPs and TruSeq small RNA sequencing data, we will be able to establish the microRNA interactome of Musashi family of RBPs. Data from this study can help us to design therapeutic RNA‐decoys that can target the expression of oncogenic musashi proteins.