bluuebunny/crossref_metadata_2025_split huggingface dataset:
PF398 KNOCKDOWN OF LASP1 IN CXCR4 EXPRESSING CML CELLS PROMOTES CELL PERSISTENCE, PROLIFERATION AND TKI RESISTANCE
Authors: Herrmann A.B. , Müller M.‐L. , Orth M.F. , Müller J.P. , Zernecke A. , Hochhaus A. , Ernst T. , Butt E. , Frietsch J.J. 
Published: June 2019

Background:Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by a fusion protein, the constitutively active BCR–ABL tyrosine kinase, leading to expansion of differentiated granulocytes. Although tyrosine kinase inhibitors (TKI) have significantly improved patient care, minimal residual disease (MRD) remains a clinical challenge. Recently, the LIM and SH3 domain protein 1 (LASP1) has been identified as a novel BCR–ABL substrate, which is hyperphosphorylated at Y171 in CML cells. LASP1 is associated with proliferation, migration, tumorigenesis and chemoresistance. Furthermore, the protein can bind to the chemokine receptor 4 (CXCR4), known to be involved in homing of leukemic stem cells and relapse of CML patients.Aims:These two LASP1‐influenced disease promoting effects prompted us to investigate the effect of LASP1 and CXCR4 on processes involved in initiation, progression and maintenance of CML in order to identify and exploit BCR‐ABL‐independent pathways and other extrinsic factors, which may help to eradicate MRD.Methods:Using a CRISPR/Cas9‐based LASP1 knockout system and a lentivirus‐mediated CXCR4 overexpression in the CML cell line K562, the biological influence of CXCR4 and LASP1 was characterized in apoptosis, viability, cell cycle, migration and adhesion assays in the presence of nilotinib. Furthermore, comprehensive transcriptomic microarray data from a public database, immunofluorescence imaging and biochemical analysis were employed to elucidate the roles of LASP1 in CML.Results:Microarray analysis revealed that LASP1 is significantly lower expressed in samples of CML patients not responding to imatinib therapy. The in vitro data indicate that not only the overexpression of CXCR4, but also knockdown of LASP1 contributed to proliferation, reduced apoptosis and impaired cell migration. Additionally, we show that LASP1 depletion leads to decreased cytokine release and reduced natural killer (NK)‐cell mediated cytotoxicity. Finally, we describe a phosphorylation‐dependent loss of direct binding between pLASP1‐Y171 and CXCR4 in CML, which most likely results in receptor destabilization.Summary/Conclusion:Taken together, our results indicate that in CML, reduced levels of LASP1 alone and especially in combination with high CXCR4 expression contribute to TKI resistance and stem cell persistence.
PF427 FOSTAMATINIB, A SPLEEN TYROSINE KINASE INHIBITOR, FOR THE TREATMENT OF WARM ANTIBODY AUTOIMMUNE HEMOLYTIC ANEMIA: INITIAL RESULTS OF THE OPEN‐LABEL EXTENSION PERIOD OF THE SOAR PHASE 2 STUDY
Authors: Kuter D. , Richy A. , Boxer M. , Broome C. , Arnold D. , Field J. , Murakhovskaya I. , Rogers K. , Lowe A. , Numerof R. , Zayed H. , Tong S. , Duliege A.‐M. 
Published: June 2019

Background:Warm antibody autoimmune hemolytic anemia (wAIHA) is a rare and often serious disease resulting from antibody‐mediated destruction of red blood cells (RBCs). The SYK inhibitor, fostamatinib, markedly improved Hgb levels in patients with wAIHA during a phase 2, open‐label, multicenter study, in which 9 of 21 (43%) met the primary endpoint (Hgb >10 g/dL with an increase of ≥2 g/dL from baseline by Week 24 without rescue therapy or RBC transfusion).Aims:We report the results of the ongoing extension period of the study.Methods:Adults with primary or secondary wAIHA had to have failed ≥1 prior treatment for wAIHA, have hemoglobin (Hgb) <10 g/dL, an IgG‐positive direct antiglobulin test, haptoglobin <10 mg/dL, and lactate dehydrogenase (LDH) >ULN. Fostamatinib 150 mg BID was taken orally with no food restriction (dose reduction permitted based on tolerability). To enter the extension, patients had to meet the primary endpoint OR show a marked improvement in Hgb and had to have tolerated study drug.Results:Nine patients who completed the initial treatment phase entered the extension: 7 patients met the primary endpoint, 1 was a late responder, and 1 had a beneficial trend during the initial treatment phase. For baseline characteristics, see table. Median Hgb levels increased over the study. Five of 9 patients have an ongoing response to fostamatinib as of July 2018, and none have had rescue therapy or an RBC transfusion. Six of 9 patients are still on the study, and 3 discontinued due to lack of response plus AE (1), consent withdrawn (1), and unknown (1).Nine patients had ≥1 AE, 6 with treatment‐related AEs. AEs were mostly mild to moderate, and the most common AEs were diarrhea and upper respiratory tract infection. Three Grade 3 AEs were reported in 2 patients. AEs resulted in dose reduction in 2 patients, dose interruption in 2, and study drug withdrawn in 1.Summary/Conclusion:Fostamatinib markedly improved Hgb levels in 9 of 21 (43%) patients with wAIHA during a phase 2, open‐label, multicenter study. Adverse events (AE) were manageable and consistent with those previously reported for fostamatinib in other conditions. A randomized, placebo‐controlled, Phase 3 trial is underway.image
PF442 TREATMENT WITH 5‐AZACYTIDINE RESULTS IN EXPRESSION OF LONG TERMINAL REPEAT (LTR) ELEMENTS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF PATIENTS WITH MDS AND AML: FIRST PILOT STUDY
Authors: Daskalakis M. , Haubitz M. , Steiner D. , Helf M. , Goyal A. , Brocks D. , Pleyer L. , Greil R. , Plass C. , Baerlocher G.M. , Oppliger Leibundgut E. 
Published: June 2019

Background:Epigenetic drugs are used for the treatment of several hematologic malignancies, but their pharmacological mechanism remains poorly understood. By genome wide analysis of transcription start sites (TSS), methylation status and chromatin dynamics, we showed for DNA methyltransferase and histone deacetylase inhibitors (DNMTi and HDACi) global reactivation of long terminal repeat elements (LTRs) in vitro (cell line models) and in vivo (neuroblastoma mouse xenograft model). The LTR reactivation is resulting in numerous fusion transcripts that encode novel protein isoforms which have the potential to influence cell proliferation, seem to be an explanation for the priming effect of epigenetic therapy and might be used as a potential marker for epigenetic treatment response.Aims:To investigate the reactivation of LTRs in sequential peripheral blood samples of AML and MDS patients upon epigenetic drug treatment with 5‐Azacytidine (DNMT‐inhibitor) by qRT‐PCR and ddPCR and to correlate the expression results with treatment response.Methods:Sequential RNA samples from peripheral blood mononuclear cells (PBMCs) of three AML and four MDS patients treated with 5‐Azacytidine were analyzed. Consensus primers covering the transcript variants of LTR12C as well as particular primers for specific LTR elements were used. Expression of LTRs was analyzed by qRT‐PCR technique with SYBRGreen as well as ddPCR technique with EvaGreen. Expression results were associated with treatment response.Results:In AML and MDS patients, we could detect LTR expression in sequential samples from PBMCs over time with 5‐Azacytidine treatment. LTR12C expression values measured by qRT‐PCR were confirmed by ddPCR and allowed to assess specific LTR elements. Patients with response to 5‐Azacytidine showed increased LTR12C expression whereas patients without treatment response had no increase in LTR12C expression. In contrast to the results from our previous NSCLC cell line model, specific LTR elements were only partially expressed in sequential PBMC samples from AML patients treated with 5‐Azacytidine.Summary/Conclusion:In this first in‐vivo pilot study, we detected LTR expression in sequential PBMC samples of AML and MDS patients treated with 5‐Azacytidine. In this group of patients, treatment response correlated with LTR expression over several treatment cycles with 5‐Azacytidine. These are the first results in AML and MDS patients showing expression of LTRs upon epigenetic drug treatment. Larger patient cohorts are necessary to confirm these results by either PCR‐ or genome wide‐analysis of transcription start sites (TSS) (Cap analysis of gene expression (CAGE) sequencing) as well as to evaluate the association of LTR expression and treatment response.
PF443 ADOPTIVE IMMUNOTHERAPY OF INVASIVE ASPERGILLOSIS BY T CELLS VACCINES AGAINST ASPERGILLOSIS IN MOUSE MODEL
Authors: Xing H. , Chen D. , Wang M. , Tian W. , Sun H. , Jiang Z. 
Published: June 2019

Background:Invasive aspergillosis is a common cause of life‐threatening infection in immunocompromised patients, especially those who require aggressive immunosuppressive treatment, as Aspergillus fumigatus is the most common pathogen. Despite advances in early diagnosis and new antifungal agents, the majority of cases still associated with high morbidity and unacceptable mortality. The reconstitution of specific immunity against A. fumigatus during periods of severe immunosuppression has the potential to impact enormously on the health and well being of patients.Aims:To screened the amino acid sequences of A. fumigatus recombinant protein ASP f16 by bioinformation software and determine the potential CTL epitopes processed and presented by mature DCs to prime specific CTL cells.Methods:We confirmed the killing ability of Asp f16 peptides specific CTLs against A. fumigatus by conidiacidal and hyphae killing assays, which indicated that CTLs culture supernatant contains substances that killed fresh A. fumigatus conidia and CTLs have killing activity directly against the hyphae in vitro. In our study, we also accessed the evaluation of the protection against A. fumigatus in vivo by adoptive transfer peptides specific CTLs to an invasive aspergillosis model of HLA A0201 transgenic mouse.Results:The results demonstrated the adoptive transfer of ASP f16 peptides specific CTLs significantly altered the course of the Aspergillus infection, as indicated by statistical significantly extended survival hours after the infection and reduced fungal burden in the lung tissue, as opposed to mice not receiving T cells or receiving nonrelated peptides (NPM1) specific T cells, which all died faster with extensive fungal growth.Summary/Conclusion:Generate Asp f16 specific CTL clones in vitro and adoptive transfer to the recipients when they’re susceptive to or involved in IA, will be a promising potential option to protect the recipients against the fatal fungal infection.
PF537 THE STAT SIGNALING BIOSIGNATURE OF CD4+ T CELL SUBSETS REFLECT THE IMMUNOGENICITY OF HIGH‐RISK MDS AND PREDICT AZACYTIDINE TREATMENT OUTCOME
Authors: Lamprianidou E. , Kordella C. , Zoulia E. , Papoutselis M. , Bezirgiannidou Z. , Vrachiolias G. , Spanoudakis E. , Vassilakopoulos T. , Galanopoulos A. , Papageorgiou S. , Pappa V. , Vakalopoulou S. , Garipidou V. , Papaioannou M. , Hatjiharissi E. , Diamantopoulos P. , Viniou N.‐A. , Kotsianidis I. 
Published: June 2019

Background:Azacytidine (AZA) is the mainstream treatment in high‐risk Myelodysplastic Syndromes (MDS), but the exact mechanism of action and resistance is largely unknown. AZA potentially acts, at least partially, by upregulating the antitumor immune response, but literature reports are still contradictory. Similarly, CD4+ T cells appear to play a critical role in the antitumor immune response in MDS, even though the exact mechanism remains unclear.Aims:As STAT proteins are key regulators of both physiological and pathological polarization and differentiation of CD4+cells, we investigated the STAT signaling profile of high‐risk MDS patients during AZA treatment and its correlations with clinical and biological parameters.Methods:Peripheral blood mononuclear cells were isolated before the initiation of AZA from 67 high‐risk MDS patients and 13 age‐matched healthy donors. We applied phosphospecific flow cytometry to measure both basal and potentiated levels of pSTAT1, pSTAT3 and pSTAT5. A signaling profile (SP) was constracted for T conventional (Tconv) and T regulatory cells (Tregs) and their functional subsets: PD1+ cells, central memory (TCM), naïve (TN), effector memory (TEM) and terminal effector memory (TEMRA) cells. We further characterized the functional and polarization state of T cells by staining with Perforin, IFNg, IL4, IL17 and Helios.Results:pSTAT signaling profile of Tconv cells revealed three signaling clusters (SC). SC#2 was characterized by higher potentiated responses of pSTAT3 after IL‐6 stimulation (IL‐6/pSTAT3) and was enriched in patients with longer median‐overall survival (mOS, p = 0.047, figure 1A). The SP of both PD1+ Tconv and TEM revealed three SCs. In both cases patients with shorter median event free survival (mEFS) segregated in SCs with downregulated potentiated responses (p = 0.055 and p = 0.04 respectively). The pretreatment SP of Tregs was also associated with mEFS though without reaching significance (p = 0.068), whereas the SP of PD1+ Tregs separated patients with intermediate potentiated responses which showed longer OS (p = 0.023).Summary/Conclusion:Collectively, are results reveal for the first time the clinically significant heterogeneity of CD4+ T cell subsets and their diverse role in the antitumor immunity in MDS. Moreover, the beneficial effect of the activation of IL‐6/pSTAT3 pathway in CD4conv cells comes in line with current data in CAR‐T cells and further suggests that the STAT signaling biosignature on CD4+ cells may represent a response biomarker to AZA and a therapeutic target for high‐risk MDS.image
PF547 FACTORS ASSOCIATED WITH THE NEED FOR TRANSFUSIONS IN PATIENTS WITH LOWER RISK MYELODYSPLASTIC SYNDROME (MDS). DATA FROM THE REGULAR CARE MDS‐REGISTRY IN GERMANY
Authors: Steinmetz H.T. , Toczek‐Thiel J. , Hellmich M. , Lipke J. , Liersch R. , Sauer A. , Tesch H. , Hessling J. , Schmitz S. 
Published: June 2019

Background:In 2009 we started a registry to evaluate the course of MDS in routine care in Germany.Aims:The aim of the current evaluation was to analyze factors associated with the need for red blood cell transfusions in patients (pts) with IPSS low and intermediate‐1 (int‐1) risk at diagnosis and in the course of the disease.Methods:2,447 patients (pts) with MDS were included in the regular care MDS‐registry from July 2009 till December 2016, provided that the diagnosis was confirmed by bone marrow biopsy and the pts had given their written informed consent. Baseline parameters at diagnosis and the clinical course were quarterly documented in an online database (IoStudy by Iomedico) by 90 centers all over Germany.imageResults:At the data‐cut in April 2017 1,240 of 2,428 evaluable pts (50.7%) had a low‐ (612 pts/49,4%) or an int‐1 ‐risk MDS (628 pts. /50.6%). The median age of the lower risk pts was 74 years (range 26–94), 484 (39%) were women and the median time of observation was 25 months (mo, range 0–97, mean 30,62mo). At diagnosis 114 (18.6%) low‐ and 169 (26.9%) int‐1‐ risk pts were transfusion‐dependent (TD). The median time to become TD was significantly different (log rank (Mantel‐Cox) p = <0.01) between low‐ (28mo, SD 4.030, 95% CI 20.1 – 35.9) and int‐1‐ risk pts (9mo, SD 1.380, 95% CI 6.295 – 11.705). Survival (OS) was estimated by Kaplan‐Meier curves for pts without TD mean 82,661mo (SD 1,813mo, 95%>CI 79,108 ‐ 86,214) and pts with TD mean 51,261mo (SD 1,453mo, 95%>CI 48,413 ‐ 54,109)(fig. 1A). Furthermore, OS after becoming TD was estimated by a time‐to‐TD stratified Kaplan‐Meyer curve (fig. 1B), that shows a significant difference (0.00 Log Rank, Mantel‐Cox). In an univariate analysis the following baseline parameters were significantly associated with a shorter duration to become TD: age ≥80years, hemoglobin (hb), count of reticulocytes, LDH, endogenous erythropoietin level (epo), ferritin, and fibrosis in bone marrow histology. The following parameters were not associated: sex, thrombocyte‐, leucocyte‐ and granulocyte‐count, folic‐acid‐, vitamin B12 level, and CRP. Del‐5q and trisomy 8 were the only cytogenetic abnormalities significantly associated with a shorter duration to become TD. In a cox regression analysis (table 1) hb and epo were significant only.imageSummary/Conclusion:The sooner pts becomes TD in the course of MDS, the poorer is the prognosis. It should be tested if a therapy that respites TD can prolong OS.Supported by an unrestricted grand from Celgene, Munich, Germany
PF568 INVESTIGATING MECHANISMS OF ELOTUZUMAB AND LENALIDOMIDE THERAPY IN MULTIPLE MYELOMA
Authors: Richardson K.J. , Robbins M. , Bezman N.A. , Quach H. , Harrison S.J. , Prince M.H. , Ritchie D.S. , Jenkins M.R. , Beavis P.A. , Darcy P.K. , Neeson P.J. 
Published: June 2019

Background:Multiple myeloma (MM) is currently incurable. To investigate new treatment options, patients with refractory relapsed (RR) MM were treated with combination of Elotuzumab (Elo, anti‐SLAMF7 antibody) and Lenalidomide (Len, IMiD) and had a 84% objective response rate. We hypothesized this Elo+Len clinical efficacy was due to repair of NK dysfunction in MM patient NK cells.Aims:To explore the mechanisms whereby Elo+Len rescued MM patient NK cell function.Methods:We co‐cultured MM patient PBMCs with myeloma cells and drug combinations in vitro, and compared changes in NK cell activation, cytotoxicity, cytokine/chemokine levels, and adhesion molecule expression between healthy donor (HD) and MM patient cohorts. We also used a humanized MM model to explore the in vivo efficacy of the Elo+Len combination.Results:We showed that Elo engaged NK cell FcγRIIIa, initiated anti‐myeloma cell cytotoxicity and NK cell secretion of pro‐inflammatory cytokines (IFNγ, TNFα) and chemokines (CCL3, CCL4, CCL5), suggesting recruitment of other immune effector cells to the tumour. Elo+Len treatment significantly enhanced in‐vitro Elo‐induced cytotoxicity of healthy donor (HD) and newly diagnosed MM (NDMM) patient PBMCs. In contrast, RRMM patient NK cells had divergent responses to Elo+Len treatment, including impaired cytotoxicity (7/11 patients), and normal cytotoxicity (4/11 patients) (Fig 1A). Len significantly increased the chemokine secretion of HD PBMCs and to a lesser extent, NDMM and RRMM patient PBMCs, with the exception of CCL5 which was upregulated similarly between all groups. Interestingly, both MM‐derived NK cells and OPM2 myeloma cells upregulated CD54 following Elo and Len therapy, strongly correlated with myeloma cell killing (P = 0.002, R2 = 0.76). This was most evident on the 4 responding RRMM patient PBMCS and their OPM2 targets (Fig 1A‐B, data points highlighted in red). Surprisingly, NK cell CD107a was upregulated equally on all groups in response to Elo, regardless of killing activity. This suggests MM patient dysfunctional NK cells are sufficiently activated to degranulate, but are unable to kill myeloma cells due to inefficient adhesion and synapse formation. We also found that Elo induced in‐vivo therapeutic efficacy of human NK cells against RPMI8226.huSLAMF7 (RPMI8226 cells engineered to express human SLAMF7) multiple myeloma tumors, this was further enhanced with Len co‐treatment (Fig 1C).Summary/Conclusion:Our data suggests that Len improved Elo‐induced tumor control via increased cytotoxicity, chemotactic recruitment of effector cells and enhanced NK‐target synaptic adhesion. These data also suggest that monitoring an increase in CD54 expression on MM patient myeloma cells and NK cells may be a useful biomarker that tracks with Elo+Len efficacy.image
PF603 FASTER & SUSTAINED IMPROVEMENT IN HEALTH‐RELATED QUALITY OF LIFE IN TRANSPLANT‐INELIGIBLE NEWLY DIAGNOSED MULTIPLE MYELOMA PTS TREATED WITH DARATUMUMAB, LENALIDOMIDE & DEXAMETHASONE (D‐RD) VS RD: MAIA
Authors: Perrot A. , Facon T. , Plesner T. , Usmani S.Z. , Kumar S. , Orlowski R.Z. , Bahlis N.J. , Nahi H. , Mollee P. , Ramasamy K. , Roussel M. , Chaleteix C. , Araujo C. , Jaccard A. , Delforge M. , Karlin L. , Arnulf B. , Chari A. , Wang J. , Kobos R. , McKay C. , Gries K.S. , Trudeau J. , Hulin C. , Weisel K. 
Published: June 2019

Background:MAIA, an ongoing phase 3 trial of transplant‐ineligible patients with NDMM, demonstrated significant improvement in progression‐free survival with D‐Rd vs Rd alone. Assessment of patient‐reported outcomes (PRO) alongside efficacy endpoints provides patient perspective on their quality of survival and overall value of health‐related quality of life (HRQoL) while on treatments.Aims:To utilize PRO assessments as a tool in capturing the patient perspective on quality of survival and HRQoL changes in MAIA.Methods:The EORTC QLQ‐C30 and EQ‐5D‐5L questionnaires were completed by patients using an electronic device at baseline and every 3 months during treatment; interim results are presented for first 12 months. Treatment effects were assessed using repeated measures, mixed effects models and thresholds for clinically meaningful benefit were based on established criterion from the literature.Results:Compliance rates in completing the assessment tools were high and comparable at baseline (>90%) and through month 12 (>80%) for both groups (D‐Rd [n = 368]; Rd [n = 369]). Improvement in Global Health Status (GHS) occurred in both groups; however, for D‐Rd, significantly greater improvement was observed at cycle 3 (LS mean change; D‐Rd: 4.5 [95% CI: 2.4, 6.6], Rd: 1.5 [95% CI: −0.7, 3.7]; [p = 0.0454]) and increasing improvement occurred across all time points. Significant improvement and clinically meaningful benefit in HRQoL for D‐Rd was also observed in EQ‐5D‐5L Visual Analog Scale (VAS) scores (LS mean change; D‐Rd: 10.1 [95% CI: 8.1, 12.1], Rd: 4.9 [95% CI: 2.8, 7.0]; [p = 0.0002]). The VAS median time to worsening was 10 mo longer for D‐Rd. Of note, meaningful differences were observed between the treatment groups in two subscale scores, pain symptoms and cognitive functioning. Statistically significant less pain was reported early with D‐Rd (LS mean change at cycle 3; D‐Rd: −17.9 [95% CI: −20.7, −15.0], Rd: −11.0 [95% CI: −14.0, −8.1]; [p = 0.0007]); clinically meaningful reduction in pain symptoms was sustained with D‐Rd. There was a decline in cognitive functioning through Cycle 12 in both treatment arms with the peak difference occurring at Cycle 9, but mean differences between groups were not statistically significant.Summary/Conclusion:Faster and sustained improvement in patients treated with D‐Rd was observed using HRQoL assessments compared with Rd, with similar findings reflected across the pain subscale.