bluuebunny/crossref_metadata_2025 huggingface dataset:
Obinutuzumab-Related Adverse Events: A Systematic Review and Meta-Analysis
Authors: Amitai Irina , Gafter-Gvili Anat , Raanani Pia , Gurion Ronit
Published: November 2019

Background:

Rituximab, the first FDA-approved anti-CD20 monoclonal antibody has dramatically improved outcomes for patients with CD20 positive lymphoproliferative disorders for 2 decades. Obinutuzumab was developed to potentiate activity and overcome resistance to rituximab. Clinical data suggest obinutuzumab is superior to rituximab in specific lymphoproliferative disorder, at the potential cost of increased toxicity, especially infections.

In order to better define the toxicity profile of obinutuzumab as opposed to rituximab, we conducted a systematic review and meta‐analysis of all randomized controlled trials comparing obinutuzumab with rituximab, either alone or combined with chemotherapy for any CD20 positive lymphoproliferative disorder, in order to assess safety.

Methods:

A comprehensive search was conducted until June 2019. Two reviewers appraised the quality of trials and extracted data. The Primary outcome was grade 3 to 4 infections; secondary outcomes included any adverse events, serious adverse events, and other grade 3 to 4 hematologic toxicity. Relative risks (RRs) with 95% confidence intervals (CIs) were estimated and pooled. A fixed‐effect model was used to pool data unless there was significant heterogeneity, in which case a random‐effects model was used.

Results:

Our search yielded 4 randomized controlled trials conducted between the years 2009 and 2014, including 3429 patients. Median age of patients in the trials was 58 to 62 years. The trials included patients with follicular lymphoma (FL) (2 trials), chronic lymphocytic leukemia, (1 trial), and diffuse large B cell lymphoma (1 trial). All trials compared between obinutuzumab and rituximab therapy: in 3 trials the antibody was combined with chemotherapy and in 1 trial it was given alone. In 2 trials, which included FL patients, the antibody was given also as maintenance therapy for up to 2 years.

There was a statistically marginally increased rate of grade 3-4 infections (RR 1.17 [95% CI, 1.0‐1.36]) and febrile neutropenia (RR 1.23 [95% CI, 1.0‐1.5]) and a statistically significant increased rate of grade 3-4 adverse events (RR 1.15 [95% CI, 1.09‐1.2]) in the obinutuzumab arm vs rituximab. Also, the obinutuzumab arm showed increased risk of grade 3-4 thrombocytopenia (RR 2.8 [95% CI, 1.92‐4.06]), infusion related reactions (RR 2.8 [95% CI, 2.16‐3.64]) and cardiac events (RR 1.65 [95% CI, 1.11‐2.46]). There was no significant difference in grade 3-4 anemia and neutropenia rates, nor in the mortality rate at 36 months (RR 0.93 [95% CI, 0.78‐1.11]).

Conclusions:

Our systematic review and meta-analysis demonstrates that obinutuzumab has a more severe toxicity profile as compared to rituximab. As better clinical outcomes were reported with obinutuzumab in several CD20 positive lymphoproliferative disorders, but with more toxicity, clinicians are faced with a challenge upon deciding which therapy to choose for their patients.

Disclosures

Gurion: Roche: Consultancy.
Unveiling a Critical Role of Thrombin in Enhanced CD8+ T Cell Response to Cancer
Authors: Cantrell Rachel , Rosenfeldt Leah A. , Mureb Duaa , Sharma Balkrishan , Revenko Alexey , Monia Brett P , Palumbo Joseph S.
Published: November 2019

A serious and life-threatening cancer-associated sequelae is venous thromboembolism (VTE). Indeed, VTE is the second leading cause of death in cancer patients, second only to the malignancy itself. Cancer patients with VTE or at high risk for VTE are generally treated with anticoagulants, which limit thrombin generation. While it's been widely accepted that thrombin plays a role in cancer progression, the effects thrombin has on other cell types within the tumor microenvironment (TME) have not been thoroughly studied.

An understudied role of thrombin may be found in its ability to drive T cell functions. Recently, we have identified thrombin as a potential enhancer of CD8+ T cell effector functions by signaling through the protease activated receptor 1 (PAR-1). Our preliminary data shows that thrombin increases CD8+ T cell survival in a PAR-1 dependent fashion. CD8+ tumor infiltrating lymphocytes (TILs) play a critical role in tumor clearance through their cytolytic and anti-tumor cytokine producing capacity. However, the hostile tumor microenvironment (TME) promotes a gradual reduction in CD8+ TIL capacity to produce cytokines and kill targets. Specific components of the TME, including PDL1 expression, are associated with loss of T cell functionality. A promising strategy to block the interaction of CD8+ TILs and the inhibitory TME components is immune checkpoint inhibition (ICI) therapy, as shown by effective blockade of PD1 signaling by anti-PD1 antibodies. However, these ICI therapies leave many patients unresponsive, highlighting the necessity to uncover additional underlying mechanisms involved in modulating CD8+ T cell responses against cancer. Our preliminary findings lead us to hypothesize that thrombin, in conjunction with PD1 blockade, may work in synergy to promote CD8+ T cell killing of tumors.

Consistent with our hypothesis, preliminary results suggest that thrombin is necessary for a robust anti-tumor immune response following ICI in vivo. Here, cohorts of C57BL/6 mice with low or normal circulating prothrombin levels bearing B16 tumors were treated with an anti-PD1 antibody or control IgG. Anti-PD1 therapy significantly limited tumor growth in mice with normal prothrombin levels, but had no impact on tumor growth in mice with low prothrombin levels.

A major implication of our findings is that limiting thrombin generation with anticoagulants may be detrimental in the context of immune checkpoint inhibition treatment. Better defining the potential risk of reducing ICI efficacy by concurrent treatment with anticoagulants will require a detailed understanding of the role thrombin plays in cancer immunobiology.

Disclosures

Revenko: Ionis Pharmaceuticals: Employment. Monia:Ionis Pharmaceuticals: Employment. Palumbo:Ionis Pharmaceuticals: Research Funding.
Application of a Standardized Flow Cytometry Panel for Defining and Monitoring the Immunophenotype of CAR-T Cells
Authors: Scarfò Irene , Gallagher Kathleen , Maus Marcela V. , Larson Rebecca , Sheehan Maegan , Brini Gabrielle , Bornheimer Scott , Hanley Mary Beth , Frigault Matthew , Leick Mark , Chekmasova Alena
Published: November 2019

Chimeric antigen receptor T-cells (CAR-T) have emerged as an extremely promising therapy for hematological malignancies. The immunophenotype of apheresis material and the CAR-T cell product is known to be predictive of the likelihood of response to treatment of certain malignancies. Central memory and stem cell-like memory T cell phenotypes are associated with a more sustained proliferative response and long-term CAR-T persistence (Fraietta et al, Nature Medicine, 2018).

There is an unmet need for standardized methods and reagents to reliably profile the memory phenotype of CAR-Ts to better evaluate product quality, and support improvements in CAR-T manufacturing. The BD Biosciences dried memory T-cell panel contains a pre-validated mixture of 7 antibodies for the identification of naïve, stem cell memory, central memory and effector memory CD4+ and CD8+ T cell subsets. The pre-mixed dried antibody tube offers consistency in staining profiles over time and reduces the risk of operator errors. Additional drop-in antibodies can complement the panel and enable more in-depth evaluation of the T cell phenotype. Here we demonstrate the use of this panel with drop-in markers to monitor changes in expression of PD-1, TIM-3, LAG-3, HLA-DR, CD45RO, and CXCR3 on T cells transduced to express our novel anti-CD37 CAR. Cells were stained at day 0 prior to transduction, day 7, and following resting and re-stimulation, and acquired on a 12 color BD FACS Lyric.

The use of a standardized memory T-cell panel will allow us to more accurately evaluate how T-cell phenotype impacts on the efficacy and longevity of response in patients receiving CAR-T therapies.

Disclosures

Maus: INFO PENDING: Other: INFO PENDING. Bornheimer:BD Biosciences: Employment. Hanley:BD Biosciences: Employment. Frigault:Novartis: Patents & Royalties: Royalty; Arcellx, Celgene, Foundation Medicine, Kite/Gilead, Nkarta, Novartis, and Xenetic: Consultancy.
Clostridium Difficile Infection in Hematopoietic Stem Cell Transplant Patients: A National Study
Authors: Vishnuvardhan Nivetha , Naaraayan Ashutossh , Hasan Amrah , Jesmajian Stephen
Published: November 2019

Introduction

Clostridium difficile infection (CDI) is the leading cause of infectious diarrhea among hospitalized patients. Patients undergoing hematopoietic stem-cell transplant (HSCT), either autologous stem cell transplant (Auto-SCT) or allogeneic stem cell transplant (Allo-SCT), are at high risk for CDI. We aim to describe the incidence and epidemiological trends for CDI in Auto-SCT and Allo-SCT in the United States, using the National Inpatient Sample (NIS) database provided by Healthcare Cost and Utilization Project (HCUP).

Methods

A descriptive, retrospective study was conducted on the National Inpatient Sample (NIS) Database for the years 2005-2014. Admissions with diagnosis of CDI were selected based on International Classification of Diseases-Ninth Revision (ICD-9), Clinical Modification diagnoses codes (00845). ICD-9 procedure codes were used to identify HSCT hospitalizations (autologous: 4101, 4104, 4107, and 4109; allogeneic: 4102, 4103, 4105, 4106, and 4108). Complex survey design, weights and clustering were accounted for during analysis.

Results

The mean age of patients undergoing HSCT was 45.69 + 20.35 years and 41.13% were female. There were total of 89,374 Auto-SCT patients and 66,044 Allo-SCT patients hospitalized between 2005-2014. Auto-SCTs constituted 55.5% of all the HSCTs. The incidence of Auto-SCT related hospitalizations increased from 205 per million admissions (pma) in 2005 to 291 pma in 2014 with an annual percentage change (APC) of 5.8, p<0.001. During the same period the incidence of Allo-SCT related hospitalizations increased from 151 pma to 224 pma with and APC of 6.3, p<0.001. Overall 6.67% of patients with Auto-SCT and 9.96% of Allo-SCT were diagnosed with CDI. There were statistically higher CDI rates in Allo-SCT when compared to Auto-SCT (p<0.001). The incidence of CDI in Auto-SCT patients showed a non-significant decrease from 2005-2009 and a significant increase from 2009-2014 (APC 7, p<0.001). The incidence of CDI in Allo-SCT patients increased significantly from 2005 to 2014 with an APC of 5.9, p<0.001.

Conclusion

The number of individuals being hospitalized for HSCTs in the United States is increasing and this increase is seen for both Auto-SCT and Allo-SCT procedures. One in fifteen patients undergoing Auto-SCT and one in ten patients undergoing Allo-SCT were diagnosed with CDI during hospitalization. There were significantly more CDIs in patients with Allo-SCT when compared to Auto-SCTs. The incidence of CDI in patients undergoing both Autologous and Allogeneic HSCT increased from 2005-2014 in the United States.

Disclosures

No relevant conflicts of interest to declare.
Features of an Unusual AML with t(4;12)/Pdgra-ETV6 As the Sole Cytogenetic Abnormality Associated with Myelodysplastic Changes: A Case Report and Literature Review
Authors: De Jitakshi , Medeiros L. Jeffrey
Published: November 2019

The t(4;12) cytogenetic abnormality is rare in AML, and is associated with a unique morphologic and immunophenotypic profile. Pseudo-lymphoid morphology of myeloid blasts (appearing as atypical lymphocytes), multilineage dysplasia, absence of eosinophilia, aberrant CD7 and lack of myeloperoxidase (MPO) expression, low frequency of FLT3 mutations, and treatment refractoriness are some of the characteristics of this AML subtype previously described in the literature.

We report a case of AML with t(4;12) in a middle-age male who presented with pancytopenia: WBC 3.34 (65% lymphocytes), Hgb 6.9, Plt 13, and no known prior history of a myeloid neoplasm. Bone marrow aspirate revealed 78% blasts that appeared large with uneven chromatin distribution, prominent nucleoli, and inconspicuous granules; and significant dysplastic features in the erythroid and megakaryocyte elements. Immunostains performed on the trephine core biopsy showed blasts expressed CD34 (subset), CD71 (subset), and were CD117+ Bcl-2+ CD43+ CD7+ MPO-. Flow cytometry identified 74% myeloblasts, positive for CD34, CD38, CD123, CD117, CD33, HLA-DR, CD13 (subset), CD56, CD7, CD71; negative for monocyte-specific markers. The morphologic and immunophenotypic features were compatible with AML with MDS-related changes.

Karyotype analysis identified t(4;12)(q12;p13) in 18/20 cells, and no additional chromosomal abnormalities. PDGFRA translocation to 12p was confirmed using PDGFRA and ETV6 FISH probes. Analysis of frequent genomic alterations in AML identified BCOR p.Leu1646Profs, TET2 p.Gln1627Ilefs, U2AF1 p.Ser34Phe mutations; and no FLT3 mutation.

Conclusions: In AML with t(4;12)/PDGFRA-ETV6, though lack of a FLT3 mutation is relatively favorable, BCOR and U2AF1 mutations and multilineage dysplasia are unfavorable prognostic factors. Synergism of the additional oncogenic mutations with the PDGFRA activating mutation can be postulated. The t(4;12)/PDGFRA-ETV6 should be recognized in the WHO classification as a recurrent balanced translocation in AML with MDS-related changes.

Disclosures

No relevant conflicts of interest to declare.
M6PR-Specific Targeting of Lysosomal Heparanase Regulates Platelet Hemostatic Function in Mice
Authors: Eaton Nathan , Drew Caleb , Dlugi Theresa A. , Hoffmeister Karin M. , Falet Hervé
Published: November 2019

Besides α-granules and dense granules, which play critical roles in and beyond hemostasis, circulating blood platelets and their precursor cells megakaryocytes contain lysosomes, the contents of which are also secreted during platelet activation. In their delivery to the lysosome, acid hydrolases bearing phosphomannosyl residues are trafficked from the trans-Golgi network to the acidic late-endosomal compartment via the mannose 6-phosphate receptor (M6PR) pathway. To determine the role of M6PR-specific targeting of lysosomal enzymes in platelet function, platelet parameters were investigated in M6pr-/- mice lacking the 46-kDa M6PR, the physiological role of which is unclear. M6pr-/- mice had normal platelet count but displayed an increased number of distinct proplatelet-like cells compared to control mice, as determined by immunofluorescent microscopy. Moreover, transmission electron microscopy revealed the presence of abnormal membrane tubulations, elongated and electron-dense granules, and large vacuole-like structures within resting M6pr-/- platelets. M6pr-/- platelets expressed normally major glycoproteins on their surface and von Willebrand factor and fibrinogen in their α-granules. M6pr-/- mice were hyper-thrombotic, as assessed by tail bleeding time, and M6pr-/- platelets adhered to type I collagen with a significantly greater propensity than control platelets under arterial shear in in vitro flow experiments. Heparanase, an endo-β-glucuronidase that cleaves extracellular matrix heparan sulfate proteoglycans, is the most abundant lysosomal enzyme in platelets. Thus, its contribution to the phenotype of M6pr-/- mice was investigated further. Heparanase expression was decreased in the bone marrow megakaryocytes and blood platelets of M6pr-/- mice and increased in M6pr-/- plasma, as evidenced by immunoblot and fluorescent microscopy analysis, consistent with its mistargeting in the absence of M6PR. Interestingly, pharmacological inhibition of heparanase with OGT 2115 normalized the adhesion of M6pr-/- platelets to collagen in vitro, indicating that increased plasma heparanase contributes to the thrombotic phenotype of M6pr-/- mice. Taken together, the data suggest that the M6PR-specific targeting of lysosomal heparanase plays a critical role in platelet function, thereby regulating hemostasis.

Disclosures

No relevant conflicts of interest to declare.
Simultaneous Inhibition of BCR-ABL1 Tyrosine Kinase and PAK1/2 Serine/Threonine Kinases Exerts Synergistic Effect Against Chronic Myeloid Leukemia Cells
Authors: Flis Sylwia , Bratek Ewelina , Chojnacki Tomasz , Piskorek Marlena , Skorski Tomasz
Published: November 2019

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of BCR-ABL1 tyrosine kinase - positive chronic myeloid leukemia in chronic phase (CML-CP). However, it is unlikely that TKIs will "cure" the disease in majority of patients because CML-CP cells are elusive targets even for the most advanced therapies employing second and third generation of TKIs. Therefore, new treatment modalities are necessary to improve therapeutic outcomes.

We showed before that class I p21-activated serine/threonine kinases (PAKs) remained active in TKI-naive and TKI-treated CML-CP leukemia stem and early progenitor cells. The aim of the study was to test whether simultaneous inhibition of signaling pathways activated by BCR-ABL1 and PAK kinases may improve the treatment of CML. Special attention was focused on PAK1 and PAK2, which are expressed in hematopoietic cells and can play an important role in the promotion of CML cells proliferation and survival. PAK kinases were targeted by small molecule inhibitor IPA-3 (inhibitor of PAK1) and shRNA construct for PAK2, BCR-ABL1 kinase was inhibited by imatinib. The studies were carried out using (i) primary CML-CP stem/early progenitor cells and normal hematopoietic counterparts isolated from the bone marrow of newly diagnosed CML-CP patients and healthy donors, respectively, (ii) CML-blast phase cell lines (K562 and KCL-22), and (iii) BCR-ABL1-transformed 32Dcl3 cell line cells.

We show here that inhibition of PAK1 or/and PAK2 kinases activity enhanced the effect of IM against CML cells without affecting normal counterparts. We observed that the combined use of IM with IPA-3 increased growth inhibition and apoptosis of leukemia cells. To evaluate the type of drugs interaction median effect analysis method was used. The studies revealed that the type and strength of drug interaction depend on drug concentration. Generally, combination of IM with IPA-3 at the 50% of the cell kill level (EC50) generated synergistic effect. Altogether, we postulate that BCR-ABL1 kinase inhibitor should be combined with PAK1/2 inhibitor to facilitate eradication of CML cells.

Disclosures

No relevant conflicts of interest to declare.
Vaccine Response to a Neo Polyssacharide Antigen Typhim Vi on the Identification of Secondary Immunodeficiencies in Hematological Malignancy
Authors: Ochoa-Grullón Juliana , Benavente Cuesta Celina , Cordero Torres G , Pérez López Cristina , Peña Cortijo Ascensión , Rodríguez de la Peña Antonia , Álvarez Carmona Ana , Mateo Morales Marta , Rodríguez de Frías Edgard , Guevara-Hoyer Kissy , Fernández-Arquero Miguel , Fernández-Paredes Lidia , Perez de Diego Rebeca , Sánchez-Ramón Silvia
Published: November 2019

An increasing healthcare challenge in the management of hematological malignancy (HM) is secondary immunodeficiency (SID), either caused by the underlying malignancy or by treatments, including B-cell-targeting therapies. From January 2019, the EMA (European Medicines Agency) included the evaluation of specific antibody (Ab) responses to better select patients for immunoglobulin replacement therapy (IgRT). Antibody response to polysaccharide immunizations is primordial in the immunological evaluation of the patients and it is thought to be the first Ab response to be lost in the rising of an immunodeficiency. Clinically, an impaired polysaccharide response means that the patient may not be protected to new encounters with encapsulated bacteria, having therefore higher risk of severe or recurrent infections. We evaluated Ab responses to pneumococcal (PPV) and Salmonella typhi (TV) pure polysaccharide immunization in a cohort of 42 HM patients and 24 healthy controls. Pre-post specific Ab serum concentrations were measured by ELISA (Binding Site, UK), before immunizations and at 4 weeks. Globally, the prevalence of TV titers pre-immunization was lower (9%) compared to PPV pre-immunization titers (76%) (p<0.001). There were more HM patients' non-responders for TV (88%, unable to mount a >3-fold increase in TV titers) than PPV non-responders (62%) (p<0.0001), and no-response to TV correlated better to infectious history. By ROC analysis, pre-post 5-fold TV increase was the best cut-off to discriminate HM with recurrent infections and controls (sensitivity 91%, specificity 100%). TV Ab responses were superior to PPV to identify SID and defective primary responses, notably in patients with high PPV baseline titers in the conjugate vaccine era, therefore overcoming the limitations in identifying patients with impaired polysaccharide responses after pneumococcal conjugate vaccine immunizations. Our results suggest that specific Ab response to S typhi polysaccharide is a useful complementary assay in the diagnosis and management decision of SID to HM, that may help to predict patients more prone to infections and guide a more risk-adapted infection-prophylaxis.

Disclosures

No relevant conflicts of interest to declare.
Ruxolutinib in Steroid Refractory Graft Versus Host Disease (SR-GVHD): Systemic Literature Review
Authors: Mohammed Saleh Mostafa F. , Hashmi Shahrukh K.
Published: November 2019

Background: Graft versus host disease (GVHD) is a main cause of morbidity and mortality in patients having undergone allogeneic hematopoietic stem cell transplantation (HSCT). About 30-40% of patients have steroid‐refractory GVHD (SR‐GVHD) after the first‐line use of high doses of corticosteroids with a poor prognosis .Ruxolitinib is a promising treatment for SR-GVHD. However, data regarding optimum dosing, response rates and associated adverse events are scarce. Herein, we provide the first systemic review of literature for the use ruxolutinib in GVHD.

Methods: A Medline (PubMed), google scholar, OVID and Cochrane Database of Systematic Reviews search using key words "Ruxolutinib and GVHD", "Ruxolutinib and SR-GVHD" was undertaken in June 2019. Only peer reviewed databases were searched and search was restricted to human studies of acute and chronic GVHD only.

Results: 16 publications, as listed in Table 1. Only one was a prospective trial, all others were retrospective studies, case series (5), and case reports (2). Overall response, ranged 45% - 100%, complete response was noted in 5.2% -80% patients. Time to response was variable from 1-12 weeks. Cytopenias and infectious complications were frequently reported with dose reduction or interruptions needed in most studies. Maintained responses were reported in a small proportion after ruxolutinib discontinuation.

Conclusion Ruxolutinib has promising efficacy in SR-GVHD , however cytopenias and infectious complications reported frequently mandate close monitoring. Results of ongoing prospective trials could provide answers for optimum dosing and response assessment, and management of related adverse events.

Table

Disclosures

No relevant conflicts of interest to declare.
An External Validation Study for Current Risk Scoring Models in Elderly Patients with Newly Diagnosed Acute Myeloid Leukemia
Authors: Liu Chia-Jen , Ying-Chung Hong , Yeh Chiu-Mei , Tsai Chun-Kuang , Hsiao Liang-Tsai , Wang Hao-Yuan , LIU Yao-Chung , Gau Jyh-Pyng , Ko Po-Shen , Liu Jin-Hwang , Chen Po-Min
Published: November 2019

Background

Acute myeloid leukemia (AML) is a common hematologic neoplasm in the elderly. The high mortality in elderly AML patients is reported to be associated with old age, poor performance status, and several disease characteristics. Several risk stratification models have been reported. Our aims were to explore risk factors for early mortality in older AML patients and compare the discrimination ability of existing prognostic models.

Methods

We enrolled newly diagnosed AML patients age 60 and above at Taipei Veterans General Hospital, a national medical center in Taiwan, between July 1, 2008 and May 31, 2017. Our primary endpoint was early mortality, defined as death within two months after initial AML diagnosis. Performance of several existing scoring systems were compared by using the Akaike information criteria (AIC) and Bayesian information criterion (BIC) calculations. Model discrimination ability was also estimated by Harrell's C statistics.

Results

A total of 478 AML patients were diagnosed during the eight-year follow-up period. After excluding young patients (age < 60) and those without a histopathologic diagnosis, the final cohort included 277 patients. The median age was 74 (range 60-96), and 171 (61.7%) of them were male. One hundred sixteen patients (41.9%) had Eastern Cooperative Oncology Group performance (ECOG) ≥ 2 and 33.9% patients had poor/adverse cytogenetics or molecular abnormalities. The two-month mortality rate was 29.9% (95% confidence interval [CI] 24.8%-35.9%). Age ≥ 80 (adjusted HR 1.95, 95% CI 1.12-3.42), having an antecedent hematologic disorder (adjusted HR 1.86, 95% CI 1.01-3.43), ECOG ≥ 2 (adjusted HR 2.06, 95% CI 1.20-3.54), complex karyotype (adjusted HR 3.13, 95% CI 1.76-5.55), BM blasts ≥ 70% (adjusted HR 1.79, 95% CI 1.02-3.13), WBC ≥ 100 ×109/L (adjusted HR 3.27, 95% CI 1.58-6.75), and creatinine > 1.3 mg/dL (adjusted HR 2.04, 95% CI 1.23-3.39) were identified as independent predictors for early mortality in the multivariate analysis. Furthermore, we systematically reviewed existing prognostic models for elderly AML. We found five scoring models that don't require additional specific examinations beyond clinical practice and later applied them to our elderly AML cohort. The performance of the five models is shown in Table. Kantarjian's prognostic model (Kantarjian H, et. al. Blood 2010) had the highest Harrell's C statistic and the ALMA score (Ramos F, et. al.Leukemia Research 2015) had the lowest AIC and BIC compared with the other prognostic models.

Conclusion

We identified seven risk factors for early mortality and compared the performance of five prognostic models for elderly AML patients. The finding may help clinicians to stratify patients and initiate appropriate management.

Table

Disclosures

No relevant conflicts of interest to declare.
Good Tolerance and Durable Remission for Anti-CD19 Chimeric Antigen Receptor T-Cell Therapy in Refractory/Relapsed Mantle Cell Lymphoma
Authors: Ye Shiguang , Zhou Lili , Li Shaoguang , Li Ping , Liang Aibin
Published: November 2019

Mantle cell lymphoma (MCL) is one subtype of the B cell non-Hodgkin lymphomas (NHL) and has a distinguash course. Despite all efforts, MCL is nearly incurable that refractory or relapse(r/r) course will occur in almost all patients. Due to the rapid development of chemotherapy resistance, it is difficult to treat r/r MCL. A number of treatment regimens have been evaluated with various degrees of success. Cellular immunotherapy has the potential to lead significant and sustained clinical remissions in lymphoma patients, in which modification of T cells with chimeric antigen receptors (CARs) is a powerful regimen. T cells containing CARs with costimulatory domains show better activity against tumor cells. We conducted a clinical trial testing a "second-generation" CD19-specific CAR with 4-1BB costimulatory domains in patients with r/r MCL.

Six patients with r/r MCL were enrolled and all were received T-cell infusions. The age of patients ranged from 52 to 81 years old. Five patients were male and one patient was female. Five patients had stage IV MCL with bone marrow involvement and one patient was stage II. Four patients had received more than 3 lines regimens and two patients had received first-line chemotherapy regimen. Four patients received FC regimen before CAR-T infusion and two patients were not received fludarabine due to age ≥80 years old.

Treatment was well tolerated, two patients developed transient infusion reaction. No patients have grade 3-4 Cytokine Release Syndrome (CRS). Three patients have grade 2 CRS and two patients have grade 1 CRS. Objective response rate is 66.67%. One patient achieves complete remission(CR) and three patients have partial remission(PR). The response of the other two patients is stable disease(SD). The patient who has CR response has remained progression-free for 36 months and is still being followed up. Two patients who have PR response have progressed in 3 months and the other one has durable response for 7 months. In the patients who has response, the peak of fever appears at approximately day 10 after CAR-T infusion, moreover interleukin(IL)6,IL2αand interferon(IFN)-γ almost reaches the peak on the day 14.

In conclusion, adoptive immunotherapy with CD19-specific T cells was well tolerated and was associated with antitumor activity. Further large-sample and multicenter studies are needed to fully evaluate this strategy for such patients.

Disclosures

No relevant conflicts of interest to declare.
Rituximab for Desensitization during HLA-Mismatched Stem Cell Transplantation in Patients with a Positive Donor Specific Anti-HLA Antibody: A Prospective Study
Authors: Chang Ying-Jun , Xu Lan-Ping , Wang Yu , Zhang Xiao-Hui , Chen Huan , Chen Yu-Hong , Wang Feng-Rong , Han Wei , Sun Yu-Qian , Yan Chenhua , Tang Fei-Fei , Huo Ming-Rui , Mo Xiao-Dong , Zhao Xiang-Yu , Liu Kai-yan , Huang Xiao-Jun
Published: November 2019

A prospective, clinical trial in non-manipulated haploidentical allografts was initiated to define the efficacy of a single dose of 375 mg/m2 rituximab as a desensitization regimen for donor-specific anti-HLA antibody (DSA)-positive patients with 2,000 ≤ mean fluorescence intensity (MFI) < 10,000. In the clinical cohort, compared to pretransplantation [median, 4791, n=28], the median MFI levels at day 7 [0], 14 [0], 21 [0], 30 [0], and 45 [0] following transplantation were significantly decreased (P<0.0001 for all). The incidence of primary poor graft function (PGF) in the clinical cohort (n=55) was comparable to that in the matched-pair cohort (n=110) negative for the DSA (5% vs. 1%, P=0.076), both of which were significantly lower than that in the historical cohort (n=22) with 2,000 ≤ MFI<10,000 without receiving any treatment to cope with DSA (27%, P<0.001, for all). Rituximab desensitization was associated with a reduced incidence of primary PGF (HR 0.200, P=0.023). The 3-year non-relapse mortality of patients in the clinical cohort and the matched-pair cohort were 23% and 24%, respectively, both of which were lower than that of patients in the historical cohort (37%), although no statistical significance was observed. These results led to a low 3-year overall survival in patients in the historical cohort (58%) compared to those in the clinical cohort (71%) and the matched-pair cohort (73%). These results suggest that a single dose of rituximab could be effectively used to desensitize patients and prevent the onset of primary PGF in patients who receive HLA-mismatched allografts.

This study is registered at http://www.chictr.org.cn/ChiCTR-OPC-15006672.

Disclosures

No relevant conflicts of interest to declare.
Deregulated CXCR4-CXCL12 Signaling Impacts on the Pathogenesis of DLBCL
Authors: Pansy Katrin , Feichtinger Julia , Ehall Barbara , Uhl Barbara , Greinix Hildegard T. , Prochazka Katharina , Beham-Schmid Christine , Neumeister Peter , Wrodnigg Tanja , Fechter Karoline , Deutsch Alexander
Published: November 2019

Introduction:

The interaction of the chemokine receptor CXCR4 and its ligand CXCL12 appears to be implicated in many important biological processes such as proliferation, survival, migration, and/or invasion. Furthermore, it is important for normal leukocyte trafficking. Deregulation of this axis is frequently observed in several hematologic malignancies. In diffuse large B cell lymphomas (DLBCL), the CXCR4-CXCL12 axis is still largely unexplored and published data are contradictive. Hence, we comprehensively studied the CXCR4-CXCL12-axis in our DLBCL cohort as well as the effects of CXCR4 antagonists on lymphoma cell lines in vitro.

Methods:

We determined the CXCR4 and CXCL12 expression levels in NGCB- and GCB-DLBCL consisting of primary and transformed follicular lymphomas (n=77 in total), the corresponding bone marrow samples (n=63) and non-neoplastic germinal center-B cells (GC-B, n=5) serving as non-malignant control. To investigate the effects of CXCR4 antagonists in vitro and their function in regulation of important pathways (JNK, ERK1/2 and NF-κB) known to be involved in lymphomagenesis, we treated lymphoma cell lines with three different CXCR4 antagonists, AMD070, AMD3100 and WK1 (a novel nicotinic acid derivative of AMD070 - synthesized by us), followed by functional assays and gene expression profile.

Results:

CXCR4 was 140-fold higher expressed in DLBCL compared to non-neoplastic GC-B cells. Interestingly, higher CXCR4 expression correlated to a clinically advanced stage, to bone marrow infiltration and worse cancer-specific survival in DLBCL. Further expression analysis by using the corresponding bone marrow biopsies demonstrated that CXCL12 expression correlated to the lymphoma infiltration rate and that CXCR4 expression was reduced in remission under therapy. Moreover, two CXCR4 antagonists - AMD070 and especially WK1 - exerted pro-apoptotic effects on CXCR4 positive lymphoma cells in vitro and induced the expression of certain pro-apoptotic genes in CXCR4 positive cell lines. Remarkably, these effects were more pronounced for the WK1. Finally, WK1 treatment resulted in reduced expression of JNK-, ERK1/2- and NFκB/BCR-target genes.

Conclusion:

Our data demonstrate that the CXCR4-CXCL12 axis is involved in the pathogenesis of DLBCL. Since CXCR4 antagonists exert pro-apoptotic effects and impact lymphoma relevant pathways, they represent interesting molecules to develop novel therapeutic agents.

Disclosures

No relevant conflicts of interest to declare.
SIX1 Is a Novel Effector Gene in CALM-AF10 Leukemia
Authors: Aumann Waitman K. , Lavau Catherine P. , Harrington Amanda , Conway Amanda E. , Wechsler Daniel S.
Published: November 2019

Background: The CALM-AF10 translocation is detected in ~10% of T-cell acute lymphoblastic leukemias (T-ALLs), and in some acute myeloid leukemias (AMLs). CALM-AF10 leukemias are characterized by high expression of proleukemic HOXA genes, which serve a critical role in hematopoiesis. We hypothesized that identification of novel CALM-AF10 effector genes may yield new therapeutic targets in this difficult to treat leukemia. We took advantage of our prior observation that the nuclear export factor CRM1/XPO1 tethers CALM-AF10 to HOXA genes by interacting with a nuclear export signal (NES) in CALM. Using next generation sequencing, we determined that, SIX1, similar to HOXA genes, is increased in CALM-AF10 leukemias and decreased in response to CRM1 inhibition with Leptomycin B (LMB). Design/Methods: RT-qPCR and Chromatin Immunoprecipitation were performed using both bone marrow progenitors and murine embryonic fibroblasts (MEFs) transduced with CALM-AF10 or an empty vector, with and without LMB. The ability of SIX1 to enhance self-renewal of hematopoietic progenitors was examined by measuring the colony-forming ability of transduced fetal liver hematopoietic progenitor cells. CRISPR-Cas9 was used to silence SIX1 in Human Embryonic Kidney 293 (HEK293) cells. Results: RT-qPCR confirmed overexpression of SIX1 in both CALM-AF10 transduced MEFs and CALM-AF10 leukemias, with decreased SIX1 expression observed in the presence of LMB. ChIP analysis showed that CALM-AF10 binds to the SIX1 gene locus. Overexpression of SIX1 in fetal liver cells was sufficient to increase the self-renewal potential of colony-forming progenitors. SIX1 was successfully knocked out in HEK293 cells without a significant effect on HEK293 proliferation. Conclusions: The SIX1 homeobox gene is highly expressed during development and its expression is silenced post-embryogenesis. Increased SIX1 expression has been reported in numerous solid tumors. We have determined that SIX1 is upregulated in CALM-AF10 leukemias, and increases the self-renewal potential of hematopoietic progenitors. Using CRISPR-Cas9 to silence SIX1, we have demonstrated that SIX1 is not essential for cell survival, and that its inhibition may impair CALM-AF10 leukemia cell proliferation. Thus, SIX1 may play a pathogenic role in leukemogenesis and is a potential therapeutic target in CALM-AF10 leukemias.

Disclosures

No relevant conflicts of interest to declare.
Impact of Iron Overload and Iron Removal Therapy on Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in the Patients with Severe Aplastic Anemia
Authors: Pan Tianzhong , Tang Baolin , Zhu Xiaoyu , Liu Huilan , Song Kaidi , Wan Xiang , Yao Wen , Sun Zimin
Published: November 2019

Abstract:The aim of this study was to evaluate the Impact of iron overload and iron removal therapy on the outcome of allogeneic hematopoietic stem cell transplantation (SCT) in patients with severe aplastic anemia (SAA). Forty-five transplant patients with SAA were retrospectively analyzed. Patients were divided into two groups according to whether there was iron overload or not: iron overload group (n=23) and non-iron overload group (n=22). The iron overload group had higher 1-year transplant-related mortality (TRM) (30.4% vs. 4.5%, P = 0.02), lower 1-year transfusion-free survival (TFS) (40.6% vs. 81.8%, P = 0.007) and lower 1-year overall survival (OS) (54.8% vs. 90.2%, P = 0.003) than the non-iron overload group. However, there was no significant difference in implantation rate, pre-engraftment syndrome (PES) and acute graft-versus-host disease (aGVHD, grade III-IV) between the two groups. Furthermore, the multivariate analysis revealed that iron overload was an independent risk factor affecting OS (HR = 36.88, P = 0.03). The patients in iron overload group were divided into two subgroups according to the time of iron removal using deferasirox 20mg/kg/d. Specifically, group A (n=17) was treated with deferasirox 20mg/kg/d for 3 months or less and group B (n=6) treated for more than 3 months. The results showed that group B had a lower one-year TRM (0% vs. 41.2% , P = 0.07), higher 1-year TFS (66.7% vs. 31.4%, P = 0.18) and higher 1-year OS (100% vs. 31.4% , P = 0.02) than group A. There were no significant difference in implantation rate, PES and aGVHD ( III-IV) between the two groups. In conclusion, the results indicate that iron overload before transplantation was associated with increased TRM and decreased OS, suggesting that iron overload was associated with worse transplantation outcomes. However, standardized iron removal therapy could reverse the adverse effects of iron overload on the outcomes of transplantation to a certain extent and improve the prognosis significantly.

Disclosures

No relevant conflicts of interest to declare.
Elevated ANXA1 Expression Causes Glucocorticoid Resistance in Acute Lymphoblastic Leukemia Via Activating the Wnt/β-Catenin Signaling Pathway
Authors: Liu Ping , Ma Dan , Wang Jishi
Published: November 2019

Background: Acute lymphoblastic leukaemia (ALL) is one of the most common clonal malignant diseases in children, and it stems from unchecked proliferation of lymphoid progenitor cells. Glucocorticoids (GCs) such as prednisolone and dexamethasone are used as a chemotherapeutic drug in the treatment of ALL. GC-induced cell mortality is first mediated by the activation of glucocorticoid receptor (GR), followed by its translocation into the nucleus to activate or inhibit gene transcription. However, up to ~20% patients with leukemia relapse and become resistant to GCs. Therefore, a better understanding the molecular basis of chemoresistance in ALL would provide novel therapeutic opportunities for patients. Methods: By analyzing the published mRNA expression profiles (GSE5280; GSE94302) obtained from NCBI (https://www.ncbi.nlm.nih.gov/geo/), we found that higher expression of ANXA1 was significantly associated with decreased overall survival of ALL patients. We also examined the expression of ANXA1 at mRNA and protein levels in a variety of ALL cell lines by using qRT-PCR and western blot analyses. The mRNA and protein expression of ANXA1 in ALL cell lines and patients were determined using Real-time PCR and Western blot respectively. Functional assays, such as CCK-8, FACS, and Tunel assay used to determine the oncogenic role of ANXA1 in ALL progression. Furthermore, western blotting and luciferase assay were used to determine the mechanism of ANXA1 promotes chemoresistance in ALL cells. Results: The expression of ANXA1 was markedly upregulated in ALL cell lines and patients, and high ANXA1 expression was associated with relapsed/refractory ALL patients. ANXA1 overexpression confers glucocorticoids (GCs) resistance on ALL cells; however, down-regulated of ANXA1 sensitized ALL cell lines to GC both in vitro and in vivo. Additionally, ANXA1 upregulated the levels of FPRs by promoting Wnt/β-catenin signalling. Conclusions: Our findings provided evidence that ANXA1 is a potential therapeutic target for patients with ALL. Targeting ANXA1 signaling may be a promising strategy to enhance GC response during ALL chemo-resistance.

Disclosures

No relevant conflicts of interest to declare.
A Case of Acute Lymphocytic Leukaemia with t(3;13) and Central Nervous System Leukemia after Allogenic Cord Blood Transplantation
Authors: Hong Yaqun , Li Xiaofan , Jiafu Huang , Xu Zhenshu , Li Nainong
Published: November 2019

Background: Acute lymphoblastic leukemia (ALL) is a neoplastic cancer characterized by clonal expansion of leukemic cells in lymph organs and bone marrow. Lots of kinds of different chromosomal translocation can be found in those leukemic cells. However, the role of the abnormal chromosomals and genes in leukemogenesis is not yet fully understood. Identifying new chromosomal translocation can facilitate a better understanding of pathogenesis of this disease.

Case presentation: We report a rare case of acute lymphocytic leukaemia with t(3;13)(q29,q21). The patient was diagnosed pre-B-ALL with no abnormal chromosomal or gene fusion and achieved complete remission (CR) after induction chemotherapy. Ten months later, she relapsed in the consolidation with cytogenetics test showing 46,XX,t(3;13)(q29,q21). Given no CR after 2 chemotherapy regimens, she received salvage cord blood transplantation. Regular intrathecal methotrexate was applied to prevent central nervous system leukemia. Good graft-versus-leukemia (GVL) effect was induced by daily injection of low dose of IL-2 two months post transplantation. Minimal residual disease (MRD) negativity was maintained until central nervous system leukemia was found 8 months after transplantation. A whole exome sequencing was performed. Nine driver mutation genes and seven tumor genes were found.

Conclusions: We highly suspect that the relapse in central nervous system after transplantation is associated with the rare chromosomal translocation.

Disclosures

No relevant conflicts of interest to declare.
Molecular Classification of Small B-Cell Lymphomas Using Digital Multiplexed Gene Expression Applicable to Formalin-Fixed Paraffin-Embedded Tissues
Authors: Xiao Min , Zhou Jianfeng , Zhang Wei
Published: November 2019

Background: Small B-cell lymphomas encompass a group of lymphoid neoplasms with high heterogeneity. However, the lack of relatively specific diagnostic markers for most of these diseases make their diagnosis challenging.

Methods: Using NanoString platform, a random forest-based molecular classification model was trained on 203 malignant and 98 non-malignant formalin-fixed paraffin-embedded (FFPE) tissues. Candidate genes were selected from microarray gene expression data of 891 small B-cell lymphomas. All malignant biopsies were derived from individuals diagnosed as a well-defined small B-cell lymphoma entity, including 17 chronic lymphocytic leukemia/small lymphocytic B-cell lymphoma (CLL/SLL), 74 follicular lymphoma (FL), 34 classical mantle cell lymphoma (cMCL), 5 non-nodal mantle cell lymphoma (nnMCL), 56 mucosa-associated lymphoid tissue lymphoma (MALT), 3 splenic marginal zone lymphoma (SMZL), and 14 nodal marginal zone lymphoma (NMZL). A leave-one-out prediction (CLL/SLL, FL, MCL, MZL, and non-malignancy) was applied to test the accuracy of prediction of the model, and Gini Index of each gene was taken into consideration in simplifying the molecular assay applicable to routine test.

Results: A total of 154 candidate genes were initially selected for training the molecular classification model. Genes were initially selected for training the molecular classification model. Thirty-two genes were specifically highly expressed in a single subgroup with Gini Index more than 0.001. The most important genes for classification were CCND1, ZBTB32, MME, BHLHE41, SOX11, and RGS13. The most distinguishable entity was CLL/SLL (ZBTB32, CLNK, and CD200), followed by cMCL/nnMCL (CCND1 and SOX11), and FL (MME, RGS13, and ELL3). Using the molecular classification model trained on the most specific 33 genes, the consistency of diagnosis were 97.5%.

Conclusions: In conclusion, our molecular model robustly recognized different subtypes of small B-cell lymphomas in leukemic FFPE samples, which provides a novel approach to precise diagnosis and classification of small B-cell lymphomas.

Figure

Disclosures

Zhou: Nanjing Iaso Biotherapeutics Co. Ltd.: Other: Chairman of Advisory Committee of Science and Medicine.
The Role of Gα13 in Integrin β2-Dependent Neutrophil Transendothelial Migration
Authors: Chang Claire W , Cheng Ni , Du Xiaoping
Published: November 2019

Upon sensing chemoattractant signals, leukocytes migrate towards the chemoattractant. If the signal is extravascular, circulating leukocytes roll on the surface of endothelial cells, firmly adhere and migrate through the endothelial monolayer to the inflammation site. Transendothelial migration of leukocytes requires integrins, particularly β2 family of integrins. We previously demonstrated that the heterotrimeric G protein subunit Gα13 interacts with the cytoplasmic domains of certain integrin β subunits including β2. To understand the role of Gα13 in integrin-dependent neutrophil migration, myeloid-specific Gα13 deficient mice have been generated by cross-breeding lysozyme M-cre mice with Gα13-floxed mice. Neutrophil migration was attenuated in myeloid-specific Gα13 knockout mice in a thioglycolate (3%) induced peritonitis model in vivo, and was also attenuated in transendothelial or mouse ICAM-1-coated transwell migration assays ex vivo. In contrast, endothelial cell/ICAM-independent transwell migration was not affected. Importantly, on an ICAM-coated surface, only the speed of migration of Gα13-deficient neutrophils were attenuated but migration directionality was not affected, suggesting that Gα13 plays an important role in motility rather than chemoattractant sensing. To further determine the role of Gα13-β2 integrin interaction in leukocyte migration, we examined the effect of a peptide, MB2mP6, derived from the Gα13 binding site of integrin β2 subunit. Like Gα13 deficiency, MB2mP6 inhibited integrin-dependent neutrophil transendothelial migration, but had minimal effects on leukocyte transwell migration in the absence of endothelial cell monolayer. Gα13 plays dual role in RhoA regulation. GPCR-activated Gα13 binds to and activates RhoGEFs resulting in RhoA activation, but Gα13 binding to integrin cytoplasmic domain is associated inhibition of RhoA. Interestingly, treatment with MB2mP6 enhanced RhoA activity of neutrophils adherent on ICAM1, suggesting that MB2mP6 mainly affects Gα13-β2 interaction. These data suggest that Gα13-integrin interaction plays an important role in the integrin-dependent transendothelial migration. Thus, Gα13-β2 is important in the immune and inflammatory functions of neutrophils.

Disclosures

No relevant conflicts of interest to declare.