bluuebunny/crossref_metadata_2025_split huggingface dataset:
5-Azacitidine Plus Vorinostat As Maintenance Therapy of Second Remission in AML Instead of High Doses of Consolidation with Cytarabine
Authors: Ovilla Roberto , Barrera-Carmona Claudia , Guzman-Bouilloud Nicolas , Buganza-Torio Elizabeth , Jimenez-Alvarado Rosa , Monreal-Alcantara Claudia 
Published: October 2019

Abstract
Abstract 4348
Patients with refractory AML after failure of reinduction of remission treatment (usually the clasical 7+3) have few options of effective reinduction regimen. Once a second remission is obtained, the standard strategies implies an allogenic BMT or consolidation treatment with high doses of cytarabine but the BMT requires a match or alternative donor and the chemotherapy implies myelotoxicities and some patients have high risk of severe complications versus recurrent relapse and death.
A 36 years old male with AML M4 intermediate risk since april 2010 was treated conventionally with 7+3 regimen (Cytarabine + Idarubicin), after that he received 4 cycles of high doses of Cytarabine as consolidation. On October 2010 he received an autologous BMT (ABMT) because he does not have an HLA compatible donor. After 12 months of complete remission post ABMT he relapsed on October 2011. He received as reinduction regimen 7+3 (Cytarabine + Doxorubicin) and he failed to obtain remission. He received a salvage treatment with high dose of Cytarabine 3 gr/m2 (6 doses) followed by high doses of Etoposide 60 mg/kg in continuous infusion. He achieved complete remission and then developed Aspergillus pneumonia during the myelosupressed period and a thoracoscopy was performed for treatment, he was discharged at the end of November 2011.
In the face of the impossibility of conventional consolidation therapy, and in the presence of poor general conditions, we started a treatment model based on epigenetic alternative therapy with the objective to maintain remission. In December 2011 he was started an ambulatory treatment based on subcutaneous administration with 5-azacitidine 75mg/m2/day during 7 days every 28 days for two cycles; during treatment he developed myelosuppression without the need of stimulating factors or transfusions. Posteriorly he continued with two new cycles of 5-azacitidine 50mg/m2/day during 10 days plus Vorinostat 200 mg every 24 hours during 14 days. Each month since the beginning of the epigenetic therapy, BMA was performed with flow cytometry and immunophenotype performed that showed a persistent remission until May 2012 when he relapsed.
Therefore epigenetic therapy maintained in remission a high risk patient, improved his general conditions, and posteriorly allowed him to be able to receive an haploidentical bone marrow transplant.

Disclosures:
No relevant conflicts of interest to declare.
Only High Concentration of Immunoglobulin Inhibits Activation of Lymphocytes: Potential Use of Immunoglobulin for Preventing Gvhd
Authors: Maeba Hideaki , Kuroda Rie , Hujiki Toshihiro , Mase Shintaro , Araki Raita , Koizumi Shoichi , Yachie Akihiro , Nishimura Ryosei 
Published: October 2019

Abstract
Abstract 4376
High-dose intravenous immunoglobulin (IV-IG) is used to treat many autoimmune and inflammatory disorders, yet precise mechanisms have not been understood. In organ transplant, some studies demonstrated that IV-IG therapy, even moderate-dose, given to highly sensitized patients led to reduction in allo-sensitization, fewer acute rejection episodes, and better long-term results for cardiac and renal allograft recipients. Although historically IV-IG has been widely used for mainly prophylaxis of CMV infection in hematopoietic stem cell transplantation, only a few reports mentioned that IV-IG contributed to reduce GVHD severity. The aim of this study is to explore whether IV-IG has immunomoduraroty role against cells involved in GVHD developments or not, if so, appropriate concentration of immunoglobulin and administration schedule for clinical settings should be discussed. First, mixed lymphocyte reaction (MLR) was performed using irradiated dendritic cells (DCs) from C57BL6 as stimulators and splenocytes from Balb/c as responders with immunoglobulin. MLR was strongly inhibited when the concentration was above 25 mg/mL. Next, to identify when immunoglobulin give immunomoduratory function to DCs or T-cells, or both, immunoglobulin treated DCs or splenocytes for 24h before MLR were prepared and washed to remove extra immunoglobulin, then MLR was performed without addition of immunoglobulin. MLR was not suppressed when not added to immunoglobulin during reactions, suggesting that sustained immunoglobulin interaction to DCs, T-cells, or both could be required for sustained immunomoduratory effects. Next, to clarify whether IV-IG inhibit T-cell proliferation via DCs or T-cells directly, we stimulated splenocytes (Balb/c) with phytohemagglutinin (PHA) in the presence of various concentrations of immunoglobulin. Immunoglobulin inhibited PHA-stimulated T-cells, with similarity to the result of MLR using DCs as stimulators as shown in the figure below. It suggested that IV-IG mainly act on T-cells directly, not to DCs. Similar results were obtained using human samples. Finally, to elucidate whether immunoglobulin induce arrest of T-cell proliferation with increased apoptotic cells or not, we measured the early apoptotic cells using annexin V and 7-AAD staining combined with CFSE proliferation assay. Only a few early apoptotic cells were increased when immunoglobulin was added to PHA-stimulated T-cells, demonstrating that IV-IG immunomoduratory effects were mainly brought about T-cell arrest. In conclusion, high concentration of immunoglobulin, in which only high dose IV-IG could be achieved in vivo, contributes to profound and sustained inhibition of T-cell activation. To use IV-IG to prevent GVHD in clinical settings, much higher dose of IV-IG than ever might be needed.

Disclosures:
No relevant conflicts of interest to declare.
The Combination of AZT/Interferon-α Therapy with the HDAC Inhibitor Valproic Acid for the Treatment of Adult T-Cell Leukemia/Lymphoma
Authors: Reis Isildinha , Manrique Michele , Cabral Lisa , Diaz Luis , Toomey Ngoc , Ruiz Phillip , Ramos Juan Carlos 
Published: October 2019

Abstract
Abstract 4877
Adult T-cell leukemia/lymphoma (ATLL) carries a dismal long-term prognosis and is generally chemotherapy resistant. We and other groups have demonstrated that the combination of AZT and interferon (IFN) alpha can effectively suppress ATLL long-term; however, these drugs fail to eradicate malignant ATLL clones as patients ultimately progress. We recently tested our hypothesis that histone deacelytase (HDAC) inhibitors would re-activate latent HTLV-I in ATLL cells harboring intact provirus thus helping to eliminate residual disease after cytoreductive treatment. Histone acetylation can result in HTLV-I promoter activation and viral transcription. We found that HDAC inhibitors, including the inexpensive drug valproic acid (VPA), reactivated HTLV-I expression in ATLL cells and caused apoptosis. Based on these concepts, we recently completed a pilot trial for ATLL using AZT/IFN and adding VPA during the maintenance treatment phase. Thirteen subjects with aggressive acute-type ATLL were enrolled in the study, including 11 treatment-naïve patients. The estimated 12-month overall survival rate was 46%. In 12 evaluable subjects (10 naïve) the complete response (CR) rate was 33% and overall response 42% (5 patients). A total of eight subjects (66%) had a hematologic response, including 5 complete hematologic responses (38%). VPA was added at the beginning of month 3 during AZT/IFN maintenance in 3 subjects. One subject achieved a molecular remission and clearance of ATLL after adding VPA as measured by serial multiplex PCR studies. This subject remains disease-free 2.5 years later. Our findings were surprising, as previous studies performed on long-term responders treated with AZT/IFN alone had not demonstrated any molecular remissions. Our data suggest that VPA could potentially eradicate ATLL clones in vivo. The dual anti-neoplastic and viral inducing roles of HDAC inhibitors can be exploited in the treatment of ATLL. This exciting approach may help advance the cure for this disease. We will present our updated interim clinical trial results at the conference.

Disclosures:
No relevant conflicts of interest to declare.
Preferential HLA-DRB1*11 Dependent Presentation of CUB2 Derived Peptides by ADAMTS13 Pulsed Dendritic Cells
Authors: Sorvillo Nicoletta , van Haren Simon D. , Kaijen Paul H. , ten Brinke Anja , Fijnheer Rob , Meijer Alexander B. , Voorberg Jan 
Published: October 2019

Abstract
Abstract 489
Autoantibodies directed against ADAMTS13 prohibit the processing of VWF multimers initiating a rare and life-threatening disorder called acquired thrombotic thrombocytopenic purpura (TTP). Recently, HLA-DRB1*11 has been identified as a risk factor for the development of acquired TTP. Here, we identified ADAMTS13-derived peptides presented on MHC class II alleles. Dendritic cells from a panel of both HLA-DRB1*11 positive and negative donors were pulsed with ADAMTS13 and the HLA-DR-presented peptide repertoire was analyzed by mass spectrometry. Interestingly, pulsing of dendritic cells of HLA-DRB1*11 positive donors with 100 nM ADAMTS13 resulted in presentation of a single CUB2 derived ADAMTS13 peptide. This peptide was not presented by HLA-DRB1*11 negative donors. Pulsing of HLA-DRB1*0301 positive cells with 100 nM ADAMTS13 resulted in presentation of a different CUB2 domain derived peptide in 2 out of 3 donors analyzed. Pulsing of dendritic cells employing higher concentrations of ADAMTS13 (500 nM) resulted in increased presentation of ADAMTS13 derived peptides by both HLA-DRB1*11 positive and negative donors. In DRB1*11 negative donors peptides derived of multiple domains were presented which included spacer, TSR2-8, metalloprotease and disintegrin domains. Interestingly, the CUB2 domain peptide (specific for DRB1*11 when dendritic cells were pulsed with 100 nM ADAMTS13) was also presented under these conditions. Apparently, this peptide can be presented by multiple MHC class II alleles although higher concentrations of ADAMTS13 are required for its presentation on DCs derived of non-DRB1*11 positive donors. Interestingly, the diversity of ADAMTS13 derived peptides presented by iDCs of donors HLA-DRB1*11 was not affected by pulsing of iDCs with higher concentration of ADAMTS13. Also, under these conditions the only peptides that were presented were derivatives of the CUB2 domain derived peptide that was also presented at lower concentrations of ADAMTS13. Our results clearly demonstrate that this peptide is efficiently presented when compared to other ADAMTS13-derived peptides. Therefore, we hypothesize that efficient presentation of this CUB2 domain derived peptide on DRB1*11 may provoke proliferation of low affinity self-reactive CD4+ T cells that have escaped negative selection in the thymus and contribute to the onset of acquired TTP. Together these findings may provide further insight in the initiation of the autoimmune reactivity against ADAMTS13 in patients affected by TTP.

Disclosures:
No relevant conflicts of interest to declare.
Ofatumumab Can Induce Remission in Refractory Burkitt's Lymphoma – A Case Report
Authors: Sever Matjaz , Zver Samo , Novakovic Barbara Jezersek , Pretnar Joze 
Published: October 2019

Abstract
Abstract 4895

Introduction:
Burkitt's lymphoma (BL) is a rare condition accounting between 1– 5% of Non Hodgkin's lymphomas. Standard treatment consists of intensive chemotherapy with fractionated alkylating agents and cell cycle phase specific agents that cross the blood brain barrier. Patients who achieve only partial response after front-line treatment or in first relapse can be treated with autologous stem cell transplantation (SCT) or in rare cases with allogeneic SCT. Rituximab added to various chemotherapy regimens can improve the results. Ofatumumab is a new anti-CD20 monoclonal antibody active in refractory or high risk patients with chronic lymphocytic leukemia (CLL). We present a patient with refractory BL after standard chemo/immunotherapy and autologous SCT who achieved remission after ofatumumab treatment.

Case report:
A 31-year old male patient was diagnosed with Burkitt's lymphoma (stage IIIb) in April 2011. He was put on BMF protocol but progressed after two cycles. Rituximab was added in therapy. After two additional cycles there was no response to treatment. A salvage protocol DA-R-EPOCH was employed and after four cycles patient went into partial remission. Stem cell mobilization was performed with rituximab/cyclophosphamide/filgrastim and plerixafor because of poor initial mobilization result. In September 2011 patient received autologous SCT after BEAM conditioning. Six weeks after the procedure assessment of disease showed presence of 0.14 % BL cells on bone marrow flow cytometry and residual disease in abdomen on PET-CT. The patient started with ofatumumab according to protocol used in CLL and began with local radiotherapy. After seven weeks on ofatumumab bone marrow showed no residual BL on flow cytometry. Due to high risk disease and poor graft function after autologous SCT we decided for additional allogeneic SCT which was performed in January 2012 after myeloablative conditioning with cyclophosphamide and total body irradiation. The donor was a 9/10 HLA match. Post transplant period was complicated with cytomegalovirus reactivation and side effects of cyclosporine. On day +66 the patient presented with Pneumocystis carinii pneumonia that required ventilation support. Bone marrow examination in April 2012 showed no residual BL. After short improvement the patient's condition was complicated with secondary pneumonia, acute respiratory distress syndrome and septic shock. The patient expired on day +94 after allogeneic SCT.

Conclusion:
Ofatumumab induced remission in a patient with refractory BL after two chemotherapy regimens, rituximab and autologous SCT. The patient went into remission after eleven weeks on ofatumumab CLL protocol and was able to proceed to allogeneic SCT. He remained in remission three months post SCT. The cause of patient's death was infection. Studies would be required to address ofatumumab's role in refractory BL.

Disclosures:
Off Label Use: Ofatumumab is registered for treatment of CLL.
Anti-Apoptotic Bcl2 and Bcl-Xl Proteins Involved in Stroma-Induced Drug Tolerance to Hsp70 and Hsp90 Inhibitors in Leukemia and B-Cell Lymphoma
Authors: Lopes Eloisi Caldas , Correa Fabian M , Shen Ling-Bo , Shieh Jae-Hung , Taldone Tony , Chiosis Gabriela , Moore Malcolm A.S. 
Published: October 2019

Abstract
Abstract 4900

Background:
Multiple studies have demonstrated that the bone marrow stromal microenvironment contributes to the survival of hematologic malignant cells, eventually leading to relapse. However, molecular mechanisms associated with this stromal niche remain unclear. The human bone marrow stromal cell lines, HS-5 and HS-27, provide physical contact with hematologic cells, while HS-5 cells secrete more growth factors and cytokines than HS-27 stromal cells. Our objective is to dissect the mechanisms underlying stromal-mediated drug tolerance in leukemia and lymphoma cells, which could potentially lead to novel therapies for various leukemia.

Methods and Results:
A panel of leukemia and B-cell lymphoma cell lines were used in this project, including Kasumi1 (AML: Acute Myeloid Leukemia) and OCILy1 (DLBCL: Diffuse Large B-Cell Lymphoma) cells and their respective sub-lines resistant to heat shock protein-70 and −90 (HSP70/90) inhibitors. To determine the ability of stromal cell lines to confer tolerance to HSP-inhibitors, Kasumi1 and OCILy1 (sensitive and resistant) cells were cultured alone or in the presence of the HS-27 or HS-5 cells with HSP70 inhibitor or HSP90 inhibitor for 48h. The resulting cultures were then harvested and analyzed for apoptosis and by western blot. Both HS-5 and HS-27 stromal cells markedly protected OCILy1 and Kasumi1 cells from HSP70 inhibitor induced apoptosis. At a dose of 0.5 μM, % apoptotic cells were 74.0±1.6% for OCILy1 alone, 38.3±2.1% for OCILy1 with HS-5 and 42.2±1.8% for OCILY1 with HS-27. At a dose of 1 μM of HSP90 inhibitor, apoptosis rate are 61.9±1.5% for OCILy1 alone, 28.2±2.2% for OCILy1 with HS-5 and 36.4±1.9% for OCILy1 with HS-27. A similar HSP inhibitor induced apoptosis was also observed in Kasumi1 cells. In contrast, both Kasumi1 and OCILy1 HSP70/90 inhibitor resistant sub-lines in the presence or absence of the stromal cells did not respond to treatment with respective inhibitors. Further study reveals the stromal cells up-modulated the expression of the anti-apoptotic proteins Bcl2 and Bcl-xL in both Kasumi and OCILY1 cells.

Conclusions:
Our results demonstrate that the stromal niche is able to mediate tolerance to HSP70 and HSP90 inhibitors in Leukemia and B-cell lymphoma via up-regulation of antiapoptotic proteins such as Bcl2 and Bcl-xL. The Bcl2 protein is deregulated and plays a crucial role in diffuse large B-cell lymphoma (DLBCL) with the t(14;18) translocation. Our finding elucidates one of the drug-specific mechanisms that suggest a promising combination therapy targeting both HSP70 and HSP90 to reduce antineoplastic resistance and relapse, and thereby improve survival for patients with leukemia and lymphoma.

Disclosures:
No relevant conflicts of interest to declare.
Human FcγRIII (CD16) Polymorphism Screening Is Enhanced with Pyrosequencing Analysis
Authors: Matlawska-Wasowska Ksenia , Gale James , Khalili Parisa , Wilson Bridget S , Vasef Mohammad , Winter Stuart S. 
Published: October 2019

Abstract
Abstract 4911
Surface specific antigens expressed on the cell membrane of hematopoietic cells are attractive target for antibody mediated cancer cells therapy. Monoclonal antibodies involve various mechanisms to eliminate cancer cells, including antibody dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) mediated by immune effector cells such as NK cells and macrophages bearing FcγRIIIA (CD16) receptor. Previous studies reported that clinical efficacy of monoclonal antibodies can be linked to the single nucleotide polymorphism found at position 559 in cDNA of the gene encoding FcγRIIIA. This allelic polymorphism generateses the following allotypes V/V, F/V or F/F at amino acid position 158 and can affect binding of mAbs and immune cell effector function. CD16-mediated binding is most efficient with the V/V genotype, and least efficient with the F/F genotype, leading to a range of efficacy in mAb-mediated targeted therapies. Currently, many patients are not screened for CD16 heterozygosity. Nevertheless there is a clear need for a diagnostic assay that will allow estimating the allelic polymorphism of a patient undergoing treatment with monoclonal antibodies utilizing ADCC/ADCP. Here we hypothesized that the pyrosequencing might improve a screening for polymorphisms of human FcγRIIIA-158 receptor. We studied 42 normal human subjects for the incidence of V/V, F/V and F/F CD16 polymorphisms using pyrosequencing technologies and compared to nested PCR-based allele-specific restriction assay. Compared to pyrosequencing, the nested PCR-based allele-specific restriction assay was 0. 33 sensitive and 1. 0 specific in discriminating the V/V and F/F genotypes, and 0. 33 sensitive and 0. 7 specific for the V/V and F/V genotypes (Table 1). Compared to pyrosequencing, the nested PCR-based allele-specific restriction assay was relatively insensitive and not specific in distinguishing the V/V genotype from other genotypes. Since the efficacy of the mAb-based targeted immunotherapy may be highly dependent upon the CD16 polymorphism in any given individual, we propose that pyrosequencing of the CD16 receptor be routinely evaluated in all patients. Such practices might prevent patients from randomizing to receive targeted therapies to that hematological malignancies for that have little or no therapeutic potential.
Table 1 V/V F/V F/F pyrosequencing 6 16 20 allele-specific restriction assay 2 23 17 sensitivity - 0.33 0.33 specificity - 0.7 1.0

Disclosures:
No relevant conflicts of interest to declare.
Activity of Lenalidomide in a Phase II Single Institution Study in Non-Del(5q) Transfusion Dependent, Patients with Low and Intermediate-1 Risklower-Risk, Non-Del(5q) Myelodysplastic Syndromes (MDS))): Results From a Single-Institution Phase II Study
Authors: Raza Azra , Falkenstern John , Yeh Fiona , Castagna Ginevra , De Los Reyes Antonietta , Galili Naomi 
Published: October 2019

Abstract
Abstract 4929
In a previous multi-center Phase II study, lenalidomide resulted in a 43% overall hematologic response with 26% of patients achieving transfusion independence (TI) among 214 non-del(5q) red blood cell (RBC) transfusion-dependent patients with International Prognostic Scoring System (IPSS) lower-risk MDS (Raza et al Blood. 2008). A single institution follow-up trial was conducted in patients with low or Int-1 risk non-del(5q) MDS, a platelet count of >50, 000 and requiredat least 2 units of blood required in 8 weeks. Fifty-six patients received lenalidomide at a starting dose of 10 mg qday. There were 41 males and 15 females, and the median age was 71 years. By IPSS, 27 had low-risk disease and 22 had Int-1-risk disease, while IPSS could not be assigned for 7 patients. By cytogenetics, 38 patients had a normal karyotype, 12 showed abnormalities, while data could not be obtained for 4 patients due to culture failure. Morphologic classification consisted of: RA=17, RCMD=16, RARS=4, RCMD-RS=7, RARS-T=1 and RAEB-1=11. Median duration of MDS was 12 months (range 1–120 months). Median transfusion requirement was 2 units in 8 weeks prior to starting therapy. Median duration of lenalidomide therapy was 4 months (range, 1–36+ months). Treatment was generally well tolerated. The most common Grade 3/4 toxicity was myelosuppression, with 17 (30%) experiencing thrombocytopenia, 12/(21%) neutropenia and 1 leukopenia (2%). Other Grade 3/4 toxicities included diarrhea (7%) rash (2%), and fatigue (2%). At least one dose reduction was required for 33 (59%) patients. Intent-to-treat analysis showed hematologic response (HI) by the IWG-R criteria in 23 (41%) patients, no response in 25(44%) patients, and other failure in 8 (14%) patients. Among the 23 responders, 18 (32%) achieved TI. Median time to response was 2 cycles (6 weeks), with 6 patients responding in cycle 1, 9 in cycle 2, 5 in cycle 3 and 1 each in cycles 4, 5, 6, respectively. Median duration of response was 294 days (approximately 10 months), with durations ranging from 44+ days to 936+ days (+ indicates continuing response). We confirm in this 56-patient, single institution phase II study that lenalidomide has substantial clinical activity in transfusion-dependent, lower-risk non-del(5q) MDS, with results comparable to those previously reported in the multi-center phase II study.

Disclosures:
No relevant conflicts of interest to declare.