bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability In Precursor B ALL Killing With Moxetumomab Pasudotox (CAT-8015) Linked To Differential Binding and Endocytic Trafficking
Authors: Matlawska-Wasowska Ksenia , Nickl Christian K. , Winter Stuart S. , Burke Patricia , LaVallee Theresa , Wilson Bridget S.
Published: October 2019

Precursor-B acute lymphoblastic leukemia (pre-B ALL) is the most common malignancy in children and can be cured in a majority of patients. However, cure remains elusive in approximately 20% of patients for reasons that are not well understood. Moxetumomab pasudotox is one of several CD22-targeting therapies currently under investigation in clinical trials for subjects with B-cell malignancies, including pediatric subjects with pre-B ALL. Moxetumomab pasudotox (MP) is a second-generation immunotoxin composed of disulfide-stabilized, affinity matured VL and VH regions of the mouse anti CD22 monoclonal antibody RFB4 fused to PE38, a truncated form of Pseudomonas exotoxin E. We evaluated in vitro activity of MP against six pre-B ALL cell lines (697, Nalm6, MHH-Call3, RS4;11, SupB15, REH), as well as freshly isolated patient blasts. We found the most sensitive cell line to be Reh, followed by 697, MHH-Call3, and the least sensitive cell lines to be Nalm6 and RS4;11. Toxicity of MP on ALL cell lines and patient blasts was not well-correlated with the number of the CD22 receptors present on the cell surface. However, we found that cleavage of MP by ALL cell lines into active toxin correlated with uptake and inhibition of protein synthesis. Using ALL cell lines, we also demonstrated that binding and internalization of MP/CD22 complexes was correlated with pre-B ALL cell line responses to MP. In addition, the Fv MP/CD22 complexes internalized more slowly than the parent RFB4 antibody/CD22 complexes. In addition to evaluating cell lines, we applied similar assays to 7 patient samples of bone marrow blasts, where we evaluated bound and internalized MP with cellular toxicity up to 72 hours. Our results suggest that some of the heterogeneity observed in in vitro responses to treatment with MP may be related to differences in internalization. Additional studies evaluating intracellular cleavage and trafficking/processing of MP in cell lines and patient blasts is ongoing. These studies, combined with planned in vivo studies evaluating MP antitumor efficacy using ALL cell lines and patient blasts, will provide a more comprehensive picture for differences in ALL response to treatment with MP.

TLaVallee currently affiliated with Kolltan Pharmaceuticals, New Haven, CT, USA; work related to this abstract occurred at MedImmune.

Disclosures:

Burke: MedImmune: Employment. LaVallee:MedImmune: full employee when work was conducted Other.
IPI In Selecting Patients With Diffuse Large B Cell Lymphoma in Rituximab Era
Authors: Genadieva-Stavrik Sonja , Pivkova Alexandra , Stojanoski Zlate , Georgievski Borce
Published: October 2019

Nowadays, goal of treatment approach in diffuse large B cell lymphoma is cure and first step towards it is to achieve complete remission. DLBCL is a potentially curable disease, with curability highly dependent on clinical and biological features. According to the WHO classification of Hematological Malignancies, the entity of DLBCL is characterized by rapidly growing mature B cell tumors with large or relatively large cells and /includes a number of disease variants/entities / encompassing several distinct clinopathologic diseases, several different histologic variants and clinical subtypes. There is no unique treatment for all patients with diffuse large B cell lymphoma. Different subgroup of patients with DLBCL needs different treatment. In the pre-rutuximab era International Prognostic Index (IPI) was considered to be the most important prognostic factor for survival and the strongest indicator for identification of high-risk patients, who are unlikely to be cured with standard chemotherapy. Having in mind that IPI is based on 5 clinical characteristics (age, performance status, stage, extranodal involvement, LDH level) and it is constructed in the pre-rituximab is clear that R-IPI should be tested in rituximab era to provide any information of its validity.

We retrospectively analyzed unselected population of 80 patients with confirmed diagnose of diffuse large B cell lymphoma treated at University hematology department in the period of 2005-2010. All patients were uniformly treated with R-CHOP regiment as initial treatment with curative intent. There were 80 patients with mean age 54, 5 years (15-84), male 35 and female 45. Older than 60 years were 29 patients (36, 25%). More than half of the patients (42) were diagnosed in advanced stage of the disease. We analyzed five prognostic factors: age, performance status, stage, extranodal involvement, LDH level and through the multifactorial analyses we selected two groups of patients. One with 0 to 2 factors as patients with low risk. Patients with more than 3 factors are considered as high risk. There is statistically significant difference in overall survival between two groups with five –years overall survival 70% for low risk patients and 47% for high risk. High-risk patients may be candidates for autologous transplantation as initial treatment, having in mind that in the rituximab era relapses occur very early in the first year and are difficult to be treated.

R-IPI score is significant predictor and should be used for risk stratification of patients with aggressive B-cell lymphoma. However, these findings should be validated prospectively in an independent population of patients.

Disclosures:

No relevant conflicts of interest to declare.
Outcome Of Rapamycin Therapy For Post Transplant- Lymphoproliferative Disorder After Kidney Transplantation: Case Series
Authors: Ashrafi Farzaneh , Shahidi Shahrzad , Ebrahimi Zeinab , Mortazavi Mojgan
Published: October 2019

Background

   Post transplant  lymphoproliferative  disorders (PTLD) , are  a   complication of chronic  immunosuppressive  therapy  in  solid organ  transplantation with a  high mortality  rate. Alternative treatments such as rapamycin have been explored.

Methods

    A detailed retrospective analysis was performed according to data collected from thirteen patients with PTLD.  At the time of PTLD diagnosis, immunosuppressive therapy was decreased and rapamycin administered. Overall survival and disease free survival of patients and graft survival were determined.

Results

Among 590 kidney transplant recipients, thirteen adult patients with PTLD were included in this study. The mean age of the patients was 42.15 (range: 25-58) years at the time of PTLD diagnosis, and 9 patients were male. Histology was distributed in 9 diffuse large B cell, 1 Malt lymphoma, 1 Burkitt lymphoma, 2 Hodgkin-like PTLD. The response rate to rapamycin alone was 30.8%. The mean overall survival period is 27.4 months with 9 patients still living. In total, 10 patients (76.9%) achieved a complete remission, with functioning graft in 11 (84.6%) patients.

Conclusions

Despite to retrospective and limited number of patients, this study provides promising results regarding the effectiveness of stopping calcineurin inhibitors and switching to rapamycin for patients with PTLD.

Disclosures:

No relevant conflicts of interest to declare.
90Yttrium-Ibritumomab-Tiuxetan As First-Line Therapy Or As Consolidation Treatment In Advanced Stage Follicular Non-Hodgkin Lymphoma: Long-Term Results After a Median Follow-Up Of 61 Months
Authors: Troppan Katharina , Valentin Angelika , Linkesch, MD Werner
Published: October 2019

Purpose

Radioimmunotherapy combines biologic and radiolytic mechanisms to target and destroy tumor cells. 90Y-Ibritumomab-Tiuxetan (90YIT) is a murine anti-CD20 monoclonal antibody engaged for radioimmunotherapeutic targeting of CD20+ lymphoma cells. We report on our long-term follow-up data of 90YIT as first-line or consolidation treatment in advanced stage follicular Non-Hodgkin lymphoma (FL).

Patients & Methods

Between March 2004 and October 2010, forty-seven patients with CD20+ FL grade 1 to 3a in stages II, III, or IV were treated with a single dose of 90Yttrium-Ibritumomab-Tiuxetan (90YIT) at our institution. The median age was 61 years (range 41-83; male 55%) and 77% (n=36) of patients were in an advanced stage of the disease (stage III/IV). 90YIT was administered on an outpatient basis on day 8 after pretreatment with Rituximab (250mg/m²) on day 1. A mean of 1122 MBq (range 680-240) 90YIT was administered. Fourteen patients received 90YIT as first-line therapy, twenty-seven patients were treated with 90YIT after a median of 2 pretreatment courses (range 1-5) as consolidation therapy in remission (15 patients in CR, 12 patients in PR), and six patients showed progressive disease (PD) at time of 90YIT treatment. Median follow-up was 61 months (range 0-111).

Results

After a median follow-up of 61 months (range 0-111 months), 32 patients are still alive, including 21 patients in CR since 90YIT treatment. There was no significant difference concerning PFS and OS between first-line treatment and consolidation treatment, but we found a significant difference, comparing these two groups versus PD (PFS 51 months vs. 48 months vs. 8 months, p<0.023; OS 59 months vs. 71 months vs. 10 months, p<0.002) (figure 1 & 2). Survival rates were 85% (first-line), 67% (consolidation) and 33% (PD), respectively. Patients who maintained a CR after 90YIT treatment, showed significantly longer OS compared to patients with relapse after 90YIT (71 months vs. 52 months, p<0.001). No significant difference in PFS and OS was seen, concerning sex, age, or clinical stage. No unexpected toxicities emerged during long-term follow-up.

Conclusion

90YIT as first-line, as well as consolidation therapy after achieving at least PR, provides a cost-efficient, long progression-free and overall survival in advanced stage FL. No benefit is shown in patients with PD, where we don't recommend 90YIT treatment.

Disclosures:

No relevant conflicts of interest to declare.
Rituximab With Or Without Chlorambucil For The Treatment Of Extranodal Marginal Zone B-Cell Lymphoma (MALT Lymphoma) Results From a Monocentric Study
Authors: Rigacci Luigi , Puccini Benedetta , Benelli Gemma , Kovalchuk Sofia , Fabbri Elisa , Bosi Alberto
Published: October 2019

Introduction

Standard therapy of MALT lymphomas is not defined apart from H Pylori eradication for gastric localization.

Aim

This study was designed to evaluate the use of Rituximab (R) alone or in combination with Chlorambucil (RC) in the treatment of patients with diagnosis of MALT.

Patients and methods

All patients with histologically confirmed diagnosis of MALT lymphoma were selected from our data base. Only patients treated with R or RC were analysed and evaluated. The scheme: rituximab 375 mg/sqm weekly for 4 doses, then monthly for 4 infusions alone or in combination with chlorambucil at the dosage of 0,1 mg/Kg/die for 45 days, then on days 1 to 15 monthly for 4 months.

Results

From January 2000 to December 2012, 136 patients were diagnosed and treated in our Institution, 76 were selected because of uniformly treated with R or RC. The median age at diagnosis was 68 years (range 32-85). In 20 patients the disease was localized in conjunctiva; 17 in the stomach; 14 in the lung; 13 in salivary glands; 3 intestine; 2 respectively in lacrimal gland, liver, skin; 1 in breast, cheek and tongue. Stage was IA in 63 patients (83%), IB in 1, IIA in 5 patients and IIB in 1, IIIA in 1 patient, IVA in 4 patients and IVB in 1. Bone marrow biopsy was negative in 59 patients, positive in 5 and not performed in 12 patients. The proliferative index was evaluated in 50 patients with Mib1 monoclonal antibody: 42 patients showed less than 30% of positivity and 8 had more than 30% of positivity. The diagnosis of MALT in 4 patients was associated with Sjogren Syndrome, in 4 patients with a positive HCV and in 1 with scleroderma. According to treatment 61 patients were treated with the combination of Rituximab and Chlorambucil and 15 were treated with Rituximab alone. At the end of treatment 69 patients (91%) obtained a complete remission and 7 (9%) a partial remission with an overall response rate of 100%. With a median observation period of 54 months (range 1-160) the overall survival was 89%. Eight patients died 5 for progression of disease (2 after a relapse) and 3 for causes not related to the lymphoma. Ten patients (14%) relapsed, 8 of these patients were retreated with Rituximab and obtained a new complete remission.

Conclusions

After a long follow-up the combination of Rituximab and Chlorambucil or Rituximab alone proved to be low toxic, feasible and effective therapy for MALT lymphomas.

Disclosures:

No relevant conflicts of interest to declare.
Obinutuzumab (GA101) More Potently Engages Phagocytic-Lineage Cells Resulting In Enhanced Monocyte and Macrophage Activity When Compared To Rituximab and Ofatumumab
Authors: Herter Sylvia , Klein Christian , Umana Pablo , Bacac Marina
Published: October 2019

Therapeutic antibodies possess several clinically relevant mechanisms of action including cell death induction, perturbation of tumor cell signaling, activation of complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC), antibody dependent cellular phagocytosis (ADCP) and induction of adaptive immunity. Obinutuzumab (GA101) is a novel humanized, glycoengineered Type II anti-CD20 monoclonal antibody engineered for displaying enhanced FcγRIIIa (CD16) binding affinity and characterized by stronger induction of ADCC and direct tumor cell death when compared to wild-type, Type I anti-CD20 antibodies rituximab and ofatumumab. In light of the important role of phagocytic lineage cells in the mechanism of action of therapeutic antibodies, we compared GA101, rituximab and ofatumumab for their ability to trigger FcγR-dependent monocyte and macrophage effector functions. We show that, due to glycoengineering, GA101 displays superior CD16-dependent binding to monocytes, M1 and M2c macrophages in presence of nonspecific, competing, human endogenous IgGs, a situation that more closely mimics physiological conditions. Subsequently, GA101 more strongly engages monocytes and macrophages and leads to significantly higher elimination of CD20-expressing tumor cells as shown by assays detecting total antibody activity (ADCP, ADCC and direct effects). In support of the stronger GA101 activity, higher nitric-oxide (NO) levels are also detected in supernatants of tumor/macrophage co-cultures treated with antibody. Taken together, our data show that in addition to stronger NK-cell mediated ADCC and direct cell death induction due to Type II CD20 binding, GA101 more potently engages phagocytic-lineage cells resulting in enhanced monocyte and macrophage activity under conditions that more closely resemble physiological settings.

Disclosures:

Herter: Roche: Employment. Klein:Roche Glycart AG: Employment. Umana:Roche: Employment, Equity Ownership. Bacac:Roche: Employment.
ONO-4059, A Novel Bruton’s Tyrosine Kinase (Btk) Inhibitor: Synergistic Activity In Combination With Chemotherapy In a ABC-DLBCL Cell Line
Authors: Yasuhiro Tomoko , Yoshizawa Toshio , Birkett Joseph TP , Kawabata Kazuhito
Published: October 2019

Purpose

Bruton’s tyrosine kinase (Btk) is a key regulator of the B-cell receptor (BCR) signaling pathway and abberant BCR signaling has been implicated in the survival of malignant B-cells. Recent studies indicate that targeting Btk is effective in the treatment of B-cell malignancies. ONO-4059 is a highly potent and selective oral Btk inhibitor with an IC50 in the sub-nmol/L range. The activated B-cell-like (ABC) sub-type of diffuse large B-cell lymphoma (DLBCL) correlates with poor prognosis and a substantial unmet need still exists. The standard treatment with Rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) for ABC-DLBCL in particular being associated with a poorer outcome. The combination of ONO-4059 with the Bcl-2 inhibitor, ABT-263 has demonstrated greater apoptosis in ABC-DLBCL cell lines than that seen with single agent treatment (Ryohei K. et al., EHA 2013 meeting). To explore rational combinations, ONO-4059 combined with chemotherapy drugs was evaluated in a ABC-DLBCL cell line.

Methods

ABC-DLBCL cell line (TMD-8) was incubated with ONO-4059 monotherapy (1-1000 nmol/L) and in combination with various agents that target various pathways thought to be involved in DLBCL. Cell viability was determined by the CellTiter-Glo Luminescent Cell Viability Assay. Apoptosis was determined by AnnexinV-FITC/7AAD (AnnV+/7AAD-) staining.

Results

ONO-4059 inhibited the TMD-8 cell growth and Btk phosphorylation in a concentration-dependent manner, with an IC50 of 3.59 for 72 hr and 23.9 nmol/L for 4 hr respectively. Furthermore, the decrease in Btk phosphorylation subsequently down-regulated Erk phosphorylation. At the 48 hr time-point, 7% of apoptosis occurred in TMD-8 cells at 10 nmol/L, an earlier time-point than that observed for dead cell. After the combination of 10 nmol/L of ONO-4059 with 25 nmol/L of doxorubicin, 500 nmol/L of etoposide, 1.5 nmol/L of vincristine and 1000 nmol/L of dexamethasone, the increased apoptosis ratio was observed, 25, 20, 17 and 29%, respectively. Synergy was observed when ONO-4059 was combined with the CHOP regimen.

Conclusion

Recent studies indicate that targeting Btk induces BIM expression, the pro-apoptotic protein, following inhibition of Erk phoshphorylation. Our results demonstrate that treatment with ONO-4059 in combination with chemotherapy results in a synergistic effect, inducing apoptosis and is more effective compared with respective monotherapies. ONO-4059 is currently being developed in a Phase I clinical trial for the treatment of B-cell malignancies. Additional combination studies are underway using the TMD-8 xenograft model, testing ONO-4059 in combination with various agents.

Disclosures:

Yasuhiro: Ono Pharmaceutical Co., Ltd.: Employment. Yoshizawa:Ono Pharmaceutical CO., Ltd: Employment. Birkett:Ono Pharma UK: Employment. Kawabata:Ono Pharmaceutical Co., Ltd.: Employment.
CD20-Specific Engineered Toxin Body Demonstrates Direct Cell Kill Of Multiple B-Cell Non-Hodgkin's Lymphoma Types
Authors: Rajagopalan Sangeetha , Wirth Rachel , Erdman Jennifer , Brieschke Brigitte , Null William , Liu Jensing , Willert Erin , Higgins Jack
Published: October 2019

The B-cell membrane protein CD20 is expressed by both benign and neoplastic lymphocytes. It has been a superb target for immunotherapies targeting B-cell derived diseases. There are several anti-CD20 antibodies which have been developed for B-cell lymphoma therapy. The most successful example of this targeted approach is rituximab, which is approved for front and second line therapy of Non-Hodgkin lymphoma (NHL). However, rituximab has limited direct cell-kill effects, acting primarily through indirect immune responses induced by antibody-dependent cell-mediated cytotoxicity (ADCC) and/or complement dependent cytotoxicity (CDC). While CD20-targeted radiotherapeutics have shown promise, their administrative challenges have curtailed their clinical utility. Thus, a therapeutic approach with direct cell-kill activity against CD20-expressing cells would be clinically useful. We have developed an engineered toxin body (ETB) comprising a CD20 specific scFv and a modified Shiga-like Toxin A (3F7) capable of specifically recognizing and killing CD20 expressing cells. 3F7 is selectively cytotoxic against B-cell NHL cell lines and against NHL cells obtained from patients. It demonstrated potent cytotoxicity against Burkitt’s lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, and mantle cell lymphoma with IC (50) values ranging from 1.4 nM to 12 nM. Through immunofluorescent tracking, 3F7 internalizes within one hour after binding to CD20 (+) B cells. Consistent with the in vitro activity, 3F7 demonstrated anti-tumor efficacy in mice bearing Raji xenograft tumors. These results show that 3F7 is a promising targeted therapeutic agent against CD20 positive B-cell lymphomas and is currently under further development.

Disclosures:

Rajagopalan: Molecular Templates: Employment. Wirth:Molecular Templates: Employment. Erdman:Molecular Templates: Employment. Brieschke:Molecular Templates: Employment. Null: Molecular Templates: Employment. Liu:Molecular Templates: Employment. Willert:Molecular Templates: Employment. Higgins:Molecular Templates: Employment.
Progression Of Large Lymphoma Is Significantly Impeded With a Combination Of Gemcitabine Chemotherapy and Dendritic Cells Intra-Tumor Vaccination
Authors: Zhu Xue-Jun , Yang Zhong-Fa , Wang Li-Xin , Rosmarin Alan G.
Published: October 2019

Relapsed, refractory Hodgkin’s or non-Hodgkin’s lymphoma remains to be a challenge and lacks efficient treatment. A small number of tumor cells that escape from treatment become resistant or unresponsive to chemotherapeutic agents. These cells grow rapidly and soon regenerate into large tumors. Immune vaccination with dendritic cells (DCs) efficiently inhibits growth of small size tumor only. The progression of tumors induces accumulation of Gr-1+CD11b+ myeloid derived suppressor cells (MDSCs) in the lymphatic organs and vicinity of tumor cells. MDSCs enable tumor cells to escape from host or exogenous immune cells mediated surveillance and attack. Gemcitabine is the chemotherapeutic agent used for lymphoma treatment. Gemcitabine has been reported to selectively eliminate MDSCs in tumor bearing animals. Thus, gemcitabine not only eliminates the majority of tumor to leave fewer resistant cells, it also reduces MDSCs to improve the immune environment favorable for the subsequent tumor vaccination. In this presentation, we used A20 cells to establish a large size, murine B-cell lymphoma model. We confirmed the accumulation of MDSCs in the spleen of lymphoma-bearing mice. Gemcitabine induced increased apoptosis in isolated, cultured MDSCs. In vivo injection of gemcitabine eliminated the majority of MDSCs in the spleen of lymphoma-bearing mice. Gemcitabine treatment combined with intratumoral injection of DCs markedly reduced the size of tumor, and significantly improved the survival of the lymphoma-bearing mice. We demonstrated that intra-large-size-lymphoma injection with inactivated DCs in combination with gemcitabine chemotherapy enhanced the therapeutic efficacy of either DC-based vaccination or chemotherapeutic reagent alone. Together with other studies, our report supports the hypothesis that gemcitabine-mediated reduction in MDSCs significantly reduces the immune suppression in tumor-bearing animal environment. This study established novel experimental foundation for the combination of immune-chemotherapy to treat relapsed or refractory lymphoma in large size with enhanced efficacy.

Disclosures:

No relevant conflicts of interest to declare.
ABC Expression As Additionally Marker To Monitoring Response In CML - A Preliminary Study
Authors: Alves Raquel , Gonçalves Ana Cristina , Freitas-Tavares Paulo , Couceiro Patrícia , Rodrigues-Santos Paulo , Sarmento-Ribeiro Ana Bela
Published: October 2019

Chronic myeloid leukemia (CML) is a mieloproliferative disorder characterized by the presence of the BCR-ABL gene fusion, which encodes an oncoprotein with a deregulated tyrosine kinase activity. This oncoprotein became the main therapeutic target of the disease with the introduction of specific tyrosine kinase inhibitors (TKIs). Additionally, the fusion gene expression level is used as a monitoring tool to determine the molecular response of each patient. However, several patients show incomplete or loss of response and even in some cases resistance to the TKI therapy. Leukemia stems cells, as normal stem cells, could present ABC transporters to protect them-self against therapeutic agents which could contribute to therapeutic failure. One of the most described ABC transporters is PgP and Imatinib and other TKIs are substrates for these efflux transporters. The precise link between ABC transports and response to therapy in CML is not fully understood.

The aims of this work were to evaluate the expression levels of ABC transporters, namely PgP and BCRP, in CML patients and to correlate them with the BCR-ABL levels.

We examined in CD34+ cells obtained from peripheral blood of 46 patients with CML, the expression levels of PgP and BCRP by flow cytometry using monoclonal antibodies. The BCR-ABL quantification was determined according to the international guidelines for CML management and at the time point of the study 26 patients (56,5%) present a positive quantification of BCR-ABL while the remain 20 patients (43,5%) were BCR-ABL negative. The median patient age at diagnosis was approximately 48 years (24–88), gender M/F=24/22, and 95% of the patients are under treatment with TKIs.

Our preliminary results show that patients with no detectable BCR-ABL mRNA (negative) present a higher percentage of CD34+ cells than patients positive for this fusion gene. Furthermore, 80% of these negative patients (n=16) expressed PgP and/or BCRP in cell membrane and 56,2% of these patients would present a positive quantification of BCR-ABL levels in the first 6 months and 75% at the end of one year.

These results suggest that the presence of ABC transporters in CD34+ cells of patients without detectable levels of BCR-ABL could constitute an earlier marker of loss of response and may be an additional tool for monitoring response in CML patients. However, further analysis should be performed, namely an increased number of patients, to confirm our results and the clinical relevance.

Disclosures:

No relevant conflicts of interest to declare.
Clinical Observation Of Decitabine Treatment In Selected Patients With Lower Risk Myelodysplastic Syndromes
Authors: Chang Chunkang , Zhang Zheng , Zhao Youshan , Li Xiao
Published: October 2019

Purpose

To assess the efficacy and tolerability of lower and conventional dose regimens of decitabine in patients with selected lower risk myelodysplastic syndrome (MDS).

Patients and Methods

The patients recruited in this study, in addition to having an IPSS score ≤ 1.0, also had to have at least one of the following indicators (with the tendency of malignant clonal expansion): (1) more than 2% marrow blasts, or more than 2% of CD34+ cells in CD45 positive subset. (2) poor karyotype by IPSS scoring, (3) unfit for immunosuppressive treatment(IST), (4) not benefited from best supportive care. The tested patients received decitabine by two different regimens: group A: 15mg/m2×5 days every 28 days , and group B: 20mg/m2×5 days every 28 days. Primary efficacy end point was overall response rate (ORR), complete remission [CR], marrow CR [mCR], CR without platelet recover [CRp], hematologic improvement [HI] or marrow CR plus hematologic improvement [mCR+HI]), cytogenetic response, hematological adverse effects .Secondary end points were progression free survival (PFS) and overall survival (OS).

Results

Total 34 patients were treated by decitabine（Group A, n = 23; group B, n=11）.

The median time of the 34 patients from MDS diagnosis to treatment was 6 months and 100% of them were de novo MDS. The total ORR and CR rate for the 34 patients were 70.6% (24/34) and 26.5% (9/34) respectively. ORR was 69.6% for group A and 72.7% for group B, and CR was 30.4% and 18.2% for group A and B respectively. The cytogenetic response in group A and group B were 55.6% (5/9) and 100%(1/1) respectively. All the difference was statistically insignificant. Also, no statistically differences were observed in secondary end points, OS from the diagnosis of MDS was 43 months in group A and not reached in group B respectively. And PFS were 44 months in group B and not reached in group A respectively. There were no difference between two groups in incidence of grade 3-4 neutropenia and thrombocytopenia. No therapy related death occurred in the 34 patients.

Conclusion

Decitabine is effective and safe in selected patients with lower-risk MDS. Lower and conventional dose of decitabine showed the same efficiency and safety in these patients.

Disclosures:

No relevant conflicts of interest to declare.
Incidence and Survival Outcomes Of Myelodysplastic Syndrome In The United States: A SEER Analysis 2001 - 2010
Authors: Ravipati Hari Prasad , Annangi Srinadh , Kota Vamsi
Published: October 2019

Introduction

Myelodysplastic syndromes (MDS) are a group of hematological disorders leading to ineffective hematopoiesis and excess blast formation. We aimed to establish the incidence rates and median survival periods in MDS by gender, race and geographic location in a large population cohort.

Methods

We performed a retrospective analysis of the United States (US) SEER database for MDS cases diagnosed between 2001 and 2010 using ICD-0-3 histology codes 9980/3, 9982/3, 9983/3, 9984/3 and 9986/3. Incidence rates were calculated using the 2000 US standard population. Five-year relative survival rates were measured using the Kaplan-Meier method after excluding cases diagnosed by death certificate and autopsy.

Results

14,920 cases were identified of which 87.2 % (n = 13,009) were present in age group sixty years and above. Age-adjusted incidence rates (per 100,000) for males were 14.8, 10.0, and 12.7 for white, black and other races respectively. The rates for females were 7.7, 7.1, and 7.0. On US county wise MDS case analysis, 11296 (86.8%) of cases were diagnosed in metropolitan counties and 1694 (13%) cases in nonmetropolitan counties. Median relative survival for white, black and other males were 27 months, 36 months and 24 months respectively ; 35 months, 38 months and 37 months for females. Five-year relative survival for white, black, and other males were 32.5% (95% CI 30.7- 34.3), 36.1% (95% CI 28.3 - 43.9) and 30% (95% CI 24.2 - 36.0) vs. 36.2% (95%CI 34.1 - 38.3), 41.1% (95% CI 34.4 - 47.8) and 37.3% (95% CI 30.2 - 44.5) for females. Median relative survival for cases from metropolitan and non-metropolitan counties were 31 months and 31 months respectively. Five-year relative survivals were 35.1% (95% CI 33.7-36.5) and 32.6% (95% CI 29.1-36.0) for metropolitan and non-metropolitan counties MDS cases respectively.

Conclusion

The incidence of MDS was higher in males compared to females with the highest rate in white males. Survival rates were similar in both sexes. No significant difference in survival rates were seen among the racial groups. No significant difference in the median survival and five-year relative survival rates were noticed between metropolitan and non-metropolitan groups.

Disclosures:

No relevant conflicts of interest to declare.
Increased Population Of Myeloid-Derived Suppressor Cells In Patients With Myelodysplastic Syndromes Overexpress ARG1 and Mediate CD8+ T Cell Inhibition
Authors: Shao Zonghong , Jiang Huijuan , Fu Rong
Published: October 2019

Objective

To investigate the proportion and activation of myeloid- derived suppressor cells (MDSC) in bone marrow from patients with myelodysplastic syndromes (MDS).

Methods

The proportion of MDSC (Lin-HLA-DR-CD33+) in bone marrow of 30 MDS patients and 19 normal controls were measured by flow cytometry assay(FCM). MDSC and CD8+ T cell were isolated from bone marrow of 14 MDS patients and 14 normal controls among them by FCM and microbeads. The expressions of arginase 1(ARG1) and inducible nitric oxide synthase (iNOS) were analyzed by qPCR and western bolting. Co-cultures with CD8+ T cell were proved the MDSC-mediated inhibition of CD8+ T cell.

Results

MDS patient’s median MDSC were 7.29% which was higher than that of controls (2.91%). The expression of ARG1 and iNOS mRNA in MDSC of high-risk MDS patients was higher than that of low-risk MDS patients. But the protein of ARG1 was overexpressed rather than that of iNOS. After co-cultured, the apoptosis ratio of CD8+ T cells of MDS((64.17±4.86) %) was increased compared to pure CD8+ T cells ( (54.58±9.95)%). Further more, the production of IFN-γsecreted by CD8+ T cells co-cultured with MDSC ((551.94±47.39) pg/ml)was lower than that of pure CD8+ T cells ((586.04±46.65) pg/ml) There was no significant difference in level of TNF-βbetween co-cultured with MDSC and pure CD8+ cells.

Conclusion

The proportion of MDSC in bone marrow was increased significantly in MDS. MDSC overexpressed ARG1 in patients with MDS and correlated to the malignant degree of this disease. Further more, MDSC can increased the apoptosis ratio of CD8+ T cell, and inhibited the secretion of IFN-γ. These findings suggested MDSC mediated the response of immunosuppression in MDS.

Disclosures:

No relevant conflicts of interest to declare.
Long-Term (10 Years or More) Survivors Of Multiple Myeloma: A Population-Based Analysis Of The US National Cancer Data Base
Authors: Raghavendra Meghana , Al-Hamadani Mohammed , Go Ronald S.
Published: October 2019

Introduction

Long-term survivors in multiple myeloma (MM), described as those surviving >10 years since their diagnosis, are uncommon. There is paucity of data describing this subgroup of patients and how they differ clinically from the rest.

Methods

Patients with MM diagnosed from 1998 to 2000 were identified in the National Cancer Data Base (NCDB). We obtained data associated with socio-demographics, type and location of care facility, as well as the use high dose chemotherapy/autologous stem cell transplant (ASCT) as initial treatment option. Four cohorts were created based on overall survival (OS): subgroup 1 (OS: < median); subgroup 2 (OS: median to 2X-median), subgroup 3 (OS: 2X-median to <10 years) and subgroup 4 (OS: >10 years).

Results

There were 27,987 MM patients. The median OS for the whole group was 26.7 months. Among them, 2,196 (7.9%) were long-term survivors. Subgroups 1, 2, and 3 comprised 54.8%, 19.0%, and 18.3% of the remaining patients, respectively. Majority were males (54.3%) with a mean age at diagnosis of 67.2 years (range, 19-90). Compared to the other subgroups (1/2/3), the long-term survivor subgroup had a significantly higher proportion of patients with high educational level (37.8% vs 28.4%/31.6%/33.9%; P < 0.001), high annual household income (41.5% vs 31.0%/34.2%/36.4%; P < 0.001), residence in a metro area (79.2% vs. 77.8%/78.7%/78.3%).; P=0.003), initial treatment at an academic center (46.6% vs 28.1%/34.6%/39.0%; P < 0.001), and had ASCT as part of initial therapy (16.5% vs 2.5%/6.4%/10.9%; P < 0.001). Multivariable analyses showed that younger age, non-Black race, lower educational level, non-Medicare/Medicaid primary payor, treatment at academic centers, and receipt of ASCT as part of initial treatment were significant independent predictors of survival > 10 years. In contrast, sex, ethnicity, type or geographic location of residence, and median annual household income were not significant.

Conclusions

In the US, approximately 1 in 13 MM patients diagnosed in 1998-2000 are long-term survivors. There are disparities in long-term outcomes according to socio-demographic characteristics, type of treatment facility, and receipt of ASCT as part of initial therapy.

Disclosures:

No relevant conflicts of interest to declare.
Ras-Pathway Inhibition With Targeted Therapies Abrogates Self-Renewal In Acute Myelogenous Leukemia
Authors: LaRue Rebecca S. , Nguyen Hanh , Sachs Karen , Mohd Hassan Nurul Azyan , Diaz-Flores Ernesto , Rathe Susan K. , Sarver Aaron G. , Bendall Sean C. , Ha Ngoc A. , Diers Miechaleen D. , Nolan Garry P. , Shannon Kevin , Sachs Zohar , Largaespada David A.
Published: October 2019

Hyperactivated Ras-pathways serve as oncogenic drivers in multiple human tumors including acute myelogenous leukemia (AML) (Ahearn et al. Nat Rev Mol Cell Biol 2011). The specific functions of these pathways in AML are unclear, thwarting the rational application of targeted therapeutics. Recently, we have shown that NRASG12V–activated signaling pathways are critical to leukemia stem cell maintenance (Sachs et al. submitted). To elucidate which Ras-activated signaling molecules mediate self-renewal in AML, we employed a murine model that harbors Mll-AF9 and a tetracycline repressible, activated NRAS (NRASG12V) and develops AML (Kim et al. Blood 2009). Primary leukemia cells were treated with therapeutic agents targeting Ras-activated signaling pathways. We used PD325901 to inhibit the Mek-Erk pathway, GDC0941 to inhibit the Pi3k pathway, and RAD001 to inhibit the mTor pathway. Using MTS assays, we identified the IC50 dose for each of these agents. Inhibitor-treated leukemia cells were submitted for RNA sequencing in order to investigate the effects of these agents on leukemia gene expression. Previously, we identified a list of NRASG12V responsive genes in our model. In these studies, we identified that PD325901-treatment most closely recapitulates the effect of NRASG12V inhibition on this comprehensive list of RAS-responsive genes. However, when we study the effects of these inhibitors on the subset of RAS-responsive genes that mediate leukemia self-renewal, we find that both PD325901 and RAD001 independently recapitulate the effects of NRASG12V withdrawal on this subset of genes implicating the Mek and mTor pathways in leukemia self renewal. Next, we treated primary leukemia cells with the IC50 dose of each drug and plated them in colony forming assays. We found that Mek or mTor inhibition, but not Pi3k inhibition, abrogated secondary colony formation corroborating our gene expression analyses and showing that, at doses that have equivalent effects on cell growth, only the Mek and mTor pathways are important for leukemia cell stem cell maintenance. These studies provide potential targets for leukemia stem cell-specific therapies.

Disclosures:

Sachs: Silicon Valley Biosystems: Consultancy. Bendall:DVS Sciences: Consultancy. Nolan:SAB for DVS Sciences and Nodality: Chairman Other; Cell Signalling Technologies and Becton Dickenson, Inc: Consultancy. Largaespada:Discovery Genomics, Inc: Consultancy, Share Holder Other; NeoClone Biotechnology, Inc: Consultancy, Share Holder, Share Holder Other.
Transferrin Deficiency Leads To Specific and Partially Reversible Iron Overload
Authors: Bartnikas Thomas Benedict , Herrera Carolina , Pettiglio Michael A.
Published: October 2019

Studies in hpx mice, a model of inherited transferrin deficiency, have demonstrated that transferrin is essential for iron delivery to the erythron and regulation of expression of hepcidin, a hormone that inhibits dietary iron absorption. Here we address two other putative roles for s transferrin. First, we determined if transferrin is essential for metabolism of metals other than iron. Metal content analysis of fractionated mouse sera indicated that iron was the most abundant metal in transferrin-rich fractions. Organ metal content analysis demonstrated severe imbalances for iron and minimal to moderate imbalances for copper, zinc and manganese in hpx tissues. Analysis of metal-dependent gene expression and organ metal content in a mouse model of inherited hepcidin excess suggested that hpx tissue imbalances in copper, zinc and manganese levels were not all physiologic or specific to primary transferrin deficiency. Second, we tested if transferrin modulates the mobilization of tissue iron stores. Transferrin treatment of hpx mice decreased iron levels in most tissues analyzed. Iron mobilization was independent of hepcidin, as iron levels decreased in hpx mice deficient in hemojuvelin, a membrane protein essential for hepcidin expression. Iron mobilization led to decreased ferritin iron and heavy chain levels. The decrease in liver ferritin iron stores did not match the decrease in total liver iron stores, suggesting that iron was mobilized from multiple storage sites. Overall, our analysis suggests that the primary consequences of transferrin deficiency are largely specific to iron and that transferrin can modulate the mobilization of tissue iron stores.

Disclosures:

No relevant conflicts of interest to declare.
Clinical Outcomes For Patients With Sickle Cell Disease: 24-Month Follow-Up In An Ongoing 3-Year, Prospective, Non-Interventional Registry Trial
Authors: Heeney Matthew M , Mueller Brigitta U. , Baltz Brad , Adams-Graves Patricia , Yang Elizabeth , Paley Carole , MSHS Jason Esposito , MSHS CCRA McNamara Katie , Vichinsky Elliott
Published: October 2019

Introduction

Patients (pts) with sickle cell disease (SCD) experience a heterogeneous clinical course, with a range of symptoms and sequelae. We describe clinical outcomes and treatment patterns from a prospective registry of pediatric and adult pts with SCD.

Methods

Pts ≥2 years old with HbSS, HbSC, or HbS/β-thalassemia were enrolled from 57 US centers and assessed every 6 months (mos) for up to 3 years. Differences between pediatric and adult pts at 24 mos follow-up are reported. (ClinicalTrials.gov NCT01220115).

Results

A total of 498 pts completed the baseline visit (74.1% HbSS disease, 15.3% HbSC, and 10.4% HbS/β-thalassemia) (Table 1

). At baseline, the following conditions were more frequent in adults: avascular necrosis, gallbladder disease, leg ulcers, and pulmonary hypertension. Pediatric pts had more frequent asthma/reactive airway disease, dactylitis, and splenic sequestration. The nature of sickle-related events varied between adult and pediatric pts (Table 2

). Prior to study, adults had higher frequencies of pain crises, strokes, and priapism, while pediatric pts had more frequent infections and acute chest syndrome (ACS)/pneumonia. On study, a similar proportion of pediatric and adult pts (56.4% overall) were hospitalized, most frequently due to pain, fever, and ACS/pneumonia; a greater proportion of pediatric pts were hospitalized due to fever (P<0.05). The percentage of pts who received a transfusion and/or chelation while on study was similar between adult and pediatric pts. Almost half of the pediatric and adult groups received hydroxyurea prior to and during the study. High rates of absenteeism were observed, with 51% of pediatric pts and 44.4% of adults missing 1 to 10 days of school or work in the year before study.

Conclusions

Despite advances in care, SCD is associated with significant morbidity that contributes to high rates of hospitalization and absenteeism in both pediatric and adult pts. Continued follow-up in this registry will provide additional information about disease patterns and pt management.

Disclosures:

Heeney: Novartis: Consultancy, Research Funding; Eli Lilly: Research Funding. Off Label Use: Hydroxurea is indicated to reduce the frequency of painful crises and to reduce the need for blood transfusions in adult patients with sickle cell anemia. It is not approved for use in children. Mueller:Novartis: Research Funding. Adams-Graves:Novartis: Consultancy, Speakers Bureau. Paley:Novartis: Employment. Esposito:Novartis: Employment. Katie:Novartis: Employment. Vichinsky:Novartis: Consultancy, Research Funding; ApoPharma: Consultancy, Research Funding; ARUP: Research Funding, Research Laboratory, Research Laboratory Other.
Hemoglobinuria Is a Risk Factor For Kidney Disease Progression In Sickle Cell Anemia
Authors: Saraf Santosh L. , Zhang Xu , Kanias Tamir , Lash James P. , Molokie Robert E. , Gowhari Michel , Hassan Johara , Gladwin Mark T. , Gordeuk Victor R.
Published: October 2019

Chronic kidney disease (CKD) is a frequent complication of sickle cell anemia (SCA) and is a predictor of early mortality. To determine the predictors of deteriorating kidney function in SCA, we followed 164 patients treated at the University of Illinois at Chicago for a median of 32 months (range 3-88 months). Steady-state estimated glomerular filtration (eGFR), albuminuria, and hemoglobinuria assessments were obtained at baseline and during the follow-up period. Steady-state was defined as greater than four weeks from a vaso-occlusive pain episode or a red blood cell transfusion. Hemoglobinuria was defined as positive for blood on dipstick and < 2 red blood cells on microscopy. Fifty-six (34%) of the patients had hemoglobinuria at baseline. We confirmed in a subset of 43 patients that dipstick positive hemoglobinuria (n=17) was associated with higher urine cell-free hemoglobin concentrations determined by ELISA than dipstick negative urine (n=26) (23.1 vs. 11.5 ng/mL, p<0.0001) (Figure 1). Age and mean arterial blood pressures were similar in patients with hemoglobinuria at baseline compared to those without but markers of hemolysis were higher (LDH, indirect bilirubin, AST, and reticulocyte percentage; p<0.0001). Sixty-one percent (95%CI: 48-73%) of patients with hemoglobinuria at baseline had hemoglobinuria at most recent follow up compared to 9% (95%CI: 5-18%) of patients without hemoglobinuria at baseline (p<0.0001). The proportion of patients with CKD progression defined by a 50% reduction in eGFR calculated by the CKD-EPI formula or requirement for hemodialysis or kidney transplant was higher in patients with baseline hemoglobinuria (13%, 7/56) versus without hemoglobinuria (1%, 1/108) (HR 14, 95%CI: 2-113; logrank p=0.001) (Figure 2). Progression of albuminuria category from normoalbuminuria (albuminuria < 30mg/g creatinine) to either microalbuminuria (albuminuria = 30-300 mg/g creatinine) or macroalbuminuria (albuminuria > 300mg/g creatinine) or microalbuminuria to macroalbuminuria was also higher in patients with baseline hemoglobinuria (42%, 11/26) versus without hemoglobinuria (13%, 9/67) (HR 3.1, 95%CI: 1.3-7.7; logrank p=0.004) (Figure 3).

In conclusion, hemoglobinuria determined by urinalysis at steady-state is a valid assessment of increased urine cell-free hemoglobin concentration and is fairly consistent on repeat testing at steady-state visits. The presence of hemoglobinuria is significantly associated with a greater risk for progression of CKD and albuminuria. Our findings are consistent with the possibility that cell-free hemoglobin contributes to the progression of kidney disease in SCA. Further research including measures to decrease cell-free hemoglobin exposure to preserve kidney function are warranted.Figure 1Figure 1. Figure 2Figure 2. Figure 3Figure 3.

Disclosures:

No relevant conflicts of interest to declare.