bluuebunny/crossref_metadata_2025_split huggingface dataset:
Outcomes of Patients (pts) with Myelodysplatic Syndrome (MDS) and Chronic Myelomonocytic Leukemia (CMML) Post Clofarabine Failure
Authors: Ghanem Hady , Manero Guillermo Garcia , Faderl Stefan , Takahashi Koichi , Ravandi Farhad , Cortes Jorge E. , O'Brien Susan , Daver Naval G. , Katragadda Lakshmikanth , Pemmaraju Naveen , Pierce Sherry A. , Quintás-Cardama Alfonso , Kadia Tapan M. , Kantarjian Hagop M. , Jabbour Elias J. 
Published: October 2019

Abstract
Abstract 1722

Introduction:
Clofarabine is a nucleoside analogue that has shown activity in pts with myeloid disorders. The outcome of pts with MDS and CMML post clofarabine is unknown.

Aims:
To evaluate the outcome of pts with MDS or CMML treated and failed clofarabine based chemotherapy as a first line or salvage regimen.

Methods:
We reviewed data of 89 pts with MDS and 21 patients with CMML treated with a clofarabine based chemotherapy at MDACC between 6/2001 and 5/2012. Thirty-nine pts (36%) received clofarabine as first line therapy and 71 pts (64%) received clofarabine as salvage therapy. Ninety-six pts (87%) received single agent clofarabine and 14 pts (13%) received a clofarabine containing combination. Response assessment followed standard criteria. Overall survival (OS) was measured from the time of therapy till the time of death or last follow-up.

Results:
One hundred and ten pts with a median age of 68 years (range, 42–88) were assessed. Sixty-five percent of the pts were older than 65 years. At the time of MDS diagnosis, 68 (61%) had a high or intermediate-2 risk International Prognostic System Score (IPSS). Thirty-one pts (27%) had complex cytogenetics. Sixty-one pts (55%) had failed therapy with a hypomethylating agent (HMA) before initiation of a clofarabine containing salvage therapy. Of the pts who received frontline clofarabine treatment, 15 (23%) achieved complete remission (CR) and 2 (3%) CR with incomplete platelet recovery (CRp), for an overall response rate (ORR) of 26%. Of the pts who received salvage clofarabine treatment, 4 (9%) achieved CR and 5 (11%) CRp, for an ORR of 20%. The median duration of response to clofarabine was 6 months. ORR was 14% among the 61 patients who had received a prior HMA. At time of clofarabine failure, 20 (18%) had progressed to acute myelogenous leukemia (AML). Fifty-eight patients received salvage therapy after clofarabine failure. Among these, 13 patients received allogeneic stem cell transplant, 17 patients received a high dose Ara-C containing regimen and 25 patients received only investigational treatments. Only 8 (14%) responded (median duration of response not reached) (range, 0–40 months). Within a median follow-up of 3 months from clofarabine failure, 13 pts (14%) remained alive. The median OS post clofarabine failure was 5.1 months and the 1-year survival rate of 25% (figure 1).

Conclusion:
Outcome of patients with MDS post clofarabine failure is poor, with a median survival of 5.1 months. These patients should be offered investigational strategies.

Disclosures:
Off Label Use: Use of clofarabine is investigational in MDS.
46/1 Haplotype Permits to Follow JAK2 Homologous Recombination: Modeling JAK2V617F clonal Architecture in PV Patients
Authors: Hasan Salma , Le Couedic Jean Pierre , Favale Fabrizia , Monte-Mor Barbara , Lacout Catherine , Casadevall Nicole , Solary Eric , Villeval Jean-Luc , Plo Isabelle , Vainchenker William 
Published: October 2019

Abstract
Abstract 1757
Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell (HSC) disorders characterized by excess proliferation of one or several myeloid lineages. More than 95% polycythemia vera (PV) and 50–60% essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients harbor a somatic 1849 G>T mutation in JAK2 gene. Moreover about 30% of PV patients are homozygous for this mutation due to a loss of heterozygosity after a mitotic homologous recombination (HR). Among 92 haplotypes of chromosome 9p, 46/1 haplotype is strongly associated with the cis-aquisition of JAK2V617F mutation. The purpose of this study was to estimate the clonal frequency of WT, JAK2V617F/+ and JAK2V617F/V617F in progenitors compartments. Here, we have modeled the JAK2V617F clonal architecture in 9 PV patients heterozygous for the 46/1 haplotype by using the level of JAK2 and the 46/1 haplotype as a marker to follow HR. First we measured the global JAK2V617F and 46/1 allele burden in CD34+ cells either by allele-specific PCR or by Ion Torrent sequencing in order to calculate the expected WT, JAK2V617F/+ and JAK2V617F/V617F clones. Next, we compared the results with the experimental clonal frequency of WT, JAK2V617F/+ and JAK2V617F/V617F cells in individual colonies derived from the CD34+CD38+ compartment. In majority of patients, the observed values corresponded to the expected values suggesting that JAK2 46/1 haplotype can be used to estimate JAK2V617F clonal structure in PV patients. In three JAK2 46/1 heterozygous hemochromatosis patients used as controls, no JAK2 46/1 homozygous clone was observed showing that 46/1 haplotype itself was not responsible for HR. Furthermore, we have studied the proliferative advantage of the mutated clones in patients. No proliferative advantage of JAK2V617F clone has been observed in between CD34+CD38− and CD34+CD38+ progenitors stages whereas strong amplification of JAK2V617F clone was found in terminally differentiated polynuclear neutrophils (PNN). Moreover, during evolution of MPN in one patient, we observed an amplification of the JAK2V617F/V617F clone in both the CD34+CD38− and CD34+CD38+cell compartments suggesting acquisition of a proliferative advantage of the homozygous clone over time.
This simple modeling could help to understand the effect of treatments on the JAK2V617F clonal structure without working at the unicellular level.

Disclosures:
No relevant conflicts of interest to declare.
The Role of 14-3-3ζ in Regulation of Proteasome Inhibitor Bortezomib Sensitivity in Multiple Myeloma
Authors: Gu Yanyan , Kaufman Jonathan L. , Boise Lawrence H. , Lonial Sagar 
Published: October 2019

Abstract
Abstract 1845
The 14-3-3 proteins are a highly conserved protein family which includes β, γ, ε, η, σ, τ and ζ isoforms in mammalian cells. Through interacting with a number of protein clients, such as Cdc25, Bad, Raf1, and Foxo, 14-3-3 proteins act as integrators of diverse cell signaling pathways and participate in metabolism, cell cycle regulation, survival and apoptosis. We have previously demonstrated that expression of 14-3-3ζ is increased in the transition from MGUS to multiple myeloma (MM), and among all MM subsets, is expressed highest in the high risk genetic subsets [Gu et al. Blood (ASH Annual Meeting Abstracts), Nov 2011; 118: 1369]
Using our 14-3-3ζ knockdown and overexpression stable MM cell lines, we found 14-3-3ζ played important roles in MM cell proliferation and growth. We also found that silencing 14-3-3 appeared to impair bortezomib-induced cell apoptosis in LP1 cells as well as to another proteasome inhibitor MG132. To further explore the function of 14-3-3ζ in MM cell biology, we performed co-immunoprecipitation followed by mass spectrometry to identify the potential 14-3-3ζ binding partners in the LP1 14-3-3ζ overexpressed cell lines. Analysis using IPA (Ingenuity Pathway Analysis) revealed critical functions and pathways related to EIF2, eIF4, p70S6K and mTOR signaling, protein ubiquitination pathway and aminoacyl-tRNA biosynthesis. Among all the identified binding candidates, we also found proteasome subunits, which could explain the impact of overexpression on sensitivity to bortezomib.
To verify whether 14-3-3ζ can directly interact with the proteasome, we performed a His pull down assay using purified His-14-3-3ζ and LP1 cell lysate. We found that 14-3-3ζ can bind the 11S proteasome activator, PA28α. Using our LP1 14-3-3ζ overexpression stable cell line, we also confirmed the interaction between 14-3-3ζ and PA28α. Further experiments using native gel electrophoresis and western blot revealed more proteasome complexes formation in LP1 14-3-3ζ knockdown cells, suggesting 14-3-3ζ may regulate the function of proteasome through modulating proteasome assembly.
In summary, 14-3-3ζ expression appeared to be critical for MM cell proliferation, and may influence sensitivity to proteasome inhibition by its interaction with proteasome subunits. Our data provides invaluable information on the molecular mechanism of resistance to proteasome inhibitor in MM and also helps to develop new strategies to overcome proteasome resistance. Given the importance of 14-3-3ζ overexpression among the high risk cohort of MM patients, 14-3-3ζ represents an important therapeutic target in high risk MM.

Disclosures:
Kaufman: Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy. Lonial:Millennium: Consultancy; Celgene: Consultancy; Onyx: Consultancy; Merck: Consultancy; Novartis: Consultancy; BMS: Consultancy.
Pim1 Serine/Threonine Kinase Regulates the Number and Functions of Murine Hematopoietic Stem Cells.
Authors: An Ningfei , Lin Yingwei , Mahajan Sandeep , Wang Yong , Kraft Andrew , Kang Yubin 
Published: October 2019

Abstract
Abstract 2303

Background:
The genes and pathways that govern the functions and expansion of hematopoietic stem cells (HSC) remain to be elucidated. Pim (proviral insertion in murine lymphomas) protein kinases are a small family of constitutively active, highly conserved oncogenic serine/threonine kinases and have 3 members: Pim1, Pim2, and Pim3. Currently, little is known about the contribution of each Pim kinase in hematopoiesis. Pim1 was recently found to be important in the regulation of CXCR4 expression in HSCs (Grundler R et al, J. Exp Med 2009, 206:1957). However, the roles of Pim1 in HSC proliferation, self-renewal, and long-term repopulation are unclear. In the current study, we performed detailed hematological and bone marrow transplant studies to address these questions.

Methods:
We generated Pim1 transgenic (Tx) mice bearing human PIM1 under the control of vav hematopoietic promoter (vav-hPIM1 Tx). Pim1−/−, Pim2−/−, Pim3−/− single knockout (KO) mice were also utilized. We quantified the number of hematopoietic stem/progenitor cells (HSPCs) in these mice using flow cytometry, colony forming units (CFUs) and cobblestone area forming cell colonies (CAFCs) assays. In vivo BrdU labeling was performed to determine the proliferation status of long-term HSCs in these mice. CXCR4 expression and the homing of HSCs to bone marrow and spleen were also analyzed. Additionally, we performed noncompetitive, competitive, and serial transplantation assays to examine the role of Pim1, Pim2 and Pim3 in hematological reconstitution in lethally irradiated recipient mice. Finally, a limiting dilution competitive bone marrow transplantation assay using purified long-term HSC cells (Lin− Sca-1+c-kit+ CD34−) was performed to calculate the frequency of active HSCs in vav-hPIM1 Tx and Pim1−/−mice.

Results:

Conclusion:
Our current studies demonstrate a novel role of Pim1 serine/threonine kinase in the regulation of self-renewal, proliferation, and long-term repopulation of HSCs. The functions of Pim1 in hematopoiesis do not overlap with Pim2 or Pim3.

Acknowledgment:
We thank Richard Peppler at the Hollings Cancer Center Flow Cytometry Core for performing flow cytometry analysis. This work is supported by MUSC Hollings Cancer Center Startup Fund, Hollings Cancer Center ACS IRG, ASCO Conquer Cancer Foundation Career Development Award, NIH 1K08HL 103780–01A1, and NIH 3P30CA138313–01S3.

Disclosures:
No relevant conflicts of interest to declare.
Gonadal Function in Survivors After Hodgkin Lymphoma (HL) Treatment within the German Hodgkin Study Group (GHSG) HD13–15 Trials.
Authors: Behringer Karolin , Mueller Horst , Goergen Helen , Thielen Indra , Eibl Angelika , Stumpf Volker , Wessels Carsten , Wiehlpuetz Martin , Rosenbrock Johannes , Halbsguth Teresa , Reiners Katrin S. , Schober Thomas , Renno Joerg H , von Wolff Michael , van der Ven Katrin , Kuehr Marietta , Fuchs Michael , Diehl Volker , Engert Andreas , Borchmann Peter 
Published: October 2019

Abstract
Abstract 2636

Purpose:
To improve fertility advice in HL patients before treatment and counseling during survivorship, detailed information on the impact of chemotherapy is needed. Therefore, we analyzed gonadal function in survivors after treatment of early favorable, early unfavorable and advanced stage HL.

Methods:
Women <40 years and men <50 years at diagnosis in ongoing remission at least one year after treatment within the GHSG HD13–15 trials were included. Hormone parameters, menstrual cycle, symptoms of hypogonadism, measures to preserve fertility, pregnancies, and offspring were evaluated.

Results:
A total of 1,323 (55%) of 2,412 contacted female and male survivors were evaluable for the current analysis. In women and men, mean age at fertility assessment was 32 and 38 years and mean observation time from the end of treatment was 46 and 48 months, respectively. Comparison of the participating and non-participating patients qualifying for our analysis showed no relevant differences. Hormone levels correlated significantly with therapy intensity (p<.001). After 6–8 cycles BEACOPP (bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, prednisone), mean Anti-Muellerian hormone (AMH) levels in females were 0μg/l and 88.8% of males had Follicle-stimulating hormone (FSH) and inhibin B levels corresponding to oligospermia. Furthermore, low birth rates were observed in survivors after advanced-stage treatment within the observation time (women: 6.5%, men: 3.3%). Regular menstrual cycle was reported by >90% of early-stage HL female survivors and time to resumption of menstrual activity was mostly reached within one year. After advanced-stage treatment, menstrual activity was strongly related to age. 82% of women younger than 30 years had a regular cycle, compared to only 45% in the older age group (p<.001) and time to recovery was considerably longer than in early-stage patients. 34% of women >30 years suffered severe menopausal symptoms (3–4 fold more frequently than expected). In contrast, male survivors had mean levels of testosterone within the normal range and reported no increased symptoms of hypogonadism.

Conclusions:
The present analysis in a large group of female and male HL survivors provides well-grounded information on gonadal toxicity of the currently used treatment regimens. Accordingly, the results allow a risk adapted planning of fertility preservation before therapy and a comprehensive support during survivorship.

Disclosures:
No relevant conflicts of interest to declare.
Genetic or Pharmacological Reductions in DNA Methylation Selectively Inhibit Peripheral T-Cell Lymphomagenesis.
Authors: Trowbridge Jennifer J. , Li Mingjie , Roberts Charles W.M. , Orkin Stuart H. 
Published: October 2019

Abstract
Abstract 2760
The significance of mutations in components of the DNA methylation machinery in blood cancer has become a topic of intense investigation. Unlike genetic modifications, the reversible nature of DNA methylation and other epigenetic changes makes them attractive therapeutic targets. Very recently, mutations in the DNA methyltransferase DNMT3A and the DNA demethylase TET2 were identified in human peripheral T cell lymphoma (PTCL) [1]. These findings provided a novel link between the development and progression of PTCL with deregulation of DNA methylation processes. Importantly, this finding also extended the few known mutations associated with both T-cell lymphoma and myeloid leukemia. Our previous work identified acute sensitivity of MLL-AF9–induced myeloid leukemia (AML) to DNA demethylation through loss or haploinsufficiency of the DNA methyltransferase Dnmt1 [2]. Here, we investigated the sensitivity of PTCL to DNA demethylation. Lymphoma was induced in mice by inactivation of Snf5, a core subunit of the SWI/SNF chromatin remodeling complex, driven by CD4Cre (CD4Cre-Snf52lox). Inactivation of Snf5 leads to rapid onset of mature CD8+ PTCL with a median survival of 10 weeks of age. Strikingly, loss of Dnmt1 in this model (CD4Cre-Snf52lox-Dnmt12lox) completely abrogated development of lymphoma. Furthermore, haploinsufficiency of Dnmt1 was sufficient to increase event-free survival to 13 weeks of age (p=0.0008). Loss or haploinsufficiency of Dnmt1 did not impact normal T cell development in the thymus with the exception of a modest reduction in CD8+ CD44hi memory T cells. Based on the selective response of PTCL to reduced levels of Dnmt1 and DNA methylation, we screened a panel of pharmacological DNA demethylating agents for efficacy in PTCL. We found three putative DNA methylation inhibitors; the nucleoside inhibitor zebularine and non-nucleoside inhibitors RG108 and procainamide, which inhibited proliferation of primary murine PTCL in vitro. These inhibitors were effective at doses that did not restrict the proliferation of normal CD8+ T cells. When these inhibitors were evaluated for efficacy in vivo, both zebularine and procainamide were found to inhibit growth of primary murine PTCL. Together, these results suggest that therapy of PTCL with DNA methylation inhibitors or other DNA demethylating agents may achieve a favorable therapeutic index. Further, these results support the concept of a shared competitive advantage of myeloid leukemia and T-cell lymphoma in carrying mutations in the DNA methylation machinery. [1] Couronne L et al., NEJM, 2012, 366:95-6; [2] Trowbridge et al., Genes Dev, 2012, 26:344-9.

Disclosures:
No relevant conflicts of interest to declare.
Higher Than Expected Incidence of Chronic Myeloid Leukemia in Solid Organ Transplant Recipients.
Authors: Dhanarajan Asha R. , Hsu Jack W , Wingard John R. , Chang Myron N , Soldevila-Pico Consuela , Rehman Shehzad , Baz Maher , Norkin Maxim 
Published: October 2019

Abstract
Abstract 2799

Background:
Chronic immunosuppression, a known risk factor for many malignancies, has not been identified as a risk factor for chronic myeloid leukemia (CML). Here we report higher than expected incidence of CML in organ transplant recipients observed at a single institution over a 12 year period.

Methods:
We report all cases of CML diagnosed in adult solid organ transplant recipients at a single institution from 2000–2011. These organ transplant patients were followed at our institution for their transplant related care, which enabled a detailed review of the cases of CML. The observed incidence of CML cases during the 12 year period was compared to the published national CML incidence in the general adult population by the exact binomial test.

Results:
As reported to the Organ Procurement and Transplant Network, our institution performed 3,223 adult solid organ transplants from 2000–2011. Four of these organ transplant recipients developed CML at various intervals post-transplant (Table 1). All patients had CML diagnosed in chronic phase after the evaluation of abnormal leukocytosis and splenomegaly. No additional cytogenetic abnormalities besides Philadelphia chromosome t(9;22) were observed in any of these patients. All patients were treated with imatinib and achieved a complete cytogenetic response (CCyR) within 12 months of therapy. Two patients subsequently achieved complete molecular response, one patient remained in CCyR on imatinib and one patient died from septic shock while in CCyR.

Conclusion:
The observed 12 year incidence of CML was 4 out of 3223 transplant recipients. This incidence significantly exceeds the reported national incidence of 1.6 cases per 100,000 persons per year (p = 0.004, exact binomial test). We hypothesize that the increase in CML incidence in solid organ transplant recipients results from chronic immunosuppression. We also observed that clinical presentation and response of CML to imatinib therapy in solid organ transplant recipients were similar to non-transplant CML patients.

Disclosures:
No relevant conflicts of interest to declare.
Decreased Levels of Total or HDL Cholesterol in Primary Myelofibrosis Are Associated with Shortened Survival: DIPSS-Plus Independent Prognostic Value.
Authors: Sulai Nanna , Mengistu Biruk , Gangat Naseema , Hanson Curtis A. , Ketterling Rhett P , Pardanani Animesh , Tefferi Ayalew 
Published: October 2019

Abstract
Abstract 2851

Background:
It is widely appreciated that total cholesterol (TC) and triglyceride (TG) levels are decreased in patients with primary myelofibrosis (PMF). However, a systematic study looking into the serum lipid profile in PMF and its phenotypic and prognostic relevance is lacking.

Methods:
An updated Mayo Clinic database of 1008 karyotypically- and DIPSS-plus-annotated patients with PMF was used to identify study patients in whom serum lipid and lipoprotein levels were available at time of referral. Overall (OS) and leukemia-free (LFS) survivals were calculated from the time of referral, which was also the time of serum lipid analysis.

Results:
A total of 207 patients met the above stipulated criteria and had measurement of TC (n=207), TG (n=204), HDL cholesterol (HDL-C) (n=187), LDL cholesterol (LDL-C) (n=176) and non-HDL cholesterol (N-HDL-C) (n=184). The corresponding median (range) values (mg/dL) were 132 (57–296), 147 (42–742), 31 (8–96), 67 (11–186) and 104 (7–249). TC was significantly (P<0.05) lower in the presence of male sex, older age, red cell transfusion need, hemoglobin <10 g/dL, marked splenomegaly, circulating blasts, constitutional symptoms, JAK2 V617F, and ASXL1 mutations. TG was significantly (p<0.05) lower in the presence of JAK2 V617F, red cell transfusion need, hemoglobin <10 g/dL and thrombocytosis. DIPSS-plus risk categories showed significant differences in their TC (p<0.0001), HDL-C (p=0.004), LDL-C (p=0.004), and N-HDL-C (p=0.009) profiles with higher levels seen in lower risk patients; there were no correlations with TG levels.
In univariate analysis, lower levels of TC, HDL-C, LDL-C and N-HDL-C were all associated with shortened survival (P<0.01 for each association) whereas survival was not affected by TG level (p=0.42). Multivariable analysis in the context of DIPSS-plus confirmed the independent prognostic relevance of both TC (p=0.05) and HDL-C (p=0.02) for OS. A similar analysis disclosed no correlation with LFS. Exclusion of patients receiving statin or other anti-lipid treatment did not affect the overall results. Patients in the lower quartiles for either TC (approximately <100 mg/dL) or HDL-C (approximately <25 mg/L) compared to those with higher levels displayed significantly shorter survival (Figure; RR 2.4, 95% CI 1.6–3.7; p<0.0001) that was not accounted for by DIPSS-plus (RR 1.6, 95% CI 1.1–2.5; p=0.03).

Conclusions:
Decreased levels of total or HDL cholesterol in PMF cluster with adverse disease features and carry a DIPSS-plus independent adverse prognostic value. Measurement of TC and HDL-C in PMF might be useful in monitoring disease progression and treatment response.

Disclosures:
No relevant conflicts of interest to declare.