bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clofarabine, Etoposide and Mitoxantrone In the Therapy of Relapsed and Refractory Acute Myelogenous Leukemia
Authors: Ehmann W. Christopher , Ibrahim Sulfikar , Rybka Witold , Claxton David F. 
Published: October 2019

Abstract
Abstract 4353
Currrent therapy for acute myelogenous leukemia depends on the activity of cytosine arabinoside (ara-C). The development of regimens without this agent would potentially provide non-crossresistant treatment options for these disorders. Clofarabine, a novel agent showing significant single agent activity in AML, provides a platform for potentially effective treatment independent of ara-C. We treated 10 patients ages 30–67 (median 51) with relapsed or refractory AML with a phase I dose finding protocol employing a three drug combination based on clofarabine. The objectives were to define a maximally tolerated and recommended phase 2 dose and identify early phase 2 activity. Seven patients (70%) were refractory to 1 or 2 treatment regimens immediately prior to enrollment, the other 3 pts (30%) were relapsed following a remission. All patients had relapsed following or were refractory to standard 7+3 chemotherapy and 7/10 had received intermediate or high dose cytarabine within <52 weeks of enrollment. Patients received clofarabine 20mg/m2 (Dose level 1 – DL1 – 4 patients treated) or 25mg/m2 (DL2 – 6 patients) days 2–6, etoposide 100mg/m2 days 1–5, and mitoxantrone 8mg/m2 days 1–3. Treatment emergent non-hematological toxicities included mucositis (4 patients, ≤ grade 2) and diarrhea (2 patients, ≤ grade 3). Two out of 6 patients (33%) at DL2 failed to recover absolute neutrophils (ANC) to 500/mcL by Day 42, and this was judged a potentially treatment related toxicity given lack of residual leukemia in day 14 marrows. Seven of 9 (78%) day 14 marrows were markedly hypocellular or aplastic, and two showed residual leukemia. Four out of 10 patients (40%) showed complete remission (CR – 2 patients) or remission with incomplete hematopoietic recovery (CRi – 2 patients). Three patients survive in remission 34, 98, and 236 days from enrollment.
We conclude that the clofarabine, etoposide and mitoxantrone combination has acceptable toxicity and is an active regimen for significantly pretreated acute myelogenous leukemia. The total response rate compares favorably with other AML salvage regimens. As there has been delayed myeloid recovery at higher doses, we are pursuing DL1. The activity of this regimen is potentially non-crossresistant with ara-C, therefore larger studies are justified. Currently, patients are enrolling in an expanded cohort at the recommend phase 2 dose.

Disclosures:
Claxton: Genzyme: Research Funding. Off Label Use: Clofarabine for AML therapy.
The Histone Methyltransferase Inhibitor, DZNep, Upregulates TXNIP, Increases ROS Production and Targets Leukemia Cells In AML
Authors: Zhou Jianbiao , Bi Chonglei , Liu Shaw-Cheng , Tay Kian-Ghee , Cheong Lip-Lee , Koh Tze-Loong , Yu Qiang , Chng Wee-Joo 
Published: October 2019

Abstract
Abstract 4355

Background/Hypothesis:
Targeting epigenetic abnormalities is an emerging therapeutic strategy in AML. Unlike inhibition of DNA methylation and histone deacetylase, inhibition of histone methylation, has been under-explored in AML.

Methods:
A novel histone methytransferase inhibitor, DZNep, was used to treat a panel of AML cell lines (in vitro and in mouse models), primary patient cells and leukemia stem cells (LSCs). Flow cytometry was used to determine apoptosis and reactive oxygen species (ROS) production. RNA interference (RNAi), gene expression profiling (GEP), and chromatin immunoprecipitation (ChIP) were used to study the molecular mechanism of DZNep.

Result:
DZNep depleted EZH2, a histone methyltransferase, and induced robust apoptosis in AML cell lines, both in vitro and in mouse model, in primary AML cells, and targeted LSCs while sparing normal haematopoietic stem cells. On GEP, polymerase chain reaction (PCR) and western blot, TXNIP, a major redox control molecule, was one of the most upregulated molecules upon DZNep treatment. Either DZNep treatment or EZH2 knockdown reactivated TXNIP and increased ROS, leading to apoptosis. TXNIP over-expression also produced the same phenotype. Furthermore, TXNIP was downregulated in AML and a direct target of EZH2-mediated gene silencing. We also saw a signature of downregulation of endoplasmic reticulum (ER)-stress regulated pro-survival genes, suggesting a novel function of EZH2 in regulation of stress response.

Discussion and Conclusion:
DZNep and EZH2 inhibition has therapeutic potential in AML, in which treatment has not change in 20 years. We delineated that the effect of DZNep is specifically mediated through EZH2 and TXNIP, and highlighted the importance of histone methylation, redox regulation and ER stress in AML biology.

Disclosures:
No relevant conflicts of interest to declare.
Clofarabine In Combination with Cyclophosphamide for Treatment of Relapsed/Refractory Acute Leukemia In Adult Patients
Authors: Chawla Bobby , Kanate Abraham Sebastian , Osman Salman , Tse William , Hamadani Sayed Mehdi , Craig Michael , Cumpston Aaron 
Published: October 2019

Abstract
Abstract 4367

Introduction:
Clofarabine is a purine nucleoside analogue which is approved for pediatric patients with relapsed or refractory acute lymphoblastic leukemia. A number of small phase I and II studies have shown activity in adult patients with newly diagnosed and relapsed/refractory acute myeloid leukemia (AML). Promising activity of clofarabine in combination with cyclophosphamide and etoposide has been reported in the pediatric setting (Hijiya et al., Leukemia 2009; Locatelli et al., Br J Haematol 2009). This combination has limited data in adult patients. We present a series of five cases in which clofarabine was combined with cyclophosphamide in adult patients with relapsed or refractory acute leukemia.

Methods:
We retrospectively reviewed patient charts of five patients treated with clofarabine in combination with cyclophosphamide.

Results:
Three patients received clofarabine 30mg/m2 + cyclophosphamide 340mg/m2, both on Days 1–5. Two patients received clofarabine 40mg/m2 + cyclophosphamide 440mg/m2 + Etoposide 100mg/m2, each drug on Days 1–5. Median age was 21 (range: 17 – 54). Patients had received 2 to 4 prior induction regimens (median of 3). Three patients were AML, one ALL, and one biphenotypical acute leukemia. Two patients were primary refractory and the other three were relapsed disease. Two out of the five patients achieved a morphologic complete remission (CR), one patient had a morphologic complete remission with incomplete blood count recovery (CRi) and the other 2 patients had treatment failure per Cheson criteria. Three patients went on to receive allogeneic transplants after clofarabine salvage therapy. Two patients that received allogeneic transplant had achieved complete remission (CR) after clofarabine/cyclophosphamide. The third patient was transplanted with a hypocellular marrow 38 days after clofarabine therapy. This patient ultimately achieved CR that was documented post-transplant, making it difficult to determine if the clofarabine regimen or allogeneic transplant achieved the remission status. Event-free survival ranged from 5 to 265+ days (median: 82 days). Treatment was complicated by neutropenic fever (n=5), grade III-IV mucositis (n=4), prolonged aplasia >30 days (n=4). One patient died of sepsis before completing the regimen.

Conclusion:
Clofarabine in combination with a cyclophosphamide-containing regimen appears to have anti-leukemic potential in adult patients. This regimen might be used to achieve cytoreduction before considering allograft transplant with refractory disease, in selected patients. More studies with this combination in adults are warranted.

Disclosures:
Hamadani: Celgene: Honoraria, Speakers Bureau; Otsuka: Research Funding, Speakers Bureau.
Hematology Experience with Perioperative Anticoagulation at a Tertiary Hospital
Authors: De Sancho Maria Teresa , Bardarova Svetoslava 
Published: October 2019

Abstract
Abstract 4399

Introduction:
The purpose of our study was to evaluate the peri-procedure management of patients on chronic vitamin K antagonists (VKA) and to assess adherence to the 2008 American College of Chest Physicians (ACCP) guidelines.

Methods:
We retrospectively reviewed the electronic medical records of patients on chronic VKA who required temporary discontinuation of anticoagulation due to an invasive or surgical procedure at New York Presbyterian Hospital from January 2006 to June 2010. Dermatological or oral procedures were excluded. Demographics, indications of VKA, underlying thrombophilia, cancer or inflammatory bowel disease, type of invasive or surgical procedure, method of bridge therapy and complications were recorded. When the ACCP guidelines were published, we compared our previous practice and modified our management accordingly.

Results:
A total of 48 procedures where performed in 34 patients. The demographic and clinical characteristics of these patients are shown in Table 1. The type of procedure, anticoagulant bridge therapy and complications are shown in Table 2. The majority of the procedures were managed using bridge therapy with low molecular heparin (LMWH) treatment dose. There were no thrombotic episodes, however there were 3 bleeding complications. All occurred prior to the publication of the 2008 ACCP guidelines. The patients who had bleeding complications were on therapeutic dose LMWH/Fondaparinux bridge therapy. One patient with the antiphospholipid syndrome developed severe thrombocytopenia after surgery that responded to intravenous gamma globulin.

Conclusion:
Adherence to the ACCP guidelines for the perioperative management of anticoagulation minimizes bleeding complications and improves patient outcomes.

Disclosures:
No relevant conflicts of interest to declare.
Pro–angiogenic Induction of Myeloid Cells for Therapeutic Angiogenesis Can Favor MAPK p38–dependent Foam Cell Formation
Authors: Rohde Eva , Schallmoser Katharina , Reinisch Andreas , Hofmann Nicole A , Pfeifer Thomas , Rechberger Gerald , Kratky Dagmar , Fröhlich Eleonore , Strunk Dirk 
Published: October 2019

Abstract
Abstract 4442

Background:
Clinical trials for therapeutic angiogenesis use blood- or marrow-derived transplants containing hematopoietic cells, endothelial progenitor cells (EPCs) and mesenchymal stem and progenitor cells (MSPCs) to support vascular regeneration. Recently concerns have emerged, as bone marrow-derived stem cell preparations also include these three cell types which probably may contribute to atherosclerosis. We therefore asked whether human myelomonocytic hematopoietic cells, EPCs or MSPCs after pro-angiogenic induction can accumulate lipid droplets (LDs) and develop into foam cells.

Method:
LD accumulation was quantified by flow cytometry, confocal microscopy and cholesterol measurement in each of the tested cell types. The impact of an initial three-day pro-angiogenic culture on subsequent foam cell formation was studied to mimic a relevant setting already being used in clinical trials. The phosphorylation state of intracellular signaling molecules in response to pro-angiogenic stimulation was determined to delineate the operative mechanisms and to establish a basis for interventional strategies.

Result:
Foam cells were formed by monocytes but neither by EPCs nor by MSPCs after pro-angiogenic induction. Mitogen-activated protein kinase (MAPK) p38 phosphorylation was enhanced in monocytes after pro-angiogenic stimulation. Kinase inhibition almost abrogated intracellular LD accumulation.

Conclusion:
These data suggest that hematopoietic cell preparations containing monocytes bear the risk of foam cell formation after pro-angiogenic induction. EPCs and MSPCs instead may drive vascular regeneration without atherogenesis aggravation. A thorough understanding of cell biology is necessary to develop new strategies combining pro-angiogenic and anti-atherogenic cellular effects during therapeutic angiogenesis.

Disclosures:
No relevant conflicts of interest to declare.
Proteasome Inhibition Leads to Dephosphorylation and Downregulation of Protein Expression of Members of the Akt/mTOR Pathway In MCL
Authors: Hutter Grit , Zimmermann Yvonne , Rieken Malte , Hartmann Elena , Hiddemann Wolfgang , Rosenwald Andreas , Dreyling Martin H. 
Published: October 2019

Abstract
Abstract 4449

Background:
Mantle cell Lymphoma (MCL) is a distinct B-cell subtype characterized by the chromosomal translocation t(11;14)(q13;q32), an especially poor clinical outcome and low response to chemotherapy. The proteasome inhibitor bortezomib is approved for treatment of relapsed and refractory MCL and achieves a response rate of 30–40%. However, little is known which molecules represent the critical targets of proteasome inhibition and how different regulators of cell cycle and apoptosis are affected. Bortezomib has been shown to inactivate the NFkB pathway in MCL, but recent findings indicate Bortezomib is also active in a proteasome –independent manner suggesting Bortezomib targets multiple pathways.

Method:
Four MCL cell lines (HBL2, Granta 519, Jeko-1, NCEB-1), two CLL cell lines (Mec1, Mec2) and two hematological control cell lines (Jurkat, Karpas 422) were exposed to Bortezomib at a previously defined cytotoxic concentration (25nmol). Western blot and mRNA analysis were performed for various members of the PI3K/Akt/mTOR and the MEK/ERK pathway after 24h Bortezomib exposure. Results were compared to cell proliferation (WST1, trypan blue staining), induction of apoptosis (Annexin V PE/7-AAD staining) and cell cycle data (FACS).

Result:
Western blot analysis revealed reduced phosphorylation of Akt at Ser473 in all cell lines while autophosphorylation of mTOR at Ser2481 was completely downregulated only in the susceptible cell lines. In addition further members of the mTOR pathway were affected by bortezomib treatment. Dephosphorylation of the 4EBP1, downregulation of p70S6 protein expression was detected in all cell lines whereas EIF4E dephosphorylation was only observed in the sensitive MCL cell lines. In contrast Bortezomib did not affect members of the MEK/ERK pathway (MEK1/2, p42/44MAPK). Interestingly the mRNA and protein expression profile of CCND1 were differently altered suggesting an involvement of bortezomib in the regulation of translation initiation. This data were also confirmed by microarray analysis.

Conclusion:
In this study Bortezomib treatment was shown to target the Akt/mTOR pathway especially by dephosphorylation of the translation initiation factor EIF4E and other molecules of this signal pathway. This knowledge will play a crucial role in the development of future combinations of biologicals to target the molecular pathogenesis of MCL.

Disclosures:
Dreyling: Johnson & Johnson: support of investigators initial trials.
Serious Late Complications After Hematopoietic Stem Cell Transplantation (HSCT) Following Myeloablative Conditioining (MAC) In Infants.
Authors: Yasui Masahiro , Yamada Kayo , Kondo Osamu , Sato Maho , Sawada Akihisa , Tokimasa Sadao , Kawa Keisei , Inoue Masami 
Published: October 2019

Abstract
Abstract 4501

Background:
Recently, HSCT has been widely used as a curative therapy for refractory hematological/malignant diseases. However, late complications after HSCT such as endocrine disorders, infertility, short stature and secondary cancers have been recognized as serious problems in children. Late complications are assumed to be much more serious in younger children, especially in infants. Therefore, we retrospectively evaluated late complications among patients who underwent HSCT before one-year-old age in our institute to clarify this big issue.

Methods and results:
We performed HSCT in 530 children from 1993 to 2009. Among these 530 patients, 33 were infants (younger than 1- year - old) at HSCT. 23 infants with malignant disorders consisted of neuroblastoma 10, hepatoblastoma 2, rhabdomyosarcoma 1, retinoblastoma 1, acute lymphoblastic leukemia 5, myelodysplastic syndrome 2, acute myelogenous leukemia 2, and 10 infants with non-malignant disorders consisted of immunodeficiency 5, familial hemophagocytic lymphohistiocytosis/hemophagocytic syndrome 2, congenital metabolic disorder 1, severe aplastic anemia 1, pure red cell aplasia 1 were included. 9 infants underwent autologous HSCT and 24 underwent allogeneic HSCT. 22 infants received MAC and 11 received reduced-intensity conditioning (RIC). 26 out of 33 patients have been alive (MAC, 18/22 = 81.8 %; RIC, 8/11 = 72.7 %). Body height (BH) of 5 patients in RIC group who have been surviving longer than 5 years after HSCT is equal or taller than -2 standard deviation (SD) of BH. However, BH of 6 out of 13 evaluable patients in MAC group remains shorter than -2 SD (the shortest, -5.3 SD) of BH. All survivors in MAC group are suffering from one or more late complications such as growth hormone secretion insufficiency, premature puberty, hypothyroidism, gonadal failure and secondary cancers, therefore, they needs treatment and support for these late complications.

Conclusions:
The survival rate is similar (81.8 % versus 72.7 %) between MAC and RIC in infants, however, infants who underwent MAC-HSCT are suffering from late complications much more frequently and need treatment and support. These results suggest that less toxic conditioning should be adopted for infants who undergo HSCT to avoid serious late complications.

Disclosures:
No relevant conflicts of interest to declare.
Linac Based Total Marrow Irradiation and Myeloablative Chemotherapy In Allogeneic Stem Cell Transplantation for High Risk Patients.
Authors: Patel Pritesh R. , Aydogan Bulent , Rondelli Damiano 
Published: October 2019

Abstract
Abstract 4526
Intensity modulated total marrow irradiation (IM-TMI) represents an innovative technique to irradiate the bone marrow in hematologic malignancies. IM-TMI has been performed previously using tomotherapy in combination with a reduced intensity preparative regimen. Here we report 2 cases where IM-TMI 300cGy was delivered using a linear accelerator in combination with fludarabine/IV busulfan.
To plan IM-TMI, 5 mm-slice CT scanning from top of the head to the mid femur was performed with immobilization using a customized whole body alpha cradle. All bones (excluding the arms and lower extremities) were contoured as the clinical target volume. A 3 mm margin was added to obtain the planning target volume (PTV). The organs at risk (OAR) including the brain, lenses, lungs, liver, kidney, small bowel and heart were identified and contoured. The IM-TMI technique consisted of three separate treatment plans: the head and neck; trunk; and pelvis.
Patients received fludarabine 40mg/m2 on days -8 to -5. IV busulfan was given on days -5 to -2 targeting an AUC of 4800microM/min based on a pretransplant test dose. IM-TMI was delivered on day -5. The patients received a total of 300 cGy IM-TMI dose in two fractions, 8 hours apart.
Two patients were treated: one is a 63 year old male with multiple myeloma who relapsed within 6 months after an autologous transplant with new cytogenetic abnormalities; and the second is a 52 years old female with AML who failed initial induction chemotherapy and at the time of transplant was in complete remission after receiving a second induction and one consolidation chemotherapy. Both patients received PBSC from HLA matched siblings.
IM-TMI technique achieved 95% coverage of the PTV. The mean doses to the lenses and lungs were 99 and 195 cGy, respectively. Overall doses delivered to OAR were reduced by 20–67% on average when compared to standard total body irradiation. Treatment time was 44 min and 32 min for the beam-on and set-up, respectively, using the Varian 21 EX linac and MV imaging.
Both patients suffered Bearman grade 1 mucositis. No other extramedullary toxicities were observed. Both engrafted in a timely manner achieving neutrophil >0.5 × 109/L at day 13 and 14, and platelet >20 × 109/L at day 8 and 9, respectively. Full donor chimerism was noted by day +30. After follow up of 246 and 218 days, respectively, both patients are alive and in remission. One developed a grade 2 acute GVHD and none of them has chronic GVHD.
This study demonstrates for the first time the use of IM-TMI using a linear accelerator. The possibility of adding higher doses of IM-TMI to a myeloablative regimen without toxicity will be tested in a dose escalating clinical trial.

Disclosures:
No relevant conflicts of interest to declare.
Evaluation the Risk Factor of Transplantation-Associated Thrombotic Microangiopathy.
Authors: Zheng Weiyan , Luo Yi , Tan Yamin , He Jingsong , Shi Jimin , Wei Guoqin , Sun Jie , Ye Xiujin , Lin Maofang , Cai Zhen , Huang He 
Published: October 2019

Abstract
Abstract 4527

Background:
Transplantation-associated thrombotic microangiopathy (TA-TMA) is lifethrewten though rare complication of allogeneic hematopoietic stem cell transplantation (HSCT). Diagnosis of TA-TMA is difficult due to its variation of criteria. Recently two new diagnositic criteria for TA-TMA have recently been proposed: the Bone Marrow Transplant Clinical Trials Network (BMTCTN) and the International Working Group (IWG) criteria. Our purpose is to investigate the indence and risk facter of TA-TMA in our institute.

Study design and methods:
All 8 cases of TA-TMA previously diagnosed at our institution between October 2005 and August 2010 were retrospectively evaluated and analysised. Table I showed the transplant details and patients characteristics.

Results:
Six patients performed Matched Unrelated Donor HSCT, two were haploidentical donor HSCT. Four patients complicated with hypohepatia, but only three patients had renal insufficient. The incidence of central nervous symptom abnormalities or dysfunction was very high (sever of eight patients). Four of eight patients were CSA linked TA-TMA, withdrawing CSA resulted in complete response. The other four patients were no CSA linked TA-TMA and developed aGVHD or CMV infection before TA-TMA. They had badly response to common treatment including plasma exchange (PE), steroid treatment and immunosuppression decreased. All of them died of multiple organ failure. Table II showed TA-TMA manifestations and associated circumstance of the patient.

Conclusion:
Our experience suggests that CSA linked TA-TMA is totally different from no CSA linked TA-TMA. The former had good response and prognosis, the later were always associated with GVHD, hypohepatia and virus infectious. The mortality of no CSA linked TA-TMA is high, they had poor prognosis and badly response.

Disclosures:
No relevant conflicts of interest to declare.