bluuebunny/crossref_metadata_2025 huggingface dataset:
Addition of Hemoglobin Level Into the Prognostic Scoring System Together with White Blood Cell and Platelet Count Provides Better Prognostic Stratification for Treatment-Related Mortality and Overall Survival, but Not for Relapse Risk In Adult Patients with Acute Promyelocytic Leukemia
Authors: Yi Jun Ho , Jung Chul Won , Han Boram , Lee Ha Yeon , Jang Jun Ho , Kim Kihyun , Kim Hyeoung Joon , Kim Yeo-Kyeoung , Lee Won-Sik , Joo Young-Don , Kim Min Kyoung , Hyun Myung Soo , Kim Hawk , Park Jae Hoo , Kim Dong Hwan (Dennis)
Published: October 2019

Abstract 4371

Background:

Although the introduction of all-trans retinoic acid (ATRA) and combined chemotherapy improved clinical outcomes of acute promyelocytic leukemia (APL), treatment failure still occur due to early death or disease relapse. The PETHEMA study suggested that the risk adopted stratification of disease risk into 3 groups (low, intermediate and high risk) according to the white blood cell (WBC; 10×109/L) and platelet counts (40×109/L) could improve treatment outcomes of APL patients. However, this stratification system needs to be validated in an independent cohort of patients. The current study attempted to validate the prognostic system based on WBC and platelet counts, hemoglobin level, risk stratification system by PETHEMA and proposed prognostic system consisting of WBC and platelet counts and hemoglobin level.

Methods and patients:

Total of 164 patients was included retrospectively from 5 institutes in Republic of Korea. In patients receiving Idarubicin/ATRA based combination chemotherapy. Consolidation therapy was given with Idarubicin monotherapy in 79 patients, or Idarubicin plus cytarabine in 42 patients.

Result:

With median follow-up of 2.94 years, the CR rate following remission induction treatment was 83.9% in overall patients, while the 3 years OS, TRM and relapse rate was 77.6±3.5%, 20.4±3.3, and 9.6±3.1%, respectively. The combined prognostic system provided better stratification of APL patients according to their prognosis compared to single variable comparison such as WBC counts, platelet counts or hemoglobin level. In addition, the risk stratification system by PETHEMA could predict OS (p=0.06) and TRM (p=0.05), but not CR rates (p=0.1) or relapse (p=0.7). However, the proposed 3 score prognostic system could provide better stratification of APL patients in term of the CR rates (p=0.01 vs 0.1 between 3 score system vs PETHEMA risk stratification), OS (p=0.02 vs. 0.06) and TRM (p=0.006 vs 0.05), but not of relapse risk (p=0.9 vs 0.7).

Conclusion:

This retrospective study suggested that the proposed 3 score prognostic system could provide better stratification of APL patients in term of the CR rates, OS and TRM, but not of relapse the risk. Further study will be needed to reach a clear conclusion of better prognostic stratification of APL patients with large number of patients.

Disclosures:

No relevant conflicts of interest to declare.
Imaging Thromboembolism with 99mtc Labelled Chimeric Monoclonal Anti-Platelet Glycoprotein Iiia Antibody Fragment chSZ21F(ab)2: Evaluation In Beagle Canines
Authors: Ji Shundong , Fang Wei , Dong Ningzheng , He Zuoxiang , Ruan Changgeng
Published: October 2019

Abstract 4387

Purpose

A mouse/human chimeric monoclonal antibody F(ab)2 fragment, with high affinity for platelet glycoprotein IIIa was labelled with99mTc (99mTc-chSZ21F(ab)2), and evaluated in canine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE).

Methods

ADP-stimulated platelet aggregation was performed to determine the affinity and specificity of chSZ21F(ab)2 to the GPIIb/IIIa receptor on plates of human or canine. ChSZ21F(ab)2 was modified with 2-iminotholane and incubated with 99mTc-glucoheptonate for imaging of 24-h-old DVT and PE in a canine model. Animals were imaged for up to 3 h after injection, heparinized, and sacrificed. Lungs and other tissues, including blood and normal lungs, were harvested and, concurrently, 99mTc was counted for determination of target to tissue ratios and the percentage of injected dose per gram of tissue.

Results

The concentration of chSZ21F(ab)2 required to inhibit 50% of platelet aggregation (IC50) in platelet-rich plasma was 11.6±7.9 nM for human and 24.9±18.8 nM for canine. In vivo, focal uptake was observed in planar images as early as 30 min (DVT), and 60 min (PE) after injection. Lesion uptake of 99mTc-chSZ21F(ab)2 at 3 h after injection was calculated in terms of percentage injected dose per gram (%ID/g) of tissue and averaged 0.076%ID/g PE and 0.083%ID/g DVT. Lesion-to-background ratios averaged 12.8 (PE-to-lung), 7.2 (DVT-to-blood), and 117.0(DVT-to-muscle).

Conclusion

99mTc-chSZ21F(ab)2 with its modest affinity and high DVT and PE uptake is a promising agent for imaging vascular thrombosis.

Disclosures:

No relevant conflicts of interest to declare.
aPTT Versus Anti Xa Monitoring of Unfractionated Heparin - a Retrospective Review of Clinical Outcomes
Authors: Dhami Sabina , Lorinsky Michael , Johnson Susan , Smith Michael , Healy Abigail , Kapur Nisha , Taylor Roseleigh , Slater Dennis E , Dhami Mandeep S
Published: October 2019

Abstract 4391

In May 2008, The William W. Backus Hospital changed the unfractionated heparin dosing protocol and the monitoring parameter for the treatment of thromboembolic disease. The original protocol utilized the Rashke's method (Bolus dose 80 units/kg and initial infusion of 18 units/kg/hour) monitored with aPTT (Therapeutic range 61–80.9 seconds). The newer protocol is a novel model utilizing a bolus dose of 26 units/kg and initial infusion rate of 15 units/kg/hour, calculated using the methodology designed by Rosbourough et al monitored with anti-Xa (Therapeutic range 0.3–0.7 anti Xa units). This is a retrospective study comparing of the efficacy and safety of each protocol.

Methods:

Data abstraction was completed through electronic medical record review of two hundred patients. Time point 0 was the date of changing to the new protocol. One hundred patients in reverse chronological order were reviewed for the original protocol and one hundred patients in chronological order with the new protocol. Data included demographics, duration of time prior to achieving therapeutic parameters, number of dosage changes, diagnosis of cancer, bleeding events and recurrent thrombotic events. Unpaired Student t tests were utilized to statistically analyze the differences between the cohorts.

Results:

Conclusion:

Both methodologies achieved therapeutic levels rapidly. The Rosbourough method required statistically significant less dosage changes when compared to the Rashke method. The incidence of major and minor bleeding was similar between the two dosing algorithms. Although not statistically significant, the incidence of recurrent thromboses was numerically higher with the Rosbourough method compared to Rashke method. This is concerning and suggests that the higher loading dose may be more appropriate. A prospective comparison of these two monitoring methods using Rashke dosing is planned.

Disclosures:

Off Label Use: Discuss alternative dosing and anti Xa monitoring of unfractionated heparin infusion.
(AVK) Anti Vitamin K Treatment In patients with Fontan Surgery
Authors: Infante Maria Stefania , Izquierdo Cristina Pascual , Lopez Fernando Carretero , Ramirez Jose Manuel Sanchez , Huerta Ana Maria Rodriguez , Rus and Jose Luis Diez Martin Gloria Perez
Published: October 2019

Abstract 4397

OBJECTIVES

Thrombotic events have been reported as a major cause of morbidity after the Fontan procedure. There is no consensus about the type and duration of postoperative anticoagulation prophylaxis, due to the high risk of bleeding complications, the difficulties in monitoring and the questionable therapeutic compliance in children. In spite of the lack of long term prospective studies in this situation, the ACCP has recommended in their guidelines OAT following Fontan or Glenn operation for at least 6 months. This has also been our practice in our institution during the period of study.

AIM OF THE STUDY

To analyze the efficacy and complications of OAT in our pediatric patients after undergoing the Fontan operation.

METHODS

Retrospective chart review of all the children treated with OAT in our institution between 1995 and 2009. All patients were treated initially with acenocumarol 0,2 mg/kg, except the Fontan patients, who received 0,1 mg/kg. Target INR was 2–3 for all patients.

The Mann-Whitney test was used to compare the rate of complications, and the percentage of visits out of target INR between the Fontan patients and the rest of the cohort.

RESULTS

There were 61 children (26 female/35 males) aged between 1 month and 17 years, who received OAT with a range of follow up between 4 months and 14 years: 27 after Fontan operation (Group A), an 34 for other reasons (Group B: n=13 non prothetic valve cardiopathy, n=21 treatment of thromboembolic disease).

The average follow-up was similar in both groups (median of 6.5 months in group A vs.7.5 months in group B). There were few complications: 1 mild epistaxis and 1 thrombotic event in group B, and none in group A. There were no differences in the proportion of controls in normal range between both groups; there was a moderate proportion of controls outside the target range of INR, with higher distribution below the range than above the range. The median dose used to achieve the target INR was 0.3 mg/kg/d in Group A and 0.4 mg/kg/d in Group B.

CONCLUSIONS

Oral Anticoagulant therapy is safe and effective in pediatric patients,with very low rates of thrombotic or hemorragic complications including those undergoing the Fontan surgery. There were not any differences between both groups in any of the analizyed parameters.

Disclosures:

No relevant conflicts of interest to declare.
Eltrombopag Can Stimulate Trilineage Hematopoiesis In Patients with Refractory Severe Aplastic Anemia
Authors: Olnes Matthew J. , Tang Yong , Soto Susan , Sloand Elaine M , Scheinberg Philip , Young Neal S. , Dunbar Cynthia E.
Published: October 2019

Abstract 4427

Severe aplastic anemia (SAA) is characterized by trilineage marrow hypoplasia and a paucity of hematopoietic stem cell progenitors. SAA is treated with immunosuppression or allogeneic stem cell transplantation (SCT), with a successful outcome in a majority. However, 20–40% of patients without a suitable donor for SCT do not respond to immunosuppression and may have persistent severe thrombocytopenia. Thrombopoietin (TPO) is the principal regulator of platelet production, and it exerts its effects through binding the megakaryocyte progenitor TPO receptor mpl, which stimulates production of mature megakaryocytes and platelets. Eltrombopag, a small molecule TPO mimetic that binds to mpl, increases platelet counts in healthy subjects, and in patients with chronic immune thrombocytopenic purpura. Both TPO and eltrombopag stimulate more primitive multilineage progenitors and stem cells in vitro. Patients with SAA and thrombocytopenia have very elevated TPO levels; nevertheless, we asked whether pharmacologic doses of eltrombopag could stimulate hematopoiesis in these patients without other options. We are conducting a pilot phase II study of eltrombopag in SAA patients with severe thrombocytopenia refractory to immunosuppressive therapy. Consecutive eligible adult patients were treated with oral eltrombopag at an initial dose of 50 mg daily, with escalation to a maximum dose 150 mg daily, with the goal of maintaining a platelet count of >20,000/uL above baseline. Treatment response was measured after three months and was defined as platelet count increases to 20,000/uL above baseline, or stable platelet counts with transfusion-independence for a minimum of 8 weeks. Nine patients have been enrolled and six are evaluable for response to date. Two patients did not respond to treatment. Three patients achieved platelet responses by 12 weeks of treatment, and all have sustained their responses (median follow up 10 months). Four patients exhibited improved hemoglobin levels 12 weeks after starting treatment (median hemoglobin increase of 2.1 g/dL) and two patients who were previously dependent on packed red blood cell transfusions have achieved transfusion-independence. Three neutropenic patients exhibited increased neutrophil counts after treatment with eltrombopag (median increase 0.46K cells/uL). These results provide evidence that eltrombopag can improve platelet counts in patients with severe refractory thrombocytopenia, and perhaps more surprisingly, have a clinically relevant impact on erythropoiesis and myelopoiesis. Updated data will be presented at the Society's meeting.

Disclosures:

Off Label Use: Eltrombopag for thrombocytopenia in refractory severe aplastic anemia patients.
Oxidative Stress in CML Stem and Progenitor Cells Correlates with Response to Imatinib
Authors: del Castillo Santiago , García Regina , Hernandez Agustin M , Campos Arturo , Entrena Laura , Llano Ma Paz Queipo De , Rosell Ana , Sanchez Guacimara , Ramirez Gemma
Published: October 2019

Abstract 4473

Introduction:

The BCR/ABL kinase alters the oxidative environment in chronic myelogenous leukemia (CML) cells, but the consequences of the increased reactive oxygen species (ROS) levels on signaling pathways remain unknown. Increased intracellular peroxides in progenitors cells have been linked to DNA damage, and promote self-mutation which subsequently render imatinib to resistance and failure to eliminate all leukemia cells.

Material and Method:

A total of 8 patients and 3 health controls were included in this study. 1 patient only at diagnosis, 3 patients at diagnosis and 3 months after treatment with Imatinib, 1 case after 3 and 6 month with Imatinib, 2 cases are long follow-up resistant patients and 1 with long follow-up and good response. Oxidative stress biomarkers were studied by flow cytometry in the bone marrow progenitor cells.

Result:

Not only levels of BCR-ABR and the number of CML stem cells were lower with the treatment, the oxidative stress biomarkers were lower too in normal controls and in CML cells in patients with response to imatinib but in the resistant ones oxidative stress biomarkers were higher in all stem and progenitor cells.

Conclusion:

The levels of oxidative stress are significantly higher in CML cells than in healthy subjects and correlate with tumor burden as well as the response to imatinib. This data demonstrate a role of oxidative stress in restore normal hematopoiesis in CML patients and probably in imatinib resistance.

Disclosures:

García: Celgene: Research Funding.
A Disease Model to Predict the Long-Term Outcomes Associated with Treatments for Chronic Myelogenous Leukemia (CML).
Authors: Taylor Matthew , Lewis Lily , Patton Thomas , Hirji Ishan , Davis Catherine
Published: October 2019

Abstract 4480

Introduction

Dasatinib, a BCR-ABL inhibitor 325 fold more potent than imatinib, has been studied in DASISION a randomized comparison vs. imatinib in patients with newly diagnosed chronic phase CML. A computer simulation disease model was developed to examine long-term survival outcomes following treatment with dasatinib, imatinib, or nilotinib in this patient population.

Methods

A disease model was developed to estimate the lifetime health outcomes associated with each form of treatment. Five initial best-response categories were used (no response (NR), complete hematologic response (CHR), partial cytogenetic response (PCyR), complete cytogenetic response (CCyR) and molecular response (MR)), which were each linked to a disease prognosis based on previously published evidence. Mutually exclusive initial response rates for NR, CHR, PCyR, CCyR and MR came from the DASISION trial for dasatinib and imatinib while those for nilotinib were identified from published ENESTnd data. A quality of life (QoL) utility value was assigned to each health state (chronic phase with response, chronic phase without response, progressed, and dead), also from previous publications. Adverse events were accounted for in terms of their impact upon QoL utility values. Extrapolation beyond the published data was undertaken by calculating trend rates for the final three years of follow up and applying age related mortality rates. Uncertainty was incorporated into the analysis by fitting distributions to survival and using simulation techniques to run 1,000 iterations. The model calculated survival based on the mean number of years’ survival per patient, across the entire cohort. Adjusted QoL utility values were calculated by assigning a QoL utility value weight to each state (see above) and calculating the mean total outcome for the entire cohort. Incremental survival was calculated by comparing the mean survival associated with each treatment.

Results

The quality adjusted life years (QALYs) and life years (LYs) are given in Table 1. The QALYs and LYs were 12.238 and 14.727 for dasatinib, 11.506 and 13.822 for imatinib and 12.016 and 14.426 for nilotinib, respectively.

Conclusion

Based on simulation modeling, results suggest that treatment with dasatinib may be associated with long-term survival as well as QoL-adjusted survival benefits. Long-term follow-up of ongoing studies will be needed to confirm these predicted benefits.

Disclosures:

Taylor: Bristol Myers-Squibb: Consultancy. Lewis:Bristol Myers-Squibb: Consultancy. Patton:Bristol Myers-Squibb: Consultancy. Hirji:Bristol Myers-Squibb: Employment. Davis:Bristol Myers-Squibb: Employment.
The Use of Intravenous Antibiotics at the Onset of Neutropenia In Patients Receiving Hematopoietic Stem Cell Transplants: A Pre-Emptive Strategy.
Authors: Hamadah Abdulaziz
Published: October 2019

Abstract 4516

Background:

Hematopoietic Stem Cell Transplant (HSCT) recipients are at risk for fatal bacterial infections during the engraftment period. Empirical antibiotic(s) at the onset of febrile neutropenia remain the standard of care. HSCT recipients began receiving intravenous once daily ceftriaxone at the onset of neutropenia (neutrophils< 1.0) regardless of fever as part of The Ottawa Hospital Blood and Marrow Outpatient Programme policy from Jan 2009; “pre-emptive” approach. We examined the impact of this policy on HSCT recipient outcomes.

Methods:

A retrospective “before-after” study was conducted to compare 2 cohorts [Jan 2008 - Dec 2008 (Empiric strategy) vs. Jan 09 - Dec 2009 (Pre-emptive strategy)] of patients receiving HSCT. Baseline characteristics between the groups were compared with 2 sample tests. Categorical variables and continuous variables were compared using Chi-squared and Wilcoxan rank-sum tests respectively.

Results:

There were 238 HSCTs performed between Jan 2008 and Dec 2009 with 127 and 111 in the earlier and later cohorts respectively. Baseline characteristics between the cohorts were similar. Infection related mortality at 100 days after HSCT and during the engraftment period was similar with a pre-emptive strategy compared to an empiric strategy (7.2% vs 10.2%; p=0.41 and 3.6% vs 7.1%; p=0.24) respectively. Further, there were no differences in ICU admissions or length of hospital stay. Both microbiologically (MDI) and clinically documented infections (CDI) were reduced (11.7% vs 29.1%; p=0.001 and 18.2% vs33.9%; p=0.007) with the pre-emptive strategy compared with an empiric strategy. Importantly, recipients of autologous HSCT appear to have a lower infection related mortality and reduced infection related ICU admissions during the engraftment period with the pre-emptive strategy compared to an empiric strategy (0% vs 6.8%; p=0.03 and 2.9% vs 12.2% p= 0.04). The need for escalation of antimicrobial treatments, resistance pattern of MDIs and cost of antimicrobial treatment were not different between the two groups.

Conclusion:

The use of once daily intravenous ceftriaxone at the onset of neutropenia in patients receiving HSCT is safe and effective particularly in patients receiving autologous HSCT. Further studies are warranted to study the impact of this “pre-emptive” strategy.

Disclosures:

No relevant conflicts of interest to declare.
Application of Mesenchymal Stem Cells Derived From the Umbilical Cord Instead of Bone Marrow In Hematopoietic Stem Cells Transplantation.
Authors: Peng Ching-Tien
Published: October 2019

Abstract 4544

Bone marrow-derived mesenchymal stem cells (BMMSCs) have been found to enhance engraftment of hematopoietic stem cell transplantation (HSCT), plus show effect against graft-versus host disease (GVHD) because of their immunosuppressive properties. However, harvesting these cells is an invasive and painful procedure. To substitute BMMSCs from alternative sources is necessary. We intravenously infused ex vivo-expanded third-party umbilical cord-derived mesenchymal stem cells (UCMSCs) obtained from a bank 8 times in 3 patients who developed severe, steroid-resistant acute GVHD after allogeneic HSCT. The acute GVHD improved with each infusion of UCMSCs. Besides, after cotransplantation of cord blood and UCMSCs in 5 patients, we found UCMSCs enhanced absolute neutrophil counts and platelet counts recovery. No adverse effects after UCMSCs infusions were noted. We also found that UCMSCs had superior proliferative potential and greater immunosuppressive effects than BMMSCs in vitro. This is the first report of UCMSCs in human clinical application. These findings suggest UCMSCs are effective in treating aGVHD and can enhance hematopoiesis after HSCT. Considering that they are not only easy to obtain but also proliferate rapidly, UCMSCs would be the ideal candidate for cell-based therapy, especially for diseases associated with immune responses because of their immunosuppressive effects.

Disclosures:

No relevant conflicts of interest to declare.
Gene-Expression Profile of Steroid-Refractory Acute Graft-Versus-Host Disease.
Authors: Verner Jan , Kabathova Jitka , Zdrahal Zbynek , Tomancova Alexandra , Volejnikova Jana , Brychtova Yvona , Pospisilova Sarka , Mayer Jiri
Published: October 2019

Abstract 4549

Steroid-refractory acute graft-versus-host disease (aGVHD) remains to be the major complication of allogeneic hematopoietic stem cells transplantation (allo-HSCT). aGVHD is characterized by tissue injury and is associated with high morbidity and mortality, most notably in cases of severe course and/or resistance to corticoids. aGVHD appears usually within the first 100 days after transplantation. This study should lead to identification of molecular patterns characterizing patients’ sensitivity or resistance to corticoid therapy. We performed an oligonucleotide microarray analysis (whole genome Human OneArray, Phalanx) of 13 patients with hematological malignancies who received allo-HSCT. Peripheral blood samples were collected at the time of aGVHD manifestation and subsequently mononuclear cells were isolated (Ficoll-Paque gradient). In total, five patients with resistance, and eight patients with sensitivity to corticoids were included in the analysis. The significance analysis of micorarrays (SAM) revealed a set of differentially expressed genes: GBP5 (guanylate binding protein 5), PRG3 (proteoglycan 3), CDK5RAP2 (CDK5 regulatory subunit associated protein 2), and, especially, ARG1 gene (arginase, liver) whose expression was significantly higher in the group of resistant patients (with 4.89-fold change). As published earlier, arginase is released from human granulocytes during purulent inflammatory reactions and induces a suppression of T-cell proliferation and cytokine synthesis (Munder et al., 2006). These findings might confirm our hypothesis that expression levels of ARG1 gene could reflect the severity of aGVHD. ARG1 gene was detected apparently in a fraction of immature forms of granulocytes which are released into the peripheral blood after allo-HSCT. Thus, both immature granulocytes and mononuclear cells are then isolated using Ficoll-Paque gradient. To validate arginase as a marker of unfavorable grade of aGVHD, it is necessary to examine expression profile of ARG1 gene in neutrophils. Therefore, it is important to separate both mature and immature forms of neutrophils (using different method than Ficoll gradient), as well as examine gene expression profile of a down-regulated CD3ζ chain in T-cells. Down-regulation of CD3ζ chain is due to arginase-mediated depletion of arginine in the T-cell environment (Munder et al., 2006). We assume that ARG1 gene expression profile might have a potential to influence patients′ response to corticoid therapy of unfavorable grade of aGVHD. This study is in progress and further analyses will be focused on monitoring of ARG1 and CD3ζ chain expression levels in a larger cohort.

Supported by IGA MZ CR NS9683-4/2008 and MSMT CR MSM0021622430.

Disclosures:

No relevant conflicts of interest to declare.
Comparative Analysis of Single-Institute Transplantation From Unrelated Cord Blood and Related Adult Donors In Adults with Hematologic Malignancies.
Authors: Sun Zimin , Liu Huilan , Geng Liangquan , Wang Xingbing , Ding Kaiyang , Zhou Chengyang , Tang Baolin , Tong Juan , Yao Wen , Wang Zuyi
Published: October 2019

Abstract 4570

We compared the clinical outcomes of allogeneic hematopoietic stem-cell transplantation among 126 adults with hematologic malignancies: 40 received unrelated cord blood transplantation (CBT) and 86 received related bone marrow transplantation (BMT) and/or peripheral blood stem cells transplantation (PBSCT). All patients received myeloablative transplantations which performed from 2001 through 2010.Recipients of unrelated CBT were younger (median, 23.5 vs. 30 years of age; P<0.001) and had more advanced disease at the time of transplantation (68% vs. 34%, P<0.001) than recipients of related BMT/PBSCT. All related transplants were HLA matched, whereas 77 percent of CBT grafts were HLA mismatched (P<0.001). The median number of nucleated cells infused was 0.37×108 per kilogram of the recipient's body weight for CBT and 5.39×108 per kilogram for BMT/PBSCT recipients (P<0.001). Neutrophil recovery was significantly delayed after CBT (median, 19 vs. 12 days post transplantation, P<0.001), however, overall engraftment rates were almost the same for both grafts. Multivariate analysis demonstrated no apparent differences in transplantation-related mortality (TRM) (33% in CBT and 21% in BMT/PBSCT recipients), relapse rate (15% in CBT and 15.1% in BMT/PBSCT recipients), the incidence of grades III to ‡W acute graft-versus-host disease (aGVHD) (7.5% in CBT and 5.8% in BMT/PBSCT recipients), 2 years disease free survival (DFS) (52.5% in CBT vs. 62.8% in BMT/PBSCT recipients) and over survival (OS) (62.5% in CBT vs. 67.4% in BMT/PBSCT recipients) between both groups, but extensive chronic GVHD (cGVHD) was lower in CBT recipients (2.5% vs. 17.4%). These data suggest that unrelated CBT could be as safe and effective as matched related BMT or mobilized PBSCT for adult patients with hematologic malignancies.

Disclosures:

Sun: International Cooperation Research Fund of Anhui Provincial Scientific and Technologic Committee (08080703026): Research Funding; Fund of the Key Medical Project of Anhui Provincial healthy department (2010A005): Research Funding; Anhui Provincial “115” Industrial Innovation Program: Research Funding.
Encouraging Results of Reduced-Intensity Conditioning (RIC) Followed by Hematopoietic Stem Cell Transplantation (HSCT) from an Alternative Donor for Acute Lymphoblastic Leukemia (ALL) In Children.
Authors: Inoue Masami , Yasui Masahiro , Tokimasa Sadao , Sawada Akihisa , Sato Maho , Kondo Osamu , Yamada Kayo , Kawa Keisei
Published: October 2019

Abstract 4572

Background:

RIC has been applied mainly for elderly patients and patients with comorbidity to expand opportunity for such adult patients to undergo HSCT. The burden of late effects after HSCT followed by myeloablative conditioning is not negligible in pediatric patients. RIC should be introduced to avoid not only treatment related morbidity (TRM) but also late effects for children even if they are not ineligible for myeloablative transplantation. However, enhanced graft-versus-leukemia (GVL) effect by choosing an alternative donor in the setting of RIC-HSCT for pediatric ALL hasn't been clarified, so far.

Methods:

We retrospectively analyzed 22 children with ALL who underwent RIC followed by HSCT from an alternative donor between 2001 and 2008 in our institute.

Results:

The median age of 22 patients at HSCT was 9 years (range one year - 19 years). 8 patients in CR1, two in CR2 and 12 beyond CR2 underwent HSCT from an alternative donor followed by Flu 180mg/m2 and LPAM 140 mg/m2 containing RIC. 8 patients who relapsed after myeloablative HSCT and 5 patients with Ph1-ALL were included. Unrelated bone marrow (BM) in 7 patients and unrelated cord blood in 4 were transplanted. 11 patients were transplanted from a haplo-identical parent (8, BM; 3, selected CD34 positive peripheral blood mononuclear cells). Engraftment was confirmed in 21 transplants out of 22 (95.4%). Death of TRM within 100 days after transplant was observed in 3/22 (13.6%). Acute graft-versus-host disease (GVHD) grade IV wasn't observed. Acute GVHD grade II and III occurred in 8/21 (38.1%) and 6/21 (28.6%), respectively. Chronic GVHD was seen in 8/16 (50%). 14 patients (63.6%) out of 22 are surviving after RIC-HSCT for median 36 months (range, 24 – 100 months). 9 patients (90%) out of 10 in CR1/CR2 and 5 (41.7%) out of 12 beyond CR2 are surviving.

Conclusion:

These results suggest RIC-HSCT from an alternative donor for pediatric ALL can be performed safely and similar outcome can be expected compared to myeloablative transplantation.

Disclosures:

No relevant conflicts of interest to declare.
Allogeneic Stem Cell Transplantation for Patients with AML and FLT-3 Mutations.
Authors: Schleuning Michael , Judith Dirk , Heshmat Mansoor , Burlakova Irina , Jedlickova Zuzanna , Salm Elisabeth , Baurmann Herrad , Schwerdtfeger Rainer
Published: October 2019

Abstract 4573

Patients with acute myeloid leukemia (AML) with FLT-3 mutations have an extremely high risk of relapse after conventional chemotherapy. The role of allogeneic stem cell transplantation (SCT) for this patient cohort has been discussed controversially in recent years. This retrospective analysis reports our cumulative experience in a cohort of 42 consecutive patients (age 17–70, median 51 years) allografted for FLT-3 positive AML in a single centre. In more than 80% a FLAMSA-RIC based conditioning regimen was used, in 5% BCNU/Melphalan/Fludarabine, and in 14% conventional radiation- or Busulfan- based regimens. Most patients received mobilized peripheral blood stem cells as graft and 10 patients had a sibling and 32 an unrelated donor (MUD), respectively. Half of the patients were allografted in complete remission and twenty with active, mostly refractory disease. With a median follow-up for surviving patients of nearly 2 years (range 64 – 1746 days) the Kaplan-Meyer procedure estimates a 48% probability of survival at 2 y after transplantation. Interestingly, there is no difference what so ever in survival if patients had an identical sibling donor or a MUD. Similarly, neither patient age below or above the median, nor the applied conditioning regimen did affect the outcome. The only significant variable for improved survival was being in complete remission at transplantation with a 2-year overall survival probability of 60% as compared to 30% for patients with active disease. Thirteen patients (31%) relapsed after allografting, which is substantially lower as to what is reported after conventional chemotherapy. Three of these patients could be salvaged by a second transplant, whereas 10 patients finally died from leukaemia. Non relapse mortality was 24% with 2 patients dying from acute GVHD, 7 from infections and 1 from suicide, despite being well physically. In conclusion, our data support the notion that allogeneic SCT is a highly effective treatment option for patients with AML and FLT-3 mutations and that, if the patient is eligible, it should be undertaken whenever possible in 1. complete remission. However, even patients with primary induction failure have a reasonable chance to be salvaged by allogeneic SCT.

Disclosures:

No relevant conflicts of interest to declare.
Successful Rescue of Childhood Acute Leukemia In Non-Remission by Non-T-Cell Depleted HLA-Haploidentical Hematopoietic Cell Transplantation.
Authors: Kobayashi Shogo , Kikuta Atsushi , Ito Masaki , Sano Hideki , Mochizuki Kazuhiro , Akaihata Mitsuko , Ohto Hitoshi , Hosoya Mitsuaki
Published: October 2019

Abstract 4582

Refractory acute leukemia who do not achieve second or subsequent complete remission (CR) have an extremely poor prognosis. Non-T-cell depleted (TCD) HLA-haploidentical hematopoietic cell transplantation (haplo-HCT) is a form of adoptive cellular therapy that has a high degree of efficacy in hematologic malignancies. The major problems of non-TCD haplo-HCT are severe graft-versus-host disease (GVHD), graft failure (GF) and high-risk of early death. We conducted non-TCD haplo-HCT for children with acute leukemia in non-remission as a novel therapeutic strategy.

Five consecutive children under 15 (0-13) years old with hematological malignancies underwent non-TCD haplo-HCT from family donors between November 2002 and July 2010 at Fukushima Medical University Hospital. All patients were in non-remission at transplantation. One donor was mother and the other 4 donors were fathers of the patients. One patient was in 3 loci, and 4 patients were mismatched 4 loci of the allele level for HLA-A, -B, -C and -DRB1. The blast count in the marrow before transplantation was 80%, 75%, 34%, 10% and 96%, respectively. There were two acute myelogenous leukemia and three acute lymphoblastic leukemia. There were two refractory diseases to chemotherapy and three relapses after HSCT. All of them received myeloablative conditioning (2 Busulfan based, 3 TBI based). Type of graft were bone marrow in one and peripheral blood stem cell in 4. Total of 9.9 ×108/kg of nucleated bone marrow cells were infused in the patient received BMT. The median number of TNC and CD34+ cell doses were 11 (8-21.4)×108/kg and 7.9 (6.5-8.8)×106/kg in PBSCT, respectively. GVHD prophylaxis were combination of tacrolimus, methotrexate was given in one patient, combination of tacrolimus, methotrexate and prednisolone in one, combination of tacrolimus, methotrexate, prednisolone, and antihuman thymocyte immunoglobulin (ATG) in 3.

All patients achieved primary engraftment at median of 13 days (11 -15) and achieved complete remission. Five patients developed acute GVHD, with grade 1 in two patients, grade 2 in two patients, grade 3 in one patient. Chronic GVHD occurred in 2 of 4 evaluable patients. Infectious complications including 2 CMV reactivation, 1 CMV-IP, 1 invasive aspergillosis, 1 candida sepsis were observed. One patient died from CMV-IP in remission, remaining 4 patients survived disease-free + 4, + 9, + 10 and + 94 months after non-TCD haplo-HCT, respectively.

These preliminary results suggested that non-TCD haplo-HCT is effective strategy in children with refractory leukemia.

Disclosures:

No relevant conflicts of interest to declare.
Oral Supplementation with Omega3 Fatty Acids Inhibits NFkB Activation In Chronic Lymphocytic Leukemia (CLL) Cells.
Authors: Ballester Oscar F. F , Fahrmann Johannes , Witte Theodore , Ballester Gabriela , Hardman W. Elaine
Published: October 2019

Abstract 4607

Introduction:

Nuclear factor kappa B (NFkB) is a critical transcription factor involved in the growth and survival of CLL cells. NFkB is recognized as an important target for the development of novel therapies for the treatment of various malignancies. In vitro and in experimental animal models, OMEGA-3 fatty acid (O3FA) supplementation has been shown to inhibit NFkB activity.

Patients and Methods:

Patients with early stage CLL (Rai stages 0-II) who required no therapy, where accrued to this phase I-II trial. O3FA supplements were given for a total of 12 months at doses ranging from 2250 mg (EPA plus DHA), escalated to 4500 mg and 6750 mg per day as tolerated. NFkB activity was measured in peripheral blood samples after separation of mononuclear cell by gradient centrifugation and expressed as luminescence units/μ g of protein. Baseline and multiple serial samples were obtained during the study period. In-vitro cytotoxicity assays to doxorubicin were conducted using standard LD50 methods. Compliance was monitored by analysis of red cell and lymphocyte membrane lipid composition by gas chromatography.

Results:

Fifteen patients have been accrued to the trial, 8 of them have currently completed the planned 12 months of the study period. No significant clinical changes in disease activity were noted. O3FA was well tolerated. Supplementation resulted in a dose-dependent increase of O3FA composition of red cell and lymphocyte membranes in a dose dependent manner. At baseline, CLL patients had NFkB above the range observed in normal controls (2.05 × 104 to 2.32 × 105 NFkB lum units/μ g). The median value in CLL patients at baseline was 11.60 × 106 NFkB lum units/μ g (range 0.9 × 105 to 23.12 × 106). Among 5 patients with the highest baseline levels of NFkB, a decrease in NFkB activity ranging from 0.02 to 0.19 of the baseline value, was noted at the 2 higher doses of O3FA supplementation. Similar results were seen in patients with relatively lower levels of baseline NFkB activity (0.9 × 105 to 2.96 × 106 lum units/μ g). In vitro, significant doxorubicin cytotoxicity (>50%) was noted in samples obtained during supplementation, at μ gM concentrations which produced no detectable cell kill in baseline samples.

Conclusions:

O3FA supplementation resulted in significant inhibition of NFkB activity in leukemic cells from patients with CLL. In-vitro, after O3FA supplementation CLL cells became more sensitive to doxorubicin. Preliminary analysis of whole genome micro arrays revealed significant down-regulation of multiple genes associated with O3FA supplementation.

Disclosures:

No relevant conflicts of interest to declare.
Histone Deacetylase Activity In Chronic Lymphocytic Leukemia.
Authors: Kafeel Muhammad I. , Avezbakiyev Boris , Chen Chi , Sun Yiwu , Rathnasabapathy Chenthil , Kalavar M. , He Zili , Burton Jack , Lichter Stephen M. , Wang Jen-Chin
Published: October 2019

Abstract 4622

Elevated histone deacetylase (HDAC) enzyme levels have been described in patients with carcinoma and leukemia. Using HDAC inhibitor (HDACi) to treat carcinoma has been promising and is currently undergoing intense research. In order to be better in using HDACi to treat chronic lymphocytic leukemia (CLL), HDAC isoenzyme levels were measured in 32 patients with CLL and compared with 17 normal volunteer controls. Peripheral blood CD20+ cells from patients with CLL and normal volunteer controls were isolated by using Progenitor Cell Isolation Kits (Miltenyi Biotec, Auburn, CA). Isolated CD20+ cells were confirmed by flow cytometry studies to have more than 92% purity. Patient and control CD20+ cells were then lysed in denaturation buffer. Total RNA was extracted, then cDNAs were prepared and quantitative RT-PCR was performed using premixed primer and FAM- and TAMRA-labeled probes obtained from ABI. The results showed: 1) HDAC1, -3, -6, -7, -9, and -10 and SIRT1, -2, and -6 were significantly over-expressed, suggesting that, in CLL, elevated HDAC activity are not restricted to one class. Therefore, HDAC inhibitor therapy may need to be directed to more than one specific class of HDAC; 2) Patients with ZAP70+ were associated with more advanced Rai clinical stage and higher HDAC activity than Zap70– patients and HDAC activity were correlated to the expression levels of CD44 and Pin1, suggesting that higher HDAC values may indicate a poor prognosis and more advanced disease stage.

Disclosures:

No relevant conflicts of interest to declare.
Fludarabine Versus No-Treatment In the Patients with CLL Stage A
Authors: Cahn Jean-Yves , Ivanaj Arben , Pivot Xavier , Dobi Erion , Pulluqi Polikron , Xhumari Pal
Published: October 2019

Abstract 4639

Background.

Fludarabine is an effective treatment for chronic lymphocytic leukemia (CLL) alones and in combined terapy in untreatment CLL. The standard recomandation for the stage A Binet, is to delay any treatement until progression. We compared the benefit of early exposure to fludarabine versus no-treatment in the patients with CLL stage A.

Methods.

Between 2000 and 2004, we randomzed 77 patients with CLL stage A to be treated; fludarabine 25 mg/m2, administered intravenously daily for 5 days every 28 days versus no treatment until disease progression. The treated group with received the assigned treatment for a maximum of 6 cycles. Both groups evaluated evry 2 month diseases progression. The NCI-WG response criteria for CLL was refered for analized result.

Results.

Among the 38 patients treated by fludarabine. Complet response and parcial response were observed 21 % and 74 % of cases respectively. The median Progression Free Survival (PFS) was 32 month in the treated group versus 31.5 months in the 39 patients of control group, (p 0.9). The median survival were 124 and 122 months respectively, p 0.7. Existing deletion p53, high risk stage A CLL had no impact on the result. The commonest grade III-IV toxicities were neutropenia (12 %) and trombocytopenia (11 %) in the tretaed group.

Conclusions.

Fludarabine did not prolong PFS and survival in patients with stage A CLL. Despite the low tolerability of fludarabine there is no need to provide an early exposure in patients with stage A CLL.

Disclosures:

No relevant conflicts of interest to declare.
Activation of Paired-Homeobox Gene PITX1 by Del(5)(q31) In T-Cell Acute Lymphoblastic Leukemia (T-ALL)
Authors: Nagel Stefan , Venturini Letizia , Przybylski Grzegorz K. , Grabarczyk Piotr , Schneider Björn , Meyer Corinna , Kaufmann Maren , Schmidt Christian A. , Scherr Michaela , Drexler Hans G. , MacLeod Roderick AF
Published: October 2019

Abstract 4644

Aberrant activation of various oncogenes, including homeobox genes encoding fundamental transcription factors, during T-cell development contributes to T-cell acute lymphoblastic leukemia (T-ALL). Neoplastic chromosome rearrangements are known to deregulate Antennapedia-class homeobox genes of the NKL-family (TLX1, TLX3, NKX2-5) and HOXA-cluster genes of the Extended-Hox-family. Following analysis of T-ALL cell lines and primary cells, we describe leukemogenic involvement of a third homeobox gene group, the Paired (PRD)-class. Ascertainment was performed in an early stage-arrested T-ALL cell line (LOUCY) which revealed chromosomal deletion at 5q31, removing the downstream regulatory region of the PRD-homeobox gene PITX1. Comparative expression analysis confirmed ectopic PITX1 expression, consistent with aberrant activation by del(5)(q31) which removes a STAT1 binding site. STAT1 mediates repressive IL2-STAT1 signaling, implicating IL2-pathway avoidance as a possible activation mechanism. Furthermore, we detected expression of the physiologically similar PITX2 in 11/24 (46%) T-ALL cell lines, 5 with genomic PITX2 gains. Among primary T-ALL samples, 2/22 (9%) – both pediatric pre-T-ALL - ectopically expressed PITX1 but not PITX2. Forced expression of PITX1 by lentiviral transduction of JURKAT cells and subsequent analysis by expression profiling, prompted upregulation of RUNX2 and JUN and inhibition of RUNX1 and NKX3-1, indicating impaired T-cell differentiation. Taken together, our data show leukemic activation of PITX1, a novice PRD-class homeobox gene in the T-ALL repertoire, which may promote leukemogenesis by inhibiting differentiation.

Disclosures:

No relevant conflicts of interest to declare.
Frequent Epigenetic Inactivation of MSX2 In Acute Myeloid Leukemia
Authors: Zhao Chen , Han Xin , Zhang Yu H. , Huang Xiaoyan , Dai Aili , Lu Gary , Yin C. Cameron , Chen Ling , You M. James
Published: October 2019

Abstract 4645

DNA hypermethylation has been implicated in the tumorigenesis and prognosis in acute myeloid leukemia (AML). To identify and validate relevant methylated genes in AML, we have compared expression levels and methylation status of 26 candidate genes. One of the interesting candidates identified in our study is MSX2. MSX2 is a member of muscle segment homeobox gene family. MSX2 plays a role in promoting cell growth under certain conditions and may be an important target for RAS signaling pathways. However, the mechanism of transcriptional regulation and functional role of MSX2 in hematological malignancies, especially AML, are poorly understood. In our study, we determined the methylation status, and analyzed the expression levels of MSX2 in AML cell lines and primary AML cells using RT-PCR and/or Taqman real-time PCR. MSX2 mRNA expression was robust in the normal granulocytes and blasts of human bone-marrow, but was either absent or significantly diminished in 6 of 9 (66.7%) AML cell lines. The expression levels of MSX2 in those 6 AML cell lines were restored after treatment of 5-aza 2′-deoxycytidine. In addition, COBRA (Combined Bisulfite Restriction) analysis demonstrated hypermethylation of MSX2 in those AML cell lines (6 of 9, 66.7%), and partial methylation in 3 of 9 AML cell lines. The methylation status was inversely correlated with the mRNA expression levels of MSX2 in those cell lines. Furthermore, the expression levels and methylation status of MSX2 in human primary AML cells were evaluated. COBRA analysis demonstrated frequent hypermethylation of MSX2 in primary AML patient samples (19 of 32, 59.3%). Importantly, the mRNA expression levels of MSX2 as shown by Taqman real-time PCR in those 19 primary AML patient samples were inversely correlated with the methylation status of MSX2. These findings confirmed the role of frequent DNA hypermethylation in silencing MSX2 in AML. We are in the process of determining the functional role of MSX2 in the pathogenesis of AML. In addition, diagnostic and prognostic values of MSX2 in AML are being pursued.

Disclosures:

No relevant conflicts of interest to declare.
Dysregulation of miRNAs In AL Amyloidosis
Authors: Weng Liangping , Spencer Brain , Hoo Pam Soo , Connors Lawreen , O'Hara Carl , Seldin David C
Published: October 2019

Abstract 4648

Bone marrow plasma cells (BMPC) were purified from aspirates obtained from patients with AL amyloidosis using anti-CD138 immunomagnetic beads, and from controls. Expression levels of micro RNAs (miRNAs) were compared by microarray. The levels of ten miRNAs were found to be increased more than 1.5-fold in BMPC of AL amyloidosis patients. These results were confirmed using stem-loop RT-qPCR for miR-148a, miR-26a, and miR-16, the most highly upregulated miRNAs in the AL samples. miR-16, a micro RNA linked to other hematopoietic diseases, was significantly increased in the AL group at baseline and also in treated patients with persistent monoclonal plasma cells in the bone marrow, but not in patients who achieved a hematologic remission after therapy and normal polyclonal BMPCs. miR-16 can be derived from the miR-16-1/mirR-15a cluster on chromosome 13 or the miR-16-2/miR-15b cluster on chromosome 3. The expression of miR-15b was much higher than miR15a in AL and control BMPC samples; this suggests that miR-16 in plasma cells is mostly derived from chromosome 3. The anti-apoptosis gene BCL-2, a putative target mRNA that can be down-regulated by miR-16, was present in the BMPCs from the AL group despite the elevated levels of miR-16. Our data suggest that miRNAs are dysregulated in clonal plasma cells from AL amyloidosis patients and that abnormal levels of miRNAs may be potential biomarkers for disease.

Disclosures:

No relevant conflicts of interest to declare.