bluuebunny/crossref_metadata_2025 huggingface dataset:
T Cell Repertoire Diversity After Umbilical Cord Transplant Predicts Mortality From Infection
Authors: Delaney Colleen , Emerson Ryan O , Milano Filippo , Sherwood Anna , Papermaster Adrienne , Guthrie Katherine A. , Carlson Christopher S , Warren Edus H. , Robins Harlan
Published: October 2019

Abstract 4202

Background

In a transplant study run at Fred Hutchinson Cancer Research Center, 34 patients with high risk hematological malignancies underwent a myeloablative procedure and were subsequently transplanted with double umbilical cord blood units. Peripheral blood samples were collected from each patient before myeloablation, and at 28, 56, 100, 180, and 360 days post-transplant.

Methods

At each time point, we used the immunoSEQ platform to perform high-throughput sequencing of rearranged T Cell Receptor (TCR) loci. Using immunoSEQ data, we were able to track the presence and frequency of individual TCR clones in each patient across time-points, as well as measuring the diversity of the TCR repertoire as a whole. We correlated our measure of TCR repertoire diversity with clinical outcomes in this cohort.

Results

The study produced two primary results. First, using the ability to track clones, the reconstituting TCR repertoire is shown to oscillate wildly with nearly complete turnover of the T cell repertoire occurring at least monthly after CB transplant. The largest T cell clones present in each blood draw drop below detection within weeks, contrasting with control data in which the top clones in healthy patients are not only observed in multiple subsequent time-points, but remain at high frequency. The second result is a test of the hypothesis that diversity of the T cell repertoire is a measure of immunocompetence, as a clinical application of high-throughput sequencing. Of the 34 patients, six died between Day 100 and Day 360 of non-relapse causes. At both Day 56 and Day 100, the diversity of the T cell repertoires of those six patients were far lower than the T cell repertoire diversity values of the remaining patients (P-value = 0.015).

Conclusions

We have demonstrated that the reconstitution of clinical immunity in cord blood transplantation patients is characterized by a highly unstable T cell compartment with very rapid turnover of T cell clones. Despite the transience of individual T cell clones, however, by two months after transplant T cell repertoire diversity as measured by high-throughput TCR sequencing accurately predicts risk of non-relapse mortality.

Disclosures:

Emerson: Adaptive Biotechnologies: Employment, Equity Ownership. Sherwood:Adaptive Biotechnologies: Employment, Equity Ownership. Carlson:Adaptive Biotechnologies: Consultancy, Equity Ownership, Patents & Royalties. Robins:Adaptive Biotechnologies: Consultancy, Equity Ownership, Patents & Royalties.
Clinical Characteristics and Outcome of Isolated Extramedullary Relapse in Acute Leukemia Following Allogeneic Stem Cell Transplantation: A Single Institutional Analysis
Authors: Shi Jimin , Meng Xiaojian , Luo Yi , Tan Yamin , Zhu Xiaoli , Zheng Gaofeng , He Jingsong , Zheng Weiyan , Xie Wanzhuo , Li Li , Ye Xiujin , Zhang Jie , Cai Zhen , Lin Maofang , Huang He
Published: October 2019

Abstract 4211

Isolated extramedullary relapse (EMR) of acute leukemia (AL) is a rare occurrence although it appears to be more common following allogeneic stem cell transplantation (allo-SCT). To characterize what has been observed in isolated EMR, we investigated a total of 287 consecutive AL patients (144 acute myeloid leukemia, 138 acute lymphocytic leukemia and 5 acute mixed lineage leukemia) who underwent allo-SCT.

Forty-seven (16.4%) patients experienced relapse after allo-SCT. 12 cases (4.2%) experienced relapse of extramedullary sites without concomitant bone marrow involvement. Isolated EMR accounted for 25.5% of the overall initial relapse. The time to relapse after allo-SCT was longer in the extramedullary sites than in the marrow (median, 10 months vs. 5.5 months, P<0.05,). Sites of EMR varied widely including central nervous system, skin, bone, pelvis and breasts. The variables considered for univariate analysis included donor gender, age, primary disease, disease status, cytogenetics/molecular abnormalities, preconditioning regimen, donor type, HLA match, aGVHD and cGVHD. The variables that showed significant correlation with isolated EMR were the cytogenetics abnormalities at diagnosis. The prognosis for patients who develop EMR remained poor but was relatively better than that after bone marrow (BM) relapse (overall survival, 10 vs. 18 months, P<0.05). Compared with local or single therapy, patients treated with systemic in combination with local treatment could yield favorable prognosis. Three patients survived 63, 55 and 49 months after transplant respectively, of whom two received DLI with subsequent chemotherapy and (or) irradiation and one had surgery with subsequent chemotherapy.

In conclusion, we observed a significant number of isolated EMR of AL after allo-SCT and intensive approaches combined of local and systemic therapy can produce favorable response which may cure a percentage of these patients.

Disclosures:

No relevant conflicts of interest to declare.
Hematopoietic Stem Cell Transplantation and Secondary Primary Malignancies in Taiwan
Authors: Liu Chia-Jen , Chen Kuo-Wei , Hu Yu-Wen , Hong Ying-Chung , Huang Yu-Chung , Chiou Tzeon-Jye , Tzeng Cheng-Hwai
Published: October 2019

Abstract 4219

Objectives

Hematopoietic stem cell transplantation (HSCT) is a curative strategy for many hematological disorders. The improvement of HSCT may lead to longer overall survival of patients with catastrophic illness and the risk of secondary cancer development become an emerging issue in long-term survivors.

Patients and Methods

We conducted a nationwide population-based study of 1,881 patients with hematologic diseases undergoing HSCT between January, 1997 and January, 2007 using Taiwan's National Health Insurance Research database. Performing HSCT to treat non-hematological diseases were excluded. All patients were followed until solid cancer development, death, or the end of 2010. We did not put hematological malignancies as endpoint because solid tumors and hematological malignancies might have different carcinogensis mechanism. We used standardized incidence ratios (SIRs) to compare patterns of cancer incidence in patients with those of the general population. Multivariate analysis was undertaken using Cox proportional-hazards regression using a forward selection, likelihood ratio model to identify independent predictors of cancer development among patients after HSCT.

Results

We observed a total of 8,753.87 person-years in this study. Patients received HSCT had a significant increased risk of developing any kind of cancer (SIR 1.77, 95% confidence interval [CI] 1.15 – 2.62; p = 0.011). Specifically, patients after HSCT had increased cancer incidence of head and neck cancer (SIR 3.96, 95% CI 1.90 – 7.29; p < 0.001) and bone and soft tissue sarcomas (SIR 10.08, 95% CI 1.22 – 36.42; p = 0.035). In subgroup analyses, cancers were more likely to develop in patients aged 0 – 19 years (SIR 22.31, 95% CI 4.60 – 65.20; p < 0.001), and those who survived more than 5 years after HSCT (SIR 3.30, 95% CI 1.96 – 5.22; p < 0.001).

Conclusion

Our study demonstrates an increased incidence of cancer development in patients after HSCT, especially malignancies of head and neck and also bone and soft tissue sarcomas. Patients aged 0 – 19 years and those survived more than 5 years after HSCT have a higher incidence of developing cancer comparing to normal population. HSCT long-term survivors should therefore be monitored more carefully for cancer development and targeted with preventive intervention strategies.

Disclosures:

No relevant conflicts of interest to declare.
Safe and Effective Adoptive T-Cell Receptor Transfer with a High Affinity Single Chain p53(264–272)-Specific TCR
Authors: Echchannaoui Hakim , Petschenka Jutta , Antunes Edite , Theobald Matthias
Published: October 2019

Abstract 4226

Several studies have demonstrated the clinical efficacy of adoptive T cell therapy for targeting cancer. Using HLA-A2.1 transgenic mice, we have demonstrated the feasibility of T-cell receptor (TCR) gene transfer into T cells to circumvent self-tolerance to the widely expressed human p53(264–272) tumor-associated antigen and developed approaches to generate high-affinity CD8-independent TCR. A safety concern of TCR gene transfer is the pairing of endogenous and introduced TCR chains resulting in the potential generation of self-reactive T cells (off-target autoimmunity). Several strategies to favor matched TCR chains pairing and thus enhancing TCR cell surface expression, including optimization of TCR encoding nucleotide sequences, introduction of an additional inter-chain disulfide bond between the TCR α and β chain constant domains, coexpression of both TCR α and β encoding-genes using self-cleaving 2A virus peptide-based retroviral vectors have been applied. However, adoptive transfer of mouse T cells transduced with modified p53-specific TCRs into p53-deficient humanized (A2Kb) mice was inducing lethal autoimmunity due to the formation of self-reactive TCRs infiltrating vital organs, such as spleen, liver and bone marrow. Therefore, an optimized single chain (sc) p53-specific TCR was engineered to avoid the formation of mismatched TCR heterodimers. The safety and therapeutic efficiency of this approach were evaluated in humanized mouse models of adoptive T cell transfer and successfully demonstrated that optimized p53-specific scTCR-redirected T cells (i) do not induce OFF-target autoimmunity and (ii) mediate antitumor reactivity. Importantly, because the expression of p53 antigen on normal tissues raises the concern of potential on-target toxicity, we performed adoptive T cell transfer experiments in humanized mice expressing the Human p53 protein (Hupki mice) and did not observe any sign of TCR gene transfer-mediated GvHD in this model. In conclusion, these mouse studies suggest that the optimized p53(264–272)-specific scTCR could represent a safe and efficient approach for TCR-based gene therapy.

Disclosures:

No relevant conflicts of interest to declare.
Endocrine Sequelae and Metabolic Syndrome in Adult Long-Term Survivors of Childhood Acute Myeloid Leukemia
Authors: Blijdorp Karin , van Waas Marjolein , van der Lely Aart-Jan , Pieters Rob , van den Heuvel Marry M. , Neggers Sebastian J.C.M.M.
Published: October 2019

Abstract 4228

Background:

Survival of childhood acute myeloid leukemia (AML) has increased significantly over the past decades. Improved treatment strategies include intensive chemotherapy, by which stem cell transplantation (SCT) has been replaced in most of the current protocols for more than 80% of the cases. Limited data exist on endocrine late effects in AML survivors treated with chemotherapy only. The current study focuses on the effect of chemotherapy only on endocrine function and components of the metabolic syndrome (MetS) in adult survivors of childhood AML.

Methods:

In this prospective study with a cross-sectionally recruited controlgroup, endocrine function and components of the MetS were assessed in 12 AML survivors (3 females), treated with chemotherapy only, and in 9 survivors of myeloid leukemias treated with SCT, including TBI as conditioning regimen, after a median follow up time of 20 years (range 9–31). Data were compared with those of 60 controls (23 females).

Results:

In survivors treated with chemotherapy only no endocrinopathies were observed, although AMH and Inhibin B levels tended to be lower than in controls. In chemo-only survivors, frequency of the components of the MetS was not different from controls. In transplanted AML survivors one subject was growth hormone deficient, five had thyroid dysfunction and all survivors had gonadal dysfunction. SCT survivors had a higher risk for components of the MetS, especially a significantly higher frequency of dyslipidemia than controls (63% vs. 6%, P<0.001).

Conclusion:

At twenty years of follow up, survivors of AML treated with chemotherapy only did not show an increased risk at most endocrinopathies and metabolic syndrome as compared to healthy controls, which is in contrast to childhood AML survivors treated with SCT. Gonadal function should however be evaluated with care.

SCT: stem cell transplantation;

SCT: stem cell transplantation

Disclosures:

No relevant conflicts of interest to declare.
A Web-Based Decision Support Platform to Reduce Non Evidence-Based Treatment of Hodgkin Lymphoma
Authors: Grund Stephen , Forastiere Arlene , Flood William , Elaine Whyler
Published: October 2019

Abstract 4267

Background:

Published reports indicate 30–40% of oncology treatments deviate from evidence-based standards. Little is known about the extent of deviation from guidelines in Hodgkin Lymphoma, a highly curable cancer.

Methods:

eviti is a web-based decision support platform that incorporates all recognized guidelines (ASCO, NCI, NCCN, ASTRO and others) and supporting literature. An automated precertification code is issued if planned treatment is evidence based and meets payer language- Variances may be discussed in a peer to peer (P2P) with staff oncologists. We analyzed all treatment plans submitted for patients with stage I to IV Hodgkin's lymphoma (all pathology subtypes) between 1/1/2011 and 6/30/2012 to understand reasons for non-compliance with practice guidelines. There were six payers with a total of 605,412 covered lives encompassing 22 states.

Results:

124 treatment plans were submitted, including 37 with radiation treatment as part of the plan or as primary treatment. 48 (39%) received an automatic code, and another 63 (51%) were given preauthorization codes after submission of medical records. 25 treatment plans (20%) required a P2P and 7 (6% of all cases) were changed to evidence-based treatments as a result. 5 plans were deemed evidence-based as a result of the P2P, while13 plans (10%) did not meet evidence-based standards and did not receive a code for pre-certification even after a P2P. 3 of these were resubmitted with evidence-based plans. The most common deviations were; 1.Use of supportive drugs not consistent with guidelines 6 cases (6%); 2. Non evidence-based therapeutic regimens 2% (2 cases); 3. Non evidence-based variation in dose and/or schedule of chemotherapy 2% (2 cases). 4. Use of IMRT with IGRT.

Conclusions:

Decision support for automated pre-certification reduced non- evidence-based treatment of Hodgkin lymphoma from 16% (20 cases) to 8% (10 cases). A Web-based, point of care decision-support platform connecting providers and payers can reduce unwarranted variability, improve quality and reduce payment for unwarranted care. It facilitates analysis of variations from accepted standards of care for any hematologic malignancy at a granular level. Any such tool should promote compliance with evidence-based cancer care but allow flexibility for medically justified variances.

Disclosures:

Grund: eviti: Employment. Forastiere:eviti: Employment. Flood:eviti: Employment. Elaine:eviti: Employment.
Hospital Demand for Blood Components in Ontario Correlates with Selected Diagnostic and Procedural Activities
Authors: Pendergrast Jacob M , Zagorski Brandon
Published: October 2019

Abstract 4272

Introduction:

Demand for blood components in Canada is a significant and growing contributor to health care spending, but the drivers of this demand remain poorly characterized. While most institutions do not routinely monitor the transfusion requirements of individual diagnoses and procedures, an institution's overall demand for blood components and the types of clinical activities it provides are both well documented. Development of an institution-level inferential model may allow for more accurate demand forecasting for blood components.

Methods:

Hospital shipments of all blood components from Canadian Blood Services (red blood cells, platelets, plasma and cryoprecipitate) in the province of Ontario during the period 2006–2009 were merged with institution-level administrative data containing hospital characteristics and selected diagnostic and procedural codes as obtained from inpatient and ambulatory clinical databases maintained by the Canadian Institute for Health Information. Simple linear correlation and several nested multivariable linear regression models were fitted and compared.

Results:

From 2006–2009, our sample included 137 healthcare facilities, representing approximately 1.4 million units of RBCs, 400 000 units of plasma, 166 000 doses of platelets (defined as either one pool of whole blood-derived platelets or a single apheresis platelet), and 20 000 units of unpooled cryoprecipitate. Institutional demand for these blood components correlated with both hospital-level characteristics and diagnostic and procedural activity data. Institutional demand for red blood cells correlated most strongly with visits for cirrhosis and chemotherapy. Demand for plasma correlated most strongly with visits for cirrhosis and cardiac surgery procedures. Demand for platelets correlated most strongly with bone marrow and solid organ transplant procedures. Demand for cryoprecipitate correlated most strongly with visits for valvular heart disease and cardiac procedures. The strength of these correlations generally remained stable over the four years of analysis, during which time demand for red blood cells and platelets increased, demand for plasma decreased, and demand for cryoprecipitate remained stable.

Conclusions:

In the largest province of Canada, institutional demand for blood components correlate strongly with disease burden measured by diagnostic and procedural codes contained within administrative data.

Disclosures:

Pendergrast: Canadian Blood Services: Research Funding. Zagorski:Canadian Blood Services: Research Funding.
Acute Lymphoblastic Leukemia in Japanese Adolescents; Biology and Toxicity Profile
Authors: Suenobu So-ichi , Sato Atsushi , Takahashi Yoshihiro , Usami Ikuya , Nishimura Shin-ichiro , Hasegawa Daiichiro , Hashii Yoshiko , Suzuki Nobuhiro , Saito Akiko , Kawasaki Hirohide , Yagi Keiko , Horibe Keizo , Hara Junichi , Hori Hiroki , Oda Megumi
Published: October 2019

Abstract 4290

BACKGROUND

In the treatment for acute lymphoblastic leukemia (ALL), adolescents were reported to have worse prognosis than children because of their treatment compliance and response. In this study, we compared clinical features, treatment toxicity and outcome between children and adolescents treated with Japan Association of Childhood Leukemia Study (JACLS) ALL-02 protocol.

METHODS

The dataset of 1246 eligible patients enrolled in the study between April 2002 and May 2008 was analyzed. The patients were assigned into five categories; SR (PGR, age between 1 and 9 years, WBC<10K and no CNS disease, HR (non SR with PGR; SR with t(1;19), 11q23 other than t(4;11), or M3 marrow on day15), ER (PPR, hypodiploid, unclassified, mixed-lineage, HR with M3 marrow on day15), T (T-lineage) and F (non CR on day 33, T with M3 marrow on day15, or t(4;11)). The patients with Ph+ ALL were excluded from this analyze. The data of 249 patients older than 10 years of age (adolescent group) were compared with those of 705 aged 1 to 5 years and 292 aged 6 to 9 years. The adolescent group included 28 patients older than 15 years of age. The survival rate was estimated with Kaplan–Meier method and two –sided log-rank test using SAS version 9.1.

RESULTS

ETV6-RUNX1 and hyperdiploidy were significantly less frequent in adolescents. The rates of PGR and CR on day 33 in adolescents were significantly lower than those in younger patients (82.7% vs. 90.5%, p<0.01, and 93.1% vs. 97.2%, Ap<0.01, respectively). Five-year overall survival (OS) and event-free survival (EFS) for adolescents were significantly lower than those for children aged 1 to 5 years (78.9% vs. 93.9%, p<0.01, 70.9% vs. 87.5%, p<0.01, respectively). In comparison of adverse effects between adolescent and children groups treated with HR protocol, Grade III and IV neurotoxicity was more frequently observed in adolescents than younger patients (1.99% vs. 0.39%, p<0.01) while infection, pancreatitis or liver toxicity was not significantly different between the two groups.

CONCLUSIONS

The results indicated that poorer outcome in adolescents with ALL may not result from severe treatment toxicities, but link with some specific biology of the leukemic cells.

Disclosures:

No relevant conflicts of interest to declare.
Drug Screening of Primary Human Pediatric Pre-B Cell Acute Lymphoblastic Leukemia (pre-B ALL) Cells in Their Stromal Niche
Authors: Shieh Jae-Hung , Su Tsann-Long , Shieh Jason , Moore Malcolm A.S.
Published: October 2019

Abstract 4295

Pre-B cell acute lymphoblastic leukemia (pre-B ALL) is the most common leukemia in children and is treatable. However, no in vitro nor in vivo models are available to investigate their pathophysiology other than a number of established cell lines that grow in the absence of any cytokine dependence or stromal interaction. We developed a serum-free MS-5 cell (a murine bone marrow stromal cell line) co-culture system that is capable of expanding human primary pre-B ALL CD34+CD19+ cells in vitro. To define a population of pre-B ALL initiating cells, our study reveals that a sorted CD34bright population displays a slow proliferation and maintains a high % of CD34+ cells. In contrast, CD34dim cells/CD34− cells fraction shows a higher proliferation but expanded cells lost CD34 antigens. A group of alkylating molecules (BO-1055, -1090, 1099, -1393 and -1509) was evaluated for proliferation of the pre-B ALL CD34+ cells, the pre-B ALL CD34− cells, human mesenchymal stem cells (hMSC), murine MSC (MS-5 cells and Op9 cells), human bone marrow derived endothelial cells (BMEC), and human cord blood (CB) CD34+ cells, as well as for a week 5 cobblestones area forming (CAFC) assay with CB CD34+ cells. BO-1055 molecule efficiently suppressed the growth of pre-B ALL CD34+ cells (IC50 = 0.29 μM) and CD34− cells (IC50 = 0.31 μM). In contrast, IC50 of BMEC, MSC, CB CD34+ cells and CAFC are >10, >25, 8, and >5 μM, respectively. Pre-B ALL cells expressing green fluorescent protein (GFP) and luciferase (GFP-Lu-pre-B ALL) were created, and a xenograft of the GFP-Lu-pre-B ALL cells to NOD/SCID IL2R gamma null (NSG) mice was established. The in vivo effect of BO-1055 to the GFP-Lu-pre-B ALL cells in NSG mice is under investigation. Our stromal culture system supports primary pre-B ALL cells and closely recapitulates the growth of primary human pre-B ALL cells in their niche in vivo. Based on this co-culture system, we identified BO-1055 as a potential therapeutic agent with an excellent toxicity window between pre-B ALL cells and normal tissues including BMEC, MSC and hematopoietic progenitor/stem cells. The in vitro stromal co-culture system combined with the xenograft model of GFP-Lu-pre-B ALL cells provides an efficient and powerful method to screen new drugs for pre-B ALL therapy.

Disclosures:

No relevant conflicts of interest to declare.
Design of the Hallmarq Trial, a Phase 3 Study of Vincristine Sulfate Liposome Injection (VSLI, Marqibo®) in Adults with Newly Diagnosed, Philadelphia Chromosome Negative Acute Lymphoblastic Leukemia
Authors: Deitcher Steven R. , Silverman Jeffrey A.
Published: October 2019

Abstract 4300

Background:

Adult acute lymphoblastic leukemia (ALL) is a lethal and fulminant disease and one distinct from childhood ALL. There are approximately 2400 new cases per year in the US; approximately 80% of these will be Philadelphia chromosome (Ph) negative. Despite remarkable success in treatment of childhood and adolescent ALL, adult ALL patients are underserved by existing treatment options as reflected by the poor survival rates and extremely poor outcomes in the relapsed setting. Complete response (CR) rates in the front-line setting range from 90% in patients <30 years old to 57% in patients >60 years old and 3-year disease free survival ranges from 47% to 12% respectively. The unmet medical need in adult ALL is most pronounced in those age 60 and older. VSLI was recently granted accelerated FDA approval as a single-agent for the treatment of adults with advanced, relapsed and refractory Ph-negative ALL and has successfully completed a Phase 2 trial as a component of multi-agent therapy.

Trial Design:

HALLMARQ (NCT01439347) is a Phase 3, multi-national, randomized study to evaluate the substitution of VSLI for standard vincristine (VCR) in the induction, consolidation, and maintenance phases of combination chemotherapy in the treatment of patients ≥ 60 years old with newly diagnosed Ph-negative ALL. The chemotherapy “backbone” utilized in this trial is modified from the Cancer and Leukemia Group B 8811 protocol. Asparaginase product usage is optional. The total duration of protocol-specified therapy is up to 24 months. VCR is dosed at 1.4 mg/m2 with a per dose cap at 2 mg. VSLI is dosed at 2.25 mg/m2without a dose cap. A protocol-specified dose reduction algorithm applicable to both VSLI and VCR will be used to minimize Grade 3 neurotoxicity while also facilitating continued dosing. Growth factors (e.g., granulocyte colony-stimulating factor) and bowel regimens (e.g., daily stool softener) are recommended and will be prescribed according to investigator preference and institutional guidelines. The primary endpoint is overall survival (OS) and the study is powered for superiority. Secondary endpoints include remission rate, overall response rate, event-free survival, and safety and tolerability. Minimal residual disease (MRD) at multiple time points and pharmacokinetic parameters are being assessed.

Conclusion:

The HALLMARQ Trial will provide new insights into the frontline treatment of ALL in adults ≥60 years old as well as confirm the clinical benefit of VSLI monotherapy demonstrated in the Phase 2 RALLY Study that supported the initial product approval. HALLMARQ is based on a Special Protocol Assessment with the FDA and is currently enrolling.

*On behalf of the HALLMARQ investigators.

Disclosures:

Deitcher: Talon Therapeutics: Employment, Equity Ownership. Silverman:Talon Therapeutics: Employment.
A Phase II Trial of Decitabine and Vorinostat in Combination with Chemotherapy for Relapsed/Refractory Acute Lymphoblastic Leukemia
Authors: Burke Michael J , Lamba Jatinder , Weigel Brenda , Bachanova Veronika , Verneris Michael R. , Miller Jeffrey S.
Published: October 2019

Abstract 4307

DNA hypermethylation and histone de-acetylation are mechanisms involved in gene expression silencing and subsequent drug resistance in leukemia. Agents which target these mechanisms have been investigated in myeloid malignancies but few studies have addressed whether they have a role in lymphoid leukemia. We conducted a clinical trial evaluating the tolerability and efficacy of Decitabine and Vorinostat followed by chemotherapy for relapsed/refractory acute lymphoblastic leukemia (ALL). Patients 0–60 years of age were eligible. Protocol therapy included Decitabine (15mg/m2 iv) and Vorinostat (230mg/m2 PO div BID) days 1–4 followed by vincristine, prednisone, PEG-Asparaginase and doxorubicin. Fourteen patients with a median age of 16 (range, 3 – 54) years have been enrolled to date. Five patients failed prior allogeneic transplantation. The most common non-hematological toxicities (grade >3) at least possibly related to Decitabine and/or Vorinostat were infection (grade 3; n=6) and fever (grade 3; n=3). There was a single grade 5 toxicity related to the chemotherapy backbone. Bone marrow samples (n=11) were evaluated using the DNA LINE global methylation analysis. A decrease in total methylation was found in 10 patients comparing baseline and day 5 (4/10 showing significant reductions in hypermethylation (T-test p<0.01). Eight patients were evaluable for response. Complete remission without platelet recovery (CRp) was achieved in 4 patients, PR in 2 patients, SD and PD in 1 patient each for an overall response rate (CRp + PR) of 75%. Six patients were inevaluable for response based on not having an end of treatment marrow evaluation due to disease progression (n=2; days 4 and 16), toxic death (n=1), ineligibility (n=1) and physician/family request (n=2). The combination of Decitabine and Vorinostat for patients with relapsed ALL leads to changes in methylation patterns in the leukemic blasts. The use of these agents followed by chemotherapy appears tolerable and efficacious in patients with relapsed ALL. This study is continuing to accrual and is registered at www.clinicaltrials.gov as NCT00882206.

Disclosures:

Off Label Use: decitabine for relapsed ALL vorinostat for relapsed ALL.
Late Clearance of Circulating Leukemic Blasts (CBs) During Induction Therapy (IT) Is a predictive of Refractory Adult Acute Myeloid Leukemia (AML)
Authors: Muslimani Alaa , Rifai Aya , Chisti Mohammad Muhsin Muhsin , Margolis Jeffery , Nadeau Laura , Jaiyesimi Ishmael , Huang James
Published: October 2019

Abstract 4319

Background:

CBs are highly variable at diagnosis and during the course of IT in AML patients. Assessing response to IT carries a huge implication on the prognosis of individual patient with AML. Our study investigates whether late clearance of CBs during IT using standard cytarabine + anthracycline regimen is associated with refractory phenotype.

Methods:

We retrospectively reviewed the chart of 83 AML patients (43 males, 40 females, mean age 61.7) who received standard cytarabine and anthracycline regimen during induction between January, 2000-January, 2011 at William Beaumont Health System. Data collected include complete blood count with blast count during course of induction, and bone marrow response. AML is considered refractory if morphological evaluation, flow cytometry or cytogenetic study was positive in the first bone marrow post induction. Response to IT was assessed according to Cancer and Leukemia Group B (CALGB) criteria as complete remission versus residual leukemia or treatment failure (failing to achieve complete remission).

Results:

We noted that 57 of 83 patients (68.7%) showed CBs at the time of diagnosis. During the IT, CBs clearance occurred within 7 days (early clearance) in 38 of these 57 patients. The remaining 19 patients had CBs persistent more than 7 days (delayed clearance). The frequency of bone marrow residual disease at count recovery post IT was significant higher in patients with late clearance and those with early clearance (84% vs 42%, p=0.0015). Further analysis of data showed the frequency of bone marrow residual disease was not significantly different between patients with no CBs at the diagnosis and those with early clearance of CBs (38% vs 42%, p=0.8).

Conclusion:

Adult AML patients with persistent CBs >7 days during IT with standard induction cytarabine and anthracycline regimen are more likely to have induction failure. CBs clearance can be used as an early assessment of response to the IT.

Disclosures:

No relevant conflicts of interest to declare.
5-Azacitidine Plus Vorinostat As Maintenance Therapy of Second Remission in AML Instead of High Doses of Consolidation with Cytarabine
Authors: Ovilla Roberto , Barrera-Carmona Claudia , Guzman-Bouilloud Nicolas , Buganza-Torio Elizabeth , Jimenez-Alvarado Rosa , Monreal-Alcantara Claudia
Published: October 2019

Abstract 4348

Patients with refractory AML after failure of reinduction of remission treatment (usually the clasical 7+3) have few options of effective reinduction regimen. Once a second remission is obtained, the standard strategies implies an allogenic BMT or consolidation treatment with high doses of cytarabine but the BMT requires a match or alternative donor and the chemotherapy implies myelotoxicities and some patients have high risk of severe complications versus recurrent relapse and death.

A 36 years old male with AML M4 intermediate risk since april 2010 was treated conventionally with 7+3 regimen (Cytarabine + Idarubicin), after that he received 4 cycles of high doses of Cytarabine as consolidation. On October 2010 he received an autologous BMT (ABMT) because he does not have an HLA compatible donor. After 12 months of complete remission post ABMT he relapsed on October 2011. He received as reinduction regimen 7+3 (Cytarabine + Doxorubicin) and he failed to obtain remission. He received a salvage treatment with high dose of Cytarabine 3 gr/m2 (6 doses) followed by high doses of Etoposide 60 mg/kg in continuous infusion. He achieved complete remission and then developed Aspergillus pneumonia during the myelosupressed period and a thoracoscopy was performed for treatment, he was discharged at the end of November 2011.

In the face of the impossibility of conventional consolidation therapy, and in the presence of poor general conditions, we started a treatment model based on epigenetic alternative therapy with the objective to maintain remission. In December 2011 he was started an ambulatory treatment based on subcutaneous administration with 5-azacitidine 75mg/m2/day during 7 days every 28 days for two cycles; during treatment he developed myelosuppression without the need of stimulating factors or transfusions. Posteriorly he continued with two new cycles of 5-azacitidine 50mg/m2/day during 10 days plus Vorinostat 200 mg every 24 hours during 14 days. Each month since the beginning of the epigenetic therapy, BMA was performed with flow cytometry and immunophenotype performed that showed a persistent remission until May 2012 when he relapsed.

Therefore epigenetic therapy maintained in remission a high risk patient, improved his general conditions, and posteriorly allowed him to be able to receive an haploidentical bone marrow transplant.

Disclosures:

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

Abstract 4376

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

Disclosures:

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

Abstract 4877

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

Disclosures:

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

Abstract 489

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

Disclosures:

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

Abstract 4895

Introduction:

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

Case report:

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

Conclusion:

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

Disclosures:

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

Abstract 4900

Background:

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

Methods and Results:

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

Conclusions:

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

Disclosures:

No relevant conflicts of interest to declare.