ALBERT

Description: Background: The cure rate for advanced classical Hodgkin lymphoma (cHL) is approximately 70%, which is calculated based on data from clinical trials performed in North American and/or European countries (Canellos GP, et al. N Engl J Med. 1992;327:1478-84; Carde P, et al. J Clin Oncol. 2016;34:2028-36; Gordon LI, et al. J Clin Oncol. 2013;31:684-91). However, there are limited outcome data available in other countries, apart from some small hospital-based studies (Ramirez P, et al. Rev Bras Hematol E Hemoter. 2015;37:184-9; Law MF, et al. Arch Med Sci. 2014;10:498-504; Jaime-Pérez JC, et al. Oncologist. 2015;20:386-92; Omer Al-Sayes FM, Sawan A. J Taibah Univ Med Sci. 2006;1:48-56). The B-HOLISTIC retrospective chart review study seeks to address the paucity of data on cHL treatment patterns, clinical outcomes, and healthcare resource utilization in 13 countries across Latin America, Africa, Middle East, and the Asia-Pacific region. Methods: The study will collect data from approximately 2,600 patients aged ≥18 years and newly diagnosed with stage IIB-IV cHL or relapsed/refractory cHL (RRHL) between 01 January 2010 and 31 December 2013, and will follow them until death or chart review, whichever occurs first. The primary objective is to describe progression-free survival (PFS) in patients with RRHL. Secondary objectives include describing demographic and clinical characteristics, clinical outcomes (overall survival, best clinical response after completion of treatment, response duration), key adverse events associated with each line of therapy, and cHL-related healthcare resource use. Results: As of 14 May 2018, a total of 165 patients from 12 sites have been included in the interim analysis, predominantly from Turkey and South Korea. At this time, 150 patients had cHL and 24 patients had RRHL, including 9 patients who were enrolled in the cHL group and had a documented relapse/progression during the study period. Here, we report the results of the newly diagnosed cHL group; data from the RRHL group will be reported in subsequent publications. At diagnosis, 64.7% of the cHL group were male, with a median age of 36.5 years (range, 18-89 years); 22.7% had stage IV disease, 30% had extranodal disease, 59.3% had 'B' symptoms, and 34.9% had an International Prognostic Score (IPS) of ≥4. Patients were classified as 13.3% in stage I-IIA; 24% in stage IIB; 53.3% in stage IIIA-IVB; and 9.3% as unknown. Patients classified as stage I-IIA are a deviation from the clinical study protocol and will be removed from the final study analysis. The proportion of patients alive was 94%, with the cause of death reported as either HL-related (44.4%), due to an adverse event (11.1%), or other (44.4%). Positron emission tomography (PET) or PET-computed tomography (CT) imaging was performed in 58.5% of patients at baseline, 48% of patients at interim, and 36.6% at end-of-treatment; CT imaging was performed in 68.7% of patients at baseline, 83.6% of patients at interim, and 59.7% of patients at end-of-treatment. At frontline treatment, 95.3% of patients received chemotherapy (mostly doxorubicin, bleomycin, vinblastine, dacarbazine [ABVD], 92.3% [median number of cycles, 6; range, 2-8]), 22.7% of patients received radiotherapy, with 22% of patients receiving radiotherapy and chemotherapy (median total dose, 34.5 Gy; range, 24-45 Gy). The majority of patients received involved-field radiotherapy (53.1%), with other modalities including involved-node (21.9%), involved-site (18.8%), whole body (3.1%), or other (3.1%). The proportion of patients who achieved a complete or partial response to frontline treatment was 52.1% and 21.1%, respectively. The PFS for treatment in frontline cHL in the overall patient population at 48 months was 81% (95% CI, 73.1-86.7; Figure 1), with a median duration of follow-up of 58.9 months (range, 2.6-128.3 months). The PFS for treatment in frontline cHL excluding ineligible patients classified as stage I-IIA (13.3%) at 48 months was 78.9% (95% CI 69.7-85.6). Due to the retrospective nature of this study, adverse events were under-reported and will be presented once the data are mature. Conclusion: The B-HOLISTIC study is ongoing, with final patient enrolment anticipated in December 2018. These interim data provide real-world information on the incidence, treatment, and outcomes of cHL in countries where little is known about this patient population. Disclosures Ferhanoglu: Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Yeh:GNT Biotech & Medicals Crop.: Research Funding. Brittain:Takeda: Membership on an entity's Board of Directors or advisory committees. Karduss:Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Amgen: Honoraria; Takeda: Honoraria. Kwong:Bayer: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Astellas: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Song:Peking University Cancer Hospital (Beijing Cancer Hospital): Employment. Zerga:Bristol Myers Squibb: Other: Conference fees; Roche: Other: Conference fees; Janssen: Other: Conference fees; Takeda: Other: Conference fees. Blair:Takeda Pharmaceuticals International Co.: Employment. Dalal:Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Ltd, Cambridge, MA, USA: Employment, Equity Ownership. Wan:Takeda Pharmaceuticals International Co.: Employment. Hertzberg:Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Membership on an entity's Board of Directors or advisory committees.

Description: Arsenic trioxide (As2O3) is highly efficacious in acute promyelocytic leukemia (APL). Aquaglyceroporin 9 (AQP9) is a transmembrane protein that may be involved in arsenic uptake. In 10 of 11 myeloid and lymphoid leukemia lines, quantitative polymerase chain reaction (Q-PCR) and Western blotting showed that AQP9 expression correlated positively with As2O3-induced cytotoxicity. As a proof-of-principle, transfection of EGFP-tagged AQP9 to the hepatoma line Hep3B, not expressing AQP9 and As2O3 insensitive, led to membrane AQP9 expression and increased As2O3-induced cytotoxicity. Similarly, the chronic myeloid leukemia line K562 expressed low levels of AQP9 and was As2O3 insensitive. The K562EGFP-AQP9 transfectant accumulated significantly higher levels of intracellular arsenic than control K562EGFP when incubated with As2O3, resulting in significantly increased As2O3-induced cytotoxicity. Pretreatment of the myeloid leukemia line HL-60 with all-trans retinoic acid (ATRA) up-regulated AQP9, leading to a significantly increased arsenic uptake and As2O3-induced cytotoxicity on incubation with As2O3, which might explain the synergism between ATRA and As2O3. Therefore, AQP9 controlled arsenic transport and might determine As2O3 sensitivity. Q-PCR showed that primary APL cells expressed AQP9 significantly (2-3 logs) higher than other acute myeloid leukemias (AMLs), which might explain their exquisite As2O3 sensitivity. However, APL and AML with maturation expressed comparable AQP9 levels, suggesting that AQP9 expression was related to granulocytic maturation.

Description: Mononuclear cell mixed donor/recipient chimerism has been shown extensively to have high predictive value in disease relapse and graft rejection. Recently, donor DNA in plasma of transplant recipient has been suggested as a potential tool for post HSCT monitoring for disease relapse and graft rejection but its role has not been defined. Moreover, the impact of GVHD on plasma donor DNA remains unknown. In the current study, both the plasma and mononuclear cell donor chimerism of 40 patients post HSCT (mean age = 40; 35 myeloablative, 5 non-myeloablative) were analyzed at D28. Each patient was followed-up for one year or when disease relapse/graft rejection occurred. GVHD of grade II or above was also recorded to establish its correlation with the chimerism status. At D28, all patients were engrafted and alive. 5 (13%) patients had full donor chimerism in both plasma and mononuclear cell (Group A), 7 (18%) patients had full donor chimerism in the mononuclear cell only but not the plasma (Group B) and 28 (70%) patients failed to have full chimerism in both plasma and mononuclear cell (Group C). The sex, age, HLA-matching, donor relationship and ABO blood group matching had no impact on the chimerism status. None of the Group A patient had disease relapse/graft rejection at 1 year when compared to 13/35 (37%) of Group B and C patients (p=0.154, not significant).However, all the patients in Group A had acute GVHD which was significantly more than those in Group B and C (5/5 vs 12/35, p=0.009) and the acute GVHD would not alter the chimerism status. These results provide a foundation for further research on the potential role of plasma donor chimerism in predicting disease relapse/graft rejection and GVHD so that early intervention can be instituted.

Description: Using inverse polymerase chain reaction, we identified CD44, located on chromosome 11p13, as a novel translocation partner of IGH in 9 of 114 cases of gastric, nongastric extranodal, follicular, and nodal diffuse large B-cell lymphoma (DLBCL). Notably, these translocations involving IGHSμ were detected in follicular lymphomas and exclusively in germinal center B cell-ike (GCB)–DLBCLs. CD44 is not expressed in reactive GC B cells. The IGHSμ/CD44 translocations substitute Sμ for the CD44 promoter and remove exon 1 of CD44, resulting in the overexpression of Iμ-CD44 hybrid mRNA transcripts activated from derivative 11 that encode a new CD44 variant lacking the leader peptide and with a unique C-terminus (CD44ΔEx1). When overexpressed in vitro in the CD44− GCB-DLBCL cell line BJAB, CD44ΔEx1–green fluorescent protein localized to the cytoplasm and nucleus, whereas CD44s–green fluorescent protein (standard form) localized to the plasma membrane. The ectopic expression of CD44ΔEx1 in BJAB cells enhanced their proliferation rate and clonogenic ability, indicating a possible pathogenic role of the translocation.

Description: Internal tandem duplication (ITD) of FLT3 (fms-like tyrosine kinase 3) in acute myeloid leukemia (AML) is associated with inferior clinical outcome. Sorafenib is effective in targeting chemo-refractory FLT3-ITD+ AML. However, leukemia progresses invariably. Mechanisms of drug resistance are not completely understood. We hypothesized that a gene encoding tescalcin (TESC), which activate a sodium/hydrogen exchanger 1 (NHE1) and known to be up-regulated at leukemia progression during continuous sorafenib treatment, may underlie TKI resistance. TESC was over-expressed in FLT3-ITD+ AML lines MOLM-13 and MV4-11. Knocking down TESC by siRNA lowered intracellular pH and induced apoptosis. The results were recapitulated by treatment with a NHE1 inhibitor, 5-(N,N-Hexamethylene) amiloride (HMA). Sorafenib resistant MOLM-13 cell line (M13-RE) was generated by long term culture of sorafenib. M13-RE significantly increased its sensitivity to HMA. HMA also enhanced suppression of FLT3 signaling by sorafenib in otherwise resistant cell lines. Treating MOLM-13, MV4-11 and primary FLT3-ITD+ AML cells with HMA significantly reduced leukemia initiation in NOD/SCID mouse xenotransplantation. These observations provided novel information about the pathogenetic role of the TESC-NHE1-pHi axis in mediating sorafenib resistance in AML. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2064 Poster Board II-41 Background. Arsenic trioxide (As2O3) is a standard medication in the management algorithm of patients with acute promyelocytic leukemia (APL). With the advent of oral As2O3, outpatient treatment, convenient dosing and long-term post-remission maintenance therapy have become possible. The pharmacokinetics, efficacy and safety profile of short-term oral As2O3 therapy are well-defined. With prolonged oral-As2O3 therapy, possible accumulation of elemental arsenic and its possible long-term side effects must be determined. Materials and methods. Paired peripheral blood (PB) and bone marrow (BM) (aspirate and trephine biopsy) specimens were prospectively collected as part of an oral-As2O3 treatment protocol of patients. The samples were separated into plasma (P), white blood cell (WBC) and red blood cell (RBC) fractions. Elemental arsenic was measured by inductively coupled plasma-mass spectrometry (ICP-MS, ELAN DRCplus 6100, PerkinElmer-SCIEX, Canada) after dilution with 2% nitric acid +/– 3% methanol. Bone marrow trephine biopsies were dried at 65°C overnight, completely digested with acid, and diluted to appropriate concentrations. Results. There were 15 male and 11 female APL patients. Seven WBC specimens could not be analyzed due to inadequate material. Specimens were collected at 1 month (Group 1), 2–12 months (Group 2) and 24–41 months (Group 3) after cessation of oral-As2O3 treatment. The median cumulative dose of oral-As2O3 was 1980 (560–3680) mg. As control, samples were obtained from 12 anonymous individuals, whose specimens were collected as part of their diagnostic evaluations. These controls had no known medicinal exposure to arsenic. The mean elemental arsenic levels in the specimens were shown below. Elemental arsenic levels in group 1 were significantly higher than groups 2 and 3 in all specimens tested. However, groups 2 and 3 were comparable to controls, indicating that arsenic was rapidly excreted once oral-As2O3 treatment was stopped. In group 1 patients, all specimens tested showed comparable arsenic levels. In group 2 patients, arsenic levels were significantly higher in BM–WBC (but not PB-WBC) as compared with PB-P and BM-P (p=0.043 for both). In group 3 patients, all cellular specimens tested showed comparable arsenic levels to plasma levels. Conclusion. Immediately after cessation of treatment when plasma arsenic level was still high, elemental arsenic was distributed comparably in different compartments. However, when plasma arsenic levels started to decline, preferential concentration of arsenic occurred in the cellular compartments. This could be related to transfer of arsenic in bones to the developing hematopoietic cells in the marrow milieu. Finally, two or more years after cessation of As2O3 therapy, elemental arsenic levels returned to control levels; a reassuring observation that long-term arsenic accumulation did not take place when oral-As2O3 was used therapeutically during a finite period of time. Disclosures: Off Label Use: Oral arsenic trioxide is a novel preparation or arsenic trioxide currently under consideration for registration in Hong Kong for APL treatment. The University of Hong Kong holds the patent for the product.

Description: Introduction Enteropathy-associated T cell lymphoma (EATL) is an intestinal tumor of the intraepithelial T lymphocytes, with a median survival time of less than 1 year. It is a rare disease in general and has two main subtypes described. Type 1 EATL is a complication in patients with celiac disease, a chronic gluten-sensitive enteropathy. Type 2 EATL, characterized by smaller monomorphic lymphocytes, typically occurs sporadically in patients without celiac disease. Very little is known about the genetic mutations and gene expression signatures that define this disease, or the extent to which the two types of EATL are genetically distinct. It has been suggested that the two types of EATLs should be reclassified as separate diseases in future WHO categories. Methods In this study, we performed whole exome sequencing to 100-fold depth of 41 EATL tumors including 23 type 1 cases and 18 type 2 cases. Both alpha-beta (65%) and gamma-delta (35%) T cell receptor rearrangements were seen among these cases. Paired normal DNA was sequenced in most (N=30) cases. We defined somatic mutations, copy number alterations, and HLA genotypes in these cases from sequencing data. Additionally, we generated RNA sequencing data on the same EATL tumors. Corresponding clinical and outcome data was collected on the same cohort. Results We found that both type 1 and type 2 EATLs had overlapping patterns of mutations and similar overall survival. The most commonly mutated genes were chromatin modifier genes (34%) including ATRX and ARID1B. We also identified recurrent somatic mutations in signal transduction genes, including JAK1 and BCL9L. TP53 mutations were also recurrent (12%). Copy number amplifications in 9q, 1q, and 8q occurred most frequently and were present in both subtypes. We further compared the mutational profiles to peripheral T cell lymphoma, angioimmunoblastic T cell lymphoma, cutaneous T cell lymphoma, natural killer/T cell lymphoma, diffuse large B cell lymphoma, and Burkitt lymphoma. These comparisons identify EATL as a genetically distinct disease with a very different pattern of mutations. RNAseq identified the gene expression patterns that are unique to EATL and also identified gene expression signatures that distinguish the two types of EATL. The DQ2 or DQ8 HLA genotype is present in the majority of type 1 cases (73%) while occurring infrequently in type 2 cases (27%). Conclusions Our study defines the genetic landscape of enteropathy associated T cell lymphoma and highlights the genetic and clinical overlap between the two types. While the two types have differences in mutations and gene expression patterns, they have more in common with each other compared to other lymphoma types. Our data may inform future decisions regarding the potential separation of the two EATL types as distinct entities. Disclosures No relevant conflicts of interest to declare.

Description: Introduction and aim. Relapse following allogeneic hematopoietic stem cell transplantation (HSCT) is a major cause of treatment failure and is associated with a poor prognosis. Overall survivals are around 50% at 5 years following allogeneic HSCT in intermediate and high risk AML. Survivals remain less than 20% in poor-risk and very poor-risk patients based on the cytogenetic profile. Thus, prevention of relapse following allogeneic HSCT remains an unmet clinical need. Low-dose azacitidine maintenance post-HSCT has been shown to augment graft-versus-leukemia effect and may prolong survivals. We aim to prospectively evaluate the effect of azacitidine maintenance following allogeneic HSCT in high risk AML and MDS. Method. Consecutive patients with high-risk acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in remission following first allogeneic HSCT or second allogeneic HSCT (from the original donor) were recruited. High risk AML in this study comprised patients with poor risk karyotype, secondary AML transformed from underlying MDS, presence of fms-like tyrosine kinase 3-internal tandem duplication (FLT3 -ITD) and non-remission before HSCT. Azacitidine was administered at 100mg daily for 3 days per cycle every 28 days until progression or a maximum of 8 cycles. The clinicopathologic and treatment characteristics were determined. The occurrence of graft-versus-host disease (GVHD) was determined. DNA chimerism was determined in the bone marrow before the initiation of azacitidine, after 4th and 8th cycles of azacitidine and at 1 year. DNA chimerism was determined by quantification of polymorphic short tandem repeat sequences. The progression-free survival (PFS) and overall survival (OS) were determined by Kaplan-Meier analysis. Results. Thirty-four patients with high-risk AML (N=31) and MDS (N=3) were recruited. The median duration of follow-up was 14 months (range: 2 - 44 months). Twenty-two patients received azacitidine maintenance after first allogeneic HSCT, whereas 12 patients received azacitidine maintenance after a second allogeneic HSCT from the same donor following relapse from a first allogeneic HSCT For patients receiving azacitidine after first HSCT, at a median follow-up of 18.5 months (range: 5- 36 months), the median PFS was not reached, and the median OS was 32 months (95% confidence interval [C.I.]: 24.85-39.15). The 24-month PFS and OS were 66.1% and 73.2% respectively. Acute and chronic GVHD occurred in 7 (31.8%) and 17 patients (77%). For patients receiving azacitidine after second HSCT, at a median follow-up of 14 months (range: 9 - 46 months), the median PFS and OS were 9 months (95% C.I.:6.94-11.04) and 14 months (range: 11.77 - 16.23 months). The 24-month PFS and OS were 25% and 14% respectively. Acute and chronic GVHD occurred in 1 (8.3%) and 5 (41.7%) patients respectively. In both groups, 100% donor chimerism was achieved during azacitidine maintenance. Conclusion. Azacitidine maintenance following first allogeneic HSCT resulted in favorable 2-year survivals in selected patients with high-risk AML and MDS. Nevertheless, survivals were poor despite azacitidine maintenance after second allogeneic HSCT from the same donor. Full donor chimerism was maintained during azacitidine maintenance. Disclosures No relevant conflicts of interest to declare.