ALBERT

Description: Amyloid precursor protein (APP) has been reported to be highly expressed in AML1/ETO positive acute myeloid leukemia (AML1/ETO+ AML), and we found it express even higher in those with extramedullary infiltration in our previous study. But it’s still unknown what role APP plays and how it works in AML1/ETO+ AML. This study was designed to investigate the effect of APP gene on the prognosis and its molecular mechanism of extramedullary infiltration in the patients with AML1/ETO+ AML. 44 cases of AML1/ETO+ AML patients with median age of 29 years old, who were admitted to our hospital from February, 2006 to February, 2012 and made the diagnosis according to WHO2008 diagnosis standard, and had completed conventional induction, consolidation and intensive therapy, were investigated in this study. They were divided into high expression group (n=22) and low one (n=22) according to APP mRNA median expression level from bone marrow cells before the first chemotherapy by QRT-PCR. Some of bone marrow samples were checked by Western Blot, and 5 biopsy specimens from extramedullary infiltration were tested by APP antibody immunohistochemistry staining. Incidence of extramedullary leukemia (EML), complete response (CR), overall survival (OS), and recurrence free survival (RFS) was differentiated between the two groups. Differences of cell ultrastructure, migration, proliferation, apoptosis and expression of ERK, MMP-2, MMP-9 and CXCR4 were studied on Kasumi-1 cell line between wild, negative control (NC) and si-APP group in which the expression levels of APP gene were down regulated with application of siRNA technology.Çå The incidence of EML was significantly different (45.5% versus 9.1%) in the two groups (P=0.007) and it was positively correlative with the expression levels of APP mRNA (rp=0.435, P=0.004). Extramedullary infiltration site also showed high expression of APP by immunohistochemistry, while the control group was negative. Not only CR rate after two courses of chemotherapy, but also OS and RFS with median follow-up of 28(4-70) months, of high expression group was all significantly lower than that of low expression group (Table 1). Compared with the wild and NC group, cell apoptosis of si-APP group was significantly increased (12.33 ± 0.75 vs 19.80 ± 1.51, P=0.000); the number of microvilli on the surface of the cell membrane significantly reduced; the ability of the cell migration by Tanswell chamber migration assay significantly decreased (P=0.004); and expression of P-ERK, c-MYC, MMP-2 decreased significantly which was confirmed by ERK and c-MYC blocker treatment (Figure 1). In sum, incidence of EML is significantly higher and the prognosis is poor in the patients with AML1/ETO+ AML with high expression of APP gene. We first describe that APP gene may mediate AML1/ETO+ leukemia cells in the development of extramedullary infiltration by up-regulation of the ERK/MMP-2 pathway. Disclosures: No relevant conflicts of interest to declare.

Description: Background: Philadelphia chromosome-positive (BCR-ABL1+) ALLs benefit from the addition of a specific tyrosine kinase inhibitors (TKIs) to chemotherapy, However, treatment failures and relapses are common and new markers are needed to identify patients with poor prognosis in prospective trials. The 9p21 locus, encoding important tumor suppressors (CDKN2A/B), is a major target of inactivation in the pathogenesis of many human tumors, but only few report investigated this deletion effect on clinical prognosis in Ph+ ALL. Purpose: Many studies found that deletion of CDKN2 was associated with poor prognosis in ALL, and CDKN2 deletion also as a frequent cytogenetic aberration in Ph+ ALL patients. Here we study about the prognostic significance of the CDKN2 in Ph+ ALL in TKIs era. Patients and Methods: To explore the frequency and size of alterations affecting this locus in adult BCR-ABL1-positive ALL and to investigate their prognostic value, 135 patients (98 denovo and 37 relapsed cases) were analyzed by Paired diagnosis-relapse samples were interphase fluorescence in situ hybridization(I-FISH). Results: The prevalence of CDKN2 deletions in all study population was 27.4% (37/135). There is no difference between patients with CDKN2 deletion and wild-type patients in sex, age, white blood cells(WBC) count, BM blast percentage, and induction complete remission(CR) rate. Compared with patients with wild-type CDKN2, the patients with CDKN2 deletion had higher rates of hepatosplenomegaly, CD20 expression (p

Description: Amyloid precursor protein (APP) has been reported to be highly expressed in AML1-ETO-positive acute myeloid leukemia (AML1-ETO-positive AML), and we found it correlate with extramedullary infiltration regulated of by APP/ERK/MMP-2 signal pathway in our previous study. It is also known that C-KIT mutations highly expressed in AML1-ETO-positive AML and cooperates with full-length AML1-ETO to induce AML in mice. In this study we further described a close correlation of APP gene with C-KIT mutations, as well as APP related clinical and prognostic significance in 65 patients with AML1-ETO-positive AML. 65 cases of AML1-ETO-positive AML patients with median age of 30 years old, who were admitted to our hospital from February, 2006 to June, 2013 and made the diagnosis according to WHO2008 diagnosis standard, were enrolled into this study. APP expression in bone marrow cells before the first chemotherapy was assessed by quantitative reverse transcriptase (QRT)-PCR method. These cases were accordingly divided into APP-H group (n=33, with high level of APP by QRT-PCR) and APP-L group (n=32, with lower level of APP by QRT-PCR) according to median APP expression. Incidence of C-KIT mutations, clinical characteristics and prognosis including complete response (CR), overall survival (OS), and recurrence free survival (RFS) with median 35 (6-96) months followed-up was differentiated between the two groups. Furthermore, expression of APP and AML1/ETO fusion gene were simultaneously monitored at the time of 3, 6, 12 and 24 months or relapse after CR by QRT-PCR method. The incidence of C-KIT mutations was significantly increased in the APP-H group, as compared with the APP-L group (39.4% versus 12.5%) and it was positively correlative with APP expression (rp=0.435, P=0.004). Of the 17 patients harboring C-KIT mutations, 13 patients overexpressed APP gene (P=0.014) (Figure 1). Clinically, APP-H patients exhibited significantly elevated white blood cells count, increased extramedullary infiltration (P=0.039 and P=0.019, respectively). Moreover, APP overexpression was related to low rate of two-cycle CR, RFS and OS (P=0.020, P=0.001 and P=0.029, respectively) (Table 1). In addition, the change of APP expression was consistent with that of AML1-ETO fusion gene monitored by QRT-PCR method at different status of leukemia, though APP expressed differently in different patients with the same AML1-ETO expression. Taken together, these data suggest that APP gene is correlated with C-KIT mutations and indicates poor disease outcome and dynamic monitoring APP expression could be another choice of minimal residual disease monitoring in AML1-ETO-positive AML. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Description: Background: The application of tyrosine kinase inhibitor (TKIs) has greatly improved the overall survival (OS) and quality of life of chronic myeloid leukemia (CML) patients.However, in the TKIs era, 10% to 25% of CML patients still develop TKIs resistance, and ABL kinase point mutations are the most common reason.Most of the ABL kinase region mutations resistant to imatinib could be alleviated by second generation TKIs, but the T315I mutation resistance to the first and second generation TKIs. Ponatinib is a multi-target tyrosine kinase inhibitor, which belongs to the third generation of TKI inhibitors,and is sensitive for CML or Ph postitive ALL patients with T315I mutation. But,how to apply ponatinib bridging graft or whether ponatinib preventive therapy is needed after transplantation is uncertainty. Methods: 18 CML patients with T315I mutation detected by ABL1 kinase region mutation in Southern Hospital from March 2013 to April 2018 were retrospectively analyzed.G-banding method was used for chromosome analysis and real-time quantitative PCR method was used to detect mutations in ABL1 kinase region by BCR-ABL1 fusion gene Sanger sequencer. Result:18 CML patients with T315I mutation :13 cases chronic phase (CP) ,2 cases in accelerated phase,3 cases in blastcrisis phase(BP); 9 cases in high risk group, 6 cases in middle risk group and 3 cases in low risk grou by Sokal score score system.15 patients by imatinib ,3 patients first-line treatment with dasatinib .In imatinib group, 13 cases conversed to dasatinib because of drug resistance or intolerance, and 5 cases (5 / 13) were converted to ponatinib because of T315I mutation.One case in dasatinib group converted to ponatinib because of T 315 I mutation.A total of 6 patients (6 / 18) were treated with ponatinib. 6 patients (6 / 18) treated by allogeneic hematopoietic stem cell transplantation (Allo-SCT).The median stage of T315I mutation was 12.5 m from the beginning of treatment to the detection of T 315I mutation in 18 patients.At the end of the follow-up, 8 cases died of recurrence and 10 survived: (CMR 2 cases, CHR 1 cases, PR 3 cases, NR 3 cases, 1 cases not regularly followed up, unable to evaluate the disease state), including 6 patients with PO treatment. Conclusion:The point of T315I mutation was detected in patients with CML resistance after long-term sequential therapy frequently. The recurrence rate was still high even if these patients experience allogeneic hematopoietic stem cell transplantation.However,these patients treatment with ponatinib before and after transplantation maybe reduce the recurrence rate and improve prognosis. Key words:Chronic myeloid leukemia;BCR-ABL;T315I;ponatinib. Disclosures No relevant conflicts of interest to declare.

Description: Background Early T-cell precursor (ETP) lymphoblastic leukemia (ETP-ALL) is a neoplasm with an unique T-cell immunophenotype indicating limited early T differentiation. Ph-like ALL is a B-cell neoplasm which lack BCR-ABL1 translocation but similar expression-pattern of the BCR-ABL1-positive ALL. The optimal therapeutic approaches for ETP-ALL and Ph-like ALL are poorly characterized. Chidamide is a novel and orally active benzamide class of histone deacetylase inhibitor (HDACi) and approved for peripheral T-cell lymphoma (PTCL). Methods Based on the pediatric-inspired, PEG-L-asparaginase-intensified and MRD-directed PDT-ALL-2016 protocol, we designed two open-label, one-arm, multi-site trials, PDT-ETP-ALL (NCT03553238) and PDT-Ph-Like (NCT03564470), to evaluate the safety and effect of HDACi chidamide for adult ETP-ALL and Ph-Like-ALL group, respectively. The protocols were approved by Institutional Review Broad (IRB). Chidamide at a dose of 10mg/day will be added to ETP-ALL group from induction therapy to consolidation therapy according to PDT-ETP-ALL protocol. Chidamide and dasatinib will be added to HDACi cohort and TKI cohort, respectively, based on cytogenetics and next-generation-sequencing classification, according to PDT-Ph-Like protocol. Primary study endpoint is event-free survival and secondary study endpoints are complete remission (CR) and MRD after induction, adverse event and overall survival. Result Between FEB 2016 to DEC 2017, 24 patients with ETP-ALL were enrolled into PDT-ETP-ALL trial, 4 female patients and 20 male patients, a median age 22 years old (range, 14-22 years old). A total of 33 patients with Ph-like ALL has been enrolled into PDT-Ph-Like trial, 16 female patients and 17 male patients, a median age of 23 years old (range, 14-55 years old) 11 patients in TKI arm and 22 patients in HDACi arm. Ph-like ALL with CRLF2 high-expression, CRLF2/EPO/JAK2 rearrangement, JAK/STAT/IL-7R/SH2B3 mutation, will be assigned to HDACi arm. Targeted next-generation sequencing revealed ETP-ALL patients harbor high rates of mutations in factors involved in cytokine and JAK/STAT signaling pathway (62%), epigenetic regulation (52%) and hematopoietic development (35%). At the same time, we also performed NGS assessment with the same panel of Ph-like ALL patients. Of note, ETP-ALL and Ph-like ALL share the mutations involved in JAK/STAT signaling pathway (JAK1, JAK2, IL-7R) and histone modification (SETD2, KMT2A, EZH2, KMT2C), which might indicate the underlying mechanism of sensitivity of ETP-ALL and Ph-like ALL to HDACi chidamide. Chidadmide was well-tolerated in ETP-ALL and Ph-like ALL patients. Fatigue, nausea, vomit, neutropenia and thrombocytopenia are common chidamide-associated adverse events (AE) with Common Terminology Criteria for Adverse Events (CTCAE) grade I-II. Complete remission and Flow-MRD-negative rate after induction therapy for ETP-ALL and Ph-Like-ALL were 87% and 67%, 77% and 60%, respectively. Six patients with ETP-ALL (25%, 6/24) underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), and 11 patients with Ph-like ALL received allo-HSCT. With a median follow-up of 20 months (range, 7-31 months), estimated 2-year event-free-survival (EFS) of ETP-ALL and Ph-like ALL is 83%, 70%, respectively. Conclusion: Our preliminary data of PDT-ETP-ALL and PDT-Ph-like ALL trials suggest that a novel HDACi chidamide is effective and well-tolerated in adult ETP-ALL and Ph-like ALL, which deserve further extended clinical trial. Disclosures Zhou: CHIPSCREEN: Consultancy. Carter:novartis: Research Funding; AstraZeneca: Research Funding.

Description: Background and Objective Following the introduction of the tyrosine kinase inhibitor (TKI) imatinib in treatment of chronic myeloid leukemia (CML) patients, the allogeneic hematopoietic stem cell transplantation (allo-HSCT) scene in CML has changed dramatically. This retrospective cohort study was designed to compare medical outcomes of Imatinib mesylate and allo-HSCT for patients with CML in chronic phase. Patients and Methods From February 2002 to February 2012, 198 patients treated consecutively at the Nanfang Hospital,Southern Medical University were assigned to two groups according to treatment with imatinib or allo-HSCT. One hundred fifteen cases of imatinib group were given imatinib at an initial dose of 400mg daily and the dose was then adjusted according to the patient´s blood and therapy response. All the patients were evaluated for hematologic, cytogenetic and molecular response every 1-3months. Eighty-three cases of allo-HSCT group received myeloablative preconditioning regimen, and methotrexate (MTX) and cyclosporine A (CsA) were used for graft-versus-host disease(GVHD), parts combined with mycophenolate mofetil (MMF) and antihuman thymocyte globulin(ATG). The primary end points of the study were complete cytogenetic response (CCyR), relapse rate, overall survival (OS) and progression-free survival (PFS) after therapy. Results In total, 59 (68.9%) patients treated over 12 months achieved a CCyR after 12 months in imatinib group, while 67 (95.7%) patients in allo-HSCT group. The relapse rates were 14.8% (n=17) in imatinib group and 10.8% (n=9) in allo-HSCT group (P=0.456). Ten-year cumulative OS rates were 93.9% in imatinib group and 77.1% in allo-HSCT group(P=0.015) and ten- year cumulative PFS rates of two groups were 86.1% vs.88.0%(P=0.508). For Sokal rating stratified analysis, the ten-year OS rates of two groups were 96.4% vs.68.0% (P = 0.049) for high-risk patients,92.6% vs. 57.1% (P = 0.019) for intermediate-risk patients , while the ten-year PFS rates of two groups were 89.3% vs. 88.0% for high-risk patients (P = 0.942), 70.4% vs. 85.7% for intermediate-risk patients (P = 0.405).The ten-year OS rates and PFS rates were not significant difference for low-risk patients. The cumulative OS rates of two groups were 94.7% vs. 73.5%(P=0.019)for the patients who were not less than 30 years old,and the cumulative PFS rates of two groups were 84.2% vs. 94.1% respectively (P=0.147). Conclusion Imatinib mesylate treatment is superior to allogeneic hematopoietic stem cell transplantation for patients with chronic myeloid leukemia in chronic phase. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 4122 For acute Lymphoblastic Leukemia(ALL), several cytogenetic aberrations have been shown to play a crucial role in clinical Prognosis and also are being used as targets for response to therapy. This has led to Cytogenetics, and more recently Fluorescence In Situ ybridization(FISH), to be a tool for the detection of ALL treatment trials. Conventional cytogenetic(CC) analysis is a technically demanding and time-consuming process that is hindered by the limited availability of informative metaphase cells. Thus, interphase FISH is often used to complement CC,rule out submicroscopic rearrangements, and evaluate specimens with poor morphology or no growth in culture. The Chromoprobe Multiprobe ALL panel (Cytocell Technologies,Cambridge, UK) has been designed to detect rearrangements that occur primarily in B-cell lineage ALL, and includ some T-lineage markers. This panel detect the rearrangements of MYC, E2A, MLL, IGH, and p16; fusions of BCR/ABL and TEL/AML1 simultaneously; enumeration of chromosomes 4, 10, and 17 Probes for the specific rearrangements can also be used to assess ploidy. In this study, we performed the multi-probe FISH assay on interphase cells to detect multiple abnormalities associated with adult ALL.At prensent, We analyzed 48 samples from ALL cases using a FISH panel,the results showed that 71% cases had 1 or more genetic abnormalities. The most frequent abnormality was BCR/ABL, followed by MLL, IGH abnormalities, MYC rearrangement, TEL/AML1 fusion, +10, p16, 8 cases had MLL with IGH abnormalities and TEL/AML1 fusion, 7 cases had BCR/ABL fusion with MYC rearrangement,3cases had MLL and p16, no fusion partner was detected in 14 cases. Meanwhile,detected this samples with CC,we found that 42% cases had chromosome abnormalities,and 16% samples without growth in culture. This reults preliminary demonstrated that ALL always with multiple karyotype abnormalities, Multiprobe FISH is an essential method to refine the cytogenetic analysis. This study is going on,further study including more samples was necessary. Disclosures: No relevant conflicts of interest to declare.