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Ph-like acute lymphoblastic leukemia (also known as BCR-ABL1-like ALL) is a new disease entity of B-cell ALL (B-ALL) that exhibits a mRNA expression profile similar to that of Philadelphia chromosome-positive ALL (Ph+ ALL). Ph-like signature is presumably driven by kinase-activating gene alterations. Thus, both gene expression pattern and DNA mutational status should be assessed to make a definitive diagnosis for Ph-like ALL. A variety of approaches combining multiple methods, including RNA sequencing (RNA-seq), Taqman low-density array (LDA), fluorescence in situ hybridization (FISH) and targeted DNA sequencing, are being tested; however, such multi-omics approaches are available only in limited institutions. Since Ph-like ALL patients generally exhibit poor response to standard chemotherapy, and tyrosine kinase inhibitors (TKIs) may benefit them when used in a timely manner, a fast, accurate and generalizable diagnostic method is critically needed. In the present study, we have developed a nCounter-based diagnostic method for Ph-like ALL and validated it using a cohort of Japanese adult B-ALL cases. To identify genes that are uniquely expressed (or not expressed) in Ph+ B-ALL, we first obtained publicly-available gene expression datasets comprising 1146 B-ALL cases and identified 82 differentially-expressed genes in Ph+ ALL cases. We then assessed expression levels of those genes in an independent cohort using the nCounter, which enables fast, sensitive and accurate RNA detection. We also tested whether nCounter-based methods can detect fusion transcripts relevant for Ph-like ALL pathogenesis using probes targeting ABL1, ABL2, CSF1R, PDGFRB, and JAK2. We analyzed 123 samples (Ph+ = 42, Ph- = 81, age 16 to 67) obtained from newly-diagnosed adult B-ALL patients enrolled in two clinical trials conducted by the Fukuoka Blood and Marrow Transplantation Group (FBMTG) (Nagafuji et al. Eur J Haematol 2019). Unsupervised hierarchical clustering successfully stratified 123 cases into two disease clusters: Ph+ and Ph- subgroups. As expected, Ph+ subgroup included almost all Ph+ ALL cases (40 out of 42 cases), while 18 out of 81 Ph- ALL cases (22%) were categorized into the Ph+ subgroup. We defined these cases as Ph-like ALL. To validate the nCounter-based Ph-like ALL classification, we performed RNA-seq and target-capture DNA sequencing of all Ph- ALL cases. As expected, we detected kinase-activating fusions/rearrangements, including CRLF2 rearrangements (7 cases), PDGFRB fusions (3 cases), JAK2 fusions (2 cases), EPOR rearrangements (2 cases), ABL1 fusion (1 case), and FLT3 internal tandem duplication (1 case) in 16 Ph-like ALL cases, while no genetic alterations were detected in 2 cases. Fusion genes involving PDGFRB were consistently detected by nCounter (3/3); however, detection of those involving JAK2 (1/2) and ABL1 (0/1) were inconsistent. JAK2 and/or RAS mutations were detected in 5 of 7 Ph-like ALL cases harboring CRLF2 rearrangements. Of note, CRLF2 protein expression was detected by FACS in all CRLF2-rearranged cases. We next assessed significance of the Ph-like signature on clinical outcomes using a cohort of 40 Ph- ALL cases, in which minimal/measurable residual disease (MRD) status, assessed by IgH and/or TCR rearrangements, as well as clinical data were available (Nagafuji et al. Eur J Haematol 2019). Ph-like ALL cases exclusively exhibited MRD positivity after induction therapy as compared to non-Ph-like cases (p=0.04), indicative of the chemo-resistant nature of Ph-like ALL as previously reported (Roberts et al. N Engl J Med, 2014 and Roberts et al. J Clin Oncol, 2017). As expected, Ph-like ALL cases exhibited significantly poor disease-free survival compared with non-Ph-like ALL cases (p=0.04); however, no significant difference was evident in overall survival (p=0.62) presumably due to the fact that all MRD-positive cases were subjected to allo-HSCT after induction therapy. These data indicate that MRD-based therapy stratification could overcome chemo-resistant nature of Ph-like ALL. Our data suggest that nCounter-based diagnostic method is fast and accurate to identify Ph-like ALL. Since Ph-like signature generally dictates poor clinical outcomes, and upfront TKI therapy may improve them, our method could facilitate precision medicine in the treatment of Ph- B-ALL. Disclosures Akashi: Sumitomo Dainippon, Kyowa Kirin: Consultancy; Celgene, Kyowa Kirin, Astellas, Shionogi, Asahi Kasei, Chugai, Bristol-Myers Squibb: Research Funding.

Introduction: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease entity characterized by selective growth of lymphoma cells in the lumina of small vessels. IVLBCL has been listed in the WHO classification, which improves recognition of the disease. However, no standard therapy has been established based on the results of prospective studies. We previously reported promising efficacy of rituximab (R)-containing chemotherapy for IVLBCL (JCO 2008) and a high incidence of central nervous system (CNS) recurrence (25% at 3 y) after R-chemotherapy (Lancet Oncol 2009, Cancer Sci 2010). To explore a more effective first-line treatment, we conducted a phase 2 trial of R-CHOP combined with CNS prophylaxis including R-high-dose methotrexate (R-HDMTX) and intrathecal chemotherapy with MTX, cytarabine (Ara-C), and prednisolone (PSL) (IT). Methods: Major inclusion criteria were untreated, histologically confirmed IVLBCL, age 20-79 y, ECOG PS 0-3, and no apparent CNS involvement at diagnosis. Patients received 3 cycles of R-CHOP followed by 2 cycles of R-HDMTX (3.5 g/m2; 2 g/m2 for ≥70 y) every 2 weeks, and 3 additional cycles of R-CHOP. IT (MTX 15 mg, Ara-C 40 mg, PSL 10 mg) was performed twice during the first 3 cycles of R-CHOP and twice during the final 3 cycles of R-CHOP (4 times in total). If patients achieved complete response (CR), they were observed without any therapy until relapse or disease progression. The primary endpoint was 2-y progression-free survival (PFS), and secondary endpoints included 2-y overall survival (OS), CR rate, cumulative incidence of CNS recurrence at 2 y, patterns of progression, and adverse events. The threshold 2-y PFS was estimated to be 35%, with expected 2-y PFS estimated to be 60%. With a statistical power of 90% and a one-sided, type I error of 5%, a projected sample size of 37 was calculated in anticipation of 10% ineligible patients. The trial was registered in the UMIN Clinical Trials Registry (UMIN000005707). Results: 38 IVLBCL patients were enrolled between June 2011 and July 2016. One patient was found to be ineligible after completion of the protocol treatment due to a past history of lymphoma. The protocol treatment was completed in 34 (89%) of 38 patients. The diagnosis of IVLBCL was histologically confirmed by central pathological review in all enrolled patients. The baseline characteristics of the 37 eligible patients were: male sex, 16 (43%); median age, 66 (range 38-78) y; ECOG PS >1, 15 (41%); stage IV, 37 (100%); serum LDH >ULN, 36 (97%); WBC Conclusion: This phase 2 trial met its primary endpoint and showed favorable outcomes with a low cumulative incidence of CNS recurrence and acceptable toxicity profiles. These results indicate that R-CHOP combined with CNS prophylaxis including R-HDMTX and IT could be a reasonable treatment option for untreated IVLBCL without apparent CNS involvement at diagnosis. Disclosures Shimada: Takeda Pharmaceutical: Honoraria; MSD: Research Funding; Otsuka Pharmaceutical: Research Funding; Janssen Pharmaceutical: Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Honoraria; Eisai: Honoraria, Research Funding; Chugai Pharmaceutical: Consultancy, Honoraria; Kyowa Kirin: Honoraria, Research Funding; AstraZeneca: Honoraria. Yamaguchi:Ono Pharmaceutical: Research Funding; Teijin Pharma: Honoraria; MSD: Honoraria; Astrazeneca: Membership on an entity's Board of Directors or advisory committees; Sumitomo Dainippon Pharma: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Astellas Pharma: Research Funding; Sorrento: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Meiji Seika Kaisha: Honoraria; Kyowa Hakko Kirin: Honoraria, Research Funding; Eisai: Honoraria; Chugai: Honoraria, Research Funding. Atsuta:Chugai Pharmaceutical Co., Ltd.: Honoraria; Kyowa Kirin Co., Ltd: Honoraria; Mochida Pharmaceutical Co. Ltd: Honoraria; Janssen Paharmaceutical K.K.: Honoraria. Matsue:Celgene: Honoraria; Takeda Pharmaceutical Company Limited: Honoraria; Ono Pharmaceutical: Honoraria; Novartis Pharma K.K: Honoraria; Janssen Pharmaceutical K.K.: Honoraria. Kusumoto:Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding. Nagai:Eisai: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; AstraZeneca: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen Pharmaceutical: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; Sanofi: Honoraria; Otsuka Pharmaceutical: Research Funding; SymBio Pharmaceuticals Limited: Honoraria, Research Funding; Solasia Pharma K.K.: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; IQVIA: Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; MSD: Honoraria; Novartis Pharma: Honoraria; Mundi Pharma: Honoraria, Research Funding; Bayer Pharma: Honoraria, Research Funding; AbbVie: Research Funding. Fukuhara:Mundi: Honoraria; Celgene Corporation: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria; Eisai: Honoraria, Research Funding; Janssen Pharma: Honoraria; Kyowa-Hakko Kirin: Honoraria; Mochida: Honoraria; Nippon Shinkyaku: Honoraria; Ono Pharmaceutical Co., Ltd.: Honoraria; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Zenyaku: Honoraria; AbbVie: Research Funding; Bayer: Research Funding; Gilead: Research Funding; Solasia Pharma: Research Funding. Miyazaki:Eisai: Honoraria; Chugai: Honoraria; Kyowa Hakko Kirin: Honoraria, Research Funding; Celgene: Honoraria; Ono Pharmaceutical: Research Funding; Astellas Pharma: Research Funding; Takeda: Honoraria; SymBio Pharmaceuticals: Honoraria; Nippon Shinyaku: Honoraria; Janssen Pharmaceutical: Honoraria. Okamoto:Kyowa Kirin Co., Ltd.: Other: Scholarship donation; Chugai Pharmaceutical Co., Ltd.: Other: Scholarship donation; Takeda Pharmaceutical Co., Ltd.: Other: Scholarship donation; Taiho Pharmaceutical Co., Ltd.: Other: Scholarship donation. Uchida:Eisai: Honoraria. Tsukasaki:Daiichi Sankyo: Consultancy; Kyowa Kirin: Honoraria; Huya: Consultancy, Honoraria, Research Funding; Byer: Research Funding; Mundi Pharma: Honoraria; Ono Pharmaceutical: Consultancy; Eisai: Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Masaki:Tanabe Mitsubishi: Research Funding; Taiho: Research Funding; Kyowa Kirin: Research Funding; Astellas Pharma: Research Funding; Chugai Pharmaceutical: Research Funding; Ono Pharmaceutical: Research Funding; Pfizer: Research Funding; Eisai: Research Funding; Taisho Toyama: Research Funding; Daiichi Sankyo: Research Funding; Teijin: Research Funding; Takeda Pharmaceutical: Research Funding. Kiyoi:Sumitomo Dainippon Pharma Co., Ltd.: Research Funding; Bristol-Myers Squibb: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Astellas Pharma Inc.: Honoraria, Research Funding; Takeda Pharmaceutical Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Kyowa Hakko Kirin Co., Ltd.: Research Funding; Otsuka Pharmaceutical Co.,Ltd.: Research Funding; FUJIFILM Corporation: Research Funding; Eisai Co., Ltd.: Research Funding; Nippon Shinyaku Co., Ltd.: Research Funding; Pfizer Japan Inc.: Honoraria; Perseus Proteomics Inc.: Research Funding; Daiichi Sankyo Co., Ltd: Research Funding. Suzuki:Chugai Pharmaceutical Co.,Ltd.: Honoraria; Meiji Seika: Honoraria; Merck Sharp & Dohme: Honoraria; Takeda Pharmaceutical Co., Ltd.: Honoraria; Bristol-Myers Squibb: Honoraria; Kyowa Hakko Kirin: Honoraria; Celgene: Honoraria; Eisai: Honoraria; ONO Pharmaceutical Co., Ltd.: Honoraria; Janssen: Honoraria; AbbVie: Honoraria; Novartis: Honoraria.

[Introduction] Anthracycline-induced cardiotoxicity (ACT) has been a major problem in leukemia therapy, and reported to be associated with several candidates of single nucleotide polymorphisms (SNPs). C242T polymorphism (rs4673) in the cytochrome b-245 alpha chain (CYBA) gene, which encodes superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase light chain subunit, is focused on as one of ACT related SNPs. Several clinical studies indicated that rs4673 T allele increases the risk of ACT, however, it is unclear how rs4673 affects ACT. Here, we established a series of induced pluripotent stem cells (iPSCs) with a genotype of C/C, T/T or C/T of rs4673 in a uniform genetic background by using CRISPR/ Cas9, and evaluated the effect of each SNP genotype on ACT in vitro. [Methods and Results] To edit the SNP site using CRISPR/Cas9, three guide RNAs (gRNAs) were designed to induce double strand break (DSB) near the target site. Cas9 nuclease and gRNA expression vectors were transfected into HEK293T cells using jetPEI (Polyplus-transfection SAS), and the genome editing activity was assessed by T7 endonucleaseⅠ(T7E1) assay to select more efficient gRNA for cleavage near the target site. The indel frequencies of sgRNAs 1,2 and 3 were 29.4%, 25.6%, and 18.6%, respectively. Furthermore, oligo-DNA (100 nt) to edit single-base in the SNP site was prepared. To generate Cas9/gRNA ribonucleoprotein (RNP) complexes, 1 μg of Cas9 protein and 0.2 μg of gRNA molecules were mixed. RNP complexes and 50 pmol of oligo-DNA were electroporated into human iPSC 201B7cells (Riken BioResource Center) using Neon electroporation device (Invitrogen),single-base-edited iPSCs (C/C and T/T from C/T genotype in rs4673) were established by homology-directed repair (HDR). Successful HDR events were verified by Sanger sequencing. These established iPSCs were differentiated into cardiomyocytes using PSC Cardiomyocyte Differentiation Kit (Thermo Fisher Scientific) in vitro. To facilitate nascent mesoderm induction, TBX6 was expressed transiently by a tetracycline-inducible lentiviral vector. Differentiated cardiomyocytes were revealed to be contracting and be positive for NK2 transcription factor related locus 5 (NKX2-5) and troponin T2 (TNNT2) by immunofluorescence staining.In order to evaluate the ACT depending on the difference of single base in rs4673, doxorubicin (DOX)was administered to each edited iPSC-derived cardiomyocyte. NADP+/NADPH before and after administration of DOX (1μM) in C/C cardiomyocytes was 1±0.18 and 0.93±0.14, respectively. On the other hand, it was 1±0.07 and 1.29±0.03 in T/T cardiomyocytes (p [Conclusion] SNPs are a factor of genetic diversity among individuals, and have been revealed to be associated with various traits and diseases by Genome-Wide Association Study (GWAS). However, the diverse genetic backgrounds often hamper to analyze the influence of each SNP on the trait. In this study, we analyzed the effects of rs4673 on ACT in a uniform genetic background by using CRISPR/Cas9 edited iPSCs. Our study showed that T/T cardiomyocytes activated NADP+/NADPH cycling after administration of DOX. These results suggest that rs4673T allele may increase the risk of ACT. Genome editing mediated single-base-alteration will provide us a novel system for functional analysis of SNPs. Disclosures No relevant conflicts of interest to declare.

Introduction A clinical indication for allogeneic hematopoietic stem cell transplantation (HSCT) in adult Philadelphia-chromosome negative [Ph (-)] acute lymphoblastic leukemia (ALL) patients in complete remission 1 (CR1) remains to be clarified. Minimal residual disease (MRD) status has been reported to be a strong prognostic factor in adult ALL patients (Blood. 2006 107:1116, 2009 113:4153)( J Hematol Oncol. 2013 6:14). We prospectively monitored MRD status during induction and consolidation therapy in adult Ph (-) ALL patients to determine a clinical indication for HSCT. Materials & Methods From December 2008 to November 2013, 103 adult ALL patients were enrolled in this study. Eligibility criteria included non-L3 ALL, 16-65 years of age, and adequate organ function. Of these patients, 95 were eligible for this study and 59 were Ph (-). The treatment protocol used in this study was modified CALGB 19802. Treatment consisted of 6 courses given in the order of A-B-C-A-B-C, followed by a maintenance phase. Induction chemotherapy (course A) consisted of cyclophosphamide (1,200 mg/m2), daunorubicin (60 mg/m2 x 3), vincristine (VCR) (1.3 mg/m2 (max 2mg) x 4), L-asparaginase (3,000 U/m2 x 6) and prednisolone. Granulocyte colony-stimulating factor was started on day 4 and continued until neutrophil recovery. Consolidation B consisted of mitoxantrone (10 mg/m2 x 2), cytarabine (2,000 mg/m2/day x 4) and intrathecal (IT) administration of methotrexate (MTX). Consolidation C consisted of VCR (1.3 mg/m2 (max 2mg) x 3) and MTX (1,500 mg/m2 x 3) with leucovorin rescue and IT MTX. Patients received maintenance chemotherapy on a monthly basis: prednisolone 60 mg/m2 on days 1-5, VCR (1.3mg/m2 (max 2mg) x 3) on day 1, oral MTX 20 mg/m2 weekly, and oral 6-mercaptopurine 60 mg/m2 daily. MRD status was evaluated after induction therapy (first course A) and after second consolidation therapy (first course C). When MRD statuses after the consolidation were positive, patients were supposed to proceed to HSCT whenever possible. Results Among the 59 Ph-negative ALL patients, 51 patients (86%) could be monitored for MRD status, and the remaining 8 patients were not because of no clonal TCR/Ig targets or chimeric mRNA. The MRD status was determined by PCR analysis of major gene rearrangements and/or chimeric mRNAs (18 were positive for TCRγ, 16 for TCRδ, 13 for IgH, 1 for TCRγ and MLL-AF4, 1 for TCRγ and ETV6-RUNX1, 1 for IgH and MLL-AF4, and 1 for IgH and MLL-ENL). MRD quantifications were performed using ASO-primers with a sensitivity of ≤1 × 10−4, and MRD positivity was defined as a lower limit of detection of ≥1 × 10−3. The median follow-up time was 1597 days (range, 16-2870 days). A total of 51 patients included 29 males and 22 females, and their median age was 29 years ranging from 16 to 65. The median white blood cell count at presentation was 8.5 × 103/L (range 1.2-650.4). CR was achieved in 45 patients (88%). One patient died during induction due to intestinal bleeding. There were 29 survivors after the median follow-up period. The probability of 3-year OS and DFS in these patients with Ph-negative ALL was 69% (95%CI 54-80) and 50% (95%CI 36-63, respectively. In terms of CR1 status, MRD-negative patients after induction chemotherapy A in the first course (n = 17) showed a better 3-year DFS (65%) compared with MRD-positive patients (n = 31; 43%), as shown in Figure 1. The difference was not statistically significant (p = 0.07). There was no patient who proceeded to allogeneic HSCT among 17 MRD-negative patients after induction therapy in CR. In contrast, patients who were MRD-positive after induction but became MRD-negative after consolidation chemotherapy C in the first course (n = 11) showed a worse 3-year DFS compared with patients who were MRD-negative after induction chemotherapy A in the first course (45% vs. 65%, p = 0.08). Fourteen patients were MRD-positive after consolidation chemotherapy C in the first course. Among them, 5 patients proceeded to allogeneic HSCT in 1CR, and 9 did not. Three-year DFS with or without allogeneic HSCT were 60% (95%CI 13-88) vs 44% (95%CI 14-72, p=0.52), respectively. Discussion The present study indicates that MRD status after induction and consolidation therapies is a strong prognostic factor. Post-induction MRD-negative patients have been identified to have good-prognosis with chemotherapies, not suitable for up-front allogeneic HSCT. Figure 1. Figure 1. Disclosures Takamatsu: Taisho Toyama Pharmaceutical: Research Funding; TAIHO Pharmaceutical: Research Funding; Pfizer: Research Funding; Bristol-Myers Squibb: Research Funding; Ono Pharmaceutical: Research Funding; Astellas Pharma: Research Funding; Kyowa Hakko Kirin: Research Funding; Chugai Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Celgene: Honoraria. Akashi:Celgene: Research Funding, Speakers Bureau; Novartis pharma: Research Funding; Ono Pharmaceutical: Research Funding; Eisai: Research Funding; sanofi: Research Funding; Pfizer: Research Funding; Chugai Pharma: Research Funding; Kyowa Hakko Kirin: Research Funding, Speakers Bureau; Asahi-kasei: Research Funding; MSD: Research Funding; Otsuka Pharmaceutical: Research Funding; Taiho Pharmaceutical: Research Funding; Bristol-Myers Squibb: Research Funding, Speakers Bureau; Astellas Pharma: Research Funding; Eli Lilly Japan: Research Funding.

[Introduction] Allogeneic hematopoietic stem cell transplantation (Allo-SCT) remains the only potentially curative therapy for patients with high-risk or chemo-refractory hematologic malignancies. Recently, various methods including post-transplant cyclophosphamide (PT-CY) showed the ability to overcome the HLA disparity barrier and haploidentical hematopoietic stem cell transplantation (haplo-SCT) have been becoming an attractive method of transplantation with less rejection or graft-versus-host disease (GVHD). There have been many reports that the outcomes of haplo-SCT are equivalent to those of matched related donors and matched unrelated donors. The standard dose of PT-CY is 50 mg/kg/day for 2 days. However, optimal dose of PT-CY has not been studied extensively. In this study, we performed a clinical study of reduced dose of PT-CY (40 mg/kg/day for 2 days) haplo-SCT for hematologic malignancies. [Methods] We included adult patients with hematologic malignancies who received haplo-SCT at Kurume university hospital, Kurume, Japan between Oct 2014 and March 2018. Myeloablative conditioning (MAC) regimen consisted of fludarabine (Flu) (30 mg/m2 for 5 days), busulfan (BU) (3.2 mg/kg/day for 4 days) and total-body irradiation (TBI) 4Gy (Flu/BU4/TBI4Gy) or Flu (30 mg/m2 for 3 days) and TBI 12Gy (Flu/TBI12Gy). Reduced-intensity conditioning (RIC) regimen consisted of Flu (30 mg/m2 for 5 days), BU (3.2 mg/kg/day for 2 days) and TBI 4Gy (Flu/BU2/TBI4Gy). All patients were given PT-CY (40 mg/kg/day) on day +3 and day +4, followed by tacrolimus and mycophenolate mofetil (MMF) starting on day + 5 for GVHD prophylaxis. If there was no active GVHD, MMF was tapered off from day +30. Filgrastim 300 ug/m2 was administered starting on day +5 and continuing until neutrophil engraftment was achieved. Donors were mobilized with filgrastim 400 ug/m2 for 4 or 5 days, the peripheral blood stem cells were collected with one or two apheresis procedures. OS and PFS were calculated using the Kaplan-Meier method and the log-rank test was used for comparisons of Kaplan-Meier curves. Estimates of acute GVHD was calculated using death as the competing risk. P-values [Results] A total 15 patients with acute myeloid leukemia (AML, n=6), myelodysplastic syndrome (MDS, n=2), acute lymphoblastic leukemia (ALL, n=4), adult T-cell leukemia/lymphoma (ATLL, n=1) and malignant lymphoma (ML, n=2) were analyzed in this study. Patients median age was 54 years (range, 17 to 72); 9 patients were male, and 6 patients were female. Eight patients received MAC, 7 received RIC conditioning regimen. Disease status at transplantation was complete remission (CR) in 8 patients, non-CR in 7. The median CD34+ cell dose was 5.9 x 106 /kg (range, 2.4 to 17.4). All 15 patients achieved a neutrophil engraftment in a median 15 days (range, 13 to 19). Grade II-IV and III-IV acute GVHD occurred in 46.7% (95% confidence interval [CI], 14.4-66.8) and in 13.3% (95% CI, 0-28.9) patients, respectively. At 2 years, overall survival (OS) and progression-free survival were 36.6% (95% CI, 13.0-60.9) and 32.0% (95% CI, 10.9-55.7), respectively. The 2-years OS of patients in CR before SCT was 50.0% (95% CI, 15.2-77.5) compared to 28.6% (95% CI, 4.1-61.2) not in CR (P=0.106). The causes of death were: disease progression (n = 3), infection (n = 3), acute GVHD (n = 2), and noninfectious pulmonary complications (n = 2). Among infectious complications, two were bacterial infections and one was BK virus-associated hemorrhagic cystitis. [Conclusion] Reduced dose of PT-CY HLA haploidentical peripheral blood stem cell transplantation resulted in acceptable rate and severity of acute GVHD. However, relapse and infection remain major problems after PT-CY haplo-SCT for hematologic malignancies. Disclosures No relevant conflicts of interest to declare.

Background: High incidence of graft failure is a major obstacle for successful unrelated cord blood transplantation (UCBT). To ensure engraftment, unrelated cord blood (UCB) unit with higher total nucleated cell (TNC) and CD34 cell doses and less HLA mismatches between UCB units and patients were usually selected. However, it remains unclear whether HLA haplotype between the UCB units and patients should be matched. Using data from Japanese registry, we analyzed the effect of haplotype matching on the outcomes after single UCBT. Methods: Patients with hematologic diseases, aged 16 years or more, and have undergone their first UCBT between 2005 and 2014 were included in the study. The effect of haplotype matching (0, 1, and 2 haplotype matches) on neutrophil engraftment, overall mortality, relapse, and non-relapse mortality was analyzed after adjusting for other significant variables. Haplotype was estimated based on HLA-A, -B, -C, and -DRB1 allele information and Japanese allele frequency data. The haplotypes of both the patient and UCB unit were determined in 1,347 cases. Cases with more than 4 allele mismatches (n = 96) were excluded from the study. Results: The median age of the patients included in the study was 55 years (range 16-79 years). Median TNC and CD34 doses were 2.7 x 107/kg (range, 1.4-8.1x107/kg) and 0.8 x 105/kg (range, 0.1-5.2x105/kg), respectively. The number of allele mismatches were 0 in 82, 1 in 154, 2 in 252, 3 in 565, and 4 in 294 patients. The graft-versus-host disease (GVHD) prophylaxes were calcineurin inhibitors in combination with methotrexate in 707, calcineurin inhibitors in combination with Mycophenolate mofetil in 430, and other prophylaxes in 208 patients. The cumulative incidence of neutrophil engraftment at day 42 among groups with 0, 1, and 2 HLA haplotype matches was 79%, 82%, and 88%, respectively (Gray test, P=0.008) (Figure 1). In the multivariate analysis, the group with no haplotype match was marginally associated with worse neutrophil engraftment compared to the group with 1 haplotype match group (0 match vs. 1 match, HR 0.88, P=0.087), whereas the group with 2 haplotype matches was significantly associated with better neutrophil engraftment (2 match vs. 1 match, HR 1.39, P=0.005). Other significant variables were recipient sex, CD34 cell dose, transplant year, performance status, ABO matching, GVHD prophylaxis, and disease status. Tendency of worse neutrophil engraftment in the group with no haplotype matches was more apparent in patients with double mismatches at the same locus (0 match + no double mismatch vs. 1 match, HR 0.93, P=0.429, 0 match + double mismatch vs. 1 match, HR 0.80, P=0.050). Haplotype matching did not have any effect on overall survival and non-relapse mortality. Group with 2 haplotype matches was significantly associated with higher risk of relapse than the group with 1 haplotype match, whereas, there was no difference in the risk of relapse between the groups with no match and 1 match. Conclusions: In addition to the CD34 cell dose and HLA matching, HLA haplotype matching might be considered to obtain better neutrophil engraftment. Two haplotype matches (8 of 8 allele matches) should be avoided if the relapse risk is high. Figure 1. Figure 1. Disclosures Tanaka: Pfizer: Honoraria; Otsuka: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis Pharma: Honoraria. Ichinohe:Zenyaku Kogyo Co.: Research Funding; Celgene: Honoraria; Janssen Pharmaceutical K.K.: Honoraria; Taiho Pharmaceutical Co.: Research Funding; Mundipharma: Honoraria; Otsuka Pharmaceutical Co.: Research Funding; Nippon Shinyaku Co.: Research Funding; Sumitomo Dainippon Pharma Co.: Research Funding; MSD: Research Funding; Novartis.: Honoraria; JCR Pharmaceuticals: Honoraria; Alexion Pharmaceuticals: Honoraria; Repertoire Genesis Inc.: Research Funding; Bristol-Myers Squibb: Honoraria; Takeda Pharmaceutical Co.: Research Funding; Pfizer: Research Funding; Ono Pharmaceutical Co.: Research Funding; Kyowa Hakko Kirin Co.: Research Funding; Eisai Co.: Research Funding; CSL Behring: Research Funding; Chugai Pharmaceutical Co.: Research Funding; Astellas Pharma: Research Funding.

Transient marrow expansion of normal B-cell precursors, termed hematogones, is occasionally observed after hematopoietic stem cell transplantation (HSCT). To understand the clinical significance of this phenomenon, we enumerated hematogones in 108 consecutive patients who received allogeneic HSCT for the treatment of hematologic malignancies, including acute myelogenous leukemia, advanced myelodysplastic syndromes, acute lymphoblastic leukemia, and non-Hodgkin lymphoma. Hematogone quantitation was performed at the time of complete donor engraftment (median day 25 and 32 in patients who received bone marrow and cord blood cell transplants, respectively). Hematogones were polyclonal B cells, and their frequencies correlated positively with blood B-cell numbers, and inversely with donors’ but not recipients' age, suggesting that hematogones reflect cell-intrinsic B-cell potential of donor cells. Interestingly, patients developing hematogones that comprised5% of bone marrow mononuclear cells constituted a group with significantly prolonged overall survival and relapse-free survival, irrespective of their primary disease or donor cell source. In addition, patients with5% hematogones developed severe acute graft-versus-host diseases less frequently, which may contribute toward their improved survival. We therefore conclude that the amount of hematogones at the time of engraftment may be a useful tool in predicting the prognosis of patients treated with allogeneic HSCT.Quantitation of hematogones at engraftment is useful to predict prognosis of patients treated with allogeneic stem cell transplantation.

Allogeneic hematopoietic cell transplantation (HCT) is an effective treatment for adult T-cell leukemia (ATL), raising the question about the role of graft-versus-leukemia effect against ATL. In this study, we retrospectively analyzed the effects of acute and chronic graft-versus-host disease (GVHD) on overall survival, disease-associated mortality, and treatment-related mortality among 294 ATL patients who received allogeneic HCT and survived at least 30 days posttransplant with sustained engraftment. Multivariate analyses treating the occurrence of GVHD as a time-varying covariate demonstrated that the development of grade 1-2 acute GVHD was significantly associated with higher overall survival (hazard ratio [HR] for death, 0.65; P = .018) compared with the absence of acute GVHD. Occurrence of either grade 1-2 or grade 3-4 acute GVHD was associated with lower disease-associated mortality compared with the absence of acute GVHD, whereas grade 3-4 acute GVHD was associated with a higher risk for treatment-related mortality (HR, 3.50; P < .001). The development of extensive chronic GVHD was associated with higher treatment-related mortality (HR, 2.75; P = .006) compared with the absence of chronic GVHD. Collectively, these results indicate that the development of mild-to-moderate acute GVHD confers a lower risk of disease progression and a beneficial influence on survival of allografted patients with ATL.

Allogeneic hematopoietic stem cell transplantation (HSCT) is increasingly used as a curative option for adult T-cell leukemia (ATL), an intractable mature T-cell neoplasm causally linked with human T-cell leukemia virus type I (HTLV-I). We compared outcomes of 386 patients with ATL who underwent allogeneic HSCT using different graft sources: 154 received human leukocyte antigen (HLA)–matched related marrow or peripheral blood; 43 received HLA-mismatched related marrow or peripheral blood; 99 received unrelated marrow; 90 received single unit unrelated cord blood. After a median follow-up of 41 months (range, 1.5-102), 3-year overall survival for entire cohort was 33% (95% confidence interval, 28%-38%). Multivariable analysis revealed 4 recipient factors significantly associated with lower survival rates: older age (> 50 years), male sex, status other than complete remission, and use of unrelated cord blood compared with use of HLA-matched related grafts. Treatment-related mortality rate was higher among patients given cord blood transplants; disease-associated mortality was higher among male recipients or those given transplants not in remission. Among patients who received related transplants, donor HTLV-I seropositivity adversely affected disease-associated mortality. In conclusion, allogeneic HSCT using currently available graft source is an effective treatment in selected patients with ATL, although greater effort is warranted to reduce treatment-related mortality.

Backgrounds: Primary myelofibrosis (PMF) is associated with poor prognosis and a marked reduction in life expectancy, with median survival durations ranging from 3.5 to 6 years, according to previous studies with great variation. We conducted a 17-year nationwide survey (1999-2015) to elucidate the clinical outcomes of patients with PMF in Japan, and evaluated the change of survival duration over time. Patients and Methods: Questionnaires were sent annually to approximately 500 hematology departments of board-certified member institute of the Japanese Society of Hematology to collect data about clinical features and prognoses of patients with PMF. Newly diagnosed patients with PMF were enrolled in this study and were followed up annually to collect prognostic information. Approximately 50 patients were enrolled per year, yielding an eventual total of 780 patients with PMF that were included in a 17-year study period (1999-2015). Results: The median age at diagnosis was 66 years. At the time of the analysis, 374 enrolled patients (48%) had died after a median survival duration of 47 months (95% CI, 41-53 months). Of the patients for whom the final cause of death was known, infection (n = 89) and transformation into acute leukemia (n = 91) were the most frequent causes. The 3-year overall survival (OS) rate was 59% (95% CI, 55%-63%). Significant improvements in the 3-year OS rate were not observed during the 17-year period of analysis (p = 0.235)(Figure A). Among the proposed prognostic models for predicting the outcomes of PMF patients, the Dynamic International Prognostic Scoring System of PMF (DIPSS) plus model was the most feasible for our cohort. However, the calculated areas under ROC curves were 0.609, and only modest accuracy was observed in this regard. Forty-three patients (median age of 52 years; range, 24-66 years) received allogeneic hematopoietic stem cell transplantation (alloSCT) at a median of 343 days after diagnosis. The estimated median survival duration after first alloSCT was 134 months (range, 71 to not reached), with a 3-year OS rate of 84% (95% CI, 68%-93%). The median survival duration after diagnosis among patients who received alloSCT was 207 months (range, 105 to not reached), and this is significantly longer than that calculated for patients who did not receive alloSCT (median: 45 months; range, 38-49 months; p < 0.001)(Figure B). Ruxolitinib therapy was given to 47 patients, but did not have an impact on survival duration. Conclusions: The survival curves of patients diagnosed during different subperiods of our study period exhibited complete overlap, indicating a lack of improvement in survival duration over time. However, only alloSCT among current treatment modalities had an impact on the natural course of PMF. Regarding prognostic prediction, DIPSS plus was the optimal model for survival prediction even among Japanese patients with PMF. However, the ROC analysis indicated that the prognostic covariates in DIPSS plus were not sufficient, and additional information regarding gene mutation statuses (e.g., CALR and ASXL1) might be required to predict the precise outcomes of PMF patients. A long-term registration study is required for further evaluations of prognosis and the impact of treatments on survival. Figure Figure. Disclosures Shibayama: Novartis Pharma: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau; Takeda: Speakers Bureau; Chugai Pharmaceutical: Speakers Bureau; Ono Pharmaceutical: Speakers Bureau. Ozawa:Sumitomo Dainippon Pharma Co. Ltd: Research Funding; Takara Bio Inc: Research Funding; Celgene Japan: Consultancy; JCR Pharmaceutical Inc: Consultancy.

Background Sustained treatment-free remission (TFR) has been reported in 40-60% of patients with chronic myeloid leukemia-chronic phase (CML-CP) after discontinuation of imatinib or dasatinib following at least 1-2 years of deep molecular response (MR). We investigated safety and efficacy of discontinuing nilotinib treatment after 2 years of sustained MR4.5 (BCR-ABL1IS ≤ 0.0032%) on nilotinib in patient for whom MR4.5 was achieved by prior treatment with imatinib or nilotinib. Methods The Stop Nilotinib (NILSt) trial was a single-arm multicenter phase 2 study in Japan. CML-CP patients who obtained MR4.5 by treatment with imatinib or nilotinib were enrolled, and were further treated with nilotinib for 2 years. The patients who maintained MR4.5 during those 2 years were eligible for discontinuation of nilotinib. After treatment discontinuation, maintenance of MR4.5 was monitored by quantitative RT-PCR every month during the 1st year and every 2 months during the 2nd year. Nilotinib was reintroduced in patients who lost MR4.5. The primary endpoint was the proportion of patients who maintained MR4.5 at 1 year after the discontinuation. This study is registered, number UMIN000007141. Results 112 patients were enrolled between April 11, 2012 and November 30, 2012, and were treated with nilotinib for 2 years. 90 of those patients maintained MR4.5 during the entire 2-year period and were eligible to discontinue treatment, among which 87 patients actually discontinued nilotinib to intend a treatment-free remission period. Median follow-up after the discontinuation was 13.4 months (range 4.8-20.1). At 1 year, 53 patients (58.9%, 90% CI 49.7-67.7) maintained MR4.5, whereas 34 patients experienced loss of MR4.5 mostly within 6 months after the discontinuation (Figure 1). Thirty-two of those 34 patients (94.1%) regained MR4.5 2.2 months (median, 95% CI 1.5-2.6) after reintroduction of nilotinib. The following parameters did not significantly predict the probability of MR4.5 at 1 year after the discontinuation: age, sex, Sokal, Hasford, EUTOS scores, history of IFN-a therapy, total duration of imatinib or nilotinib therapy, time to MR4.5, or trough concentrations of nilotinib in sera. Notably, the percentages of patients maintaining MR4.5 for one year without treatment did not improve significantly with longer duration of prior MR4.5 on treatment; even some patients with a duration of prior deep MR on treatment exceeding 10 years experienced loss of MR4.5 after treatment discontinuation (Table 1). The rates of all grade (grade 3/4 in parentheses) cardiovascular events were 5.5% (2.7%), fluid retention were 14.1% (0%), and musculoskeletal pain were 9.7% (1.8%) during the 2-year treatment periods. Conclusion Nilotinib can be discontinued without relapse in more than half of the patients who maintained MR4.5 for at least 2 years. However, relapse occurred after the discontinuation following even more than 10 years of sustained deep MR in the rest of the patients. This suggests that the period of deep MR after which nilotinib can be discontinued without relapse is considerably long, if any, in a substantial proportion of patients. Biomarkers to detect such patients are awaited. Furthermore, additional strategies may be required to safely discontinue nilotinib as early as possible in such patients, in order to avoid serious adverse events caused by prolonged administration. Figure 1. Kaplan-Meier estimates of TFR after discontinuation of nilotinib Figure 1. Kaplan-Meier estimates of TFR after discontinuation of nilotinib Table 1. Rates of MR4.5 maintenance at 1 year after discontinuation of nilotinib in relation to the duration of deep molecular response before the discontinuation Table 1. Rates of MR4.5 maintenance at 1 year after discontinuation of nilotinib in relation to the duration of deep molecular response before the discontinuation Disclosures Kawaguchi: Novartis: Honoraria. Kuroda:Janssen: Honoraria; Astra Zeneca: Research Funding; Celgene: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding. Nakamae:Mochida Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Novartis Pharma KK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel/accommodation/meeting expenses, Research Funding. Matsumura:Bristol-Myers Squibb Company: Honoraria; Novartis Pharma K.K: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Consultancy, Honoraria; Pfizer Japan Inc.: Honoraria. Kanakura:Bristol Myers: Research Funding; Alexionpharma: Research Funding; Nippon Shinyaku: Research Funding; Astellas: Research Funding; Eisai: Research Funding; Pfizer: Research Funding; Chugai Pharmaceutical: Research Funding; Shionogi: Research Funding; Kyowa Hakko Kirin: Research Funding; Fujimotoseiyaku: Research Funding; Toyama Chemical: Research Funding.

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the largest subtype of lymphoma, but consists of heterogeneous groups with different prognosis. Many studies conducted to determine prognosis factors of DLBCL. Recently, several studies have been reported that the elderly Epstein-Barr virus (EBV)-positive DLBCL patients showed worse prognosis than the elderly EBV-negative DLBCL. (Oyama T et al. Clin Cancer Res 2007;13:5024-5032). On the other hand, other studies reported that EBV-positivity is not a prognosis factor in young-adult DLBCL patients (Hong JY et al. Annals of Oncology 2015;26:548-555, Nicolae A et al. BLOOD 2015;126:863-872). In the present study, retrospective analyses were carried out for patients with DLBCL diagnosed between 1990 and 2007 to analyze the clinical and prognostic significance of EBV. Patients: Those who met the following criteria were included in the study: (i) pathology confirmed de novo DLBCL, according to the WHO classification; (ii) adequate amount and quality of paraffin-embedded biopsy specimens or unstained slides for EBV-encoded RNA in situ hybridization. Statistical methods: Intergroup comparisons were carried out with Fisher's exact test for categorical variables and the Mann-Whitney test for age. For survival analysis, we carried out Kaplan-Meier and multivariate proportional hazard (Cox) analyses. Statistical analyses were carried out using the software Stata SE version 14.0. Results: A total of 456 patients were included. The median follow up duration of survivor was 100 months (range, 1.9-363). There were 236 male (51.75%) and 220 female patients (48.25%) with a median age of 67 (range, 22-94) years. 246 patients (54.0%) were in advanced (III/IV) stage, 134 (29.4%) presented with poor Eastern Cooperative Oncology Group Performance Status (ECOG-PS), 275 (60.3%) with elevated lactate dehydrogenase (LDH) level, 263 (57.7%) with extranodal involvement of 1 or more sites, and 64 (14.0%) with bulky mass. As a consequence, 211 patients (46.3%) were in high/high-intermediate International Prognostic Index (IPI) categories. 5 years overall survival (OS) was 66.2%, in total. EBV was detected in samples from 47 patients (10.3 %). The positivity was 10.6% (15 / 142) in patients of 60 years or younger, and 10.2 % (32 / 314) in those older than 60 years (p = 0.51). No differences in back ground date were found between EBV - positive and negative DLBCLs regarding age (median 66.5 vs. 64.8, P = 0.17), male sex (88.1% vs. 11.9%, P = 0.16), advanced stage (88.2% vs. 11.8%, P = 0.17), poor ECOG-PS (90.3% vs. 9.7%, P = 0.47), elevated LDH (89.5% vs. 10.6%, P = 0.48), extranodal sites of one or more (90.5% vs. 9.5%, P = 0.31), bulky mass (92.2% vs. 7.8%, P = 0.33), and higher IPI categories (88.6% vs. 11.4%, P = 0.29). The prognosis was also not different between EBV-positive and negative DLBCLs. The 5 years OS was 42.6% for EBV-positive DLBCLs, and 56.4% for EBV-negative DLBCLs (P = 0.11). The same results were found for the younger (53.3% vs. 66.9%, P = 0.30) and the elderly patients (42.9% vs. 51.8%, P = 0.18). Conclusion: In this practice based, uncontrolled study, EBV-positively wad not different in younger and elderly DLBCLs. Although EBV-positive DLBCL showed worse trend of prognosis, the difference was not statistically significant. The significance of EBV in DLBCL should be reconsidered in unbiased, large-scale patient date. Figure Figure. Disclosures Suzuki: Chugai: Honoraria; Bristol-Myers Squibb: Honoraria; Kyowa Hakko kirin: Honoraria. Suzumiya:Chugai: Research Funding, Speakers Bureau; Astellas: Research Funding; Toyama Chemical: Research Funding; Eizai: Research Funding; Takeda: Speakers Bureau; Kyowa Hakko Kirin: Research Funding.

Fas antigen (Fas Ag; CD95) is a cell surface molecule that can mediate apoptosis. Bcl-2 is a cytoplasmic molecule that prolongs cellular survival by inhibiting apoptosis. To investigate the role of both molecules in hematopoiesis, we evaluated the expression of Fas Ag and Bcl-2 on CD34+ hematopoietic progenitor cells expanded in vitro. CD34+ cells isolated from bone marrow were cultured in iscove's modified Dulbecco's medium supplemented with 10% fetal calf serum, 1% bovine serum albumin, 50 ng/mL stem cell factor, 50 ng/mL interleukin-3 (IL-3), 50 ng/mL IL-6, 100 ng/mL granulocyte colony-stimulating factor, and 3 U/mL erythropoietin for 7 days. Colony-forming unit of granulocytes/macrophages (CFU-GM) and burst-forming unit of erythroids (BFU-E) were expanded 6.9-fold and 8.8-fold in number at day 5 of culture, respectively. Freshly isolated CD34+ cells did not express Fas Ag, whereas approximately half of them expressed Bcl-2. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas Ag and rapidly lost Bcl-2 expression. Furthermore, apoptosis was induced in the cultured CD34+ population when anti-Fan antibody (IgM; 1 microgram/mL) was added, as shown by significant decrease in the number of viable cells, morphologic changes, induction of DNA fragmentation, and significant decrease in the number of clonogenic progenitor cells including CFU. GM and BFU-E. These results indicate that functional expression of Fas Ag is induced on CD34+ cells expanded in vitro in the presence of hematopoietic growth factors. Induction of Fas Ag and downregulation of Bcl-2 may be expressed as part of the differentiation program of hematopoietic cells and may be involved in the regulation of hematopoiesis.

The leukemia-specific AML1/ETO fusion gene has been shown to be detected by reverse transcriptase polymerase chain reaction (RT-PCR) analysis in patients with t(8;21) acute myelogenous leukemia (AML) in long-term remission. In the present study, the AML1/ETO mRNA could be detected by RT-PCR in bone marrow (BM) and/or peripheral blood (PB) samples from all 18 patients who had been maintaining complete remission for 12 to 150 months (median, 45 months) following chemotherapy or PB stem cell transplantation (PBSCT), whereas it could not be detected in four patients who had been maintaining remission for more than 30 months following allogeneic BM transplantation (BMT). We surveyed the expression of AML1/ETO mRNA in clonogenic progenitors from BM in these cases. Notably, 51 of 2,469 colonies from clonogenic progenitors (2.1%) expressed the AML1/ETO mRNA in 18 cases who were RT- PCR+ in BM and/or PB samples. Expression was observed in various clonogenic progenitors, including granulocyte-macrophage colonies, mixed colonies, erythroid colonies, and megakaryocyte colonies. Furthermore, we analyzed the clonality of these progenitors by X- chromosome inactivation patterns of the phosphoglycerate kinase (PGK) gene in four female patients. The AML1/ETO mRNA+ progenitors showed the PGK allele identical to that detected in the leukemic blasts from the time of initial diagnosis. Normal constitutive hematopoiesis was sustained by polyclonal BM reconstitution in these patients. Accordingly, these committed progenitor cells that express AML1/ETO mRNA during remission likely have arisen from common t(8;21)+ pluripotent progenitor cells with at least trilineage differentiation potential. These data strongly suggest that the origin of the clonogenic leukemic progenitors of t(8;21) AML may be multipotent hematopoietic progenitors that acquired the t(8;21) chromosomal abnormality.

[Introduction] Inherited bleeding disorders (IBD), such as coagulation factor deficiencies, Von Willebrand disease and Glanzmann thrombasthenia, are caused by various gene abnormalities of coagulation proteins, blood vessels, and platelets. IBD have been considered to be suited for gene therapy and clinical trials are ongoing. However, the safety and effectiveness of viral vectors has not been established. Recently, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) system, originates from the archaeal and bacterial adaptive immunity system, provides an efficient genome-editing tool in various organisms including the mammalian genome and holds potential for gene therapy. Here, we report an application of this system to gene repair using induced pluripotent stem cells (iPSCs) derived from patients of three types of IBD. [Case1] Hemophilia B (63-year-old male). Factor IX (FIX) activity was less than 1% (normal range (NR) 70-130%) and antigen level was 2.37μg/ml (average 5.0μg/ml). Molecular analysis of the FIX gene revealed an in-frame deletion in exon 2. [Case2] Factor V (FV) deficiency (55-years-old female). FV activity was less than 3% (NR 70-135%) and antigen level was less than 2% (NR 60-150%). A homozygous missense mutation was detected in FV gene of exon 14. [Case3] Factor X (FX) deficiency (4-years-old male). FX activity was less than 2.84 IU/dl (NR 50-150 IU/dl) and antigen level was 0.567 IU/dl (NR 50-150 IU/dl). A compound heterozygous missense mutation was found in FX gene of exon 6 and 8 respectively. [Methods and results] The CRISPR/Cas system comprises of a Cas9 nuclease and a sequence-specific guide RNA (gRNA). We designed gRNAs close to gene mutations. We transfected both expression vectors into HT-1080 or 293T cells, and assessed the editing activity by SURVEYOR nuclease assay. In order to repair the mutations by homology-directed repair (HDR), we prepared targeting constructs with homology arms (1.0 kbp in length) containing the corrected sequence. After introduction of Cas9, gRNA and targeting plasmid into each iPSCs generated from peripheral blood mononuclear cells (PBMCs) using Sendai virus vector expressing the Yamanaka 4-factor genes (Oct3/4, Klf4, Sox2 and c-Myc), we could obtain iPSC clones with corrected genes by HDR from all of three IBD patients. Successful HDR events were verified by PCR amplification using integration site- and targeting construct-specific primers. Locus-specific knock-in events were confirmed by Southern blot analysis. [Conclusion] We observed the cleavage of the target genome by using our designed gRNAs. Furthermore, the CRISPR/Cas system induced successful gene repair of iPSCs from three IBD patients. We are preparing hepatocytes induced from repaired iPSCs to confirm corrected coagulation factor synthesis. Gene-corrected iPSCs hold great promise as a cell source for autologous cell transplantation. Disclosures No relevant conflicts of interest to declare.

Mutation of the MYD88 has recently been identified in activated B cell like diffuse large B cell lymphoma (DLBCL) and enhanced cell proliferation systems such as JAK-STAT and NF-kB signaling pathways. However, much remains unclear about its clinical significance. In this study, we developed a highly sensitive and an automatic method utilizing guanine-quenching probes (QP) to detect mutation and investigated the relationship between MYD88 L265P mutation and clinical significance. We amplify a DNA fragment including the mutation to intend for by PCR and associate it with Q-probe with complementary sequence, using the temperature that Q-probe dissociates varying according to a conformity degree of the complementarity sequence. We judge it by detecting the fluorescence to be provided by dissociation. Results were obtained from 1ul of DNA solution(10ng) within 90 min by the method. Detected mutations were identical between QP method and allele-specific PCR (AS-PCR).Eighty-nine patients with a diagnosis of de novo DLBCL made between 1999 and 2014, and treated with CHOP or R-CHOP therapy. We retrospectively analyzed the outcome of 89 patients (age range; 21-88 and 59% were female). The median follow-up time was 4.4 y. Survival analyses were performed using the Kaplan-Meier method. None of the patients had a known history of human immunodeficiency virus infection. MYD88 L265P mutation was both assessed by Q-probe system that can detect low levels of mutant DNA and allele-specific TaqMan polymerase chain reaction assay. We performed the direct sequence method using 3130 Applied Biosystem Genetic Analyzer as antithesis. The cell-of-origin was determined based on immunohistochemical (IHC) stains for CD10, BCL-6 and MUM-1 by Hans' algorithm. MYD88 L265Pmutation was detected in 25.8% (23/89) in various tissues of DLBCL. MYD88 mutations occurred more frequently in males (P Disclosures No relevant conflicts of interest to declare.

The in vivo host range of human T-cell leukemia virus type 1 (HTLV-1) has not been definitively established. To determine if hematopoietic stem cells from patients with adult T-cell leukemia-lymphoma (ATL) are infected with HTLV-1, we used a clonogenic progenitor assay followed by the polymerase chain reaction for the detection of HTLV-1 DNA. In vitro growth characteristics of myeloid (CFU-GM) and erythroid (BFU-E) progenitor cells among nonadherent T-cell-depleted bone marrow (BM) mononuclear cells (NA-T-MNCs) from 10 patients with ATL was not significantly different from those of HTLV-1-seronegative controls (P = .20); numbers of colonies per 1 x 10(5) NA-T-MNCs were 34.9 +/- 7.6 for CFU-GM and 39.0 +/- 12.5 for BFU-E in patients with ATL, whereas those were 32.1 +/- 9.5 for CFU-GM and 41.4 +/- 12.7 for BFU-E in normal controls. HTLV-1 DNA was not detected in individual colonies formed by CD34+ cells from any of the patients. Similarly HTLV-1 DNA was not detected in 1 x 10(3) CD34+ cells sorted on a fluorescence-activated cell sorter (FACS) from six patients with ATL studied. In contrast, HTLV-1 DNA was detected in BM mononuclear cells from all patients. These observations clearly indicate that hematopoietic progenitor cells from patients with ATL are normal in their colony-forming capacity and that CD34+ cells from patients with ATL are not infected with HTLV-1 in vivo.

Myeloid cell leukemia-1 (MCL-1) is an essential survival factor for hematopoiesis. In humans, hematopoietic stem cells (HSCs) express MCL-1 at the highest level in response to FMS-like tyrosine kinase-3 (FLT3) signaling. We here show that this FLT3-dependent stem cell maintenance system also plays a critical role in survival of leukemic stem cells (LSCs) in acute myeloid leukemia (AML). The CD34+CD38− LSC fraction expresses high levels of FLT3 as well as MCL-1, even compared with normal HSCs. Treatment with FLT3 ligand induced further MCL-1 up-regulation in LSCs in all AML cases tested. Interestingly, the group of samples expressing the highest levels of MCL-1 constituted AML with FLT3–internal tandem duplications (ITD). In FLT3-ITD AML cell lines, cells expressed a high level of MCL-1, and an inhibition of MCL-1 induced their apoptotic cell death. A tyrosine kinase inhibitor suppressed MCL-1 expression, and induced apoptosis that was reversed by the enforced MCL-1 expression. Finally, transduction of FLT3-ITD into HSCs strongly activated MCL-1 expression through its signal transducer and activator of transcription 5 (STAT5)–docking domains. This effect was completely abrogated when STAT5 activation was blocked. Thus, the acquisition of FLT3-ITD ensures LSC survival by up-regulating MCL-1 via constitutive STAT5 activation that is independent of wild-type FLT3 signaling.

[Background] Body cavity-based lymphoma (BCBL) arises in body cavity effusion without mass formation. Although there have been several case reports on HHV8-negative BCBL and the term "primary effusion lymphoma (PEL)-like lymphoma" has been coined, it is very rare and not defined in the current lymphoma classification. In those reports, HHV8-negative BCBL usually expresses B-cell markers and the prognosis seems to be better than those with HHV8-positive PEL with a few reports describing spontaneous regression of effusion. However, its clinicopathological features and prognosis remain unclear due to lack of retrospective study with sufficient number. [Method] We collected data of BCBL diagnosed between 1990 and 2014 from 42 institutions in Japan and clinicopathological features were retrospectively analyzed. We focused on clinicopathological features and prognosis of HHV8-negative BCBL, which was defined as HHV8-negative lymphoma that developed in body cavity effusion (pleural effusion, pericardial effusion, and ascites) without mass formation or extra-cavitary lesions at diagnosis. HHV8 status was assessed with immunohistochemical staining with anti-LANA-1 antibody (n=34) and/or polymerase chain reaction for HHV8 (n=31) of body-cavity effusion sample.Overall survival (OS), progression free survival (PFS), and time to progression (TTP) were calculated using Kaplan-Meier method. In patients without any systemic treatment for 3 months from diagnosis, failure of the first systemic treatment was considered as an event for PFS or TTP. [Results] Case report form of 71 patients with BCBL was collected. With central review, 4 patients did not meet the criteria of BCBL (existence of tumor mass or no objective evidence of lymphoma by morphology or immunophenotype) and 67 patients with BCBL were identified. Out of them, 50 and 6 were compatible with the diagnosis of HHV8-negative BCBL and PEL, respectively. In another 11 cases, HHV8 status could not be evaluated. In the 50 patients with HHV8-negative BCBL, male to female ratio was 1.3 : 1, and median age at the diagnosis was 76 years (57-98), HIV was negative in all of the 46 patients who were tested. Twenty-four patients (47%) had an underlying medical condition leading to fluid overload such as cirrhosis, cardiac disease, and renal dysfunction. Involved sites were pleural effusion (76%) followed by pericardial effusion (60%), and ascites (12%). Multiple sites were involved in 21 cases. The other clinical characteristics at the time of diagnosis were as follows: ECOG PS 0-1 (50%); B symptoms (14%); and elevated LDH (68%). Tumor cells expressed CD10 in 11/45 and CD20 in 48/50. Immunoglobulin light chain restriction was detected in 28/34. EBER in situ hybridization was positive in 4/32 (13%). The most common first-line systemic therapy was CHOP or CHOP-like with or without rituximab (n=38) followed by rituximab alone (n=2), rituximab with etoposide (n=2), and hyperCVAD/MA (n=1). One patient died within a month before initiating treatment, and five more patients had no systemic treatment at diagnosis for reasons such as comorbidity or frailty. Of the 43 patients treated with systemic therapy, the overall response rate was 98% with 70% achieving a complete remission. With a median follow up of 22 (0-147) months, 2-year OS, PFS, TTP of HHV8-negative BCBL was 83.6%, 76.8%, and 90.5%, respectively (Figure 1-3). Fifteen patients relapsed after achieving response: the same body-cavity effusion alone (n=7), different body-cavity effusion with or without the same site (n=2), intra- or extra-cavitary tumor mass formation (n=6). Eleven patients died and the causes of death were lymphoma (n=8) and others (n=3). Of the 5 patients without systemic treatment at diagnosis, systemic treatment was initiated in only 1 patient at 30 months due to re-emergence of effusion. The remaining 4 patients had had no systemic treatment for a median of 24 (5-147) months and 3 patients were alive without disease without any systemic therapy at last follow-up. [Conclusion] To the best of our knowledge, this is the largest retrospective study on HHV8-negative BCBL. HHV8-negative BCBL had distinct clinicopathological features from PEL. It affected HIV-negative elderly and the lymphoma cell was positive for B cell markers in most cases. Almost all of the patients responded to systemic treatment and its prognosis was favorable. Figure 1 Figure 1. Figure 2 Figure 2. Figure 3 Figure 3. Disclosures No relevant conflicts of interest to declare.

We have reported that S-phase kinase-associated protein 2 (Skp2) expression in tumor cells is an unfavorable prognostic factor in diffuse large B cell lymphoma (DLBCL) with CHOP-R. Therapeutic strategies other than CHOP-R should be needed for DLBCL patients exhibiting a high Skp2 expression at the time of diagnosis. High dose chemotherapy followed by autologous peripheral blood stem cell transplantation (APBSCT) is mainly adapted for DLBCL patients in high and high intermediate risk groups in IPI. However, the definite beneficial evidence for APBSCT in DLBCL remains unclear. In the present study, we investigated the clinical significance of Skp2 expression in the patients with DLBCL treated with CHOP-R plus high-dose chemotherapy followed by APBSCT. We retrospectively analyzed the outcomes of 93 patients (age range: 14-65). The patients were newly diagnosed as having DLBCL from 2002 to 2012, and were treated with either CHOP-R plus upfront APBSCT (n=31) or CHOP-R (n=62) in the19 hospitals in Kyushu, Japan. All patients had high and high intermediate risk in IPI. All biopsy specimens were immunohistopathologically reconfirmed by one pathologist with expertise before entering into this study. The median follow-up time was 2.3 y. Survival analyses were performed using the Kaplan-Meier method and the Cox proportional Hazard model with inverse probability of treatment weight (IPTW). In background of the patients, age was younger in transplant group (mean age 52) than in non-transplant group (mean age 59). CR rate was higher in non-transplant (30.7%) than in transplant (12.9%). Sex, stage, PS, LDH extranodal lesion and IPI showed no difference in both group. Overall survival (OS) for 3 years were 77.0% and 59% in transplant group and in non-transplant group (P=0.077), respectively. Progression-free survival (PFS) for 3 years, 65.7% and 53.2% in transplant and non-transplant group (P=0.233), respectively. In Skp2 high expression (positive rate >40%) group (n=37), 3y-OS was 44.9% and 16.4% in transplant (n=13) and non-transplant (n=24) group (P=0.065), respectively. 3y-PFS was 40.3% and 7.5% in transplant and non-transplant (P=0.032), respectively (Fig A). However, in low Skp2 expression group (n=56), OS was 100% and 92.7% (P=0.254), PFS was 83.6% and 82.6% (P=0.945)(Fig B)in transplant (n=18) and non-transplant (n=38) group, respectively. In propensity score analysis using center effect, age, extranodal lesion, IPI and CR rate as logistic regression model, transplant group showed the excellent benefit in OS ( OR= 0.469, 95%CI =0.266-0.825, P=0.009) and PFS (OR=0.456, 95%CI=0.255-0.815, P=0.008) in Skp2 high expression group (n=37).P value for transplant x Skp2 interaction was P=0.643 in OS and P=0.020 in PFS. In conclusion, Skp2 was a good biomarker for indication of ABSCT for high risk DLBCL patients. In low expression of Skp2, patients should not be treated with high dose chemotherapy followed by APBSCT, even though in patients with high risk in IPI. However, ABSCT have some advantage in DLBCL patients with high expression of Skp2. Disclosures: No relevant conflicts of interest to declare.

Abstract 2581 Introduction A clinical indication for allogeneic hematopoietic stem cell transplantation (HSCT) in adult Philadelphia-chromosome negative [Ph (−)] acute lymphoblastic leukemia (ALL) patients in complete remission 1 (CR1) remains to be clarified. An international study showed that matched related donors HSCT for ALL in CR1 provides survival benefits for standard-risk ALL patients compared to chemotherapy (Blood. 2008 111:1827). Minimal residual disease (MRD) status has been reported to be a strong prognostic factor in adult ALL patients (Blood. 2006 107:1116, 2009 113:4153). We prospectively monitored MRD status during induction and consolidation therapy in adult Ph (−) ALL patients to determine a clinical indication for HSCT. Materials & Methods From July 2002 to August 2008, 110 adult ALL patients were enrolled in this study. Eligibility criteria included non-L3 ALL, 16–65 years of age, and adequate organ function. Of these patients, 101 were eligible for this study and 59 were Ph (−). The treatment protocol used in this study was modified CALGB 19802. Treatment consisted of 6 courses given in the order of A-B-C-A-B-C, followed by a maintenance phase. Induction chemotherapy (course A) consisted of cyclophosphamide (1,200 mg/m2), daunorubicin (60 mg/m2 × 3), vincristine (VCR) (1.3 mg/m2 (max 2mg) × 4), L-asparaginase (3,000 U/m2 × 6) and prednisolone. Granulocyte colony-stimulating factor was started on day 4 and continued until neutrophil recovery. Consolidation B consisted of mitoxantrone (10 mg/m2 × 2), cytarabine (2,000 mg/m2/day × 4) and intrathecal (IT) administration of methotrexate (MTX). Consolidation C consisted of VCR (1.3 mg/m2 (max 2mg) × 3) and MTX (1,500 mg/m2 × 3) with leucovorin rescue and IT MTX. Patients received maintenance chemotherapy on a monthly basis: prednisolone 60 mg/m2 on days 1–5, VCR (1.3mg/m2 (max 2mg) × 3) on day 1, oral MTX 20 mg/m2 weekly, and oral 6-mercaptopurine 60 mg/m2 daily. MRD status was evaluated after induction therapy (first course A) and after second consolidation therapy (first course C). When MRD statuses after the consolidation were positive, patients were supposed to proceed to HSCT whenever possible. Results A total of 59 patients were Ph (−). MRD status of 41 of these patients (69.5%) could be monitored by the major rearrangement patterns of TCRƒÁ, TCRƒÁ, and IgƒÈ chain genes, and secondarily for IgH gene rearrangements (Blood. 1991 77:331), and chimeric RNA analysis (TCRƒÁ n=14, TCRƒÁ n=9, IgƒÈ n=6, IgH n=1, other n=1, E2A-PBX1 n=3, MLL-AF4 n=1). There were 21 male and 20 female patients. The median age was 31.0 (range 17–63 years). The median white blood cell count at presentation was 10,900/ml (range 1,000–408,700). A total of 36 patients (85.7%) achieved CR. The probability of 3-year overall survival and progression-free survival (PFS) were 59.3 % and 48.9 %, respectively. In terms of CR1 status, patients who were MRD (−) after induction therapy (first course A)(n = 22) had a significantly better 3-year PFS compared with those who were MRD (+)(n = 13)(72.2 % vs. 33.6 %, p = 0.011). Those MRD (−) patients also had a significantly lower 3-year probability of relapse compared with MRD (+) patients (27.8 % vs. 58.0 %, p = 0.031). Patients who were MRD (+) after consolidation therapy (n=3) had an ominous prognosis without HSCT (3-year PFS 0%), while the MRD (+) patients with HSCT (n=3) had 66.7 % 3-year PFS. On multivariate analysis, age (≥35 vs. Discussion HSCT for CR1 ALL has the greatest anti-ALL activity. However, HSCT has higher morbidity and mortality rates than chemotherapy. Thus, HSCT should be avoided in patients who have good prognosis with chemotherapy alone. Our results show that patients with molecular remission after induction therapy have an excellent PFS without HSCT, and patients who are MRD (+) after several consolidation therapies have very poor PFS without HSCT. The present study indicates that MRD status after induction and consolidation therapies is a significant prognostic factor. MRD monitoring is useful to determine a clinical indication of HSCT for patients who achieve CR1. For CR1 patients with MRD (+) status after several consolidation therapies, further intensification of chemotherapy may be possible when HSCT is not a suitable option. Disclosures: No relevant conflicts of interest to declare.

Abstract 1180 Background: Although peripheral blood stem cell (PBSC) donation has been considered safe and less stressful, certain fetal or life-threatening acute (within 30 days of post donation) adverse events as well as late occurrence of hematological malignancies have been reported among donors. Since the Japan Marrow Donor Program requires the confirmation of safety and risk of PBSC donation at family donors prior to applying this technique for volunteer donors, the Japan Society for Hematopoietic Cell Transplantation (JSHCT) performed nation-wide consecutive pre-registration and follow up for PBSC family donors from 2000 to 2010. This time, we report the comprehensive outcome of this project. Methods: The JSHCT mandated the registration of every PBSC family donor at the donor registration center then, issued donor identification number to each donor. The society required every harvest center to observe the JSHCT standards for donor eligibility, stem cell mobilization and harvest. The society also required to notify it of any severe adverse events, the results of the day30 clinical and laboratory check and of the annual health check for five years. Findings: Among 3,264 pre-registered donors, 47 emergency reports were submitted for 5 years and it was revealed that acute unexpectedly severe adverse events such as interstitial pneumonitis or anginal attack occurred at 0.58 % of donors although no mortality cases within 30 days of post donation were found. The relationship between donors' basic information such as age or gender and clinical and laboratory abnormalities obtained from 2,882 day 30 reports was studied and it revealed the followings; the risk factor for fatigue, headache, insomunia, anorexia and nausea was female, the risk factors for prolongation of hospitalized period were older age, low body weight, high total dose of granulocyte colony stimulating factor (G-CSF), the presence of past or current health problems and the episode of past stem cell donation, the risk factors for thrombocytopenia were older age and high total dose of G-CSF, the risk factors for splenomegary were older age and high total dose of G-CSF, the risk factors for poor CD34+ cell mobilization were older age, female and the episode of past stem cell donation, the risk factor for over CD34+ stem cell mobilization was younger age. The information from 6,233 annual health checks from 1,708 donors for 5 years showed the followings; the incidence of non-malignant but significant health problems was 1.5%, the incidence of non hematological malignancies was 0.7%, the incidence of hematological malignancy was 0.06%. It was also confirmed that the incidence of hematological malignancies among PBSC donors was not high compared with that among retrospectively surveyed bone marrow family donors. Interpretation: The consecutive donor pre-registration and annual follow up system that sets strict standards for donor eligibility, cell mobilization and harvest is effective in preventing real life-threatening acute adverse events and also is useful to know the real figures on PBSC donors and to assure donor safety. Such a system should be applied to all hematopoietic stem cell (family and volunteer, bone marrow and peripheral blood) donors. Disclosures: No relevant conflicts of interest to declare.

Abstract 2284 Poster Board II-261 Background: To evaluate the role of autologous and allogeneic SCT in the treatment of PTCLs, Japan Study Group for Cell Therapy and Transplantation conducted a multicenter retrospective survey in Japan and Korea. Methods: After excluding patients with adult T-cell leukemia/lymphoma and NK-cell tumors, patient data were newly collected from 330 patients (222 male and 108 female) with a median age of 49 years (range, 13–71) who underwent SCT between 9/1991 and 12/2008 (196 autologous and 134 allogeneic including 31 patients with previous autograft). Allogeneic SCT (53 BM, 54 PB, 1 BM+PB, 26 CB) was performed using a reduced-intensity conditioning (RIC) in 84 patients (63%). While a pathologic central review will be performed, currently there were 159 (48%) patients with PTCL, not otherwise specified, 63 (19%) with angioimmunoblastic T-cell lymphoma, 47(14%) with anaplastic large cell lymphoma (23 ALK-negative, 14 ALK-positive and 10 unknown), 12 (4%) with enteropathy-associated T-cell lymphoma, and others. The disease status at transplant in the allo-group was significantly worse than that in the auto-group (Table 1). The median number of chemotherapy regimens was 2 (range, 1–7), and the median duration between diagnosis and transplant was 267 days (range, 120-4889 days). Results: The median follow-up for surviving patients was 45 mo (range, 2.3–141 mo). There was no significant difference in overall survival among different groups, including histological subtypes, RIC and myeloablative conditioning in the allo-group and high-dose chemotherapy regimens in the auto-group. Early survival rate after transplant was significantly better for auto-group than allo-group (Wilcoxon P=0.001), but the difference was marginal in the total course (Logrank P=0.06) (Figure). The non-relapse mortality (NRM) in the auto-group was significantly lower than that in the allo-group (P1), cell source (CB/BM+PB), and performance status (PS; >1), stage, chemorefractory disease, international prognostic index (IPI; H-I/H risk) and prognostic index for PTCL, unspecified (PIT; group 3/4) at transplant. The risk factors in the allo-group were bulky mass at diagnosis, age (>50 years), cell source, and PS, stage, IPI and PIT at transplant, while those in the auto-group were age (>40 years), recurrence after frontline therapy, number of chemotherapy regimens, and stage, chemorefractory disease, IPI and PIT at transplant. Conclusions: Despite a worse disease status at transplant in the allo-group, the overall survival was comparable to that in the auto-group. This supports the notion that early allogeneic SCT is a valuable treatment option for PTCLs, although a large-scale randomized trial to identify a suitable upfront-transplant type for chemosensitive patients with PTCLs is warranted. Disclosures: No relevant conflicts of interest to declare.

Primary B lymphoid lineages development from hematopoietic stem cells occurs in the bone marrow. During their development, B lymphoid precursors progress through a series of distinct developmental stages defined by CD34+CD38+CD10+CD19−Lin− early-B cells, CD34+CD38+CD10+CD19+Lin− pro-B cells, and CD34−/loCD38+CD10−CD19+CD20+ pre-B cells. These immature B lymphoid cells are more prominent in pediatric bone marrow, and the number of B lymphoid precursors is gradually declined with aging. Benign immature B lymphoid cells, originally termed hematogones, can be observed in the bone marrows during hematopoietic recovery phase in some patients who received chemotherapy or allogeneic bone marrow transplantation (allo-BMT) for hematologic disorders. However, little is known about the mechanisms of occurrence of hematogones and no study concerning hematogones has been available following unrelated cord blood stem cell transplantation (UCBT). We retrospectively analyzed populations of B lymphoid precursors of bone marrow samples from 67 patients who received allogeneic stem cell transplantation (SCT). Patients studied included 28 women and 39 men, with a median age of 49 years (19–66 years). The underlying diseases of 67 patients varied; 26 acute myelogenous leukemia, 10 acute lymphocytic leukemia, 3 chronic myelogenous leukemia, 10 myelodysplastic syndrome, 14 malignant lymphoma, and 4 others. 46 patients underwent allo-BMT and 21 underwent UCBT. Mean number of the infused cells amounted of 2.74 x 108 cells/kg (0.92–4.02 x 108) for allo-BMT recipients and 2.66 x 107 cells/kg (1.92–5.00 x 107) for UCBT recipients. 44 patients received myeloablative conditioning regimen (total body irradiation/cyclophosphamide for 32 patients and buslfan/cyclophosphamide for 12) and 23 received reduced intensity conditioning regimen. Graft-versus-host disease (GVHD) prophylaxis included 2 cyclosporine (CSP) alone, 3 CSP and mycophenolate mofetil, 18 CSP and methotrexate, 2 tacrolimus alone, and 42 tacrolimus and methotrexate. Median time between day 0 of transplant and days performed on evaluation of hematogones by bone marrow aspiration was 31 days (15–140 days). At that time, engraftment of donor cells was confirmed by chimerism analysis using DNA amplification of polymorphic short tandem repeats of bone marrow cells, indicating that hematogones were proven to derive from donor-origins. Hematogones were identified averagely in 1.65% of bone marrow cells (0.01–12.27%) for allo-BMT recipients and 8.39% (0.15–55.56%) for UCBT recipients, respectively. Furthermore, UCBT recipients disclosed more prominent expansion of hematogones than allo-BMT recipients; 5 out of 21 (23.8%) UCBT recipients and 3 out of 46 (6.5%) allo-BMT recipients presented 5% or more of hematogones in their bone marrow cells. These results indicated that UCBT recipients presented much higher frequency and prominent reconstitution of hematogones compared with allo-BMT recipients (p=0.0035). We next analyzed the proportion of hematogones by comparing donors’ age with recipients’ age, since B lymphopoiesis is associated with aging under the physiologically condition. Donor’s age for UCBT was defined as 0-year-old for analyses. Donors for allo-BMT included 15 women and 31 men, with a median age of 36 years (17–66 years). Frequency of hematogones following SCT significantly declined with increasing the donors’ age (p=0.0014), but not with increasing the patients’ age. There was no statistically significant relationship between the number of hematogones and patients’ sex, underlying disease, infectious complications, conditioning regimen, and serum level of immunoglobulin following transplantation. In conclusion, predominant reconstitution of hematogones can be detected following UCBT much higher than allo-BMT, indicating that reconstitution of hematogones depends on donor’s age rather than recipient’s age. These findings obtained from allogeneic SCT suggest that primary lymphoid development may depend on the intrinsic property of stem cells and progenitors, especially aging, rather than bone marrow microenvironments. For the patients who underwent SCT, hematogones often can be confused with relapse of their disease. Our study indicated that prudent attention should be taken in UCBT recipients as well as BMT recipients, although clinical significance of expanded hematogones has not yet resolved.

Signal regulatory protein-α (SIRPA) is an immunoglobulin superfamily transmembrane protein with intracellular docking sites for two Src homology domain containing tyrosine phosphatases, and most abundantly expressed in neurons and myeloid cells. SIRPA is a critical immune inhibitory receptor on macrophages. CD47 is a ligand for SIRPA, and CD47 interaction with SIRPA serves as a ‘self-recognition’ that prevents phagocytosis of the cells expressing CD47. Recently, we (Nature immunology 2007) identified polymorphism in murine Sirpa as a critical modulator of engraftment in xenogeneic model of human-to-mouse hematopoietic stem cell transplantation, and non-obese diabetic (NOD) mouse Sirpa polymorphism has far greater reactivity with human CD47 than that of the respective alleles of other strains resulting in effective engraftment of human hematopoietic cells. In addition, as well as the mouse, human SIRPA is highly polymorphic in the IgV domain. Then, we examined whether polymorphism in SIRPA induced the difference for suppressive effect of human macrophage on hematopoiesis. First, we examined sequence alignment of SIRPA IgV domain (exon 3 of SIRPA) of healthy control 18 people. We identified two major variants; 6 people with variant1 (V1) and 12 people with variant2 (V2). The SIRPA amino acid sequences of V1 and V2 are different in 13 residues, and its residues in orthologous position between species that is polymorphic between NOD and other strains as well as between V2 and V1. Next, we examined that whether there is a difference in the effect on hematopoiesis between V1 macrophage and V2 macrophage by long term culture-initiating cells (LTC-IC) assay on MS-5 stromal cells. For macrophage preparation, peripheral mononuclear cells from healthy donors were purified by positive selection using MACS CD14 Micro Beads (Miltenyi Biotec), and they were incubated with M-CSF for 3 days. For LTC-IC assay, 5×102 differentiated macrophages were seeded onto established MS-5 stroma in 96-well tissue culture plates. The next day, human hematopoietic CD34+ cells were seeded at doses of 102 to 5×103 cells per well and cultured for 4 weeks. At the end of the culture, cells were detached and plated into methylcellulose progenitor assays. Macrophage had a suppressive effect on the number of LTC-IC in all cultures. There was tendency that V1 macrophage had a greater suppression compared to V2 macrophage, however the differences between V1 and V2 were marginal (p=0.03). These data suggests that human macrophages have suppressive effect on hematopoiesis, and human SIRPA polymorphism modulates macrophage-mediated suppression of hematopoiesis in allogenic model, likewise in xenogeneic model of human-to-mouse hematopoietic stem cell transplantation. Moreover, SIRPA polymorphism might be related to graft failure in the allogenic hematopoietic stem cell transplantation.

Background: Adult T-cell leukemia/lymphoma (ATL) is a mature T-cell neoplasm developing in a minority of individuals infected with human T-cell leukemia virus type I (HTLV-I). Although the results of conventional chemotherapy remain unsatisfactory for the management of ATL, allogeneic hematopoietic stem-cell transplantation (allo-SCT) is emerging as a promising alternative which can provide long-term remission in selected patients. Methods: To evaluate the efficacy of allo-SCT for the treatment of ATL, data on 397 patients (pts) with ATL who had received allo-SCT between 01/1996 and 12/2005 were collected through JSHCT, JMDP and JCBBN. We analyzed pts who did not have a history of previous stem-cell transplantation; who received a T-cell-replete graft; who had data on age at transplantation, sex, donor type, stem-cell source, conditioning regimen, and graft-versus-host disease (GVHD) prophylaxis. A total of 363 pts, with a median age of 51 yrs (range, 18–79), 201 males and 162 females, fulfilled these criteria: 175 received bone marrow and/or peripheral blood from a related donor; 188 received marrow or cord blood from an unrelated donor. At the time of transplantation, 91 pts were in complete remission (CR) and 226 were not in CR. Risk factors which potentially affect the survival outcomes were analyzed using proportional-hazards models. Results: The median follow-up was 21.6 months (range, 1.5–102). The unadjusted 3-year overall survival, disease-associated mortality, and treatment-related mortality (95% confidence interval [CI]) for pts in CR at transplantation were 48% (35–59%), 16% (8–27%), and 35% (24–45%), respectively, while those for pts not in CR were 22% (16–29%), 35% (28–42%), and 41% (34–48%), respectively. Multivariable analyses revealed four significant factors which adversely affected survival: older recipient age (>50 yrs)(adjusted hazard ratio [HR] 1.71; 95% CI, 1.24–2.38; P=0.001), male recipient (HR 1.46; 95% CI, 1.10–1.93; P=0.009), disease status other than CR (HR 2.21; 95% CI, 1.57–3.12; P Conclusions: Allo-SCT is effective therapy which confers long-term survival in a substantial proportion of patients with ATL but at the cost of significant treatment-related mortality. Favorable outcomes after developing mild acute GVHD in patients not in CR at transplantation suggest the presence of a graft-versus-ATL effect.

Background: The outcome of patients who suffer from GF after allogeneic transplantation is poor, primarily due to an increased risk of infectious complications and toxicities. We evaluated whether rescue with RICBT could improve survival after GF. Patients and Methods: We retrospectively surveyed the data of 63 patients (median age, 51 years: range, 17–68 years) with hematological disorders who received RICBT within 3 months of GF between Jan, 2000, and Apr, 2006. The diagnosis included AML (n=28), MDS (12), CML (2), ALL (13), lymphoma (4), and AA (4), and 28 patients were not in remission before the preceding allogeneic HCT, which had been performed with either myeloablative (29) or reduced-intensity conditioning regimens (34). Twelve patients (19%) had received unrelated BM, while 46 (73%) received CB. Fifty-one patients had developed primary GF (failure of the ANC to surpass 500/mm3 or Results: The median time interval between the preceding HCT to salvage RICBT was 47 days (27–162), and that between the diagnosis of GF to salvage RICBT was 16 days (5–61). Prior to RICBT, 21 patients (33%) were in PS 3–4, 8 (13%) had grade 3 organ toxicities according to CTCAE v3.0, and 53 (84%) had documented infections or febrile neutropenia. All patients were conditioned with fludarabine-based regimens with L-PAM (n=20), BU (15), CY (12) or thiotepa (2), with or without additional 2–4 Gy TBI. GVHD prophylaxis included CyA/FK alone (37) and a combination of MTX plus CyA/FK (10). The median number of infused TNC was 2.3 (1.0–4.3) x107/kg. Among the 46 evaluable patients who survived more than 28 days after RICBT, 33 (72%) engrafted, but 10 (22%) again experienced GF. Multivariate analysis disclosed that infusion of TNC ≥2.0x107/kg and a fludarabine/L-PAM-based regimen were associated with a higher probability of engraftment. The cumulative incidence of grade II–IV acute GVHD was 28%. The median follow-up of surviving patients was 236 days (39–937) after rescue RICBT. The 1-year overall and progression-free survival rates were 27% and 20%, respectively. Forty-five patients (70%) died at a median of 37 days (2–485) after RICBT, with a day-100 TRM of 54%. The cause of death included bacterial (14), fungal (10) and viral infections (7), and relapse (6). Multivariate analysis showed that high-risk disease, grade 3 organ toxicity before RICBT, and the use of MTX were associated with an increased risk of mortality. Conclusions: Our data support the feasibility of RICBT for patients suffering from GF, with an engraftment rate of >70%, when they receive a graft containing ≥2.0x107/kg cells. The earlier application of RICBT while patients still have better PS without infections or organ toxicities will be the subject of continued clinical research.

[Background] We report the results of a prospective multi-institutional clinical trial of BMT from an HLA-matched URD following RIC. [Patients and Methods] The conditioning regimen included cladribine 0.11 mg/kg on day -8 to day -3, busulfan 4 mg/kg po on day -6 and day -5, and 4 Gy TBI on day -1. GVHD prophylaxis included cyclosporine and short-term methotrexate. Patients with hematologic diseases were eligible for this study if they were either older than 50 years or had significant medical contraindications to undergo conventional transplantation. Primary endpoints were neutrophil engraftment and achievement of complete donor-type chimerism (CD3+ cells >90%) on day 90. Regimen-related toxicities (RRT) between day -8 and day 28 were assessed by the NCI-CTC v2.0. A total of 27 patients were registered, but one patient was removed before transplant because of severe fungal infection. [Results] The median follow-up time was 722 days (range, 324–996) among survivors. The median age of patients was 56.5 years (36–64). Nine of the 26 patients (36%) had advanced-stage diseases and 3 (11%) had failed previous high-dose autologous or allogeneic transplantation. The diagnoses included AML (n=9), MDS/MPD (n=7), NHL (n=3), ALL (n=2), CML, ATLL, PCL, biphenotypic acute leukemia, and severe aplastic anemia (n=1). The median number of infused nucleated cells was 2.2 × 108/kg. After transplant, while one patient experienced engraftment failure and subsequent sepsis, and died on day 34, the remaining 25 patients achieved neutrophil engraftment (median, 17th day). Another patient was censored from the study due to grade 4 liver dysfunction, which developed on day 19, which left 24 patients for the chimerism analysis. The percentage of donor chimerism in CD3+ cells on days 28, 56 and 90 was, respectively, 88% (21/24), 100% (24/24) and 100% (24/24). Grade 3 RRT included arrhythmia (n=1), hypoxia (n=3), hyperbilirubinemia or hypertransaminasemia (n=7), stomatitis (n=18) and diarrhea (n=4), and grade 4 RRT included hypoxia (n=1) and hyperbilirubinemia (n=1). Acute GVHD of grade II, III and IV occurred in 27%, 27% and 4%, respectively. Ten of 15 evaluable patients (67%) had extensive chronic GVHD. CMV reactivation occurred in 23 patients (89%); 4 had histologically confirmed CMV colitis, 1 had CMV pneumonitis and 1 had CMV hepatitis, while the remaining patients had asymptomatic viremia. Of the 16 patients with measurable disease at the time of BMT, 15 achieved complete remission. The 100-day and 1-year cumulative incidences of non-relapse mortality (NRM) estimated by the Kaplan-Meier method were 20% and 54%, respectively. The cause of death that contributed to NRM was infection, with grade 0–I acute GVHD in 29% and grade II–IV acute GVHD in 71%. The 100-day and 1-year cumulative incidences of relapse were 8% and 35%, respectively, and the 1-year overall and progression-free survival rates were 42% and 30%, respectively. [Conclusions] The results support the feasibility of this procedure with a high response rate, but there is still a problem with the high NRM due to uncontrollable infections primarily associated with GVHD.

The efficacy of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) for NK-cell neoplasms is unknown. We investigated the results of allo-HSCT for NK-cell neoplasms between 1990 and 2003 through questionnaires. A hematopathologist reclassified the pathological diagnoses according to the WHO classification. Of 345 patients from 76 hospitals who underwent allo-HSCT for malignant lymphoma, 32 had NK-cell neoplasms: extranodal NK/T-cell lymphoma (n=27), blastic NK-cell lymphoma (n=3), and aggressive NK-cell leukemia (n=2). Fifteen were chemosensitive and 17 chemorefractory. Nine were in CR at the time of allo-HSCT. Twenty-five had matched related donors, 3 mismatched related, 2 matched unrelated, and 1 mismatched unrelated donors. Stem-cell source was bone marrow in 11 and mobilized peripheral blood in 21. Conditioning regimens were myeloablative (n=26) and non-myeloablative (n=6). Total body irradiation was given to 23 patients. Graft-versus-host disease (GVHD) prophylaxis was cyclosporin and short-term methotrexate in 27 patients. Grade 2–4 acute GVHD and chronic GVHD developed in 13 and 9, respectively. Nine died of disease progression, 4 of infection, 2 of veno-occlusive disease, 2 of acute GVHD, 1 of interstitial pneumonitis, and 1 of thrombotic microangiopathy. Two-year progression-free and overall survivals were 33% and 38%, respectively (median follow-up, 32 months). All patients who did not relapse/progress within 10 months achieved progression-free survival during the follow-up. In multivariate analysis, stem cell source (BM vs. PB; relative risk 3.33) and acute GVHD (grade 2–4 vs. grade 0–1; relative risk 2.56) significantly affected progression-free survival. Allo-HSCT is a promising treatment for NK-cell neoplasms. Figure Figure

Two types of activating FLT3 mutations have been described in AML. FLT3/ITDs can be detected in 20% to 30% of patients with AML. Point mutations of FLT3/D835 have been described in 7% of adult AML patients. Activating FLT3 mutations has been associated with the leukocytosis and poor prognosis. We retrospectively analyzed the significance of FLT3 mutations in AML patients of normal karyotype treated with autologous peripheral blood stem cell transplantation (auto-PBSCT). METHOD: We evaluated 34 consecutive patients with first CR AML of normal karyotype who received myeloablative therapy and auto-PBSCT to analyze clinical features and outcomes between patients with and without FLT3/ITDs and FLT3/D835. There were 16 males and 18 females with a median age of 41.5 years ranging 15–74 years. Cytogenetic G-banding analysis was performed with standard method. The distribution of morphologic types of AML according to the FAB classification was as follows; one patient was M0, twelve M1, eight M2, seven M4 and six M5. The pre-transplant conditioning regimen was G-CSF combined with the high-dose chemotherapy consisting of busulfan (16 mg/kg), etoposide (40 mg/kg) and Ara-C (3 g/m2x4) (BEA regimen). DNA PCR assay was used to detect FLT3/ITDs. All abnormal longer products by agarose gel electrophoresis were subsequently sequenced. DNA PCR assay followed by direct sequence were used to detect FLT3/D835. RESULT: FLT3/ITDs were detected in 8 of 34 patients (23.5 %). FLT3 D835 mutation was detected in 2 of 34 patients (5.9%). To define clinical differences between patients with and without FLT3/ITDs, clinical variables at the diagnosis were compared. WBC (p=0.013), LDH (p=0.0147), the percentage of PB and BM blasts (p=0.0422 and P=0.0021) were significantly higher in the FLT3/ITDs patients. Other clinical parameters such as age, sex, FAB classification, Hb, Plt, remission induction therapy, interval from diagnosis to auto-PBSCT, number of infused CD34+ cells and hematological recovery after auto-PBSCT are not associated with the presence or absence of FLT3/ITDs. We analyzed the clinical significance of FLT3/ITDs mutations. OS and DFS was similar in patients with or without FLT3/ITDs (5 years OS, 71.4% vs 78.9%, p=0.5746; 5 years DFS, 72.9% vs 68.6%, p=0.9273 by the log-rank test). DISCUSSION: As far as we know, this is the first report to describe the significance of FLT3 mutations in AML patients of normal karyotype treated with auto-PBSCT. We show that FLT3 mutations have no prognostic impact in autotransplanted AML 1CR patients of normal karyotype. Our data suggest dose escalation of chemotherapy may conquer the poor prognostic implications of FLT3 mutations. The prognostic significance of activating FLT3 mutations in AML patients with normal karyotype should be evaluated in relation with post-remission therapeutic modalities.