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The presence of a JAK2 V617F or JAK2 exon 12 mutation is one of the three major criteria listed for the diagnosis of polycythemia vera (PV) in the 2017 World Health Organization Classification. However, a nationwide study has not yet been conducted in Japan since the discovery of JAK2 mutations. Therefore, the Japanese Society of Hematology (JSH) retrospectively analyzed the clinical characteristics of 596 Japanese patients with PV diagnosed between April 2005 and March 2018. Among the 473 patients with complete data on JAK2 mutations available, 446 (94.3%) and 10 (2.1%) were positive for the JAK2 V617F and JAK2 exon 12 mutations, respectively. During a median follow-up of 46 months (range: 0-179 months), 47 (7.9%) deaths occurred. The major causes of death were secondary malignancies (23.4%), acute leukemia (12.8%), non-leukemic progressive disease (10.6%) and thrombotic (6.4%) and hemorrhagic complications (6.4%). Thrombotic and hemorrhagic events occurred during the clinical course in 4.0% (n = 24) and 3.5% (n = 21) of patients, respectively. These results show that the international PV prognostic score (age, venous thrombosis and leukocytosis) is applicable to Japanese patients with PV.

Background The prognosis of Philadelphia chromosome-negative myeloproliferative neoplasms is relatively favorable, but the quality of life can be severely affected by myeloproliferative neoplasm-related symptoms such as fatigue, pruritus, night sweats, bone pain, fever and weight loss. In this study, we administered hochuekkito, a traditional herbal medicine, to patients with myeloproliferative neoplasms and investigated whether there was a reduction in myeloproliferative neoplasm-related symptoms. Methods We conducted a randomized parallel-group pilot study. Patients were assigned to a hochuekkito administration or non-hochuekkito administration group. Myeloproliferative neoplasm-related symptoms based on Myeloproliferative Neoplasm Symptom Assessment Form total symptom score and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 were examined before hochuekkito administration and 4 and 8 weeks after administration. Results Among the 42 patients included in the analysis, 21 were assigned to the hochuekkito group and 21 were assigned to the control group. After administering hochuekkito, the median values of Myeloproliferative Neoplasms Symptom Assessment Form total symptom score at 4 and 8 weeks in the hochuekkito group demonstrated a decreasing trend; however, the difference between the two groups was not significant. Conclusions In this study, we were unable to demonstrate significant differences between the hochuekkito and control groups in terms of the efficacy of hochuekkito in treating myeloproliferative neoplasm-related symptoms. However, there were cases that presented prominent improvement in symptoms in the hochuekkito group. The only reported adverse event was grade 1 impaired hepatic function. Therefore, hochuekkito might be a therapeutic option for patients with severely affected quality of life due to myeloproliferative neoplasm-related symptoms.

BACKGROUND: Although Abelson (ABL) tyrosine kinase inhibitors (TKIs) have demonstrated potency against chronic myeloid leukemia (CML), resistance to ABL TKIs can develop in CML patients after discontinuation of therapy. OBJECTIVE: Glucose metabolism may be altered in CML cells because glucose is a key metabolite used by tumor cells. We investigated whether D-mannose treatment induced metabolic changes in CML cells and reduced CML growth in the presence of ABL TKIs. METHODS: We investigated whether D-mannose treatment induced metabolic changes in CML cells and reduced CML growth in the presence of ABL TKIs. RESULTS: Treatment with D-mannose for 72 h inhibited the growth of K562 cells. Combined treatment using ABL TKIs and D-mannose induced a significantly higher level of cytotoxicity in Philadelphia chromosome (Ph)-positive leukemia cells than in control cells. In the mouse model, severe toxicity was observed as evidenced by body weight loss in the ponatinib and D-mannose combination treatment groups. CONCLUSION: Our results indicate that metabolic reprogramming may be a useful strategy against Ph-positive leukemia cells. However, caution should be exercised during clinical applications.

Ropeginterferon alfa-2b is a novel, site-selective, monopegylated recombinant human interferon alfa-2b. Safety and efficacy of ropeginterferon alfa-2b for the treatment of polycythemia vera were demonstrated in clinical studies conducted in European countries, but clinical studies in Japanese patients are lacking. This phase 2, open-label, multicenter, single-arm study investigated the safety and efficacy of ropeginterferon alfa-2b in 29 Japanese patients with polycythemia vera including young patients and patients with low thrombosis risk who are difficult to receive guideline-based standard treatments. The primary outcome of durable complete hematologic response without phlebotomy at months 9 and 12 was achieved by 8/29 (27.6%) patients. The fastest complete hematologic response was observed at week 12. A corresponding reduction in the JAK2 V617F allele burden from baseline to 52 weeks was also observed (mean ± standard deviation = - 19.2% ± 22.6%). No new safety concerns were identified in Japanese patients when compared with previous studies of ropeginterferon alfa-2b in European populations; the most common treatment-related adverse events were alopecia (55.2%), fatigue (27.6%) and influenza-like illness (27.6%). Most treatment-related adverse events were mild or moderate, with none of grade ≥ 3. Ropeginterferon alfa-2b is a safe and efficacious treatment option in Japanese patients with polycythemia vera.

L-type neutral amino acid transporter 1 (LAT1) is a heterodimeric membrane transport protein involved in neutral amino acid transport. LAT1 is highly expressed in various malignant solid tumors and plays an essential role in cell proliferation. However, its role in malignant lymphoma remains unknown. Here, we evaluated LAT1 expression level in tissues from 138 patients with Non-Hodgkin lymphoma (NHL). Overexpression of LAT1 was confirmed in all types of NHL and we found that there is a significant correlation between the level of LAT1 expression and lymphoma grade. The LAT1 expression was higher in aggressive types of lymphomas when compared with static types of lymphomas, suggesting that active tumor proliferation requires nutrient uptake via LAT1. The expression level of LAT1 was inversely correlated with patients’ survival span. Furthermore, pharmacological inhibition of LAT1 by a specific inhibitor JPH203 inhibits lymphoma cell growth. In conclusion, our study demonstrated that LAT1 expression can be used as a prognostic marker for patients with NHL and targeting LAT1 by JPH203 can be a novel therapeutic modality for NHL.

Background Myelodysplastic syndrome (MDS) is a clonal bone marrow disorder defined by cytopenia and is associated with an increased risk of transformation to acute myeloid leukemia (AML). The outcome of MDS is poor, and as a result, alternative therapeutic approaches are needed to improve survival. The inhibition of the DNA damage response pathway, including poly (ADP-ribose) polymerase-1 (PARP-1), has been approved to treat several cancers, and WEE1 is overexpressed in many cancers. Therefore, a WEE1 inhibitor in combination with a PARP-1 inhibitor could inhibit the proliferation of MDS and AML. Methods We analyzed whether WEE1 was regulated in the progression of MDS and AML. We also evaluated the efficacy of MK-1775 (WEE1 inhibitor) and talazoparib (PARP-1 inhibitor). Results WEE1 expression was higher in the AML cells than in the MDS cells. However, PARP-1 expression remained unchanged. MK-1775 or talazoparib alone inhibited MDS and AML cells after 72 hours, and cellular cytotoxicity and caspase 3/7 activity were increased. The combined use of MK-1775 and talazoparib produced superior efficacy than either drug alone, and SKM-1 colony formation was reduced. Significant cell populations in the sub-G1 phase were shown in the cell-cycle analyses. Additionally, γ-H2AX expression and caspase 3 activity were increased. The combined treatment also changed the mitochondrial membrane potential. Conclusions A combination of WEE1 and PARP-1 inhibition enhanced the efficacy and is proposed as a new therapeutic option for patients with MDS or AML. Our findings have clinical implications for a potential novel therapeutic strategy for MDS patients.

von Willebrand factor ristocetin cofactor (vWF activity) and platelet count (PLT) are negatively correlated in patients with polycythemia vera (PV) and essential thrombocythemia (ET). However, vWF activity does not always normalize upon controlling PLT in those patients. To address this issue, we investigated the correlation between vWF activity and PLT in PV and ET patients. The negative correlation between vWF activity and PLT was stronger in calreticulin mutation-positive (CALR+) ET than in Janus kinase 2 mutation-positive (JAK2+) PV or ET groups. When PLT were maintained at a certain level (600 × 10

Post-transplant lymphoproliferative disease (PTLD) is defined as a lymphoma that occurs after solid-organ or hematopoietic stem-cell transplantation (HSCT), caused by immunosuppression and Epstein-Barr virus (EBV) reactivation. It is an important post-transplant complication that can be fatal. After HSCT, most PTLD occurs within 2 years. Recent evidence suggests that tyrosine kinase inhibitors (TKIs) are expected to be effective maintenance therapy after HSCT for Philadelphia chromosome-positive leukemia. However, it is unclear whether the use of TKIs might pose a risk of developing PTLD after HSCT. We present the first case of late-onset PTLD during dasatinib treatment, which occurred 10 years after umbilical cord blood transplantation (CBT). A 59-year-old man who received CBT for chronic myeloid leukemia blast phase needed long-term dasatinib therapy for molecular relapse. Ten years after CBT, he developed diffuse-large B-cell lymphoma (DLBCL). We observed chimerism of the DLBCL sample, which indicated complete donor type and EBV-DNA, and the patient was diagnosed with PTLD. Because of treatment resistance, he died 6 months after PTLD onset. Although he received no long-term administration of immunosuppressive agents, he received long-term dasatinib treatment, which suggests that prolonged dasatinib use after CBT caused EBV reactivation and led to PTLD. Our case suggests that the potential contribution of molecular-targeted agents after HSCT to the development of PTLD should be carefully considered.

We performed a prospective observational study of chronic myeloid leukemia (CML) patients after anti-SARS-CoV-2 BNT162b2 vaccination (VC). In total, 32 CML patients with tyrosine kinase inhibitor (TKI) therapy, 10 CML patients with treatment-free remission, and 16 healthy subjects participated in the study. From April 2021 to September 2021, all cases (median age = 58 years) were vaccinated twice. Immunoglobulin G for SARS-CoV-2 spike protein (S-IgG) was measured at three timepoints (before the first VC, 1–5 weeks after the second VC (T1), and approximately 6 months after the second VC (T2)). S-IgG was not observed before the first VC in any participant. At T1, all cases had acquired S-IgG. There were no significant differences in S-IgG levels among groups. A paired sample comparison of median S-IgG titers between T1 and T2 in all groups showed a significant reduction in T2 S-IgG titers. There were no significant differences in S-IgG levels among groups. When all patients were analyzed, those aged ≥58 years had significantly lower S-IgG levels than those aged

A 73-year-old woman was hospitalized with sudden chest pain and hematemesis. Chest computed tomography and upper gastrointestinal endoscopy revealed an idiopathic submucosal hematoma from the cervical esophagus to the esophagogastric mucosal junction. Idiopathic esophageal submucosal hematoma is often prone to a bleeding tendency of an underlying disorder. The patient had a history of essential thrombocythemia (ET) and was taking aspirin. She successfully recovered after aspirin discontinuation and conservative treatment; however, died of cardiopulmonary arrest in the ward on day 9 of hospitalization. The autopsy revealed that the cause of death was pulmonary thromboembolism. This is the first report of ET with submucosal hematoma of the esophagus. The possibility of an esophageal submucosal hematoma should be considered when patients with ET complain of chest pain since ET and treatment with aspirin are considered risk factors for bleeding. Additionally, close attention should be focused on the risk of developing thrombosis if a patient with myeloproliferative neoplasm is required to discontinue antithrombotic therapy due to a bleeding event.

Essential thrombocythemia (ET) mainly affects the elderly, but can also develop in women of childbearing age. The risk of miscarriage and other complications during pregnancy in ET patients are reported to be higher than that compared to the general population. Therefore, management of pregnancy in ET patients requires special considerations. Several groups recommend interferon (IFN) therapy for ET patients with high-risk pregnancies, but currently no guidelines are available in Japan. We report the outcomes of nine ET patients with ten consecutive high-risk pregnancies. All patients were successfully managed with IFN-α during their pregnancies. All patients also received aspirin and switched to unfractionated heparin around 36 weeks of gestation. As for the seven pregnancies in which IFN-α was started after detection of pregnancy, median platelet counts decreased from 910 to 573 × 109/L after 2 months of IFN-α therapy, and median platelet counts at the time of delivery for all ten pregnancies was 361 × 109/L. All patients gave birth to healthy children. IFN-α was well tolerated, safe, and effective as a cytoreductive therapy for all patients. Although evidence is limited and the use of IFN is not approved in Japan, we suggest considering IFN therapy for high-risk ET pregnancies.

Clinical studies of Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) have progressed greatly with the discovery of mutations in three driver genes: JAK2, MPL, and calreticulin. Other genes that may play important roles in pathogenesis and progression of MPN have also been identified. Several prognostic prediction systems based on various risk factors including these genetic factors have been developed and utilized in clinical practice. All mutations of the three driver genes result in JAK2 activation, and JAK inhibitors have indeed improved clinical outcomes for primary myelofibrosis and polycythemia vera. However, they have minimal ability to inhibit clonogenic growth, far below that of ABL tyrosine kinase inhibitors in chronic myeloid leukemia. Therefore, hematopoietic stem cell transplantation (HSCT), which still has a high mortality rate, remains the only curative treatment for MPN. Efforts are being made to advance the treatment of MPN by refining HSCT methods, combining JAK inhibitors with other molecularly targeted agents, and reviewing the safety and clonogenic inhibitory effects of interferon-alfa.

Desquamative esophagitis (DE) is a rare benign condition characterized by sheet-like shedding of esophageal squamous epithelial tissue. Although cases of drug-induced DE, such as those induced by direct oral anticoagulants, have been reported, cases of DE complicated with hematopoietic stem cell transplantation (HSCT) are rare. We herein report the case of a 52-year-old woman with FLT3-ITD mutation-positive acute myeloid leukemia who presented with DE immediately after HSCT. Allogeneic peripheral blood HSCT with FBM (fludarabine 180 mg/m

Sphingosine 1-phosphate (S1P) is a bioactive lipid involved in cancer progression through its binding to S1P receptors (S1PRs). However, the association between multiple myeloma (MM) and S1P is unclear. The current study aimed to investigate the potential anti-cancer effects of fingolimod and sphingosine kinase (SK) inhibitors in myeloma cells and the effects of S1P-induced chemoresistance and neovascularization on MM cell proliferation. MM cell lines were treated with the S1PR1 antagonist fingolimod and the SK inhibitors ABC294640 and SK1-I, after which cell proliferation was measured. Protein expression was also assessed under each condition using immunoblotting. Serum S1P levels in patients with MM, monoclonal gammopathy of undetermined significance and healthy volunteers were assessed. Human umbilical vessel cells (HUVECs) were co-cultured with anti-S1P agents to assess the effect on cell migration. All treatments suppressed myeloma cell proliferation and caspase-3-mediated apoptosis by suppressing S1P activity. These findings suggest that S1P activation is associated with proliferation and survival for MM cells. S1P attenuated the proteosome inhibitor (PI) effect, while the anti-S1P agents recovered the effect. In addition, S1P promoted the migration and proliferation of HUVECs, whereas the S1P inhibitors reduced the influence of S1P. This study highlights the therapeutic potential of anti-S1P agents for MM treatment. Inhibition of S1P function may overcome resistance to PI developed by myeloma cells and inhibit the changes to the bone marrow microenvironment via neovascularization.

We conducted a large-scale, nationwide retrospective study of Japanese patients who were diagnosed with essential thrombocythemia based on the diagnostic criteria in the World Health Organization classification. We investigated clinical characteristics, survival rates, and the incidence of thrombohemorrhagic events as well as risk factors for these events. A total of 1152 patients were analyzed in the present study. Median age at diagnosis was 65 years, the median platelet count was 832 × 109/L, and the positive mutation rates of JAK2V617F, CALR, and MPL were 62.8, 25.1, and 4.1%, respectively. Compared with European and American patients, Japanese patients were more likely to have cardiovascular risk factors and less likely to have systemic symptoms including palpable splenomegaly. Thrombocytosis was identified as a risk factor for hemorrhagic events and prognosis, but not for thrombotic events. The prognostic factors and risk classifications reported in Europe and the United States were generally applicable to Japanese patients. Regarding transformations, secondary myelofibrosis progressed in a time-dependent manner, but progression to acute leukemia was low in "true" ET patients. Skin cancers were less common and gastrointestinal cancers more common as secondary malignancies in Japanese patients, suggesting ethnic differences.

Background and Methods: FLT3-internal tandem duplication (FLT3-ITD) is a type of mutation present in approximately 20-30% of patients with acute myeloid leukemia (AML) and is associated with poor prognosis. We performed a comprehensive genome profiling assay in patients with relapsed and refractory (R/R) AML, using the Foundation One Heme (F1H) panel, as a part of hematologic malignancies (HM)-SCREEN-Japan 01 (UMIN000035233), an actionable mutation profiling multicenter study. In this study, we analyzed the high frequency of FLT3 mutations in patients with R/R AML and found several patients who were positive for FLT3-N676K, a subclonal gene without concurrent ITD. Moreover, clonal evolution was observed in most patients who received kinase inhibitors, suggesting that mutations in signaling pathways downstream of FLT3 and activation of alternative pathways contribute to resistance mechanisms after FLT3 inhibitor treatment. Upon treatment failure during gilteritinib or quizartinib monotherapy, we can switch to another FLT3 inhibitor treatment in Japan. However, few reports have investigated clonal evolution after multiple FLT3 inhibitor treatment failure, and the mutational resistance profile remains unknown. Thus, we extended our investigation to examine clonal evolution during the progression of leukemia harboring FLT3-ITD and tyrosine kinase domain mutation (TKD) mutations. In this study, we performed serial comprehensive genome profiling analyses to evaluate time-dependent changes in genomic profiles of patients receiving the FLT3 inhibitors gilteritinib, and quizartinib in AML. Results: This study was initiated in January 2019, and 91 patients were recruited by March 2020. The median turnaround time between sending specimens and receiving results was 15 days (9 to 56 days). In this study, a higher incidence of FLT3 mutations was observed in patients with AML (28.6%, 26/91), and those with relapse/refractory (R/R) AML (64.8%, 59/91), FLT3-ITD (20.3%, 12/59), and FLT3-TKD (15.3%, 9/59), than previously reported in newly diagnosed patients. Particularly, FLT3 mutations were much more frequently observed in patients with R/R AML (35.6 %, 21/59), whereas those with newly diagnosed AML unfit for standard treatment (15.6 %, 5/32). Furthermore, FLT3-TKD mutations were found in 10 patients, who were potential candidates for treatment with FLT3 inhibitors, such as gilteritinib. The N676K mutation within the FLT3 tyrosine kinase domain 1, which is not detectable through conventional mutational analyses, was observed using a multiplex polymerase chain reaction in 19.2% (5 of 26) of patients who were FLT3mutation-positive, including those with subclonal mutations. Moreover, patients with RUNX1 mutation were present in this cohort, and this finding supports previous reports showing the association between the core binding factor protein complex and FLT3 N676K mutation in leukemia. Interestingly, FLT3-ITD mutations usually occur in the juxtamembrane domain, but we found three patients with other abnormalities, including ITDs in the tyrosine kinase domain, which are associated with poor prognosis. Meanwhile, during FLT3 inhibitor treatment, the resistant clonal expansion was observed due to activation of alternative pathways such as NRAS pathway or acquired FLT3 mutation. Not only activating these alternative pathways, but the cases in which TKD point mutation was added to FLT3-ITD, or new mutations were acquired without the additional mutation site among the cases showing FLT3 inhibitor resistance as the treatment progressed. Conclusions: We conclude that F1H mutational analyses for R/R AML harboring FLT3-ITD/TKD mutations may reveal novel therapeutic targets that are sensitive to FLT3 inhibitors. Moreover, improved biomarker analysis methods for detecting additional FLT3 alternations, like FLT3 N676K, could guide patient selection for the most suitable anti-FLT3 therapies. Furthermore, serial comprehensive genome profiling analysis at the time of AML progression, especially after tyrosine kinase inhibitor treatment, will provide valuable information for clinical decision-making. Table Disclosures Shibayama: Fujimoto: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Otsuka: Honoraria; Kyowa Kirin: Honoraria; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Nippon Shinyaku: Honoraria, Research Funding; Sumitomo Dainippon: Honoraria, Research Funding; Merck Sharp & Dohme: Research Funding; Takeda: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Taiho: Research Funding; Shionogi: Research Funding; Teijin: Research Funding; Astellas: Research Funding; Sanofi: Honoraria; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundi Pharma: Honoraria. Yamauchi:Otsuka: Research Funding; Ono Pharmaceutical: Honoraria; Chugai: Honoraria; Abbie: Research Funding; Solasia Pharma: Research Funding; Astellas: Research Funding; Daiichi Sankyo: Research Funding; Pfizer: Honoraria, Research Funding. Gotoh:Eisai: Honoraria; Alexion pharmaceuticals: Research Funding; Ono Pharmaceutical: Honoraria; Nippon Shinyaku: Honoraria; Takeda pharmaceutical: Honoraria; Taiho pharmaceutical: Honoraria; Chugai: Honoraria; Novartis: Research Funding. Yamamoto:Chugai: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Sanofi: Honoraria; Sumitomo Dainippon: Honoraria; Stemline Therapeutics: Consultancy; Otsuka: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; IQIVA/HUYA: Honoraria; HUYA: Consultancy; IQIVA/Incyte: Research Funding; Solasia Pharma: Research Funding; SymBio: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Yakult: Research Funding; Zenyaku: Research Funding; Astra-Zeneca: Consultancy, Research Funding; Bayer: Research Funding; Bristol-Myers Squibb: Honoraria; Aichi Cancer Center: Current Employment; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria; Mochida: Honoraria; Gilead Sciences: Research Funding; Daiichi Sankyo: Consultancy; MSD: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Fujishima:Pfizer: Speakers Bureau. Takahashi:Novartis Pharma KK: Honoraria, Research Funding; Pfizer Japan Inc.: Honoraria, Research Funding; Bristol-Myers Squibb Company: Honoraria. Usuki:Apellis: Research Funding; Alexion: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Chugai: Research Funding. ONO:Astellas Pharma Inc.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Mundipharma K.K.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Novartis Pharma KK: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb Company: Honoraria; Pfizer Japan Inc.: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Takeda Pharmaceutical Company Limited.: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Janssen Pharmaceutical K.K: Honoraria; Eisai Co., Ltd.: Honoraria. Kuroda:Sysmex: Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Asahi Kasei: Research Funding; Shionogi: Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy; Eisai: Honoraria, Research Funding; Fujimoto Pharmaceutical: Honoraria, Research Funding; Taiho Pharmaceutical: Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; MSD: Research Funding. Izutsu:Incyte: Research Funding; Eisai: Research Funding; AstraZeneca: Research Funding; Abbvie pharmaceuticals: Research Funding; Chugai: Research Funding; Novartis: Research Funding; Celgene: Research Funding; Symbio: Research Funding; Solasia: Research Funding; Janssen: Research Funding; Yakult: Research Funding; HUYA Japan: Research Funding; Sanofi: Research Funding; Daiichi Sankyo: Research Funding; Bayer pharmaceuticals: Research Funding; Ono Pharmaceutical: Research Funding. Minami:Novartis Pharma KK: Honoraria; Pfizer Japan Inc.: Honoraria; Takeda: Honoraria; Bristol-Myers Squibb Company: Honoraria.

Vitamin B6 (VB6) deficiency contributes to oncogenesis and tumor progression in certain cancers, and is prevalent in cancer patients in general. VB6 is also an essential element of heme synthesis, and deficiency can lead to anemia. Primary myelofibrosis (PMF) and secondary myelofibrosis (sMF) are myeloproliferative neoplasms often presenting with anemia along with other cytopenias. We performed a prospective study to determine whether PMF and sMF patients suffer from VB6 deficiency, and whether VB6-deficient patients show improvement of anemias with VB6 supplementation. Twelve PMF patients and 11 sMF patients were analyzed. A total of 16 of 23 patients (69.6%) were found to have VB6 deficiency, but VB6 supplementation with pyridoxal phosphate hydrate did not elevate hemoglobin levels in deficient patients. None of the patients presented with vitamin B12, iron, or copper deficiencies. Four patients showed serum folate levels below the lower limit of normal and eight patients showed serum zinc levels below the lower limit of normal; however, these deficiencies were marginal and unlikely to contribute to anemia. Compared to VB6-sufficient patients, VB6-deficient patients showed significantly lower serum folate levels and higher serum copper levels. Studies elucidating the relationship of VB6 deficiency and etiology of PMF/sMF are warranted.

Accurate staging and evaluation of therapeutic effects are important in managing plasma-cell neoplasms. Diffusion-weighted imaging with body signal suppression magnetic resonance imaging (DWIBS-MRI) allows for acquisition of whole-body volumetric data without radiation exposure. This study aimed to investigate the usefulness of DWIBS-MRI in plasma-cell neoplasms. We retrospectively analyzed 29 and 8 Japanese patients with multiple myeloma and monoclonal gammopathy of undetermined significance, respectively, who underwent DWIBS-MRI. We conducted a histogram analysis of apparent diffusion coefficient values. The correlations between each histogram parameter and staging, cell maturation, prognosis, and treatment response were evaluated. We found that the apparent diffusion coefficient values in patients with monoclonal gammopathy of undetermined significance were lower than those in patients with multiple myeloma. Pretreatment apparent diffusion coefficient values of immature myeloma were lower than those of mature myeloma. Moreover, these values decreased in proportion to stage progression in Durie-Salmon classification system but showed no significant correlation with other staging systems or prognosis. Patients were stratified as responder, stable, and non-responder based on the International Myeloma Working Group criteria. The magnitude of changes in apparent diffusion coefficients differed significantly between responders and non-responders (0.154 ± 0.386 ×10–3 mm2/s vs. -0.307 ± 0.424 ×10–3 mm2/s, p = 0.003). Although its usefulness has yet to be established, DWIBS-MRI combined with apparent diffusion coefficient measurement allowed for excellent response evaluation in patients with multiple myeloma. Furthermore, apparent diffusion coefficient analysis using DWIBS-MRI may be useful in predicting cell maturation and total tumor volume.

Non-tuberculous mycobacterial (NTM) disease is a rare cause of neutropenic fever in patients with hematological malignancies. There are few studies on the optimal management for such patients with NTM. We report a case of myelodysplastic syndrome (MDS) treated by umbilical cord blood transplantation (CBT) after Mycobacterium kansasii (M. kansasii) pneumonia. A 38-year-old man diagnosed with MDS developed severe pneumonia during induction chemotherapy. Repeated sputum culture uncovered mycobacterium infection. Then, by the polymerase chain reaction of the bronchial lavage fluid, M. kansasii infection was proven. After 140 days of anti-NTM therapy, CBT was successfully carried out and the patient recovered without recurrence of NTM infection. This case provides valuable evidence that hematopoietic stem cell transplantation is feasible after a reliable diagnosis and continuous anti-NTM therapy.

Primary effusion lymphoma (PEL) is a large B-cell lymphoma that only proliferates proliferating effusion in the body cavity. It is associated with human herpesvirus 8 (HHV8).HHV8 negative effusion lymphoma, which is different from PEL in many ways, has also been reported and is referred to as HHV8-unrelated PEL-like lymphoma. This lymphoma is very rare and its clinical characteristics have not been fully clarified.A 79-year-old male developed HHV8-negative primary effusion lymphoma during treatment for myelodysplastic syndrome.Abdominal computed tomography revealed abdominal effusion, but did not show any evidence of a tumor mass or lymph node enlargement. A cytological analysis of his pleural effusion revealed atypical lymphoid cells that were negative for CD10, and positive for CD19 and CD20. Corticosteroids were administered to treat the abdominal effusion; however, the patient died of an exacerbation of lymphoma on the 20th day after the initiation of corticosteroid therapy. We herein report the case of an HIV seronegative elderly patient with HHV8-unrelated PEL-like lymphoma.

A 71-year-old woman presented to a clinic with the chief complaint of facial edema and dyspnea; chest radiography showed mediastinal mass shadow and right pleural effusion. Computed tomography guided biopsy of the mediastinal mass had been performed by her previous doctor, and she was diagnosed with diffuse large B-cell lymphoma. She was referred to our hospital for chemotherapy. Electrocardiography performed before initiating chemotherapy showed sinus arrest for about 4 s, and Holter electrocardiography showed sinus arrest for up to about 7.4 s, which was repeatedly observed 6 times, indicating sick sinus syndrome (SSS). The mediastinal mass completely excluded the superior vena cava, and considering the risk of infection, an extracorporeal pacemaker was not inserted. We believed that the tumor effect was the cause of sinus arrest; hence, chemotherapy initiation was prioritized. R-CHOP therapy preceding vincristine and prednisolone was started, and sinus arrest was not observed after initial treatment. SSS may have been caused by carotid hypersensitivity syndrome that involved the exclusion of carotid artery pressure receptors by the tumor or the direct stimulation of the vagus nerve by microtumor infiltration.

Human herpesvirus-6 (HHV-6) reactivation is an important complication in patients receiving umbilical cord blood transplantation (CBT). Chromosomally integrated human herpesvirus-6 (ciHHV-6) is a condition in which the complete HHV-6 genome is integrated into the host germline genome and is transmitted in a Mendelian manner. The influence of ciHHV-6 in recipients or donors in cases of CBT is unknown. We report the first case with ciHHV-6 that received CBT twice for acute lymphoblastic T-cell leukemia. HHV-6 DNA in peripheral blood leukocytes (PBLs) was examined over time through two CBTs. After the first CBT, the HHV-6 viral load was significantly reduced by conversion to PBLs derived from the first donor. During the second CBT, an increase in HHV-6 DNA in PBLs and plasma were observed. However, HHV-6 mRNA was not detected in either the sample before 2nd CBT or at the time of HHV-6 DNA elevation. It is considered that the HHV-6 DNA detected in PBLs and plasma samples might be the HHV-6 genome released due to tissue damage. This case suggests that physicians should be aware of HHV-6 DNA variability during allogeneic hematopoietic stem cell transplantation in ciHHV-6 patients.

Paroxysmal nocturnal hemoglobinuria (PNH) causes clonal expansion of hematopoietic stem cells with abnormal GPI-anchor biosynthesis. The major pathological condition of PNH is that the erythrocytes lacking the complement regulatory factors CD55 and CD59, which are GPI-anchored proteins, lead to intravascular hemolysis through complement activation. Clonal expansion has been assumed to be involved in an immunological attack on hematopoietic stem cells, and the bone marrow failure associated therewith modifies the pathology to varying degrees. The introduction of eculizumab made complement control possible; however, the problems associated with it became apparent as the treatment progressed. Additionally, the PNH Reference Guide was significantly revised in 2016, partly because PNH was designated as a Japanese medical subsidy. With the revised edition of 2020, minor revisions have been added to reflect further advances in treatment and understanding of the disease, while mainly dealing with the clinical introduction of eculizumab derivative, ravulizumab, which uses recycling antibody technology. This review outlines the points of the 2020 revision, including the important points of the previous revision.

Background Multiple myeloma (MM) is a type of hematological malignancy affecting the functions of plasma cells. The treatment of MM patients has changed dramatically with the use of new agents. However, unfortunately, it is still incurable. Therefore, a new approach for treating MM is still needed to improve patient outcomes. Methods Because the histone deacetylase (HDAC) and phosphoinositide 3-kinase (PI3K) pathway is a key signal in cancer cell biology, we investigated whether dual HDAC and PI3K inhibitors could suppress the myeloma cells. Results Gene expression of HDACs is high in myeloma cells. CUDC-907, a dual inhibitor of PI3K and HDAC, inhibits HDAC activity. Akt activity and expression of BCL-XL, MCL-1, and NF-κB p65 were reduced by CUDC-907 in a dose-dependent manner. The number of apoptotic and caspase 3/7-positive cells also increased in the myeloma cells. Combined treatment of myeloma cells with carfilzomib and CUDC-907 increased cytotoxicity compared to that observed with each drug alone. Conclusions Data from this study suggested that the administration of CUDC-907 might be a powerful strategy against myeloma cells, to enhance the cytotoxic effects of proteasome inhibitors.

Essential thrombocythemia (ET) mainly affects the elderly, but can also develop in women of childbearing age. The risk of miscarriage and other complications during pregnancy in ET patients are reported to be higher than that compared to the general population. Therefore, management of pregnancy in ET patients requires special considerations. Several groups recommend interferon (IFN) therapy for ET patients with high-risk pregnancies, but currently no guidelines are available in Japan. We report the outcomes of nine ET patients with ten consecutive high-risk pregnancies. All patients were successfully managed with IFN-α during their pregnancies. All patients also received aspirin and switched to unfractionated heparin around 36 weeks of gestation. As for the seven pregnancies in which IFN-α was started after detection of pregnancy, median platelet counts decreased from 910 to 573 × 10

A 72-year-old man with ileocecal lymphadenopathy was found to have Epstein-Barr virus-positive diffuse large B-cell lymphoma using open biopsy, and an ileostoma was created. R-CHOP-like chemotherapy was initiated, but his malnutrition did not improve. After 3 cycles of chemotherapy, a 2-m-long Cestoda was removed from the stoma and was identified as Diphyllobothrium nihonkaiense using mitochondria cytochrome c oxidase subunit 1 targeted polymerase chain reaction analysis. Although D. nihonkaiense infections are asymptomatic, the ileostomy was thought to have exacerbated the malabsorption in this patient. Parasitic infections are rare; however, they should be added to the differential diagnosis of malnutrition of unknown cause during chemotherapy for hematological malignancies.

A man in his 40s was diagnosed with CML. He and his partner expressed their desire to have a child. We recommended planning the pregnancy after the achievement of major molecular response and completion of TKI therapy because we could not promise complete safety of the fetus, However, he and his partner insisted on starting the TKI therapy immediately and planned the pregnancy during the therapy. The patient was started on nilotinib 600mg/body. CCyR, MMR, and CMR were achieved in 3, 8, and 12 months, respectively. The patient's partner got pregnant when he had been on TKI therapy for 15 months, and she gave birth to a healthy boy. Since many patients with CMLcan live for a long time after receiving TKI therapy, the quality of life of these patients is more important. Even if the percentage of patients with CML who are under 50 years of age is approximately 30%, the safety information of TKI with respect to pregnancy is unsatisfactory. Doctors struggle to address the problems of the patient's wish of childbearing, priority of TKI therapy, and fetal risks of the treatment. Although only a few cases of pregnancy and delivery of the partners of male patients with CML treated with TKI have been reported, all cases showed healthy childbirth and normal child growth. Our experience also showed that the partner of a male patient with CML treated with TKI became pregnant and delivered a healthy baby.

A 81-year-old female was diagnosed with symptomatic multiple myeloma (MM; IgG κ type, DS: IIB, ISS: 2) in August 2017. Although treatment with lenalidomide and dexamethasone was started, she developed deep venous thrombosis in the lower extremities as a complication; therefore, the treatment was changed to DBd. In February 2018, she required hospitalization due to general weakness and altered consciousness. Her IgG level and κ/λ ratio were elevated at 4,156 mg/dl and 605.56, respectively, revealing that MM was treatment-resistant. A protein-cell dissociation (cell blood count, 0/µl; protein, 100.6 mg/dl) was detected in the cerebrospinal fluid, whereas the ammonia level in serum was high (172 µg/dl). T2-weighted magnetic resonance imaging showed a broad range of high-density area in deep cerebral white matter suggesting leukoencephalopathy, whereas the cerebrospinal fluid was negative for JC virus. No pathological conditions causing secondary hyperammonemia were found. Although the involvement of drug-induced leukoencephalopathy in altered consciousness could not be ruled out since the chromosome with the normal karyotype at the first visit had a complex chromosomal abnormality, an originally minor clone of MM cells with a chromosomal abnormality might have contributed to the ammonia production resulting in altered consciousness.

The majority of patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) harbor JAK2, CALR, or MPL mutations. We compared clinical manifestations of different subtypes of JAK2 and CALR mutations in Japanese patients with MPNs. Within our cohort, we diagnosed 166 patients as polycythemia vera (PV), 212 patients as essential thrombocythemia (ET), 23 patients as pre-primary myelofibrosis (PMF), 65 patients as overt PMF, and 27 patients as secondary myelofibrosis following the 2016 WHO criteria. Compared to patients with JAK2V617F-mutated PV, JAK2 exon 12-mutated PV patients were younger, showed lower white blood cell (WBC) counts, lower platelet counts, higher red blood cell counts, and higher frequency of thrombotic events. Compared to JAK2-mutated ET patients, CALR-mutated ET patients were younger, showed lower WBC counts, lower hemoglobin levels, higher platelet counts, and fewer thrombotic events. CALR type 1-like mutation was the dominant subtype in CALR-mutated overt PMF patients. Compared with JAK2V617F-mutated ET patients, JAK2V617F-mutated pre-PMF patients showed higher LDH levels, lower hemoglobin levels, higher JAK2V617F allele burden, and higher frequency of splenomegaly. In conclusion, Japanese patients with MPNs grouped by different mutation subtypes exhibit characteristics similar to those of their Western counterparts. In addition, ET and pre-PMF patients show different characteristics, even when restricted to JAK2V617F-mutated patients.

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by the Philadelphia chromosome (Ph) which is associated with BCR-ABL fusion protein. ABL tyrosine kinase inhibitor...

Background: Recently, whole exome sequencing has been used for the next-generation sequencing of acute myeloid leukemia (AML), and certain gene mutations have been identified in patients with AML. The treatment strategies for leukemia have undergone drastic changes with the rapid development of new drugs. However, the proper use of newly developed agents poses a major challenge in AML treatment. Genome profiling analysis can be used to select the optimal treatment for patients with newly diagnosed AML. Methods and Results: Hematologic malignancies (HM)-SCREEN-Japan 01 is an actionable mutation profiling multicenter study of patients with newly diagnosed AML who cannot be treated with first standard treatment or patients who have relapsed/refractory AML (R/R-AML). The objective of this study was to evaluate the frequency and characteristics of cancer-related genomic alterations in patients with AML using a comprehensive genome profiling assay (FoundationOne®Heme (F1H)) and determine the quality of specimens used in gene analysis. Before participant recruitment, approval was obtained from the institutional review board at each participating institution. The trial was registered in the UMIN Clinical Trials Registry (UMIN000035233). This study was conducted at 17 participating institutions and had a sample size of 200. The eligibility criteria were as follows: 1) histological diagnosis of AML through bone marrow aspiration; 2) fulfillment of either of the following conditions: i) newly diagnosed AML unfit for standard treatment (ND-unfit AML) or ii) R/R-AML; 3) sufficient sample collection via bone marrow aspiration; 4) Age of participants 20 years or above during registration; 5) provision of written informed consent by participants. The primary outcome was the frequency of each genomic alteration, as determined using F1H, which is a comprehensive genome profiling test based on next-generation sequencing, in the AML specimens. The secondary outcome was the association between each genomic alteration and the clinicopathological characteristics, prognosis, and quality of specimens used in the genetic analysis. Serial genome profiling analyses were performed to evaluate the time-dependent changes in the genome profiles of patients administered FLT3 inhibitors, gilteritinib, and quizartinib for treating AML. One hundred and eighty-two patients were recruited, and the F1H report was successfully obtained for 177 patients (97.3%). The median age of the 66 patients with ND-unfit AML was 73 years (63-79 years), and that of the 105 patients with R/R-AML was 50 years (41-68 years). The median turnaround time was 13 days (minimum 8 days). Recurrent alterations were observed in FLT3 (28.7%), TP53 (21.6%), RUNX1 (20.5%), DNMT3A (18.7%), NPM1 (18.7%), ASXL1 (15.2%), TET2 (14.0%), KMT2A-rearrangement (13.5%), and NRAS (13.5%). IDH1 and/or IDH2 mutations were identified in specimens collected from 30 patients (17.5%). Compared with the prevalence in 2247 patients with AML in the US and Europe who underwent F1H analysis, the frequencies of mutations in FLT3 (28.7% vs. 20.5%) and TP53 (21.6% vs. 17.0%) were higher in this Japanese cohort. Mutations in IDH2, PTPN11, and SF3B1 were observed along with KMT2A rearrangement. Mutations in TP53 tended to be exclusive to the FLT3 mutation. In comparison between the ND-unfit AML and R/R-AML, mutations in TET2 and ASXL1 tended to be more frequnt in ND-unfit AML (17.9% vs. 7.0%, p=0.038, 18.9% vs. 8.5%, p=0.055, respectively). The median expression level of WT1 mRNA at the time of sample collection was 4,490 copies/μgRNA (n=158), and WT1 mutation was frequently found in the WT1-high expression group (13.9% vs. 3.8%, p=0.03), suggesting that the mutation of WT1 may cause overexpression of WT1 as an oncogene. Conclusions: In our evaluation of the suitability of F1H for HM-SCREEN-Japan 01, we successfully identified leukemia-associated genes that can be used as therapeutic targets in AML, which have rarely been identified thus far. Figure 1 Figure 1. Disclosures Yamauchi: Astellas: Research Funding; Abbie: Research Funding; Chugai: Honoraria; Pfizer: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria; Otsuka: Research Funding; Daiichi Sankyo: Research Funding; Solasia Pharma: Research Funding. Shibayama: Celgene: Research Funding; Ono: Honoraria, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Avvie: Honoraria, Research Funding; Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Essentia Pharma Japan: Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Honoraria; Fujimoto: Honoraria; Nippon Shinyaku: Honoraria; Sanofi: Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Otsuka: Honoraria; Mundi Pharma: Honoraria. Kondo: Astellas Pharma Inc.: Consultancy, Honoraria; Otsuka Pharmaceutical: Honoraria, Research Funding; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb: Honoraria; Sumitomo Dainippon Pharma: Honoraria; Sanwa Kagaku Kenkyusho: Consultancy. Yamamoto: Eisai: Honoraria, Research Funding; IQIVA/Incyte: Research Funding; IQIVA/HUYA: Honoraria; HUYA: Consultancy; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; MSD: Honoraria; Mundipharma: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria; Solasia Pharma: Research Funding; SymBio: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Zenyaku: Honoraria, Research Funding; Micron: Honoraria; IQIVA/Genmab: Research Funding; ADC Therapeutics: Honoraria; Daiichi Sankyo: Honoraria; Chugai: Honoraria, Research Funding; Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding. Kuroda: Sanofi: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; MSD: Research Funding; Abbvie: Consultancy, Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Sysmex: Research Funding; Pfizer: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Shionogi: Research Funding; Asahi Kasei: Research Funding; Taiho Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Usuki: Nippon Boehringer Ingelheim: Research Funding; Takeda: Research Funding, Speakers Bureau; Celgene: Research Funding, Speakers Bureau; Janssen: Research Funding; Ono: Research Funding, Speakers Bureau; Brisol-Myers Squibb: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Otsuka: Research Funding, Speakers Bureau; Sumitomo Dainippon: Research Funding; Daiichi Sankyo: Research Funding, Speakers Bureau; Symbio: Research Funding, Speakers Bureau; Gilead: Research Funding; Abbvie: Research Funding; Astellas: Research Funding, Speakers Bureau; Astellas-Amgen-Biopharma: Research Funding; Nippon shinyaku: Research Funding, Speakers Bureau; Kyowa Kirin: Research Funding, Speakers Bureau; Pfizer: Research Funding; Alexion: Speakers Bureau; Eisai: Speakers Bureau; MSD: Speakers Bureau; PharmaEssentia: Speakers Bureau; Yakult: Speakers Bureau; Mundipharma: Research Funding. Yoshimitsu: Sanofi: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Ishitsuka: Eli Lilly: Research Funding; Mochida: Other: Personal fees, Research Funding; Eisai: Other: Personal fees, Research Funding; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Pfizer: Other: Personal fees; Novartis: Other: Personal fees; Janssen Pharmaceuticals: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Takeda: Other: Personal fees, Research Funding; BMS: Other; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Ono Pharmaceutical: Other: Personal fees, Research Funding; Kyowa Kirin: Other: Personal fees, Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; Shire: Other; Otsuka Pharmaceutical: Other: Personal fees; Teijin Pharma: Research Funding; MSD: Research Funding; Asahi kasei: Research Funding; Huya Japan: Other: Personal fees. Ono: DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb Company: Honoraria; Pfizer Japan Inc.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Takeda Pharmaceutical Company Limited.: Honoraria; Astellas Pharma Inc.: Honoraria; Eisai Co., Ltd.: Honoraria; Janssen Pharmaceutical K.K: Honoraria; Mundipharma K.K.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Merck Sharp & Dohme: Honoraria, Research Funding. Takahashi: Kyowahakko-Kirin: Research Funding; Ono: Research Funding; Asahikasei: Research Funding; Toyamakagaku: Research Funding; Eizai: Research Funding; Chugai: Research Funding; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Iyama: Otsuka: Honoraria, Research Funding; Novartis: Honoraria; Nippon Shinyaku: Honoraria; MSD: Research Funding; Otsuka Pharmaceuticals Factory: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; Daiichi Sankyo: Honoraria; CSL Behring: Honoraria; Astellas: Honoraria; Alexion Pharmaceuticals: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; SymBio Pharmaceuticals: Research Funding. Izutsu: Yakult: Research Funding; Takeda: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Fuji Film Toyama Chemical: Honoraria; Genmab: Honoraria, Research Funding; Huya Biosciences: Research Funding; Incyte: Research Funding; Janssen: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; MSD: Research Funding; Novartis: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Pfizer: Research Funding; Solasia: Research Funding; Symbio: Honoraria; Celgene: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; Allergan Japan: Honoraria; AbbVie: Honoraria. Minami: Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Pfizer Japan Inc.: Honoraria; Takeda: Honoraria; Astellas: Honoraria; Ono: Research Funding; CMIC: Research Funding.

Background and Methods: NPM1 mutation and KMT2A(MLL)-rearrangement/amplification are present in approximately 27% and 8.5% patients with acute myeloid leukemia (AML), respectively (data from cBioPortal). Although they have different clinical features and prognostic impact, recent studies suggest that the MLL co-factor, menin, plays a key role in maintaining self-renewal of immature leukemic cells by upregulating transcription of HOXA and MEIS (Gundry et al.). However, the real-world epidemiology of these mutations and co-existing gene alterations have not been thoroughly investigated in Japan. We launched an actionable mutation profiling multicenter study entitled Hematologic Malignancies (HM)-SCREEN-Japan 01 (UMIN000035233). In this study, a comprehensive genomic assay was performed by Foundation One Heme (F1H) panel for patients with relapsed/refractory (R/R) AML as well as patients with newly-diagnosed (ND) AML who are ineligible for standard chemotherapy. Paraffin-embedded bone marrow samples were gathered from 17 Japanese faculties and the F1H reports were returned to the patients. Results: One-hundred-eighty-two patients were recruited in this study and the F1H report was successfully returned in 177 patients (97.3%). Median age of 68 patients with ND-AML was 73 [63-79] years and those of 109 patients with R/R-AML was 50 [40-68.5] years. Median turn-around time was 13 days (minimum 8 days).We found 32 patients (18.1%) with NPM1 mutation and 23 patients (13.0%) of KMT2A(MLL)-rearrangement/amplification out of the 177 patients. These two alterations were mutually exclusive in this study. The median age of patients with NPM1 mutation (NPM1 mt.) and KMT2A-rearrangement (KMT2A-r) were 56.5 [43.5-73.8] and 62 [45-71] years, respectively. Three quarters or more patients were R/R-AML in both groups. WT1 expression levels were much higher in patients with NPM1 mt. than the other group (6,000 [77-110,000] vs. 93 [34-5,800] copies/mcgRNA). The major amino acid alteration of NPM1 was a frameshift mutation at the 288 th histidine (W288fs*12). Patterns of KMT2A(MLL)-rearrangement included MLL fusion (e.g., MLL-MLLT3) and partial tandem duplication (PTD) in ten patients each. MLL amplification was observed in three patients. Frequently co-occurring mutations with NPM1 mt. included FLT3 (56.3%), DNMT3A (46.9%), TET2 (34.4%), WT1 (18.8%), IDH1 (18.8%), and IDH2 (15.6%). Those with KMT2A-r included FLT3 (39.1%), TP53 (26.1%), PTPN11 (21.7%), DNMT3A (17.4%), and IDH2 (17.4%). Mutations of RAS pathway-related genes (e.g., KRAS, NRAS, PTPN11, and NF1) were observed in five patients with NPM1 mt. (15.6%) and 11 patients (47.8%) with KMT2A-r. None of the six patients with TP53 mutation had NPM1 mutation. The prognostic impact of each genes is currently being analyzed. Conclusions: Approximately three in ten patients with AML had NPM1 mutation and/or KMT2A(MLL)-rearrangement/amplification. No single patient had both the alterations. FLT3 and DNA methylation-associated genes (e.g., DNMT3A and TET2) were frequently seen in patients with NPM1 mt. In contrast, TP53 and RAS pathway-related gene alterations (e.g., NRAS, KRAS, PTPT11 and NF1) were relatively dominant in patients with KMT2A-r. TP53 mutation seemed unlikely to occur along with NPM1 mutation. Figure 1 Figure 1. Disclosures Shibayama: Celgene: Research Funding; Ono: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Avvie: Honoraria, Research Funding; Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Essentia Pharma Japan: Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Honoraria; Fujimoto: Honoraria; Nippon Shinyaku: Honoraria; Sanofi: Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Otsuka: Honoraria; Mundi Pharma: Honoraria. Yamauchi: Otsuka: Research Funding; Ono Pharmaceutical: Honoraria; Pfizer: Honoraria, Research Funding; Chugai: Honoraria; Abbie: Research Funding; Astellas: Research Funding; Daiichi Sankyo: Research Funding; Solasia Pharma: Research Funding. Kondo: Otsuka Pharmaceutical: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb Company: Honoraria; Sumitomo Dainippon Pharma: Honoraria; Sanwa Kagaku Kenkyusho CO.,LTD: Consultancy; Astellas Pharma Inc.: Consultancy, Honoraria; Abbvie: Honoraria. Yamamoto: Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Eisai: Honoraria, Research Funding; IQIVA/Incyte: Research Funding; IQIVA/HUYA: Honoraria; HUYA: Consultancy; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; MSD: Honoraria; Mundipharma: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria; Solasia Pharma: Research Funding; SymBio: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Zenyaku: Honoraria, Research Funding; Micron: Honoraria; IQIVA/Genmab: Research Funding; ADC Therapeutics: Honoraria; AbbVie: Honoraria, Research Funding. Kuroda: Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Taiho Pharmaceutical: Research Funding; Asahi Kasei: Research Funding; Shionogi: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Sysmex: Research Funding; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; MSD: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Usuki: Astellas: Research Funding, Speakers Bureau; Abbvie: Research Funding; Gilead: Research Funding; Symbio: Research Funding, Speakers Bureau; Daiichi Sankyo: Research Funding, Speakers Bureau; Sumitomo Dainippon: Research Funding; Otsuka: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Brisol-Myers Squibb: Research Funding, Speakers Bureau; Ono: Research Funding, Speakers Bureau; Janssen: Research Funding; Celgene: Research Funding, Speakers Bureau; Takeda: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Mundipharma: Research Funding; Astellas-Amgen-Biopharma: Research Funding; Nippon shinyaku: Research Funding, Speakers Bureau; Kyowa Kirin: Research Funding, Speakers Bureau; Pfizer: Research Funding; Alexion: Speakers Bureau; Eisai: Speakers Bureau; MSD: Speakers Bureau; PharmaEssentia: Speakers Bureau; Yakult: Speakers Bureau. Yoshimitsu: Novartis: Honoraria; Takeda: Honoraria; Sanofi: Honoraria. Ishitsuka: Kyowa Kirin: Other: Personal fees, Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; Ono Pharmaceutical: Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; BMS: Other; Takeda: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Janssen Pharmaceuticals: Other: Personal fees; Novartis: Other: Personal fees; Pfizer: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Eisai: Other: Personal fees, Research Funding; Mochida: Other: Personal fees, Research Funding; Shire: Other; Otsuka Pharmaceutical: Other: Personal fees; Teijin Pharma: Research Funding; MSD: Research Funding; Asahi kasei: Research Funding; Eli Lilly: Research Funding; Huya Japan: Other: Personal fees. Ono: DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Mundipharma K.K.: Honoraria; Celgene: Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Janssen Pharmaceutical K.K: Honoraria; Eisai Co., Ltd.: Honoraria; Astellas Pharma Inc.: Honoraria; Takeda Pharmaceutical Company Limited.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Pfizer Japan Inc.: Honoraria; Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Merck Sharp & Dohme: Honoraria, Research Funding. Fujishima: Pfizer: Speakers Bureau. Takahashi: Toyamakagaku: Research Funding; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai: Research Funding; Eizai: Research Funding; Asahikasei: Research Funding; Kyowahakko-Kirin: Research Funding; Ono: Research Funding. Iyama: Alexion Pharmaceuticals: Honoraria, Research Funding; Astellas: Honoraria; CSL Behring: Honoraria; Daiichi Sankyo: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; MSD: Research Funding; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; SymBio Pharmaceuticals: Research Funding. Izutsu: Symbio: Honoraria; Takeda: Honoraria, Research Funding; Solasia: Research Funding; Pfizer: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; MSD: Research Funding; Kyowa Kirin: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Incyte: Research Funding; Huya Biosciences: Research Funding; Genmab: Honoraria, Research Funding; Fuji Film Toyama Chemical: Honoraria; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; Yakult: Research Funding; Allergan Japan: Honoraria; AbbVie: Honoraria. Minami: Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Pfizer Japan Inc.: Honoraria; Takeda: Honoraria; Astellas: Honoraria; Ono: Research Funding; CMIC: Research Funding.

Background and Methods: Acute myeloid leukemia (AML) bearing the RUNX1-RUNX1T1 fusion gene is known to be one of the core-binding factor AML (CBF-AML) which exerts relatively good prognosis. The RUNX1-RUNX1T1 fusion gene are present in approximately 3.5% of patients with AML (data from cBioPortal). However, the real-world epidemiology of this mutation and co-existing gene alterations have not been fully investigated in Japan. We launched an actionable mutation profiling multicenter study named Hematologic Malignancies (HM)-SCREEN-Japan 01 (UMIN000035233), in which a comprehensive genomic assay was performed by Foundation One Heme (F1H) panel for patients with relapsed/refractory (R/R) AML as well as patients with newly-diagnosed (ND) AML who were ineligible for standard chemotherapy. Paraffin-embedded bone marrow samples were gathered from 17 Japanese faculties and the F1H reports were returned to the patients. Results: We found 12 patients (6.8%) with the RUNX1-RUNX1T1 fusion gene out of 177 patients who joined this study and the F1H report was successfully retuned. Eight of these patients were enrolled as R/R AML and four were enrolled as ND AML who are ineligible for standard chemotherapy. Four (50%) of R/R patients were received allogeneic hematopoietic stem cell transplantation. Among the 12 patients with the RUNX1-RUNX1T1 fusion gene, eight (66.7%) had KIT mutation. The major amino acid alteration of KIT was D816V/Y and two patients had two different point-mutations of KIT (one with D816Y plus D816V and the other with D816V plus N822K). No particular mutations, other than KIT, were predominantly co-occurred with RUNX1-RUNX1T1 fusion gene. Especially in R/R patients, 75 % of them had the KIT mutation. Two R/R patients without the KITmutation had JAK2 V617F and FLT3 D835Y respectively. Conclusions: AML with RUNX1-RUNX1T1 fusion gene is currently not indicated for transplantation in the first remission. Previous studies have demonstrated that approximately 30% of patients with CBF-AML harbored the KIT mutations at diagnosis, which might be an indicator of poor prognosis. In our study, the KIT mutations were detected much more frequently than in previously studies of newly-diagnosed CBF-AML. This result may suggest that patients with the KIT mutations were concentrated because our study targeted AML patients who were R/R to prior therapy or ineligible for standard chemotherapy. In addition, no specific mutations highly related to the RUNX1-RUNX1T1 fusion gene were detected other than the KIT mutation, suggesting the KIT mutation might be a suitable molecular marker to predict poor prognosis in AML with the RUNX1-RUNX1T1 fusion gene. Our study revealed the importance of KIT mutations in patients with R/R AML with RUNX1-RUNX1T1 fusion gene, and that the KITmutations may be a promising therapeutic target for this population. Furthermore, it is interesting that driver mutations such as JAK2 and FLT3 mutation were detected in R/R patients without KIT mutation, although further investigation is needed. This suggests that comprehensive genomic assays are highly useful in establishing precision medicine, even in this type of AML, which is generally considered to have a good prognosis. Since most of R/R patients need allo-SCT, precision medicine targeting KIT may be considered for post-recurrence treatment in AML with RUNX1-RUNX1T1 fusion gene, such as bridge therapy to transplantation, in the future. Figure 1 Figure 1. Disclosures Shibayama: Janssen Pharmaceutical K.K.: Research Funding, Speakers Bureau; Nippon Shinyaku Co., Ltd.: Speakers Bureau; Fujimoto Pharmaceutical Corp.: Speakers Bureau; Daiichi Sankyo Co., Ltd.: Speakers Bureau; Chugai Pharmaceutical Co., Ltd.: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AstraZeneca K.K.: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PharmaEssentia Japan KK: Research Funding; Eisai Co., Ltd.: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis Pharma K.K.: Research Funding, Speakers Bureau; Takeda Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; AbbVie GK: Research Funding, Speakers Bureau; Celgene K.K.: Research Funding; Ono Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Sanofi K.K.: Speakers Bureau; Bristol-Myers Squibb K.K.: Speakers Bureau. Yamauchi: Daiichi Sankyo: Research Funding; Astellas: Research Funding; Abbie: Research Funding; Chugai: Honoraria; Pfizer: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria; Otsuka: Research Funding; Solasia Pharma: Research Funding. Kondo: Astellas Pharma Inc.: Consultancy, Honoraria; Otsuka Pharmaceutical: Honoraria, Research Funding; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb Company: Honoraria; Sumitomo Dainippon Pharma: Honoraria; Sanwa Kagaku Kenkyusho CO.,LTD: Consultancy. Yamamoto: IQIVA/Incyte: Research Funding; AstraZeneca: Honoraria, Research Funding; IQIVA/HUYA: Honoraria; HUYA: Consultancy; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; MSD: Honoraria; Mundipharma: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria; Solasia Pharma: Research Funding; SymBio: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Zenyaku: Honoraria, Research Funding; Micron: Honoraria; IQIVA/Genmab: Research Funding; ADC Therapeutics: Honoraria; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Chugai: Honoraria, Research Funding; Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding. Kuroda: Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Taiho Pharmaceutical: Research Funding; Asahi Kasei: Research Funding; Shionogi: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Sysmex: Research Funding; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; MSD: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Usuki: Otsuka Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Novartis Pharma K.K.: Research Funding, Speakers Bureau; Ono Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Janssen Pharmaceutical K.K.: Research Funding; Celgene K.K.: Research Funding, Speakers Bureau; Takeda Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Nippon-Boehringer-Ingelheim Co., Ltd.: Research Funding; Mundipharma K.K.: Research Funding; Amgen-Astellas Biopharma K.K.: Research Funding; Nippon-Shinyaku Co., Ltd.: Research Funding, Speakers Bureau; Kyowa-Kirin Co., Ltd.: Research Funding, Speakers Bureau; Pfizer Japan Inc.: Research Funding, Speakers Bureau; Alexion Pharmaceuticals, Inc.: Research Funding, Speakers Bureau; Eisai Co., Ltd.: Speakers Bureau; MSD K.K.: Research Funding, Speakers Bureau; PharmaEssentia Japan KK: Research Funding, Speakers Bureau; Yakult Honsha Co., Ltd.: Research Funding, Speakers Bureau; Bristol-Myers-Squibb K.K.: Research Funding, Speakers Bureau; Sumitomo-Dainippon Pharma Co., Ltd.: Research Funding; Daiichi Sankyo Co., Ltd.: Research Funding, Speakers Bureau; SymBio Pharmaceuticals Ltd.: Research Funding, Speakers Bureau; Apellis Pharmaceuticals, Inc.: Research Funding; Gilead Sciences, Inc.: Research Funding; AbbVie GK: Research Funding, Speakers Bureau; Astellas Pharma Inc.: Research Funding, Speakers Bureau; Incyte Biosciences Japan G.K.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Sanofi K.K.: Speakers Bureau; Amgen K.K.: Research Funding. Yoshimitsu: Sanofi: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Ishitsuka: BMS: Other; Takeda: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Janssen Pharmaceuticals: Other: Personal fees; Novartis: Other: Personal fees; Pfizer: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Eisai: Other: Personal fees, Research Funding; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Ono Pharmaceutical: Other: Personal fees, Research Funding; Kyowa Kirin: Other: Personal fees, Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; MSD: Research Funding; Teijin Pharma: Research Funding; Otsuka Pharmaceutical: Other: Personal fees; Shire: Other; Mochida: Other: Personal fees, Research Funding; Asahi kasei: Research Funding; Eli Lilly: Research Funding; Huya Japan: Other: Personal fees. Ono: Novartis Pharma KK: Honoraria; Merck Sharp & Dohme: Honoraria, Research Funding; Bristol-Myers Squibb Company: Honoraria; Pfizer Japan Inc.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Takeda Pharmaceutical Company Limited.: Honoraria; Astellas Pharma Inc.: Honoraria; Eisai Co., Ltd.: Honoraria; Janssen Pharmaceutical K.K: Honoraria; DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Mundipharma K.K.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Takahashi: Kyowahakko-Kirin: Research Funding; Ono: Research Funding; Asahikasei: Research Funding; Toyamakagaku: Research Funding; Eizai: Research Funding; Chugai: Research Funding; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Iyama: Novartis: Honoraria; Nippon Shinyaku: Honoraria; MSD: Research Funding; Otsuka Pharmaceuticals Factory: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; Daiichi Sankyo: Honoraria; CSL Behring: Honoraria; Astellas: Honoraria; Alexion Pharmaceuticals: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; SymBio Pharmaceuticals: Research Funding. Izutsu: Celgene: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; Kyowa Kirin: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Yakult: Research Funding; AbbVie: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Bayer: Research Funding; Beigene: Research Funding; Chugai: Honoraria, Research Funding; Genmab: Honoraria, Research Funding; Incyte: Research Funding; Janssen: Honoraria, Research Funding; MSD: Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Pfizer: Research Funding; Symbio: Honoraria, Research Funding; Allergan Japan: Honoraria; FUJI FILM Toyama Chemical: Honoraria. Minami: Bristol-Myers Squibb Company: Honoraria; Pfizer Japan Inc.: Honoraria; Novartis Pharma KK: Honoraria; Takeda: Honoraria; Astellas: Honoraria; Ono: Research Funding; CMIC: Research Funding.

Background: Isocitrate dehydrogenase (IDH)-1 and -2 are TCA cycle-involved enzymes which convert isocitrate to alpha-ketoglutarate. Mutations that alter the enzymatic activity causes accumulation of a mal-metabolite D-2-hydroxyglutarate, which results in inhibition of DNA methylation and tumorigenesis. IDH-1 and IDH-2 mutation are present in approximately 7-10% and 10% of patients with acute myeloid leukemia (AML), respectively. Recently, whole exome sequencing has been used for the next-generation sequencing of AML, and certain gene mutations have been identified in patients with AML. The treatment strategies for leukemia have undergone drastic changes with the rapid development of new drugs. However, the proper use of newly developed agents poses a major challenge in AML treatment. Genome profiling analysis can be used to select the optimal treatment for patients with newly diagnosed AML. IDH mutant-specific inhibitors such as ivosidenib and enasidenib were already approved in the US, and combination treatment with venetoclax and Azacitidine was recently approved in Japan. Methods and Results: We lunched an actionable mutation profiling multicenter study named Hematologic Malignancies (HM)-SCREEN-Japan 01 (UMIN000035233), in which a comprehensive genomic assay was performed by Foundation One Heme (F1H) panel. The primary outcome was the frequency of each genomic alteration, as determined using F1H, which is a comprehensive genome profiling test based on next-generation sequencing, in the AML specimens. The secondary outcome was the association between each genomic alteration and the clinicopathological characteristics, prognosis, and quality of specimens used in the genetic analysis. The eligibility criteria were as follows: 1) histological diagnosis of AML through bone marrow aspiration; 2) fulfillment of either of the following conditions: i) newly diagnosed AML unfit for standard treatment (ND-unfit AML) or ii) R/R-AML; 3) sufficient sample collection via bone marrow aspiration; 4) Age of participants 20 years or above during registration; 5) provision of written informed consent by participants. Paraffin-embedded bone marrow samples were gathered from 17 Japanese faculties and the F1H reports were returned to the patients. The median turnaround time was 13 days (minimum 8 days). We found 13 patients (7.3%) with IDH1 mutation and 17 patients (9.6%) with IDH2 mutation out of 177 patients who joined this study and the F1H report was successfully returned. Only one patient had both mutations, and each mutation was mutually exclusive in all the other patients (Figure 1). The major amino acid alteration of IDH1 and IDH2 were R132C/G/H/L and R140Q/W, respectively. Frequently co-occurring mutations include FLT3 (44.8%), NPM1 (34.5%), DNMT3A (31.0%) and RUNX1 mutation (20.7%). Mutations of RAS pathway-related genes (e.g., KRAS, NRAS and PTPN11) were seen in 6 patients (20.7%). Any gene alterations didn't show statistically significant co-occurrence with IDH1 and IDH2 mutation. Serial genome profiling analyses were performed to evaluate the time-dependent changes in the genome profiles of patients administered FLT3 inhibitors, gilteritinib, and quizartinib for treating FLT3-mutated AML. Also in this cohort, we are examining the properties and distribution of IDH1/2 mutations during treatment with FLT3 inhibitors. In the several patients, expansion and persistence of IDH mutated clones seemed to be cause of resistance (Figure 2 as the representative result). The detailed clinical outcomes of AML patients with IDH1/2 mutations are under investigation. Conclusions: In our evaluation of the suitability of F1H for HM-SCREEN-Japan 01, we successfully identified IDH-1/2 mutation that can be used as therapeutic targets in AML, which have rarely been identified thus far. Figure 1 Figure 1. Disclosures Shibayama: Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Ono: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Nippon Shinyaku: Honoraria; Daiichi Sankyo: Honoraria; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Otsuka: Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Fujimoto: Honoraria; AbbVie: Honoraria, Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria; Mundi Pharma: Honoraria; Essentia Pharma Japan: Research Funding. Yamauchi: Otsuka: Research Funding; Ono Pharmaceutical: Honoraria; Pfizer: Honoraria, Research Funding; Chugai: Honoraria; Abbie: Research Funding; Astellas: Research Funding; Daiichi Sankyo: Research Funding; Solasia Pharma: Research Funding. Kondo: Otsuka Pharmaceutical: Consultancy, Honoraria, Research Funding; Novartis Pharma KK: Honoraria; Bristol-Myers Squibb Company: Honoraria; Sumitomo Dainippon Pharma: Honoraria; Sanwa Kagaku Kenkyusho CO.,LTD: Consultancy; Pfizer: Honoraria; Astellas Pharma Inc.: Consultancy, Honoraria; Abbvie: Honoraria. Yamamoto: AbbVie: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Eisai: Honoraria, Research Funding; IQIVA/Incyte: Research Funding; IQIVA/HUYA: Honoraria; HUYA: Consultancy; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; MSD: Honoraria; Mundipharma: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria; Solasia Pharma: Research Funding; SymBio: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Zenyaku: Honoraria, Research Funding; Micron: Honoraria; IQIVA/Genmab: Research Funding; ADC Therapeutics: Honoraria. Kuroda: Taiho Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Asahi Kasei: Research Funding; Shionogi: Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Sysmex: Research Funding; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; MSD: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Usuki: Astellas: Research Funding, Speakers Bureau; Abbvie: Research Funding; Gilead: Research Funding; Symbio: Research Funding, Speakers Bureau; Daiichi Sankyo: Research Funding, Speakers Bureau; Sumitomo Dainippon: Research Funding; Otsuka: Research Funding, Speakers Bureau; Novartis: Research Funding, Speakers Bureau; Brisol-Myers Squibb: Research Funding, Speakers Bureau; Ono: Research Funding, Speakers Bureau; Janssen: Research Funding; Celgene: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Nippon Boehringer Ingelheim: Research Funding; Astellas-Amgen-Biopharma: Research Funding; Nippon shinyaku: Research Funding, Speakers Bureau; Kyowa Kirin: Research Funding, Speakers Bureau; Pfizer: Research Funding; Alexion: Speakers Bureau; Eisai: Speakers Bureau; MSD: Speakers Bureau; PharmaEssentia: Speakers Bureau; Yakult: Speakers Bureau; Mundipharma: Research Funding. Yoshimitsu: Novartis: Honoraria; Takeda: Honoraria; Sanofi: Honoraria. Ishitsuka: Asahi kasei: Research Funding; Eli Lilly: Research Funding; MSD: Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; Kyowa Kirin: Other: Personal fees, Research Funding; Ono Pharmaceutical: Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; BMS: Other; Takeda: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Janssen Pharmaceuticals: Other: Personal fees; Huya Japan: Other: Personal fees; Novartis: Other: Personal fees; Pfizer: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Eisai: Other: Personal fees, Research Funding; Mochida: Other: Personal fees, Research Funding; Shire: Other; Otsuka Pharmaceutical: Other: Personal fees; Teijin Pharma: Research Funding. Ono: Pfizer Japan Inc.: Honoraria; Bristol-Myers Squibb Company: Honoraria; Celgene: Honoraria, Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Janssen Pharmaceutical K.K: Honoraria; Eisai Co., Ltd.: Honoraria; Astellas Pharma Inc.: Honoraria; Takeda Pharmaceutical Company Limited.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Novartis Pharma KK: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Mundipharma K.K.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Merck Sharp & Dohme: Honoraria, Research Funding. Takahashi: Toyamakagaku: Research Funding; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai: Research Funding; Kyowahakko-Kirin: Research Funding; Ono: Research Funding; Asahikasei: Research Funding; Eizai: Research Funding. Iyama: Alexion Pharmaceuticals: Honoraria, Research Funding; Astellas: Honoraria; CSL Behring: Honoraria; Daiichi Sankyo: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; MSD: Research Funding; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; SymBio Pharmaceuticals: Research Funding. Izutsu: Genmab: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Fuji Film Toyama Chemical: Honoraria; Eisai: Honoraria, Research Funding; Incyte: Research Funding; Huya Biosciences: Research Funding; Chugai: Honoraria, Research Funding; Symbio: Honoraria; Solasia: Research Funding; Pfizer: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; MSD: Research Funding; Kyowa Kirin: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; Allergan Japan: Honoraria; AbbVie: Honoraria; Takeda: Honoraria, Research Funding; Yakult: Research Funding. Minami: Novartis Pharma KK: Honoraria; Ono: Research Funding; Pfizer Japan Inc.: Honoraria; Astellas: Honoraria; Takeda: Honoraria; Bristol-Myers Squibb Company: Honoraria; CMIC: Research Funding.

Background and Methods: FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (FLT3-ITD) and tyrosine kinase domain mutation (FLT3-TKD) are types of mutations present in approximately 30% of patients with acute myeloid leukemia (AML). Currently, FLT3 inhibitors (FLT3i) are available in clinical practice, and the second-generation FLT3i, gilteritinib and quizartinib, are being used in Japan. However, the actual epidemiology of FLT3 mutations and co-existing gene alterations, particularly resistance mechanisms after FLT3i treatment, have not been thoroughly investigated in a Japanese population. Therefore, we conducted an actionable mutation profiling multicenter study, Hematologic Malignancies (HM)-SCREEN-Japan 01 (UMIN000035233), in which a comprehensive genomic assay was performed using the FoundationOne Heme (F1H) panel for patients with relapsed/refractory (R/R) AML and patients with newly diagnosed AML who were ineligible for standard chemotherapy (ND unfit). Paraffin-embedded bone marrow samples were used for next-generation sequencing (NGS) examination using the F1H panel. We analyzed the relationships between FLT3 gene mutations and other mutations and then chronologically evaluated the variant allele frequency (VAF) of gene mutations in the genomic profiles of patients with AML receiving FLT3i. Results: Of the 171 patients who participated in this study, 49 (28.7%) had FLT3 mutations. FLT3-ITD and FLT3-TKD accounted for 59% and 43% of all cases of FLT3 mutations, respectively. Two patients (4%) were found to have dual mutations: one with FLT3-ITD plus FLT3-TKD and another with FLT3-ITD plus FLT3-F691L. Eight patients (4.5%) were found to have the FLT3-N676K mutation, which is sensitive to gilteritinib but undetectable by currently available PCR-based companion diagnostic tools in Japan. Frequently co-occurring mutations included those of NPM1 (37%), DNMT3A (33%), IDH1/IDH2 (27%), WT1 (24%), and RUNX1 (22%). Mutations in RAS pathway-related genes (e.g., KRAS, NRAS, and PTPN11) were observed in 15 patients (31%). No gene alteration showed statistically significant co-occurrence with the FLT3mutation. However, the median number of mutations that co-exist with FLT3-TKD was slightly higher than that of FLT3-ITD (four genes [3-5] vs. three genes [2-5]). Sequential changes in the VAF of each gene alteration were investigated in nine patients with FLT3 mutations who eventually gained resistance to FLT3i. It was suggested that there were various patterns in clone evolution. Some showed the acquisition of not only CBL or NRAS as RAS pathways, but also other driver mutations: one showed a persistent FLT3mutation, one showed FLT3-ITD plus FLT3-TKD, and one showed a newly acquired FLT3 mutation substituting an existing FLT3 mutation. We also found that founder mutations, such as the DNMT3Amutation, remain even after eradication of FLT3 mutation during treatment with FLT3i, which could be the cause of the outcome of complete remission with incomplete hematologic recovery. Conclusions: This is the first report to analyze R/R and ND unfit AML cases in a Japanese cohort using F1H NGS, revealing a higher incidence of FLT3-ITD/TKD mutations than previously reported. Therefore, F1H mutational analyses for R/R and ND unfit AML patients harboring FLT3-ITD/TKD mutations may reveal novel therapeutic targets that are sensitive to FLT3i. Samples from these patients showed non-canonical gain-of-function mutations, such as N676K, S451F, V592D, and F691L, which could guide the selection of optimal anti-FLT3 therapies. In addition, longitudinal NGS analysis revealed clonal evolution in cases in which resistance to the FLT3i, gilteritinib and quizartinib were observed. Time-dependent analysis of allele frequencies can help evaluate the details of leukemia clonal evolution and provide optimal treatment options. Figure Legends Fig.1 Overview of gene mutations using F1H NGS analyses. The color of each column indicates the type of genetic mutation. Blue column; point mutation/insertion/deletion, green column; fusion gene, purple column; dual mutations. Fig.2 The chronological changes of leukemic cells fractions bearing each gene mutations during treatment with FLT3 inhibitors, gilteritinib and quizartinib. Figure 1 Figure 1. Disclosures Shibayama: Otsuka: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Sanofi: Honoraria; Nippon Shinyaku: Honoraria; Fujimoto: Honoraria; Daiichi Sankyo: Speakers Bureau; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Research Funding, Speakers Bureau; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Ono: Research Funding, Speakers Bureau; Celgene: Research Funding; Mundi Pharma: Honoraria; Essentia Pharma Japan: Research Funding. Yamauchi: Otsuka: Research Funding; Ono Pharmaceutical: Honoraria; Pfizer: Honoraria, Research Funding; Chugai: Honoraria; Abbie: Research Funding; Astellas: Research Funding; Daiichi Sankyo: Research Funding; Solasia Pharma: Research Funding. Kondo: Sumitomo Dainippon Pharma Co., Ltd.: Honoraria; Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Astellas Pharma Inc.: Consultancy, Honoraria; SANWA KAGAKU KENKYUSHO CO.,LTD.: Consultancy. Yamamoto: IQIVA/Genmab: Research Funding; Micron: Honoraria; Zenyaku: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; SymBio: Honoraria, Research Funding; Solasia Pharma: Research Funding; Sanofi: Honoraria; Otsuka: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Mundipharma: Research Funding; MSD: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria; Janssen: Honoraria; HUYA: Consultancy; IQIVA/HUYA: Honoraria; IQIVA/Incyte: Research Funding; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Chugai: Honoraria, Research Funding; Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; ADC Therapeutics: Honoraria. Kuroda: Kyowa Kirin: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; MSD: Research Funding; Abbvie: Consultancy, Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Sysmex: Research Funding; Pfizer: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Shionogi: Research Funding; Asahi Kasei: Research Funding; Taiho Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Usuki: Otsuka Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Novartis Pharma K.K.: Research Funding, Speakers Bureau; Ono Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Janssen Pharmaceutical K.K.: Research Funding; Celgene K.K.: Research Funding, Speakers Bureau; Takeda Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Nippon-Boehringer-Ingelheim Co., Ltd.: Research Funding; Mundipharma K.K.: Research Funding; Amgen-Astellas Biopharma K.K.: Research Funding; Nippon-Shinyaku Co., Ltd.: Research Funding, Speakers Bureau; Kyowa-Kirin Co., Ltd.: Research Funding, Speakers Bureau; Pfizer Japan Inc.: Research Funding, Speakers Bureau; Alexion Pharmaceuticals, Inc.: Research Funding, Speakers Bureau; Eisai Co., Ltd.: Speakers Bureau; MSD K.K.: Research Funding, Speakers Bureau; PharmaEssentia Japan KK: Research Funding, Speakers Bureau; Yakult Honsha Co., Ltd.: Research Funding, Speakers Bureau; Daiichi Sankyo Co., Ltd.: Research Funding, Speakers Bureau; Sumitomo-Dainippon Pharma Co., Ltd.: Research Funding; SymBio Pharmaceuticals Ltd.: Research Funding, Speakers Bureau; Gilead Sciences, Inc.: Research Funding; Bristol-Myers-Squibb K.K.: Research Funding, Speakers Bureau; Apellis Pharmaceuticals, Inc.: Research Funding; AbbVie GK: Research Funding, Speakers Bureau; Astellas Pharma Inc.: Research Funding, Speakers Bureau; Incyte Biosciences Japan G.K.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding, Speakers Bureau; Sanofi K.K.: Speakers Bureau; Amgen K.K.: Research Funding. Yoshimitsu: Novartis: Honoraria; Takeda: Honoraria; Sanofi: Honoraria. Ishitsuka: Eisai: Other: Personal fees, Research Funding; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Pfizer: Other: Personal fees; Novartis: Other: Personal fees; Janssen Pharmaceuticals: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Takeda: Other: Personal fees, Research Funding; BMS: Other; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Ono Pharmaceutical: Other: Personal fees, Research Funding; Kyowa Kirin: Other: Personal fees, Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; MSD: Research Funding; Teijin Pharma: Research Funding; Otsuka Pharmaceutical: Other: Personal fees; Shire: Other; Mochida: Other: Personal fees, Research Funding; Asahi kasei: Research Funding; Eli Lilly: Research Funding; Huya Japan: Other: Personal fees. Ono: Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen Pharmaceutical K.K: Honoraria; Eisai Co., Ltd.: Honoraria; Astellas Pharma Inc.: Honoraria; Takeda Pharmaceutical Company Limited.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Otsuka Pharmaceutical Co., Ltd.: Honoraria; Pfizer Japan Inc.: Honoraria; Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Mundipharma K.K.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Merck Sharp & Dohme: Honoraria, Research Funding. Takahashi: Kyowahakko-Kirin: Research Funding; Toyamakagaku: Research Funding; Otsuka Pharmaceutical: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai: Research Funding; Eizai: Research Funding; Asahikasei: Research Funding; Ono: Research Funding. Iyama: SymBio Pharmaceuticals: Research Funding; Astellas: Honoraria; CSL Behring: Honoraria; Daiichi Sankyo: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; Otsuka Pharmaceuticals Factory: Honoraria; MSD: Research Funding; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Otsuka: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding. Izutsu: Allergan Japan: Honoraria; Symbio: Honoraria, Research Funding; Pfizer: Research Funding; Ono: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; MSD: Research Funding; Janssen: Honoraria, Research Funding; Incyte: Research Funding; Genmab: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Yakult: Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; FUJI FILM Toyama Chemical: Honoraria. Minami: Bristol-Myers Squibb Company: Honoraria; Pfizer Japan Inc.: Honoraria; Takeda: Honoraria; Novartis Pharma KK: Honoraria; Astellas: Honoraria; Ono: Research Funding; CMIC: Research Funding.

Introduction: Multiple myeloma (MM) is a uniformly fatal disorder of B cells characterized by the clonal expansion of plasma cells in the bone marrow. The treatment of MM patients has been dramatically changed by new agents such as proteasome inhibitors and immunomodulatory drugs, however, many patients will relapse even if new agents provide therapeutic advantages. Therefore, a new strategy is still needed to increase MM patient survival. Metabolic reprogramming is recognized as one of the hallmarks of cancer cells. Glutamine is the most abundant circulating amino acid in blood, glutamine metabolism through glutaminolysis may be associated with myeloma cell maintenance and survival. Materials and Methods: In this study, we investigated whether glutaminolysis was involved the proliferation in myeloma cells. We also investigated whether glutaminase (GLS) inhibitor, CB-839 could suppress myeloma cells and enhance the sensitivity of myeloma cells to histone deacetylase (HDAC) inhibition. Results: We first investigated the relationship between glutamine transporter or GLS gene expression and MM patients by microarray gene expression data from the online Gene Expression Omnibus (GEO). Glutamine transporter genes such as SLC38A1 and SLC1A5 were increased in myeloma and plasma cell leukemia cells (GSE13591). In contrast, GLS1 expression was not changed. We next investigated the glutaminolysis in myeloma cells. Deprivation of glutamine in culture medium revealed that cellular growth inhibition and cell cycle arrest at G0/G1 phase. Gene expression of AURKA (aurora kinase A), AURKB (aurora kinase B), HSP90AA1 (Heat Shock Protein 90 Alpha Family Class A Member 1) and CCNB1 (cyclin B1) were reduced from the public microarray datasets (GSE59931) and protein expressions were also reduced by immunoblot analysis. We next evaluated the effect of GLS inhibitor, CB-839. 72 h treatment of MM cells were inhibited by CB-839 in a dose dependent manner. Cellular cytotoxicity was also increased. Glutamine is converted by GLS into glutamate and alpha-ketoglutarate (α-KG), and related nicotinamide adenine dinucleotide phosphate (NADP) production. Intracellular α-KG and NADPH were reduced by CB-839. As metabolites are the substrates used to generate chromatin modification including acetylation of histone, we investigated HDAC inhibitor, panobinostat in myeloma cells. 72 h treatment of MM cells were inhibited by panobinostat and histone acetylation was increased. Combined treatment with panobinostat and CB-839 caused more cytotoxicity than each drug alone. Panobinostat and CB-839 also inhibited bortezomib resistant cells. Caspase 3/7 activity and cellular cytotoxicity were also increased. Proteasomal activity was reduced. Adenosine triphosphate (ATP) is the most important source of energy for intracellular reactions. Intracellular ATP levels drastically decreased. Because mitochondria generate ATP and participate in signal transduction and cellular pathology and cell death. The quantitative analysis of JC-1 stained cells changed mitochondrial membrane potential in cell death, which were induced by panobinostat and CB-839 on myeloma cells. Immunoblot analysis revealed that protein expression of aurora kinase A, aurora kinase B, HSP90 and cyclin B1 were reduced, and cleaved caspase 3 and γ- H2AX were increased by panobinostat and CB-839 treatment. GLS shRNA transfectant cells were inhibited cellular proliferation and sub-G1 phase was increased by cell cycle analysis. GLS shRNA transfectant cells were increased the sensitivity of panobinostat compared to control cells. Conclusion: The glutaminolysis is involved myeloma cell proliferation and GLS inhibitor is effective to myeloma cells and enhance cytotoxic effects of HDAC inhibitors. We also provide the promising clinical relevance as a candidate drug for treatment of myeloma patients. Disclosures No relevant conflicts of interest to declare.

Background Controlling serum cholesterol is critical to prevent cardiovascular disease in patients with dyslipidaemia. Guidelines emphasise the need to select treatment for dyslipidaemia based on specific patient profiles; however, there is little information about the serum cholesterol levels of patients in each profile in Japan. Therefore, we aimed to describe the serum cholesterol levels and prevalence of uncontrolled cases in Japanese patients with dyslipidaemia. Methods We included data for patients with dyslipidaemia between 2003 and 2007 from the BioBank Japan Project (66 hospitals). Then, we reported their serum cholesterol levels by age, body mass index, glycaemic control (glycated haemoglobin A1c), blood pressure, smoking, drinking, comorbidity and medication profiles. Results We included 22,189 male and 21,545 female patients. The mean serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG) and non-HDL-C levels in males were 117.4 mg/dL, 51.0 mg/dL, 187.6 mg/dL and 153.6 mg/dL, respectively; the corresponding levels in females were 129.5 mg/dL, 60.5 mg/dL, 144.9 mg/dL and 157.9 mg/dL, respectively. In both males and females, the LDL-C levels were the highest in the following profiles: age 19–44 years, body mass index 18.5–22 kg/m2, glycated haemoglobin A1c, Highlights • Evidence of serum cholesterol control in Japanese dyslipidaemic patients is scarce. • We analysed data for a large-scale population in hospital settings. • Our findings provide serum cholesterol levels by different risk profiles. • Serum lipid levels were the lowest in the youngest patients. • Data should be carefully applied to patients with mild hyperlipidaemia.

Background: Acute myeloid leukemias with KMT2A (formerly known as MLL-1) fusion genes (MLL-AML) and those with NPM1 mutations (NPM1-AML) are distinct subtypes as defined by the WHO classification. Although they have different clinical features and prognostic impact , recent studies suggest that the MLL1 co-factor, menin, plays a key role in maintaining self-renewal of immature leukemic cells by upregulating transcription of HOXA and MEIS (Gundry et al.). New targeted strategies for these AML subtypes are expected as preliminary data suggest that menin-MLL1 inhibition may inhibit malignancy. In addition to classical chromosomal analysis and prefixed fusion gene screening, next-generation sequencing (NGS) should help in identifying the precise prevalence of these alterations and understanding the relationship with other pathological mutations. We launched the HM-SCREEN-JAPAN01 study (UMIN000035233) in which gene alterations are analyzed by FoundationOne Heme® in patients with AML who are relapsed/refractory to, or ineligible for standard therapies. Aiming for 200 registrations, recruitment has reached approximately 100. The interim results are described here. Methods: HM-SCREEN-JAPAN01 is an observational study and conducted by 17 participating institutions. The eligibility criteria are as follows: 1) histological diagnosis of AML must be made by bone marrow testing; 2) one of the following conditions must be fulfilled: i) a patient with newly diagnosed AML and is ineligible for standard treatment, or ii) a patient with AML who has relapsed or is refractory to prior therapy; 3) sufficient amount of bone marrow sample must be available; 4) age at registration must be 20 or more; and 5) written informed consent must be taken. All samples were analyzed by FoundationOne Heme®. Results:Nine patients (9.9%) with MLL-AML and seventeen patients (18.7%) with NPM1-AML were found among 91 available cases (either one found in 28.6%). No patients demonstrated MLL-rearrangement and NPM1-mutation simultaneously. Median age of patients with MLL-AML (42-68 y) was a decade less than that of patients with NPM1-AML (55-74 y), and the majority of cases had a clinical relapse or were refractory to prior therapies. Translocations involving chromosome 11q23.3 (e.g. t(9;11)(p21.3;q23.3)) were found in 5 of 8 patients (62.5%) with MLL-AML (data not available due to insufficient cell count in one case) and no chromosomal abnormalities were detected in 10 of 16 patients (62.5%) with NPM1-AML (chromosomal analysis was not performed in one case). In patients with MLL-AML (see Figure), FLT3 mutations were found in 3 of 9 cases (33.3%), all of which were point mutations within the tyrosine kinase domain (FLT3-TKD). PTPN11 mutations were also found simultaneously in these three cases. Co-existing NRAS and TP53 mutations with high allele-frequency (32-50%) were also seen in two different cases. A targetable mutation of IDH2 was seen in one patient (11.1%) who had an FLT3 mutation with low allele-frequency (2%). In patients with NPM1-AML (see Figure), allele-frequency of mutated NPM1 ranged from 10 to 44%. Relatively common co-existing mutations were TET2 (7 of 17; 41.2%), DNMT3A (9 of 17; 52.9%), and FLT3 (9 of 17; 52.9%). Unlike in MLL-AML patients, all FLT3 alterations were internal tandem duplication (FLT-ITD) with one case of dual FLT3-ITD and -TKD mutation. IDH1 and IDH2 mutations were found in two (11.8%) and four (23.5%) separate cases, respectively. A rare fusion gene ETV6-NTRK3 (one of primary targets of NTRK inhibitors) was detected in one patient (5.9%) who had IDH1 mutation with moderate allele-frequency (17%). Conclusion: MLL-rearrangements and NPM1-mutations were found in approximately a quarter of the 91 AML patient (mostly relapsed or refractory) bone marrow samples analyzed. These alterations appeared to be mutually exclusive. FLT3 alterations were seen in a third of the MLL-AML cases and half of the NPM1-AML cases, seemingly more frequent than that previously reported. Interestingly, FLT3-TKDs were dominant in MLL-AML cases, whereas NPM1-AML cases carried FLT3-ITD. IDH1 and IDH2 mutations commonly co-existed in both groups. This HM-SCREEN-Japan01 study is now recruiting patients, and a further understanding of genomic distribution and correlation is expected. Figure Disclosures Yamauchi: Otsuka:Research Funding;Astellas:Research Funding;Daiichi Sankyo:Research Funding;Chugai:Honoraria;Pfizer:Honoraria, Research Funding;Abbie:Research Funding;Solasia Pharma:Research Funding;Ono Pharmaceutical:Honoraria.Shibayama:AstraZeneca:Honoraria, Membership on an entity's Board of Directors or advisory committees;Sanofi:Honoraria;Pfizer:Honoraria;Fujimoto:Honoraria;Janssen:Honoraria, Research Funding;Teijin:Research Funding;Novartis:Honoraria, Research Funding;Takeda:Honoraria, Research Funding;Nippon Shinyaku:Honoraria, Research Funding;Daiichi Sankyo:Honoraria;Chugai:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Sumitomo Dainippon:Honoraria, Research Funding;Merck Sharp & Dohme:Research Funding;Shionogi:Research Funding;Astellas:Research Funding;Taiho:Research Funding;Otsuka:Honoraria;Bristol-Myers Squibb:Honoraria;Celgene:Membership on an entity's Board of Directors or advisory committees, Research Funding;Eisai:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;AbbVie:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Kyowa Kirin:Honoraria;Ono:Honoraria, Research Funding;Mundi Pharma:Honoraria.Yamamoto:Stemline Therapeutics:Consultancy;Meiji Seika Pharma:Consultancy, Honoraria;MSD:Consultancy, Honoraria, Research Funding;Chugai:Consultancy, Honoraria, Research Funding;Eisai:Consultancy, Honoraria, Research Funding;Daiichi Sankyo:Consultancy;IQIVA/HUYA:Honoraria;HUYA:Consultancy;IQIVA/Incyte:Research Funding;Mundipharma:Consultancy, Honoraria, Research Funding;Kyowa Kirin:Honoraria;Mochida:Honoraria;Gilead Sciences:Research Funding;Solasia Pharma:Research Funding;Nippon Shinyaku:Honoraria, Research Funding;Novartis:Honoraria, Research Funding;Ono:Consultancy, Honoraria, Research Funding;Aichi Cancer Center:Current Employment;AbbVie:Consultancy, Honoraria, Research Funding;Astra-Zeneca:Consultancy, Research Funding;Bayer:Research Funding;Bristol-Myers Squibb:Honoraria;Celgene:Consultancy, Honoraria, Research Funding;Zenyaku:Research Funding;Takeda:Consultancy, Honoraria, Research Funding;Yakult:Research Funding;SymBio:Research Funding;Pfizer:Honoraria;Otsuka:Consultancy, Honoraria, Research Funding;Sanofi:Honoraria;Sumitomo Dainippon:Honoraria;Janssen:Honoraria.Fujishima:Pfizer:Speakers Bureau.Takahashi:Pfizer Japan Inc.:Honoraria, Research Funding;Novartis Pharma KK:Honoraria, Research Funding;Bristol-Myers Squibb Company:Honoraria.Usuki:Alexion:Speakers Bureau;Pfizer:Research Funding;Nippon Boehringer Ingelheim:Research Funding;Mundipharma:Research Funding;Astellas-Amgen-Biopharma:Research Funding;Nippon shinyaku:Research Funding, Speakers Bureau;Eisai:Speakers Bureau;MSD:Speakers Bureau;Takeda:Speakers Bureau;PharmaEssentia:Speakers Bureau;Yakult:Speakers Bureau;Symbio:Research Funding, Speakers Bureau;Daiichi Sankyo:Research Funding, Speakers Bureau;Sumitomo Dainippon:Research Funding;Otsuka:Research Funding, Speakers Bureau;Novartis:Research Funding, Speakers Bureau;Brisol-Myers Squibb:Research Funding, Speakers Bureau;Kyowa Kirin:Research Funding, Speakers Bureau;Ono:Research Funding, Speakers Bureau;Janssen:Research Funding;Celgene:Research Funding, Speakers Bureau;Takeda:Research Funding;Astellas:Research Funding, Speakers Bureau;Abbvie:Research Funding;Gilead:Research Funding.Ono:Celgene:Honoraria, Research Funding;Kyowa Kirin Co., Ltd.:Honoraria, Research Funding;Chugai Pharmaceutical Co., Ltd.:Honoraria, Research Funding;Novartis Pharma KK:Honoraria;Mundipharma K.K.:Honoraria;TAIHO PHARMACEUTICAL CO., LTD.:Research Funding;Eisai Co., Ltd.:Honoraria;Otsuka Pharmaceutical Co., Ltd.:Honoraria;Astellas Pharma Inc.:Honoraria;Bristol-Myers Squibb Company:Honoraria;Pfizer Japan Inc.:Honoraria;Takeda Pharmaceutical Company Limited.:Honoraria;ONO PHARMACEUTICAL CO., LTD.:Honoraria, Research Funding;DAIICHI SANKYO COMPANY, LIMITED.:Honoraria;Janssen Pharmaceutical K.K:Honoraria.Kuroda:Daiichi Sankyo:Honoraria, Research Funding;Pfizer:Honoraria, Research Funding;Sysmex:Research Funding;Janssen Pharmaceutical K.K:Consultancy;Eisai:Honoraria, Research Funding;Sanofi:Consultancy, Honoraria, Research Funding;Kyowa Kirin:Honoraria, Research Funding;Otsuka Pharmaceutical:Honoraria, Research Funding;Ono Pharmaceutical:Honoraria, Research Funding;Abbvie:Consultancy, Honoraria;MSD:Research Funding;Celgene:Consultancy, Honoraria, Research Funding;Dainippon Sumitomo Pharma:Honoraria, Research Funding;Chugai Pharmaceutical:Honoraria, Research Funding;Takeda:Honoraria, Research Funding;Bristol-MyersSquibb:Consultancy, Honoraria, Research Funding;Astellas Pharma:Honoraria, Research Funding;Fujimoto Pharmaceutical:Honoraria, Research Funding;Taiho Pharmaceutical:Research Funding;Asahi Kasei:Research Funding;Shionogi:Research Funding;Nippon Shinyaku:Honoraria, Research Funding.Ishitsuka:Celgene:Other: Personal Fees;Kyowa Hakko Kirin:Other: Personal fees, Research Funding;BMS:Other: Personal fees;Chugai Pharmaceutical:Other: Personal fees, Research Funding;Takeda:Other: Personal fees, Research Funding;mundiharma:Other: Personal fees;Taiho Pharmaceuticals:Other: Personal fees, Research Funding;Janssen Pharmaceuticals:Other: Personal fees;Novartis:Other: Personal fees;Pfizer:Other: Personal fees;Astellas Pharma:Other, Research Funding;Genzyme:Other;Sumitomo Dainippon Pharma:Other, Research Funding;Eisai:Other, Research Funding;Mochida:Other, Research Funding;Shire:Other;Otsuka Pharmaceutical:Other;Ono Pharmaceutical:Other, Research Funding;Teijin Pharma:Research Funding;MSD:Research Funding;Asahi kasei:Research Funding;Eli Lilly:Research Funding;Daiichi Sankyo:Other;Huya Japan:Other.Minami:Bristol-Myers Squibb Company:Honoraria;Novartis Pharma KK:Honoraria;Pfizer Japan Inc.:Honoraria;Takeda:Honoraria.

Background:Recently, whole exome sequencing has been performed for acute myeloid leukemia (AML) by next generation sequencing. The results revealed that certain gene mutations are identified in patients with AML. Among them,FLT3(28%),NPM1(27%),DNMT3A(26%), andIDH1/2(20%) mutations are observed in 20 to 30% of cases, while the frequencies of more than 10 other types of mutations are less than 10%. Some of these low frequency mutations are actionable mutations, which are defined as genetic DNA aberrations that are expected to elicit a response to an approved targeted therapy that is available for off-label treatment or available in clinical trials. Thus, the treatment strategies for leukemia are drastically changing with the rapid development of new drugs. Moving forward, the proper use of new agents is one of the major AML treatment issues. Especially, genome profiling analysis for newly diagnosed patients will be needed to select an optimal first line treatment. The HM-SCREEN-Japan 01 is an actionable mutation profiling multicenter study of patients with newly diagnosed AML who are unsuitable for the first standard treatment or have relapsed/refractory AML. The objective of this study is to evaluate the frequency and characteristics of cancer-related genome alterations in AML using a comprehensive genome profiling assay (FoundationOne®Heme) and determine the quality of specimens that contribute to the gene analysis. Approval was obtained from the Institutional Review Board prior to starting patient accrual at each institution. This trial has been registered at the UMIN Clinical Trials Registry as UMIN000035233. Methods:This study was conducted by 17 participating institutions, with a sample size of 200. The eligibility criteria were as follows: 1) histological diagnosis of AML through bone marrow aspiration; 2) either of the following conditions fulfilled, i) patients with newly diagnosed AML unfit for standard treatment or ii) patients with relapsed/refractory AML; 3) sufficient sample is collected by bone marrow aspiration; 4) age at registration is 20 years or older; 5) written informed consent is taken. The primary outcome was the frequency of each genomic alteration in leukemia using FoundationOne®Heme (F1H), which is a comprehensive genomic profile that applies next-generation sequencing. The secondary outcomes evaluated the association between each cancer genome alteration and clinicopathological characteristics, prognosis, and quality of the specimens that contributed to the genetic analysis. In this study, we also performed serial genome profiling analyses to evaluate the time-dependent changes in genomic profiles in patients administered FLT3 inhibitors, gilteritinib, and quizartinib for AML. Results:This study commenced in January 2019, and 91 patients were recruited by March 2020. The median turnaround time between sending specimens and receiving results was 15 days (9 to 56 days). Of the 91 patients, 35.2% (32/91) were newly diagnosed with AML and unfit for standard treatment and 64.8% (59/91) had relapsed/refractory AML. Mutations were observed in the following genes in all 91 patients:FLT3(28.6%),RUNX1(25.0%),TP53(20.1%),DNMT3A(19.8%),NPM1(18.7%),IDH1/2(17.6%),CEBPA(16.5%),KMT2A(14.3%),NRAS(13.2%),TET2(12.1%),ASXL1(12.1%), and EZH2(2.2%). In 32 patients with newly diagnosed AML, mutations were observed in the following genes:FLT3(28.6%),RUNX1(20.3%),TP53(18.8%),DNMT3A(15.6%),NPM1(12.5%),IDH1/2(15.6%),CEBPA(15.6%),KMT2A(6.0%),NRAS(12.5%),TET2(9.0%),ASXL1(21.9%), and EZH2(6.3%). In 59 patients with relapsed/refractory AML, mutations were observed in the following genes:FLT3(28.6%),RUNX1(22.0%),TP53(22.0%),DNMT3A(22.0%),NPM1(22.0%),IDH1/2(18.6%),CEBPA(15.3%),KMT2A(18.6%),NRAS(13.6%),TET2(13.6%),ASXL1(6.8%), andEZH2(0%). In the FLT3 positive AML cohort, six patients were registered and one achieved remission by quizartinib after progression on gilteritinib. Conclusions:The evaluation of F1H for its use in HM-SCREEN-Japan 01 facilitates the analysis of leukemia-associated genes that can be used as therapeutic targets, which have rarely been identified in AML thus far. Figure Disclosures Shibayama: Shionogi:Research Funding;Taiho:Research Funding;Eisai:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Celgene:Membership on an entity's Board of Directors or advisory committees, Research Funding;Ono:Honoraria, Research Funding;Takeda:Honoraria, Research Funding;Merck Sharp & Dohme:Research Funding;Sumitomo Dainippon:Honoraria, Research Funding;Nippon Shinyaku:Honoraria, Research Funding;Daiichi Sankyo:Honoraria;Novartis:Honoraria, Research Funding;Janssen:Honoraria, Research Funding;Chugai:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;Kyowa Kirin:Honoraria;Otsuka:Honoraria;Bristol-Myers Squibb:Honoraria;Pfizer:Honoraria;Fujimoto:Honoraria;AbbVie:Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding;AstraZeneca:Honoraria, Membership on an entity's Board of Directors or advisory committees;Sanofi:Honoraria;Mundi Pharma:Honoraria;Teijin:Research Funding;Astellas:Research Funding.Yamauchi:Chugai:Honoraria;Pfizer:Honoraria, Research Funding;Ono Pharmaceutical:Honoraria;Otsuka:Research Funding;Astellas:Research Funding;Abbie:Research Funding;Solasia Pharma:Research Funding;Daiichi Sankyo:Research Funding.Gotoh:Alexion pharmaceuticals:Research Funding;Eisai:Honoraria;Ono Pharmaceutical:Honoraria;Taiho pharmaceutical:Honoraria;Takeda pharmaceutical:Honoraria;Nippon Shinyaku:Honoraria;Chugai:Honoraria;Novartis:Research Funding.Yamamoto:Zenyaku:Research Funding;Yakult:Research Funding;Takeda:Consultancy, Honoraria, Research Funding;SymBio:Research Funding;Solasia Pharma:Research Funding;Stemline Therapeutics:Consultancy;Sumitomo Dainippon:Honoraria;Sanofi:Honoraria;Pfizer:Honoraria;Otsuka:Consultancy, Honoraria, Research Funding;Ono:Consultancy, Honoraria, Research Funding;Novartis:Honoraria, Research Funding;Nippon Shinyaku:Honoraria, Research Funding;Mundipharma:Consultancy, Honoraria, Research Funding;MSD:Consultancy, Honoraria, Research Funding;Mochida:Honoraria;Meiji Seika Pharma:Consultancy, Honoraria;Kyowa Kirin:Honoraria;Janssen:Honoraria;Gilead Sciences:Research Funding;IQIVA/Incyte:Research Funding;HUYA:Consultancy;IQIVA/HUYA:Honoraria;Daiichi Sankyo:Consultancy;Eisai:Consultancy, Honoraria, Research Funding;Chugai:Consultancy, Honoraria, Research Funding;Celgene:Consultancy, Honoraria, Research Funding;Bristol-Myers Squibb:Honoraria;Bayer:Research Funding;Astra-Zeneca:Consultancy, Research Funding;AbbVie:Consultancy, Honoraria, Research Funding;Aichi Cancer Center:Current Employment.Fujishima:Pfizer:Speakers Bureau.Takahashi:Bristol-Myers Squibb Company:Honoraria;Novartis Pharma KK:Honoraria, Research Funding;Pfizer Japan Inc.:Honoraria, Research Funding.Usuki:Novartis:Research Funding, Speakers Bureau;Chugai:Research Funding;Apellis:Research Funding;Alexion:Research Funding, Speakers Bureau.ONO:TAIHO PHARMACEUTICAL CO., LTD.:Research Funding;Mundipharma K.K.:Honoraria;DAIICHI SANKYO COMPANY, LIMITED.:Honoraria;Janssen Pharmaceutical K.K:Honoraria;Eisai Co., Ltd.:Honoraria;Astellas Pharma Inc.:Honoraria;Takeda Pharmaceutical Company Limited.:Honoraria;ONO PHARMACEUTICAL CO., LTD.:Honoraria, Research Funding;Otsuka Pharmaceutical Co., Ltd.:Honoraria;Pfizer Japan Inc.:Honoraria;Bristol-Myers Squibb Company:Honoraria;Novartis Pharma KK:Honoraria;Chugai Pharmaceutical Co., Ltd.:Honoraria, Research Funding;Kyowa Kirin Co., Ltd.:Honoraria, Research Funding;Celgene:Honoraria, Research Funding.Kuroda:Astellas Pharma:Honoraria, Research Funding;Sanofi:Consultancy, Honoraria, Research Funding;Daiichi Sankyo:Honoraria, Research Funding;Shionogi:Research Funding;Nippon Shinyaku:Honoraria, Research Funding;Fujimoto Pharmaceutical:Honoraria, Research Funding;Sysmex:Research Funding;Eisai:Honoraria, Research Funding;Ono Pharmaceutical:Honoraria, Research Funding;Abbvie:Consultancy, Honoraria;MSD:Research Funding;Celgene:Consultancy, Honoraria, Research Funding;Takeda:Honoraria, Research Funding;Dainippon Sumitomo Pharma:Honoraria, Research Funding;Chugai Pharmaceutical:Honoraria, Research Funding;Bristol-MyersSquibb:Consultancy, Honoraria, Research Funding;Janssen Pharmaceutical K.K:Consultancy;Asahi Kasei:Research Funding;Taiho Pharmaceutical:Research Funding;Kyowa Kirin:Honoraria, Research Funding;Otsuka Pharmaceutical:Honoraria, Research Funding;Pfizer:Honoraria, Research Funding.Izutsu:Sanofi:Research Funding;Symbio:Research Funding;Solasia:Research Funding;Janssen:Research Funding;Yakult:Research Funding;HUYA Japan:Research Funding;Abbvie pharmaceuticals:Research Funding;Incyte:Research Funding;Eisai:Research Funding;AstraZeneca:Research Funding;Daiichi Sankyo:Research Funding;Bayer pharmaceuticals:Research Funding;Ono Pharmaceutical:Research Funding;Novartis:Research Funding;Chugai:Research Funding;Celgene:Research Funding.Minami:Bristol-Myers Squibb Company:Honoraria;Pfizer Japan Inc.:Honoraria;Novartis Pharma KK:Honoraria;Takeda:Honoraria.

Introduction: ABL tyrosine kinase inhibitors (TKIs) improved outcomes for patients with chronic myeloid leukemia (CML) and Philadelphia chromosome (Ph)-positive leukemia. However, ABL TKIs do not eliminate the leukemia stem cells (LSCs) in the bone marrow, which may represent the most important event in leukemia relapse after TKI discontinuation. Bone marrow is also considered a tissue with limited oxygen supply. Therefore, new approach against leukemia stem cells, which is presented in bone marrow under hypoxia, may improve the outcome of CML patients. Nicotinamide phosphoribosyl transferase (NAMPT) is the rate limiting enzyme of the primary pathway for maintaining cellular NAD+ and that regulates intracellular adenosine triphosphate (ATP) levels in mammalian cells. It has been reported that NAMPT expression is upregulated in several human cancers. Materials and methods: In this study, we established ABL TKI resistantin vitrocell line models (K562 imatinib-R, K562 nilotinib-R, K562 ponatinib-R and Ba/F3 T315I) and used Ph-positive leukemia cell lines. We also investigated whether NAMPT inhibitor could suppress Ph-positive leukemia cells including T315I mutation and ABL TKI resistant under hypoxic condition. Results: In chemical library screen of compounds, NAMPT inhibitor, CHS828 is selected the candidate drug for ABL TKI resistant cells under hypoxic condition. Drug repositioning and repurposing can be an important part of any drug discovery. Therefore, we examined NAMPT efficacy by using Ph-positive leukemia cell lines. We first investigated the NAMPT expression by microarray gene expression data from the online Gene Expression Omnibus (GEO). Gene expression of NAMPT is increased in CML patients compared to normal samples from the public microarray datasets of GSE13159. Protein expression of NAMPT is found in Ph-positive leukemia cell lines including ABL TKI resistant cells. In hypoxia, gene expression of NAMPT was increased in Ph-positive cells compare to normoxic condition. We next examined efficacy of NAMPT inhibitor, CHS828 in Ph-positive leukemia cell lines. We found that CHS828 treatment for 72 h decreased cell viability of Ph-positive cell lines in a dose dependent manner. We also found that CHS828 inhibited the proliferation of ABL TKI resistant cells (K562 imatinib-R, K562 nilotinib-R, K562 ponatinib-R) and T315I mutant Ba/F3 cells under hypoxic condition. The rate of cell cycle progression was delayed and cells were blocked in G2/M phase. Nuclear factor-kappaB (NF-kB) is also implicated in cancer development. CHS828 inhibited constitutive NF-kB activity in the time and dose dependent manner. Intracellular ATP, which is the most important source of energy for cellular reactions, was drastically decreased after CHS828 treatment. NAD+ plays a vital role in diverse cellular processes that govern human health and disease. Intracellular NAD+ was decreased after CHS828 treatment. The wound healing effect was evaluated at 0, 24, 48, and 72 h by using NIH3T3 cells. In wound healing results, CHS828 treatment inhibited cellular migration of NIH3T3 cells. We next investigated the efficacy of ABL TKI and CHS828 against Ph-positive leukemia cell lines. ABL TKI and CHS828 treatment induced cellular growth inhibition compared with each drug alone. Caspase 3/7 activity was also increased after ABL TKIs and CHS828 treatment. ABL TKI and CHS828 reduced the colony formation ability of Ph-positive cells under hypoxic condition. Thein vivoefficacies of one of ABL TKI, ponatinib and CHS828 were evaluated in a mouse xenograft model. Ponatinib and CHS828 inhibited the growth of T315I mutant Ba/F3 cellsin vivomore than the control vehicle. We also found that co-treatment with ponatinib and CHS828 increased mouse survival. Combination treatment with ponatinib and CHS828 was also well tolerated, with no animal deaths in the treated mice. Conclusion: The results of our study indicate that the ABL TKI and CHS828 may be a powerful strategy against Ph-positive cells including ABL TKI resistant cells and provide the promising clinical relevance as a candidate drug for treatment of CML stem cells of the bone marrow microenvironment under hypoxic condition. Disclosures No relevant conflicts of interest to declare.