Previously, we reported the efficacy and safety of tazemetostat in Japanese patients with relapsed/refractory follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) harboring the EZH2 mutation in a multicenter, open-label, phase II study. Here, we present a follow-up analysis of tazemetostat at a long-term median follow-up of 35.0 months. Twenty patients were enrolled: 17 in the FL cohort and three in the DLBCL cohort. In the FL cohort, the objective response rate was 70.6%, consistent with the primary analysis, and the median progression-free survival (PFS) was not reached. The 24-month and 36-month PFS rates were 72.1% (95% confidence interval [CI] 41.5%-88.6%) and 64.1% (95% CI 33.7%-83.4%), respectively. The median duration of treatment was 30.2 months. After the primary analysis at a median follow-up of 12.9 months, grade 1-2 urinary tract infection, peripheral motor neuropathy, and hypogammaglobulinemia newly emerged, but the incidence of adverse events (AEs) did not increase notably during this follow-up period. No unexpected grade ≥ 3 treatment-related AEs were reported. Long-term oral monotherapy with tazemetostat showed favorable efficacy and safety profiles, indicating that it may be a useful third-line or later treatment option for patients with relapsed/refractory FL harboring the EZH2 mutation. Trial registration: ClinicalTrials.gov: NCT03456726.

This single-arm confirmatory study (JCOG1305) aimed to evaluate the utility of interim positron emission tomography (iPET)-guided therapy for newly diagnosed advanced-stage classic Hodgkin lymphoma (cHL). Patients aged 16-60 years with cHL received two cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and then underwent an iPET scan (PET2), which was centrally reviewed using a five-point Deauville scale. PET2-negative patients continued an additional four cycles of ABVD, whereas PET2-positive patients switched to six cycles of escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP). The co-primary endpoints were 2-year progression-free survival (PFS) among all eligible and PET2-positive patients. Ninety-three patients were enrolled between January 2016 and December 2019. One patient was ineligible because of a diagnostic error. The median age of the 92 eligible patients was 35 (interquartile range, 28-48) years. Forty (43%) patients had stage III disease, and 43 (47%) had stage IV disease. The remaining nine (10%) patients had stage IIB disease with risk factors. Nineteen PET2-positive (21%) patients received eBEACOPP, 18 completed six cycles of eBEACOPP, 73 PET2-negative (79%) patients continued ABVD, and 70 completed an additional four cycles of ABVD. With a median follow-up period of 41.1 months, the 2-year PFS of 92 eligible patients and 19 PET2-positive patients were 84.8% (80% confidence interval [CI], 79.2-88.9) and 84.2% (80% CI, 69.7-92.1), respectively. Both primary endpoints were met at the prespecified threshold. This study demonstrates that iPET-guided therapy is a useful treatment option for younger patients with newly diagnosed advanced-stage cHL. Registration number: jRCTs031180218.

Not available.

BACKGROUND: Follicular helper T-cell lymphomas (TFHL) harbour frequent alterations in genes that regulate DNA methylation. Preliminary reports suggest that treatment with 5-azacitidine has clinical activity in patients with relapsed or refractory TFHL. We aimed to compare the oral form of azacitidine with investigator's choice standard therapy (ICT; ie, gemcitabine, bendamustine, or romidepsin) in patients with relapsed or refractory TFHL. METHODS: Patients older than 18 years with relapsed or refractory TFHL (angioimmunoblastic T-cell lymphoma, follicular lymphoma, or nodal T-cell lymphoma with phenotype, ie, positive with two or more markers among CD10, BCL6, CXCL13, PD1, or ICOS) based on the 2017 WHO classification of haematological neoplasms, with an Eastern Cooperative Oncology Group performance status score of 0-3, were recruited in university hospitals from five European countries and from Japan. Patients were randomly assigned 1:1 to treatment with either azacitidine given at a dose of 300 mg once a day (200 mg in Japanese patients) for 14 days in a 28-day cycle or gemcitabine, bendamustine, or romidepsin according to the investigator's choice. Random assignment was stratified by the number of previous lines of therapy and by the presence of previous or concomitant myeloid malignancy. The primary endpoint was investigator-assessed progression-free survival, presented in the intention-to-treat population. This Article is the final analysis of this trial, registered at ClinicalTrials.gov (Europe NCT03593018 and Japan NCT03703375). FINDINGS: 86 patients (median age 69 years [IQR 62-76], 50 patients were male, 36 were female) were enrolled between Nov 9, 2018, to Feb 22, 2021; 42 in the azacitidine group and 44 in the ICT group. With a median follow-up of 27·4 months (IQR 20·2-32·9), the median progression-free survival was 5·6 months (95% CI 2·7 -8·1) in the azacitidine group versus 2·8 months (1·9-4·8) in the ICT group (hazard ratio of 0·63 (95% CI 0·38-1·07); 1-sided p=0·042). Grade 3-4 adverse events were reported in 32 (76%) of 42 patients in the azacitidine group versus 42 (98%) of 43 patients in the ICT group. The most adverse grade 3 or worse adverse events were haematological (28 [67%] of 42 patients vs 40 [93%] of 43 patients), infection (8 [19%] and 14 [33%]), and gastrointestinal (5 [12%] vs 1 [2%] for azacitidine and ICT, respectively). There were two treatment-related deaths in the azacitidine group (one endocarditis and one candidiasis) and three in the ICT group (one heart failure, one COVID-19, and one cause unknown). INTERPRETATION: Although the pre-specified primary outcome of the trial was not met, the favourable safety profile suggests that azacitidine could add to the treatment options in these difficult to treat diseases especially in combination with other drugs. Trials with combination are in preparation in a platform trial. FUNDING: Bristol-Myers Squibb. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Response determined by 18[F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)-CT after induction therapy can predict progression-free survival (PFS) in follicular lymphoma (FL). However, little prospective research has examined the significance of PET after second-line therapy. We conducted a prospective multicenter phase II trial (W-JHS NHL01) of bendamustine plus rituximab (BR) without rituximab maintenance for FL in first relapse. This study aimed to evaluate the usefulness of end-of-treatment (EOT)-PET for predicting PFS in FL patients in first relapse. EOT-PET examinations were performed between 6 and 8 weeks from the start of the last BR cycle. The primary endpoint was 1-year PFS. Key secondary endpoints were overall response rate (ORR), complete response rate (CRR), and 1-year overall survival (OS). Seventy-five patients were enrolled, and 8 were excluded from analysis. ORR was 86.6% and CRR was 59.7%. One-year PFS was 88.9% (95% confidence interval [CI] 80.7-94.3%) and 1-year OS in 75 patients was 97.3% (95% CI 89.6-99.3%). One-year PFS was significantly inferior in EOT-PET-positive patients (n = 9) compared with PET-negative patients (n = 58) (77.8% vs. 93.1%; p = 0.02). We confirmed that EOT-PET after second-line BR therapy could predict early progression in FL patients in first relapse.

Protein phosphatase 6 (PP6) is a serine/threonine (Ser/Thr) protein phosphatase, and its catalytic subunit is Ppp6c. PP6 forms the PP2A subfamily with PP2A and PP4. The diverse phenotypes observed following small interfering RNA (siRNA)-based knockdown of Ppp6c in cultured mammalian cells suggest that PP6 plays roles in cell growth and DNA repair. There is also evidence that PP6 regulates nuclear factor kappa B (NF-κB) signaling and mitogen-activated protein kinases and inactivates transforming growth factor-β-activated kinase 1 (TAK1). Loss of Ppp6c causes several abnormalities, including those of T cell and regulatory T cell function, neurogenesis, oogenesis, and spermatogenesis. PP2A has been reported to play an important role in erythropoiesis. However, the roles of PP6 in other hematopoietic cells have not been investigated. We generated Ppp6cfl/fl;Tie2-Cre (Ppp6cTKO) mice, in which Ppp6c was specifically deleted in hematopoietic and vascular endothelial cells. Ppp6cTKO mice displayed embryonic lethality. Ppp6c deficiency increased the number of dead cells and decreased the percentages of erythroid and monocytic cells during fetal hematopoiesis. By contrast, the number of Lin-Sca-1+c-Kit+ cells, which give rise to all hematopoietic cells, was slightly increased, but their colony-forming cell activity was markedly decreased. Ppp6c deficiency also increased phosphorylation of extracellular signal-regulated kinase 1/2 and c-Jun amino (N)-terminal kinase in fetal liver hematopoietic cells.

PURPOSE: About a third of patients with relapsed or refractory classic Hodgkin lymphoma (r/r CHL) succumb to their disease after high-dose chemotherapy followed by autologous stem-cell transplantation (HDC/ASCT). Here, we aimed to describe spatially resolved tumor microenvironment (TME) ecosystems to establish novel biomarkers associated with treatment failure in r/r CHL. PATIENTS AND METHODS: We performed imaging mass cytometry (IMC) on 71 paired primary diagnostic and relapse biopsies using a marker panel specific to CHL biology. For each cell type in the TME, we calculated a spatial score measuring the distance of nearest neighbor cells to the malignant Hodgkin Reed Sternberg cells within the close interaction range. Spatial scores were used as features in prognostic model development for post-ASCT outcomes. RESULTS: Highly multiplexed IMC data revealed shared TME patterns in paired diagnostic and early r/r CHL samples, whereas TME patterns were more divergent in pairs of diagnostic and late relapse samples. Integrated analysis of IMC and single-cell RNA sequencing data identified unique architecture defined by CXCR5+ Hodgkin and Reed Sternberg (HRS) cells and their strong spatial relationship with CXCL13+ macrophages in the TME. We developed a prognostic assay (RHL4S) using four spatially resolved parameters, CXCR5+ HRS cells, PD1+CD4+ T cells, CD68+ tumor-associated macrophages, and CXCR5+ B cells, which effectively separated patients into high-risk versus low-risk groups with significantly different post-ASCT outcomes. The RHL4S assay was validated in an independent r/r CHL cohort using a multicolor immunofluorescence assay. CONCLUSION: We identified the interaction of CXCR5+ HRS cells with ligand-expressing CXCL13+ macrophages as a prominent crosstalk axis in relapsed CHL. Harnessing this TME biology, we developed a novel prognostic model applicable to r/r CHL biopsies, RHL4S, opening new avenues for spatial biomarker development.

Myeloid/natural killer (NK) cell precursor acute leukemia (MNKPL) has been described on the basis of its unique immunophenotype and clinical phenotype. However, there is no consensus on the characteristics for identifying this disease type because of its rarity and lack of defined distinctive molecular characteristics. In this study, multiomics analysis revealed that MNKPL is distinct from acute myeloid leukemia, T cell acute lymphoblastic leukemia, and mixed-phenotype acute leukemia (MPAL), and NOTCH1 and RUNX3 activation and BCL11B down-regulation are hallmarks of MNKPL. Although NK cells have been classically considered to be lymphoid lineage-derived, the results of our single-cell analysis using MNKPL cells suggest that NK cells and myeloid cells share common progenitor cells. Treatment outcomes for MNKPL are unsatisfactory, even when hematopoietic cell transplantation is performed. Multiomics analysis and in vitro drug sensitivity assays revealed increased sensitivity to l-asparaginase and reduced levels of asparagine synthetase (ASNS), supporting the clinically observed effectiveness of l-asparaginase.

We retrospectively evaluated long-term outcomes of high dose chemotherapy followed by autologous stem cell transplant (HDC/ASCT) in patients with diffuse large B-cell lymphoma (DLBCL). Between 2004 and 2020, 46 DLBCL patients received HDC/ASCT in our institution, including 12 patients (26.1%), who received as an upfront setting (UFS). At a median follow-up time of 69 months (range, 2-169 months), the 5-year progression-free survival (PFS) rates were 82.5% (95%CI, 46.1-95.3%) in the UFS, and 57.8% (95%CI, 38.1-73.2%) in the relapsed or refractory (R/R) patients (n=34), respectively. The 5-year PFS rates were 62.3% (95%CI, 34.0-81.3%) in primary resistant (n=13) or early relapsing (within 1 year from the initial diagnosis) patients (n=4), and 53.3% (95%CI, 25.9-74.6%) in those relapsing >1 year after the initial diagnosis (n=17), with no statistically significant difference (p=0.498). In R/R patients, multivariate analysis showed that the remission status before HDC/ASCT was an independent poor prognostic factor for progression-free survival (hazard ratio [HR], 17.0; 95%CI, 3.35-86.6; p=0.000630) and high-risk category in the international prognostic index for OS (HR, 9.39; 95%CI, 1.71-51.6; p=0.0100). The incidence of non-relapse mortality by 5 years, and 10 years were 12.2%, and 15.2%, respectively. Eleven patients (23.9%) developed second malignancies, which was the most frequent late complication after HDC/ASCT, with 5-year, and 10-year cumulative incidence of 16.9%, 22.5%, respectively. In conclusion, HDC/ASCT is effective for chemo-sensitive R/R DLBCL regardless of the timing and lines of therapy. However, careful observation is required, considering the long-term complications such as secondary malignancies.

In the phase 3 POLARIX study (NCT03274492), polatuzumab vedotin combined with rituximab plus cyclophosphamide, doxorubicin and prednisone (Pola-R-CHP) significantly improved progression-free survival (PFS) compared with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) with similar safety in previously untreated diffuse large B-cell lymphoma. Patients were randomized 1:1 to 6 cycles of Pola-R-CHP or R-CHOP plus 2 cycles of rituximab alone. For registration of POLARIX in China, consistency of PFS in an Asia subpopulation (defined as ≥50% of the risk reduction in PFS expected in the global population) was evaluated. Overall, 281 patients were analyzed: 160 patients from Asia in the intent-to-treat (ITT) population of the global study and 121 from an ITT China extension cohort. Of these, 141 were randomized to Pola-R-CHP and 140 to R-CHOP. At data cut-off (June 28, 2021; median follow-up 24.2 months), PFS met the consistency definition with the global population and was superior with Pola-R-CHP versus R-CHOP (hazard ratio 0.64; 95% confidence interval [CI], 0.40-1.03). Two-year PFS was 74.2% (95% CI, 65.7-82.7) and 66.5% (95% CI, 57.3-75.6) with Pola-R-CHP and R-CHOP, respectively. Safety was comparable between Pola-R-CHP and R-CHOP, including rates of grade 3-4 adverse events (AEs; 72.9% vs 66.2%, respectively), serious AEs (32.9% vs 32.4%), grade 5 AEs (1.4% vs 0.7%), AEs leading to study treatment discontinuation (5.0% vs 7.2%), and any-grade peripheral neuropathy (44.3% vs 50.4%). These findings demonstrate consistent efficacy and safety of Pola-R-CHP versus R‑CHOP in the Asian and global populations in POLARIX.

Tucidinostat (formerly known as chidamide) is an orally available, novel benzamide class of histone deacetylase (HDAC) inhibitor that selectively blocks class I and class IIb HDACs. This multicenter phase IIb study aimed to investigate the efficacy and safety of tucidinostat, 40 mg twice per week (BIW), in patients with relapsed/refractory (R/R) peripheral T-cell lymphoma (PTCL). The primary endpoint was overall response rate (ORR) assessed by an independent overall efficacy review committee. Between March 2017 and March 2019, 55 patients were treated, and 46 and 55 were evaluated for efficacy and safety, respectively. Twenty-one of 46 patients achieved objective responses with an ORR of 46% (95% confidence interval [CI]: 30.9, 61.0), including five patients with complete response (CR). Responses were observed across various PTCL subtypes. In angioimmunoblastic T-cell lymphoma, there were 2 CRs and 5 partial responses (PR) among eight patients, achieving an ORR of 88%. The disease control rate (CR + PR + stable disease) was 72% (33/46). The median progression-free survival, duration of response, and overall survival were 5.6 months, 11.5 months, 22.8 months, respectively. The most common adverse events (AEs) (all grades) were thrombocytopenia, neutropenia, leukopenia, anemia, and diarrhea. The grade ≥ 3 AEs emerging in ≥20% of patients included thrombocytopenia (51%), neutropenia (36%), lymphopenia (22%), and leukopenia (20%). Importantly, most of the AEs were manageable by supportive care and dose modification. In conclusion, the favorable efficacy and safety profiles indicate that tucidinostat would be a new therapeutic option in patients with R/R PTCL. (ClinicalTrials.gov identifier: NCT02953652).

INTRODUCTION: Treatment options in patients with mantle cell lymphoma (MCL) failing ibrutinib are limited, with no standard therapies defined. This study aimed to investigate real-world treatment patterns and outcomes for patients with MCL following ibrutinib. METHODS: This study utilized a de-identified hospital-based claims database (Medical Data Vision) in Japan. Eligible patients were adults who were diagnosed with MCL and had received antitumor drugs between December 2010 and July 2020. Patients were followed from the first antitumor drug treatment until the end of available data up to July 2021. Time-to-event analyses utilized the Kaplan-Meier method. Factors for receiving post-ibrutinib therapy were explored with logistic regression analysis. RESULTS: Of the 1386 patients who started antitumor drug therapy, 247 patients received and discontinued ibrutinib at any line of therapy. Among them, 137 patients (55.5%) received subsequent therapy. The median age at the end of ibrutinib therapy was 77 (range 42-95), and 44 patients had a dependent activity of daily living (ADL). Factors negatively associated with receiving post-ibrutinib therapy after discontinuation of ibrutinib were age ≥ 75 years (odds ratio [95% CI] 0.46 [0.26-0.80]) and emergency hospital admissions (0.37 [0.17-0.84]). Immediate post-ibrutinib therapy regimens were highly diverse, with BR (bendamustine, rituximab) only prescribed in more than 10% of patients. The median duration of post-ibrutinib therapy was 1.5 months (95% CI 1.07-2.07). The median overall survival from the end of ibrutinib therapy in patients regardless of the receipt of post-ibrutinib therapy (n = 247), in those who did not receive post-ibrutinib therapy (n = 110), and in those who received post-ibrutinib therapy (n = 137) was 5.6 months (95% CI 3.8-8.7), 2.3 months (95% CI 1.2-3.9), and 8.7 months (95% CI 5.6-13.8), respectively. The most common adverse event during post-ibrutinib therapy was infection, with the use of anti-infectives (17%). CONCLUSIONS: Patients with MCL previously treated with ibrutinib have poor ability to carry out ADL and experience very poor outcomes. New safe, effective therapies are needed.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive non-Hodgkin lymphoma with poor prognosis and few treatment options for patients with relapsed, recurrent, or refractory disease. We evaluated the efficacy and safety of valemetostat, a potent EZH1 and EZH2 inhibitor, in treating relapsed/refractory (R/R) ATL. This multicenter phase 2 trial (NCT04102150; https://clinicaltrials.gov/ct2/show/NCT04102150; DS3201-A-J201) enrolled patients with R/R aggressive ATL (acute, lymphoma, unfavorable chronic type). Patients received valemetostat 200 mg/day until progressive disease or unacceptable toxicity. The primary endpoint was overall response rate (ORR) centrally assessed by an independent efficacy assessment committee (IEAC). Secondary endpoints included best response in disease compartments, duration of response (DOR), pharmacokinetics, and safety. Twenty-five patients (median age, 69.0) with a median of 3 prior lines of therapy were enrolled; 24 had prior mogamulizumab treatment. The primary endpoint was met with a centrally reviewed ORR of 48.0% (90% CI, 30.5% to 65.9%), including 5 complete and 7 partial remissions. Patients pretreated with mogamulizumab had an ORR of 45.8% (4 complete and 7 partial remissions). IEAC-assessed median DOR was not reached (NR; 95% CI, 1.87 months to NR). Treatment-emergent adverse events (TEAEs) were manageable. TEAEs that occurred in ≥20% of patients included thrombocytopenia, anemia, alopecia, dysgeusia, neutropenia, lymphopenia, leukopenia, decreased appetite, and pyrexia. Grade ≥3 TEAEs included thrombocytopenia, anemia, lymphopenia, leukopenia, and neutropenia. Valemetostat demonstrated promising efficacy and tolerability in heavily pretreated patients, warranting further investigation in treating R/R ATL.

We previously reported that the antipsychotic drug chlorpromazine (CPZ), which inhibits the formation of clathrin-coated vesicles (CCVs) essential for endocytosis and intracellular transport of receptor tyrosine kinase (RTK), inhibits the growth/survival of acute myeloid leukemia cells with mutated RTK (KIT D816V or FLT3-ITD) by perturbing the intracellular localization of these molecules. Here, we examined whether these findings are applicable to epidermal growth factor receptor (EGFR). CPZ dose-dependently inhibited the growth/survival of the non-small cell lung cancer (NSCLC) cell line, PC9 harboring an EGFR-activating (EGFR exon 19 deletion). In addition, CPZ not only suppressed the growth/survival of gefitinib (GEF)-resistant PC9ZD cells harboring T790 M, but also restored their sensitivities to GEF. Furthermore, CPZ overcame GEF resistance caused by Met amplification in HCC827GR cells. As for the mechanism of CPZ-induced growth suppression, we found that although CPZ hardly influenced the phosphorylation of EGFR, it effectively reduced the phosphorylation of ERK and AKT. When utilized in combination with trametinib (a MEK inhibitor), dabrafenib (an RAF inhibitor), and everolimus (an mTOR inhibitor), CPZ suppressed the growth of PC9ZD cells cooperatively with everolimus but not with trametinib or dabrafenib. Immunofluorescent staining revealed that EGFR shows a perinuclear pattern and was intensely colocalized with the late endosome marker, Rab11. However, after CPZ treatment, EGFR was unevenly distributed in the cells, and colocalization with the early endosome marker Rab5 and EEA1 became more apparent, indicating that CPZ disrupted the intracellular transport of EGFR. These results suggest that CPZ has therapeutic potential for NSCLC with mutated EGFR by a novel mechanism different from conventional TKIs alone or in combination with other agents.

The phase II study of tirabrutinib monotherapy at a daily dose of 480 mg under fasting conditions for treatment-naïve and relapsed/refractory Waldenström's macroglobulinemia (ONO-4059-05 study) demonstrated a promising efficacy and tolerable safety profile. We conducted an unplanned analysis with a median follow-up of 24.8 months to update the efficacy and safety results and to report patient-reported quality of life. Of 27 enrolled patients, 22 patients continued receiving the study drug. The major response assessed by an independent review committee was observed in 25 patients (93%), including one and five patients who newly achieved complete response and very good partial response, respectively, after the primary analysis. The progression-free and overall survival rates at 24 months were 92.6% and 100%, respectively. Serum IgM levels in all patients except one declined and were maintained at low levels, although transient increases occurred after temporal interruption of the study drug. The disease-related symptoms including recurrent fever and hyperviscosity mostly disappeared. Health-related quality of life, assessed by cancer-specific questionnaires, was mostly maintained. Grade 3-4 neutropenia, lymphopenia, and leukopenia were newly recognized in three, two, and one patient, respectively. Grade 3 treatment-related hypertriglyceridemia was also recognized. Nine patients experienced grade 1-2 bleeding events (33%), one patient experienced grade 2 treatment-related atrial fibrillation, and one patient experienced grade 1 treatment-related hypertension. Treatment-related skin adverse events were observed in 14 patients (52%). Taken together, tirabrutinib has durable efficacy with an acceptable safety profile for treatment-naïve and refractory/relapsed Waldenström's macroglobulinemia.

PRAME is a prominent member of the cancer testis antigen family of proteins, which triggers autologous T cell-mediated immune responses. Integrative genomic analysis in diffuse large B cell lymphoma (DLBCL) uncovered recurrent and highly focal deletions of 22q11.22, including the PRAME gene, which were associated with poor outcome. PRAME-deleted tumors showed cytotoxic T cell immune escape and were associated with cold tumor microenvironments. In addition, PRAME downmodulation was strongly associated with somatic EZH2 Y641 mutations in DLBCL. In turn, PRC2-regulated genes were repressed in isogenic PRAME-KO lymphoma cell lines, and PRAME was found to directly interact with EZH2 as a negative regulator. EZH2 inhibition with EPZ-6438 abrogated these extrinsic and intrinsic effects, leading to PRAME expression and microenvironment restoration in vivo. Our data highlight multiple functions of PRAME during lymphomagenesis and provide a preclinical rationale for synergistic therapies combining epigenetic reprogramming with PRAME-targeted therapies.

This single-arm phase 3 study was conducted to confirm the results of our phase 2 study of bendamustine (B)-rituximab (R) in patients with relapsed/refractory diffuse large B cell lymphoma (rrDLBCL). The primary endpoint was overall response rate (ORR). Autologous stem cell transplantation-ineligible rrDLBCL patients with ≤ 2 prior chemotherapy regimens received R 375 mg/m2 IV on day 1 and B 120 mg/m2/day IV on days 2 and 3 every 21 days up to 6 cycles. Thirty-eight patients with a median age of 74 years (range, 43-86) received BR. The ORR and complete response rates were 76.3% and 47.4%, respectively. With a median follow-up of 19.5 months including long-term follow-up, median progression-free survival was 11.9 months. Median OS was 29.2 months. Discontinuation of treatment due to Gr3-5 TEAE was observed among 13 of 38 patients (34.2%). One patient with cytomegalovirus enterocolitis died during follow-up. This BR regimen was confirmed to be effective and tolerable in studied patients. ClinicalTrials.gov Identifier: NCT03372837 registered on 14 December 2017, NCT04354402 registered on 21 April, 2020.

We previously reported that a novel haemoglobin-platelet index (HPI) based on anaemia and thrombocytopenia was useful to predict the prognosis of patients with diffuse large B-cell lymphoma not otherwise specified (DLBCL NOS). Here, we analyse the utility of HPI in a new validation cohort with DLBCL NOS (n  = 94). As a result, we confirm that HPI was effective for differentiating progression-free survival (PFS) and overall survival in this validation cohort. So, we further compare the utility of HPI with previously reported prognostic markers such as the National Comprehensive Center Network-International Prognostic Index (NCCN-IPI), Glasgow prognostic score (GPS), and platelet-albumin (PA) score, using a larger number of 160 patients consisting of the derivation cohort (n  = 66) and a validation cohort (n  = 94). As a result, the patients with a higher HPI score had significantly worse outcomes, and HPI predicted the prognosis of DLBCL NOS independently of NCCN-IPI. HPI was more sensitive than GPS and almost the same as PA score in predicting PFS. Moreover, the patients whose lymphoma cells were positive for interleukin-6 (IL-6) (75/111 cases) judged by immunohistochemical staining had significantly lower haemoglobin levels and platelet counts than IL-6-negative cases (36/111 cases), suggesting the involvement of IL-6 produced by lymphoma cells in anaemia and thrombocytopenia in DLBCL NOS patients.

C-type lectin-like receptor 2 (CLEC-2) expressed on megakaryocytes plays important roles in megakaryopoiesis. We found that CLEC-2 was expressed in about 20% of phenotypical long-term hematopoietic stem cells (LT-HSCs), which expressed lower levels of HSC-specific genes and produced larger amounts of megakaryocyte-related molecules than CLEC-2low LT-HSCs. Although CLEC-2high LT-HSCs had immature clonogenic activity, cultured CLEC-2high LT-HSCs preferentially differentiated into megakaryocytes. CLEC-2high HSCs yielded 6.8 times more megakaryocyte progenitors (MkPs) and 6.0 times more platelets 2 weeks and 1 week after transplantation compared with CLEC-2low LT-HSCs. However, platelet yield from CLEC-2high HSCs gradually declined with the loss of MkPs, while CLEC-2low HSCs self-renewed long-term, indicating that CLEC-2high LT-HSCs mainly contribute to early megakaryopoiesis. Treatment with pI:C and LPS increased the proportion of CLEC-2high LT-HSCs within LT-HSCs. Almost all CLEC-2low LT-HSCs were in the G0 phase and barely responded to pI:C. In contrast, 54% of CLEC-2high LT-HSCs were in G0, and pI:C treatment obliged CLEC-2high LT-HSCs to enter the cell cycle and differentiate into megakaryocytes, indicating that CLEC-2high LT-HSCs are primed for cell cycle entry and rapidly yield platelets in response to inflammatory stress. In conclusion, CLEC-2high LT-HSCs appear to act as a reserve for emergent platelet production under stress conditions.

Side population (SP) is known to include therapy-resistant cells in various cancers. Here, we analyzed SP using multiple myeloma (MM) samples. The SP accounted for 2.96% in MM cells from newly diagnosed MM (NDMM). CD34 was expressed in 47.8% of SP cells, but only in 2.11% of bulk MM cells. CD34+ MM cells expressed more immature cell surface markers and a gene signature than CD34- MM cells. CD34+ but not CD34- MM cells possessed clonogenic activities and showed long-term self-renewal activities in xenotransplantation assays. Similarly, whereas 2.20% of MM cells were CD34+ in NDMM (n = 38), this proportion increased to 42.6% in minimal residual disease (MRD) samples (n = 16) (p < 0.001) and to 17.7% in refractory/relapsed MM (RRMM) (n = 30) (p < 0.01). Cell cycle analysis showed that 24.7% of CD34+ MM cells from NDMM were in G0 phase while this proportion was 54.9% in MRD (p < 0.05) and 14.5% in RRMM, reflecting the expansion of MM. Together, CD34+ MM cells with long-term self-renewal activities persist as MRD in cell cycle quiescence or remain as therapy-resistant cells in RRMM, substantiating the necessity of targeting this population to improve clinical outcomes of MM.

We previously examined the utility of rituximab-bendamustine (RB) in patients with follicular lymphoma (FL) exhibiting less than optimal responses to 2 cycles of the R-CHOP chemotherapy regimen. The aim of this study was to identify molecular biomarkers that can predict prognosis in RB-treated patients in the context of the prospective cohort. We first analyzed the mutational status of 410 genes in diagnostic tumor specimens by target capture and Sanger sequencing. CREBBP, KMT2D, MEF2B, BCL2, EZH2, and CARD11 were recurrently mutated as reported before, however none was predictive for progression-free survival (PFS) in the RB-treated patients (n = 34). A gene expression analysis by nCounter including 800 genes associated with carcinogenesis and/or the immune response showed that expression levels of CD8+ T-cell markers and half of the genes regulating Th1 and Th2 responses were significantly lower in progression of disease within the 24-mo (POD24) group (n = 8) than in the no POD24 group (n = 31). Collectively, we selected 10 genes (TBX21, CXCR3, CCR4, CD8A, CD8B, GZMM, FLT3LG, CD3E, EOMES, GZMK), and generated an immune infiltration score (IIS) for predicting PFS using principal component analysis, which dichotomized the RB-treated patients into immune IIShigh (n = 19) and IISlow (n = 20) groups. The 3-y PFS rate was significantly lower in the IISlow group than in the IIShigh group (50.0% [95% CI: 27.1-69.2%] vs. 84.2% [95% CI: 58.7-94.6%], P = .0237). Furthermore, the IIS was correlates with absolute lymphocyte counts at diagnosis (r = 0.460, P = .00355). These results suggest that the T-cell-associated immune markers could be useful to predict prognosis in RB-treated FL patients. (UMIN:000 013 795, jRCT:051 180 181).

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is typically treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, only 60% of patients are cured with R-CHOP. Polatuzumab vedotin is an antibody-drug conjugate targeting CD79b, which is ubiquitously expressed on the surface of malignant B cells. METHODS: We conducted a double-blind, placebo-controlled, international phase 3 trial to evaluate a modified regimen of R-CHOP (pola-R-CHP), in which vincristine was replaced with polatuzumab vedotin, as compared with standard R-CHOP, in patients with previously untreated intermediate-risk or high-risk DLBCL. Patients 18 to 80 years of age were randomly assigned in a 1:1 ratio to receive six cycles of either pola-R-CHP or R-CHOP, plus two cycles of rituximab alone. The primary end point was investigator-assessed progression-free survival. Secondary end points included overall survival and safety. RESULTS: Overall, 879 patients underwent randomization: 440 were assigned to the pola-R-CHP group and 439 to the R-CHOP group. After a median follow-up of 28.2 months, the percentage of patients surviving without progression was significantly higher in the pola-R-CHP group than in the R-CHOP group (76.7% [95% confidence interval (CI), 72.7 to 80.8] vs. 70.2% [95% CI, 65.8 to 74.6] at 2 years; stratified hazard ratio for progression, relapse, or death, 0.73 by Cox regression; 95% CI, 0.57 to 0.95; P = 0.02). Overall survival at 2 years did not differ significantly between the groups (88.7% [95% CI, 85.7 to 91.6] in the pola-R-CHP group and 88.6% [95% CI, 85.6 to 91.6] in the R-CHOP group; hazard ratio for death, 0.94; 95% CI, 0.65 to 1.37; P = 0.75). The safety profile was similar in the two groups. CONCLUSIONS: Among patients with previously untreated intermediate-risk or high-risk DLBCL, the risk of disease progression, relapse, or death was lower among those who received pola-R-CHP than among those who received R-CHOP. (Funded by F. Hoffmann-La Roche/Genentech; POLARIX ClinicalTrials.gov number, NCT03274492.).

Tazemetostat is a selective, reversible, small-molecule inhibitor of the histone methyltransferase enzyme, enhancer of zest homolog 2 (EZH2). In this multicenter, open-label, phase II study, we assessed the efficacy and safety of tazemetostat in Japanese patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma harboring the EZH2 mutation. Tazemetostat (800 mg twice daily) was given orally (28-day cycle) until disease progression or unacceptable toxicity. Among the 20 eligible patients, 17 were enrolled in cohort 1 (follicular lymphoma [FL]), and three were enrolled in cohort 2 (diffuse large B-cell lymphoma). At data cut-off, the objective response rate in cohort 1 was 76.5%, including six patients (35.3%) with complete response and seven patients (41.2%) with partial response (PR). All three patients in cohort 2 achieved PR. In cohort 1, median progression-free survival (PFS) was not reached at the median follow-up of 12.9 months. The estimated PFS rate at 12 and 15 months was 94.1% and 73.2%, respectively. The most common grade 3 treatment-emergent adverse event (TEAE) was lymphopenia (n = 2). Grade 4 TEAEs included hypertriglyceridemia and pneumonia aspiration (n = 1 each), which were not related to tazemetostat. Treatment-emergent adverse events leading to study drug discontinuation were reported in four of the 20 patients, indicating that the safety profile of tazemetostat was acceptable and manageable. Tazemetostat 800 mg twice daily showed encouraging efficacy in patients with R/R EZH2 mutation-positive FL with a manageable safety profile in the overall population. Thus, tazemetostat could be a potential treatment for R/R EZH2 mutation-positive FL.

The aim of this trial is to evaluate the utility of rituximab-bendamustine (R-B) for untreated advanced follicular lymphoma (FL) showing non-optimal response (nOR) to R-CHOP, and to identify clinical prognostic factors for FL patients receiving R-B. Patients who failed to achieve complete response/complete response unconfirmed (CR/CRu) [nOR-group] after 2 cycles of R-CHOP subsequently received 6 cycles of R-B. The primary endpoint was the 3-year progression-free survival (PFS) rate. Secondary endpoints included determination of prognostic factors. Fifty-six patients initially received R-CHOP, 43/56 patients (76.8%) were judged as nOR, and 33/43 patients (76.7%) completed 6 cycles of R-B. At a median follow-up of 50.6 months in the nOR-group, the 3-year PFS rate was 69.0%, and the 3-year overall survival (OS) rate was 92.7%. The most common toxicities associated with R-B were grade 3-4 lymphopenia (93.0%) and neutropenia (74.4%), both of which were manageable. A multivariate analysis including dose intensity, serum soluble interleukin-2 receptor, and FL international prognostic index-2 revealed low absolute lymphocyte count (<  869/μL) at diagnosis was an independent poor prognostic factor for both PFS and OS in the R-B-treated nOR-group. This result was further confirmed in validation cohorts including R-B-treated de novo (n = 40) and relapsed (n = 49) FL patients.

Polatuzumab vedotin (pola) is a CD79b-targeted antibody-drug conjugate delivering a potent antimitotic agent (monomethyl auristatin E) to B cells. This was an open-label, single-arm study of pola 1.8 mg/kg, bendamustine 90 mg/m2 , rituximab 375 mg/m2 (pola + BR) Q3W for up to six cycles in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who received ≥1 prior line of therapy and were ineligible for autologous stem cell transplantation (ASCT) or experienced treatment failure with prior ASCT. Primary endpoint was complete response rate (CRR) at the end of the treatment (EOT) by positron emission tomography-computed tomography (PET-CT) using modified Lugano Response Criteria. Secondary endpoints included efficacy, safety, and pharmacokinetics. Thirty-five patients (median age 71 [range 46-86] years) were enrolled. Twenty-three (66%) patients had refractory disease, and 23 (66%) had ≥2 prior lines of therapy. At a median follow-up of 5.4 (0.7-11.9) months, patients received a median of five treatment cycles. CRR was 34.3% (95% confidence interval [CI] 19.1-52.2) at EOT. Overall response rate was 42.9% at EOT, and median progression-free survival was 5.2 months (95% CI 3.6-not evaluable). Median overall survival was not reached. No fatal adverse events (AEs) were observed. Grade 3-4 AEs were mainly hematological: anemia (37%), neutropenia (31%), white blood cell count decreased (23%), thrombocytopenia/platelet count decreased/neutrophil count decreased (20% each), and febrile neutropenia (11%). Grade 1-2 peripheral neuropathy (PN; sensory and/or motor) was reported in 14% of patients; there were no ≥grade 3 PN events. This study (JapicCTI-184048) demonstrated the efficacy and safety of pola + BR in Japanese patients with R/R DLBCL who were ineligible for ASCT.

A 35-year-old male was referred to our hospital with dysesthesia of the lower extremities that had begun six months earlier. A blood test revealed the presence of various antibodies, suggesting a collagen-related peripheral neuropathy. However, a history of repeated shingles and sex with males was noted, and the patient was tested for and diagnosed with human immunodeficiency virus (HIV) infection. Based on the manifestations and laboratory data, including the results of immunological and urinary tests, he was further diagnosed with concomitant systemic lupus erythematosus (SLE). The activity of SLE improved with antiretroviral therapy. There is currently no established treatment for AIDS complicated with SLE. Indeed, because HIV treatment involves the activation of immune function and SLE treatment involves immunosuppression, any treatments for the two conditions would be in conflict. It is thus necessary to select a treatment strategy based on the condition of the individual patient. In addition, because HIV infection is relatively rare in Japan compared to other countries, rheumatologists in Japan must keep HIV infection in mind as a differential diagnosis for autoimmune diseases.

Acute myeloid leukemia (AML) is a heterogeneous disease often associated with poor prognosis. We previously showed that the localization of KIT-D816V at endolysosomes is critical to activate aberrant Akt signaling and Chlorpromazine (CPZ) perturbs the intracellular localization, leading to cell death in AML cells with KIT-D816V. We report that daily administration of CPZ, prescribed for controlling anxiety disorder in patient with AML harboring KIT-D816V, led to a dramatic reduction in AML cells. In vitro and in vivo experiments showed that CPZ inhibited the growth and survival of the patient-derived AML cells, implying potent efficacy of CPZ in AML with KIT-D816V.

Adult T-cell leukemia/lymphoma (ATL) is a mature T-cell neoplasm and is classified into four subtypes (acute, lymphoma, chronic, and smoldering) according to the Shimoyama classification, established in 1991 through several nationwide surveys based on the clinical diversity of patients diagnosed in 1983-1987 in Japan. Thereafter, no such studies have been conducted. Recently, we conducted a nationwide hospital survey using the method of the 1980s studies, collected baseline data on 996 ATL patients diagnosed in 2010-2011 from 126 hospitals, and reported their unique epidemiological characteristics. Here, we report the follow-up results of registered ATL patients with the goal of evaluating current prognoses and treatment modalities as of 2016-2017. Of 770 evaluable patients, 391 (50.8%) had acute-type, 192 (24.9%) had lymphoma-type, 106 (13.8%) had chronic-type, and 81 (10.5%) had smoldering-type ATL. The initial therapy regimens used for acute/lymphoma-type ATL were vincristine, cyclophosphamide, doxorubicin and prednisone, followed by doxorubicin, ranimustine, and prednisone and then by vindesine, etoposide, carboplatin, and prednisone (VCAP-AMP-VECP)-like in 38.5/41.7% and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-like in 14.6/13.7% of patients. Allogeneic hematopoietic stem cell transplantation was used to treat 15.9/10.4% of acute/lymphoma-type ATL patients. The 4-year survival rates (the median survival time, days) for acute-, lymphoma-, unfavorable chronic-, favorable chronic-, and smoldering-type ATL were 16.8% (252), 19.6% (305), 26.6% (572), 62.1% (1937), and 59.8% (1851), respectively. The 4-year survival rates for acute- and lymphoma-type ATL improved compared with those reported in 1991, but those for chronic- and smoldering-type ATL were not. Further efforts are warranted to develop more efficient therapeutic strategies to improve the prognosis of ATL in Japan.

We recently treated a chronic myeloid leukemia (CML) patient with liver and renal dysfunction, who was undergoing hemodialysis (HD). He was treated with 50 mg dasatinib (DAS) once daily just before HD. The maximum plasma concentration of DAS was 227 ng/mL on a non-HD day and 46.9 ng/mL on a HD day. He was subsequently treated with 200 mg bosutinib (BOS) once daily. The plasma concentration of BOS changed from 74.5 ng/mL before HD to 58.8 ng/mL after HD. Our results indicate that close monitoring of the plasma tyrosine kinase inhibitor concentrations should be considered in CML patients with organ impairment.

Despite duodenal-type follicular lymphoma (DTFL) being morphologically, immunophenotypically and genetically indistinguishable from nodal FL (nFL), this entity typically shows a significantly better prognosis. Here, we analysed the tumour immune microenvironments of diagnostic specimens from patients with DTFL (n = 30), limited-stage FL (LSFL; n = 19) and advanced-stage FL (ASFL; n = 31). The mean number of CD8+ tumour-infiltrating lymphocytes (TILs) in the neoplastic follicles was higher in DTFL (1,827/mm2 ) than in LSFL (1,150/mm2 ) and ASFL (1,188/mm2 ) (P = 0·002, P = 0·002, respectively). In addition, CD8+ PD1-  T cells with non-exhausting phenotype were more abundant in the peripheral blood (PB) of DTFL than in LSFL and ASFL, indicating that DTFL may exhibit a better and longer-lasting T cell-mediated immune response. Moreover, whereas FOXP3+ CTLA-4+ effector regulatory T cells (eTregs) were rarely observed in the neoplastic follicles of DTFL (mean: 12/mm2 ), they were more abundant in LSFL (78/mm2 ) and ASFL (109/mm2 ) (P = 2·80 × 10-5 , P = 4·74 × 10-8 , respectively), and the numbers of eTregs correlated inversely with those of CD8+ TILs (r = -0267; P = 0·018). Furthermore, DTFL showed significantly fewer circulating FOXP3hi CD45RA- CD25hi eTregs (0·146%) than ASFL (0·497%) and healthy controls (0·639%) (P = 0·0003, P = 6·79 × 10-7 , respectively). These results suggest that the augmented anti-tumour immune reactions may contribute to a better prognosis on DTFL.

Tirabrutinib is a second-generation Bruton's tyrosine kinase inhibitor with greater selectivity than ibrutinib. Here, we conducted a multicenter, phase II study of tirabrutinib in patients with treatment-naïve (Cohort A) or with relapsed/refractory (Cohort B) Waldenström's macroglobulinemia (WM). Patients were treated with tirabrutinib 480 mg once daily. The primary endpoint was major response rate (MRR; ≥ partial response). Secondary endpoints included overall response rate (ORR; ≥ minor response), time to major response (TTMR), progression-free survival (PFS), overall survival (OS), and safety. In total, 27 patients (18 in Cohort A; 9 in Cohort B) were enrolled. The median age was 71 y, and the median serum immunoglobulin M level was 3600 mg/dL. Among the patients, 96.2% had the MYD88L265P mutation. MRR and ORR were 88.9% and 96.3%, respectively (Cohort A: MRR, 88.9%; ORR, 94.4%; Cohort B: MRR, 88.9%; ORR, 100%). Median TTMR was 1.87 mo. PFS and OS were not reached with a median follow-up of 6.5 and 8.3 mo for Cohorts A and B, respectively. The most common adverse events (AEs) were rash (44.4%), neutropenia (25.9%), and leukopenia (22.2%), with most AEs classified as grade 1 or 2. Grade ≥ 3 AEs included neutropenia (11.1%), lymphopenia (11.1%), and leukopenia (7.4%). No grade 5 AEs were noted. All bleeding events were grade 1; none were associated with drug-related atrial fibrillation or hypertension. Although the follow-up duration was relatively short, the study met the primary endpoint. Therefore, tirabrutinib monotherapy is considered to be highly effective for both untreated and relapsed/refractory WM with a manageable safety profile. (JapicCTI-173646).

Mutated receptor tyrosine kinases (MT-RTKs) such as internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3 ITD) and a point mutation KIT D816V are driver mutations for acute myeloid leukemia (AML). Clathrin assembly lymphoid myeloid leukemia protein (CALM) regulates intracellular transport of RTKs, however, the precise role for MT-RTKs remains elusive. We here show that CALM knock down leads to severely impaired FLT3 ITD- or KIT D814V-dependent cell growth compared to marginal influence on wild-type FLT3- or KIT-mediated cell growth. An antipsychotic drug chlorpromazine (CPZ) suppresses the growth of primary AML samples, and human CD34+CD38- AML cells including AML initiating cells with MT-RTKs in vitro and in vivo. Mechanistically, CPZ reduces CALM protein at post transcriptional level and perturbs the intracellular localization of MT-RTKs, thereby blocking their signaling. Our study presents a therapeutic strategy for AML with MT-RTKs by altering the intracellular localization of MT-RTKs using CPZ.

BACKGROUND:  Peroral cholangioscopy (POCS) of indeterminate biliary strictures aims to achieve a diagnosis through visual examination and/or by obtaining targeted biopsies under direct visualization. In this large, prospective, multinational, real-life experience of POCS-guided evaluation of indeterminate biliary strictures, we evaluated the performance of POCS in this difficult-to-manage patient population. METHODS:  This prospective registry enrolled patients, with indeterminate biliary strictures across 20 centers in Asia, the Middle East, and Africa. The primary end points were the ability to visualize the lesion, obtain histological sampling when intended, and an assessment of the diagnostic accuracy of POCS for malignant strictures. Patients were followed for 6 months after POCS or until a definitive malignant diagnosis was made, whichever occurred first. RESULTS:  289 patients underwent 290 POCS procedures with intent to biopsy in 182 cases. The stricture/filling defect was successfully visualized in 286/290 (98.6 %), providing a visual diagnostic impression in 253/290 (87.2 %) and obtaining adequate biopsies in 169/182 (92.9 %). Procedure-related adverse events occurred in 5/289 patients (1.7 %). POCS influenced patient management principally by elucidating filling defects or the causes of bile duct stricture or dilation. The visual impression of malignancy showed 86.7 % sensitivity, 71.2 % specificity, 65.8 % positive and 89.4 % negative predictive value, and 77.2 % overall accuracy compared with final diagnosis. Histological POCS-guided samples showed 75.3 % sensitivity, 100 % specificity, 100 % positive and 77.1 % negative predictive value, and 86.5 % overall accuracy. CONCLUSION:  In this large, real-life, prospective series, POCS was demonstrated to be an effective and safe intervention guiding the management of patients with indeterminate biliary strictures.

Aplastic anemia is a rare blood disease characterized by the destruction of the hematopoietic stem cells (HSC) in the bone marrow that, in the majority of cases, is caused by an autoimmune reaction. Patients with aplastic anemia are treated with immunosuppressive drugs and some of them, especially younger individuals with a donor available, can be successfully treated with hematopoietic stem cell transplantation (HSCT). We report here a rare case of post-transplant lymphoproliferative disorder (PTLD) associated with Epstein-Barr virus (EBV) reactivation in a 30-year-old female patient who underwent allogeneic HSCT for severe aplastic anemia. The PTLD, which was diagnosed 230 days after transplantation, was localized exclusively in the central nervous system (specifically in the choroid plexus) and manifested with obvious signs of intracranial hypertension. After receiving three cycles of high dose methotrexate (HD-MTX) combined with rituximab, the patient achieved a complete clinical recovery with normalization of blood cell counts, no evidence of EBV reactivation, and no associated neurotoxicity.

The development of targeted therapies, such as rituximab-an anti-CD20 antibody targeting CD20, has undergone a paradigm shift from conventional chemotherapy for malignant lymphoma (ML). Although a subset of ML patients has been cured, the treatment of refractory and relapsed diseases remains challenging. Fortunately, growing insights on molecular biology for ML have led to the development of a number of innovative agents. Moreover, a plethora of targeted therapies, including novel antibodies targeting surface antigens, and small molecular inhibitors targeting oncogenic signaling pathways, tumor suppressors, and epigenetic regulation are currently under investigation for the improvement of dismal prognosis. In addition, immunotherapies, including immune checkpoint inhibitors, bispecific T-cell engager antibodies, and chimeric antigen receptor T-cells for ML have been rapidly developed to target tumor microenvironment. These promising mechanism-based targeted therapies could lead to a successful ML management.

We report a case with extramedullary tumors affecting the supraclavicular region that presented as a relapse of acute myeloid leukemia (AML) with FLT3-ITD mutation after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Treatment with gilteritinib resulted in remarkable response with disappearance of both the medullary and extramedullary tumors. Subsequently, a 2nd allo-HSCT was performed in an attempt to cure his AML and complete molecular response has been sustained with gilteritinib resumption without worsening GVHD. Targeted therapy with gilteritinib for medullary and extramedullary relapse of FLT3-ITD AML could be effective and suitable as a bridging therapy for allo-HSCT.

症例は35歳女性で、17歳時に再生不良性貧血-発作性夜間ヘモグロビン尿症(PNH)症候群と診断され、無治療で経過観察されていた。今回、感冒症状が出現し、全身倦怠感・褐色尿などの増悪を認めていた。自室で昏睡状態になっているのを家人が発見し救急要請された。頭部CTでは脳の正中偏移を伴う左前頭葉脳浮腫所見を認め、CT Venographyで上矢状静脈洞の描出欠損を認めた。以上より、上矢状静脈洞血栓症による脳梗塞に起因する意識障害と診断され緊急入院となった。第1病日夜間に意識レベル低下、瞳孔不同の症状が出現し、頭部CTで左前頭葉脳浮腫の増悪を認めたため、緊急開頭減圧術を実施した。さらに、術後侵襲による補体活性化と溶血再燃を抑制する目的で、術後第2病日に髄膜炎菌ワクチンとエクリズマブ投与を開始した。ワルファリンとエクリズマブ投与を継続し、溶血発作の再燃を認めることはなく、第53病日に退院となった。

PURPOSE: Ibrutinib has shown activity in non-germinal center B-cell diffuse large B-cell lymphoma (DLBCL). This double-blind phase III study evaluated ibrutinib and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in untreated non-germinal center B-cell DLBCL. PATIENTS AND METHODS: Patients were randomly assigned at a one-to-one ratio to ibrutinib (560 mg per day orally) plus R-CHOP or placebo plus R-CHOP. The primary end point was event-free survival (EFS) in the intent-to-treat (ITT) population and the activated B-cell (ABC) DLBCL subgroup. Secondary end points included progression-free survival (PFS), overall survival (OS), and safety. RESULTS: A total of 838 patients were randomly assigned to ibrutinib plus R-CHOP (n = 419) or placebo plus R-CHOP (n = 419). Median age was 62.0 years; 75.9% of evaluable patients had ABC subtype disease, and baseline characteristics were balanced. Ibrutinib plus R-CHOP did not improve EFS in the ITT (hazard ratio [HR], 0.934) or ABC (HR, 0.949) population. A preplanned analysis showed a significant interaction between treatment and age. In patients age younger than 60 years, ibrutinib plus R-CHOP improved EFS (HR, 0.579), PFS (HR, 0.556), and OS (HR, 0.330) and slightly increased serious adverse events (35.7% v 28.6%), but the proportion of patients receiving at least six cycles of R-CHOP was similar between treatment arms (92.9% v 93.0%). In patients age 60 years or older, ibrutinib plus R-CHOP worsened EFS, PFS, and OS, increased serious adverse events (63.4% v 38.2%), and decreased the proportion of patients receiving at least six cycles of R-CHOP (73.7% v 88.8%). CONCLUSION: The study did not meet its primary end point in the ITT or ABC population. However, in patients age younger than 60 years, ibrutinib plus R-CHOP improved EFS, PFS, and OS with manageable safety. In patients age 60 years or older, ibrutinib plus R-CHOP was associated with increased toxicity, leading to compromised R-CHOP administration and worse outcomes. Further investigation is warranted.

Iron overload is the accumulation of excess iron in the body that may occur as a result of various genetic disorders or as a consequence of repeated blood transfusions. The surplus iron is then stored in the liver, pancreas, heart and other organs, which may lead to chronic liver disease or cirrhosis, diabetes and heart disease, respectively. In addition, excessive iron may impair hematopoiesis, although the mechanisms of this deleterious effect is not entirely known. In this study, we found that ferrous ammonium sulfate (FeAS), induced growth arrest and apoptosis in immature hematopoietic cells, which was mediated via reactive oxygen species (ROS) activation of p38MAPK and JNK pathways. In in vitro hematopoiesis derived from embryonic stem cells (ES cells), FeAS enhanced the development of dysplastic erythroblasts but inhibited their terminal differentiation; in contrast, it had little effect on the development of granulocytes, megakaryocytes, and B lymphocytes. In addition to its directs effects on hematopoietic cells, iron overload altered the expression of several adhesion molecules on stromal cells and impaired the cytokine production profile of these cells. Therefore, excessive iron would affect whole hematopoiesis by inflicting vicious effects on both immature hematopoietic cells and stromal cells.

A 62-year-old male was diagnosed with chronic lymphocytic leukemia (CLL) and treated with a fludarabine-containing regimen which maintained the disease in a partial response. Nine years after diagnosis, a rapidly growing systemic lymphadenopathy was observed, and a biopsy specimen revealed the presence of typical Hodgkin/Reed-Sternberg (HRS) cells, surrounded by T-lymphocytes and CLL cells. Sequencing analysis of the germline complementary determining region 3 (CDR3) region of the immunoglobulin heavy chain (IGH) gene showed that the Hodgkin/Reed-Sternberg cells were clonally unrelated to the preexisting CLL cells and the HRS cells were composed of five different clones, leading to the molecular diagnosis of de novo lymphocyte-rich classic Hodgkin lymphoproliferative diseases (LPDs) with small lymphocytic lymphoma (SLL). As the initial treatment was neither effective for classic Hodgkin LPDs nor for SLL, Bendamustine, Rituximab (BR) was started and complete remission was achieved, which has continued for more than one year so far. BR may be a good therapeutic option for both entities without causing hematological toxicity.

＜文献概要＞Point ◎甲状腺悪性リンパ腫の発症頻度は,甲状腺悪性腫瘍の1〜5%と非常に稀な疾患である.◎約90%に橋本病を合併しており,中高年女性に好発する.◎中悪性度のびまん性大細胞型B細胞性リンパ腫および低悪性度のMALTリンパ腫が主な組織型である.◎超音波検査では「著明な低エコー腫瘤像」が特徴的である.

＜文献概要＞Point ◎甲状腺悪性リンパ腫の発症頻度は,甲状腺悪性腫瘍の1〜5%と非常に稀な疾患である.◎約90%に橋本病を合併しており,中高年女性に好発する.◎中悪性度のびまん性大細胞型B細胞性リンパ腫および低悪性度のMALTリンパ腫が主な組織型である.◎超音波検査では「著明な低エコー腫瘤像」が特徴的である.

分子標的治療薬を始めとした新規薬剤の開発は、悪性リンパ腫の予後を大きく改善した。一方で、これらの薬剤は高額であり、治療法の開発・進歩が医療費高騰に及ぼす影響が懸念されている。本稿では医療経済学的な観点から、高額な新規薬剤の"積極的な使用"の意義を、諸外国での分析結果を交えながら検証してみたい。(著者抄録)

分子標的治療薬を始めとした新規薬剤の開発は、悪性リンパ腫の予後を大きく改善した。一方で、これらの薬剤は高額であり、治療法の開発・進歩が医療費高騰に及ぼす影響が懸念されている。本稿では医療経済学的な観点から、高額な新規薬剤の"積極的な使用"の意義を、諸外国での分析結果を交えながら検証してみたい。(著者抄録)

Myelodysplastic syndromes (MDS) are a heterogeneous group clonal disorders of hematopoietic stem cells (HSC) characterized by ineffective hematopoiesis that lead to variable grades of impaired blood cell production. Chromosomal aberrations are often detected in MDS patients and thus cytogenetic analysis is useful for the diagnosis of these disorders. Common recurring chromosomal defects, such as the -5/5q- and -7/7q- are relatively well characterized cytogenetic abnormalities in MDS, however, the biological significance of uncommon cytogenetic alterations is unknown. We report here, two cases of peripheral blood and bone marrow hypereosinophilia in patients with MDS harboring the unbalanced translocation der(1;7)(q10;p10), a poorly characterized cytogenetic abnormality that is found in certain myeloid malignancies, including MDS. The patients reported here presented hypereosinophilia that was refractory to steroids and cytotoxic therapy, leading to severe target tissue damage that ultimately resulted in fatal end-organ failure. Potential roles of the der(1;7)(q10;p10) aberrations in the pathogenesis of aggressive eosinophilia and disease prognosis are discussed here.

Myeloproliferative neoplasms (MPNs), including polycythemia vera and essential thrombocythemia, are frequently associated with thrombotic complications. Prevention of thrombotic events is thus a primary aim of the current treatment for these disorders. Although it is known that microparticles (MPs), which are small vesicles released from cell membranes and circulate in the blood, directly contribute to thrombosis via their procoagulant activity, potential associations between plasma levels of MPs and the risk of thrombotic events in MPNs have not been reported. In the present study, we characterized plasma levels of MPs and assessed their potential association with the occurrence of thrombotic events in 59 patients with MPNs. Plasma levels of procoagulant MPs expressing tissue factor (TF+ MPs) were significantly higher in patients suffering thrombotic events than in patients without such events (median/μl plasma: 33.8 vs 47.2, p = 0.02). Among patients who developed thrombotic events, irrespective of patients' blood counts, TF+ MP were significantly higher in patients without cytoreductive therapy than in those receiving cytoreductive therapy (101.2 vs. 42.5, p < 0.001). These results suggest that elevated levels of TF+ MP may be considered as a novel surrogate marker for thrombotic events in MPN patients. Further studies are needed to clarify the mechanism involved.

Immunosuppressive therapy after solid organ transplantation is known to be a risk factor for the development of myelodysplastic syndromes (MDS). Herein, we report 2 patients, both of whom developed low-risk MDS after solid organ transplantation and were successfully treated with azacitidine (AZA). The 1st case was a 74-year-old man who had received liver transplantation. The initial immunosuppressive therapy consisted of cyclosporine and prednisolone. Nine years after transplantation, he was diagnosed as having MDS (RCMD). The 2nd case was a 47-year-old woman who had received cadaveric renal transplantation. The initial immunosuppressive therapy was comprised of cyclosporine, azathioprine, and prednisolone. Twenty-seven years after transplantation, she developed MDS (RA). Both patients received 75 mg/m2 AZA once daily for five consecutive days on a 28-day cycle. After 2 courses of therapy, both patients achieved hematological improvement (IWG 2006 criteria) without severe (grade 3/4) non-hematological adverse events. Moreover, AZA did not affect the status of organ transplantation in terms of engraftment and function of the graft. In conclusion, AZA would be a safe and effective agent for patients with MDS after solid organ transplantation. However, long-term follow-up is needed to confirm the safety and efficacy of AZA for patients undergoing solid organ transplantations.

In mammals, the small Arf GTPase-activating protein (SMAP) subfamily of An GTPase-activating proteins consists of closely related members, SMAP1 and SMAP2. These factors reportedly exert distinct functions in membrane trafficking, as manifested by different phenotypes seen in single knockout mice. The present study investigated whether SMAP proteins interact genetically. We report for the first time that simultaneous loss of SMAP1 and SMAP2 promotes apoptosis in the distal region of E7.5 mouse embryos, likely resulting in embryonic lethality. Thus, at least one SMAP gene, either SMAP1 or SMAP2, is required for proper embryogenesis. (C) 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

びまん性大細胞型B細胞性リンパ腫(diffuse large B-cell lymphoma/DLBCL)は非ホジキンリンパ腫の中で最頻のサブタイプである。本疾患に対しては、シクロホスファミド、ドキソルビシン、ビンクリスチン、およびプレドニゾロンの併用療法、いわゆるCHOP療法が長きにわたり標準治療法であった。しかし近年、CD20を標的としたキメラIgG1モノクローナル抗体であるリツキシマブがDLBCLに著効することが示され、これを加えたR-CHOPが現在では実質的標準治療となっている。一方SOX4はSOXファミリーに属する転写因子である。これは未熟B/Tリンパ球の分化増殖に関わることが知られ、さらに成人T細胞白血病リンパ腫をはじめとする複数の悪性腫瘍においては癌遺伝子として作用する。しかしながらDLBCLとSOX4との関連については未だ不明である。そこで本研究ではDLBCLにおけるSOX4発現と治療応答性および予後との相関について検証した。我々の集めたDLBCL 70症例の検討から、SOX4のタンパクおよびmRNAレベルでの発現量はともにR-CHOP応答性と負の相関を示した。また予後解析によりSOX4発現量はDLBCL患者の予後不良とも相関を示した。これらの結果よりSOX4がDLBCLの予後予測因子として有用である可能性が示された。(著者抄録)

A 68-year-old man was referred to our hospital due to a high fever and pancytopenia. Neither tumors nor infectious lesions were detected. Hemophagocytosis was observed on the bone marrow (BM) smear, although without abnormal cells. Prednisolone therapy was ineffective for the patient's high fever. Later on, we obtained the results of a BM biopsy indicating the presence of infiltration of atypical Reed-Sternberg cells, leading to a diagnosis of HIV-negative primary bone marrow Hodgkin lymphoma (PBMHL). However, the patient died of multiple organ failure before receiving chemotherapy. As the clinical course of PBMHL is rapid, physicians must keep in mind its possibility in similar cases.

CALM is implicated in the formation of clathrin-coated vesicles, which mediate endocytosis and intracellular trafficking of growth factor receptors and nutrients. We previously found that CALM-deficient mice suffer from severe anemia due to the impaired clathrin-mediated endocytosis of transferrin receptor in immature erythroblast. However, CALM has been supposed to regulate the growth and survival of hematopoietic stem/progenitor cells. So, in this study, we focused on the function of CALM in these cells. We here show that the number of Linage(-)Sca-1(+)KIT(+) (LSK) cells decreased in the fetal liver of CALM(-/-) mice. Also, colony forming activity was impaired in CALM(-/-) LSK cells. In addition, SCF, FLT3, and TPO-dependent growth was severely impaired in CALM(-/-) LSK cells, while they can normally proliferate in response to IL-3 and IL-6. We also examined the intracellular trafficking of KIT using CALM(-/-) murine embryonic fibroblasts (MEFs) engineered to express KIT. At first, we confirmed that endocytosis of SCF-bound KIT was not impaired in CALM(-/-) MEFs by the internalization assay. However, SCF-induced KIT trafficking from early to late endosome was severely impaired in CALM(-/-) MEFs. As a result, although intracellular KIT disappeared 30 min after SCF stimulation in wild-type (WT) MEFs, it was retained in CALM(-/-) MEFs. Furthermore, SCF-induced phosphorylation of cytosolic KIT was enhanced and prolonged in CALM(-/-) MEFs compared with that in WT MEFs, leading to the excessive activation of Akt. Similar hyperactivation of Akt was observed in CALM(-/-) KIT+ cells. These results indicate that CALM is essential for the intracellular trafficking of KIT and its normal functions. Also, our data demonstrate that KIT located in the early endosome can activate downstream molecules as a signaling endosome. Because KIT activation is involved in the pathogenesis of some malignancies, the manipulation of CALM function would be an attractive therapeutic strategy.

A 32-year-old woman was referred to our hospital due to systemic lymphadenopathy. The patient's peripheral blood showed expansion of CD5+CD20+ CD38+ CD23- mature lymphocytes. However, the axillary lymph nodes were infiltrated by both CD23+ large lymphocytes and CD23- small lymphocytes. Because the pattern of the rearranged immunoglobulin heavy chain gene was different between the peripheral blood and lymph node samples in a Southern blot analysis, the patient was diagnosed with Richter syndrome, in which diffuse large B-cell lymphoma develops from a clone distinct from B-cell chronic lymphocytic leukemia. After undergoing rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) therapy, the patient was successfully treated with allogeneic hematopoietic transplantation, and no relapse was observed for three years.

HIV感染者は、Epstein-Barrウイルス(EBV)陽性の悪性リンパ腫を高率に発症し、非HIV感染者に発症する悪性リンパ腫と比較すると節外性、特に中枢神経原発の悪性リンパ腫(primary central nervous system lymphoma、PCNSL)の頻度が高い。その機序を解明するため我々は、HIV感染者および健常者から、EBV陽性のBリンパ芽球細胞株(B-LCL)を樹立し、細胞表面の接着分子の発現をフローサイトメーターで解析した。リンパ球機能関連抗原-1(lymphocyte function-associated antigen-1、LFA-1)のβ鎖であるCD18の発現は、HIV感染者由来のB-LCL(B-LCLHIV)と健常者由来のB-LCL(B-LCLN)の何れにおいても、EBV感染前のB細胞と比較して増強していた。また、B-LCLHIVはB-LCLNよりCD18を強く発現していた。B-LCLHIVはB-LCLNに比較し、LFA-1のリガンドである細胞接着分子-1(intercellular adhesion molecule-1、ICAM-1)を発現するヒト頭部血管肉腫細胞株(ISO-HAS)により高率に接着した。CD18の発現強度と、ISO-HASの接着率は正に相関しており、細胞接着にCD18が関与していることが示唆された。さらに、B-LCLHIVの培養上清中では、B-LCLNの培養上清に比べIL-8が有意に増加しており、この培養上清を添加することでB-LCLNのCD18発現が増強した。本研究は、AIDS関連悪性リンパ腫細胞が、EBVの活性化、さらにオートクラインあるいはパラクラインのIL-8の刺激により、CD18の発現を亢進し、血管内皮細胞により強く接着する可能性を示唆するものである。(著者抄録)

Phosphatidylinositol binding clathrin assembly protein (PICALM), also known as clathrin assembly lymphoid myeloid leukemia protein (CALM), was originally isolated as part of the fusion gene CALM/AF10, which results from the chromosomal translocation t(10;11)(p13;q14). CALM is sufficient to drive clathrin assembly in vitro on lipid monolayers and regulates clathrin-coated budding and the size and shape of the vesicles at the plasma membrane. However, the physiological role of CALM has yet to be elucidated. Here, the role of CALM in vivo was investigated using CALM-deficient mice. CALM-deficient mice exhibited retarded growth in utero and were dwarfed throughout their shortened life-spans. Moreover, CALM-deficient mice suffered from severe anemia, and the maturation and iron content in erythroid precursors were severely impaired. CALM-deficient erythroid cells and embryonic fibroblasts exhibited impaired clathrin-mediated endocytosis of transferrin. These results indicate that CALM is required for erythroid maturation and transferrin internalization in mice.

We report a rare case of chronic myelomonocytic leukemia (CMML) with pericardial effusion. After receving the diagnosis of CMML, she had been successfully treated with hydroxycarbamide (HU). However, she was admitted to our hospital due to pericardial effusion. The majority of the cells in the pericardial fluid were monocytes. We made the diagnosis of pericardial involvement with CMML cells and intravenously administered etoposide (100 mg/body daily for 5 days). Although CMML cells disappeared from the peripheral blood, the pericardial effusion still persisted. This case indicates that pericardial effusion is a possible and life-threatening complication in CMML patients despite stably controlled leukocytes.

症例は51歳女性。慢性腎不全保存期で外来通院中であったが,2008年3月,汎血球減少が出現し,最重症型再生不良性貧血と診断された。抗ヒト胸腺細胞ウマ免疫グロブリン(ATG)療法を選択したが,効果は一時的であった。その後,維持腹膜透析(CAPD)導入となった。平成21年2月に抗ヒト胸腺細胞ウサギ免疫グロブリン(rATG)療法を施行したが,効果なく,種々の感染症により,徐々に全身状態の悪化を認めた。同胞がなく,平成21年8月にHLA半合致の長男をドナーとした母児間末梢血幹細胞移植を施行した。前処置は減量シクロフォスファミドとリン酸フルダラビンおよびrATGを,免疫抑制はFK506をそれぞれ使用し,Day10に生着を認めた。CAPD施行中の重症再生不良性貧血に対する造血幹細胞移植療法に関しては,これまでまとまった報告がなく,前処置を減量することにより,半合致ドナーからの移植でも生着を認めた貴重な症例と思われ,報告した。(著者抄録)

ELNの基準でsuboptimal responseの予後については明らかではない。しかし、各治療時期別にみると予後不良の場合と良好の場合があり、それぞれに応じた治療戦略が必要である。

We report a case of primary cardiac lymphoma (PCL) occurring in a 76-year-old man during maintenance hemodialysis. Chest computed tomography (CT) revealed a tumor with pericardial effusion in the left ventricular posterior wall. Cytological examination of the pericardial fluid revealed monotonous lymphoid cells positive for B-cell markers, and clonal immunoglobulin heavy chain gene rearrangement was detected, indicating B-cell lymphoma. Rituximab monotherapy was administered biweekly at the therapeutic level on hemodialysis. The follow-up chest CT showed tumor disappearance with pericardial fluid after two courses of therapy. Rituximab monotherapy was effective for an elderly hemodialysis patient with PCL.

Fournier's gangrene is a life-threatening disorder caused by aerobic and anaerobic bacterial infection. We report a case of genital infection as the initial warning sign of acute myeloid leukemia. We were able to prevent progression to Fournier's gangrene in our patient by immediate intensive therapy with incision, blood transfusions and intravenous administration of antibiotics. This case suggests that hematologists and dermatologists should keep in mind that genital infection can be a first sign of hematologic malignancy. Copyright © 2010 S. Karger AG, Basel.

Purpose To evaluate the efficacy of vinblastine, doxorubicin, methotrexate, and prednisone (VAMP) and cyclophosphamide, vincristine, and procarbazine (COP) chemotherapy and response-based, involved-field radiation, a combined-modality regimen that limits doses of alkylating agents, anthracyclines, and radiation, in children with advanced and unfavorable Hodgkin's disease. Patients and Methods From 1993 to 2000, 159 children and adolescents with unfavorable Hodgkin's disease received three alternating cycles (total of six cycles) of VAMP/COP chemotherapy followed by response-based, involved-field radiation therapy: 15 Gy was administered to patients achieving a complete response, and 25.5 Gy was administered to those achieving a partial response after the first two cycles of chemotherapy and to all sites of bulky lymphadenopathy. Unfavorable disease was defined as clinical stage I and II with bulky peripheral nodal disease greater than 6 cm, initial bulky mediastinal mass 33% or more of the intrathoracic diameter, and/or "B" symptoms and all stage III and IV. Results Study enrollment was closed after an interim analysis estimated a 5-year event-free survival (EFS) rate below a predefined level. Disease presentation was localized (stage I/II) in 77 patients (48.4%) and advanced (stage III/IV) in 82 patients (51.6%). At a median follow-up of 5.8 years (range, 1.3 to 10.0 years), 38 patients had events, including relapse/progression (n = 35), second malignancy (n = 2), and accidental death (n = 1); nine relapses (25.7%) occurred greater than 4 years from diagnosis. Five-year survival and EFS estimates are 92.7% +/- 2.5% and 75.6% +/- 4.1%, respectively. Conclusion Risk-adapted combined-modality therapy with VAMP/COP and response-based, involved-field radiation therapy results in an unsatisfactory outcome for pediatric patients with unfavorable presentations of Hodgkin's disease. (C) 2004 by American Society of Clinical Oncology.

[Abstract] Background :Overexpression of Tribbles homolog 1 (Tribl) and Tribbles homolog 2 (Trib2) in hematopoietic stem/progenitor cells evokes acute myeloid leukemia (AML) in murine transplantation models. Degradation of CCAAT-enhancer-binding-protein α (C/EBPα) plays a crucial role in Trib1 or Trib2-induced AML. However, because C/EBPα knockout mice do not develop AML, it is likely that Trib1 and Trib2 influence other signaling pathways besides C/EBPα. Elevated Akt phosphorylation is considered to contribute to the development of AML. In contrast, two groups recently reported that reduced Akt activity is involved in the pathogenesis of leukemia. We performed this study to reveal the role of Akt signaling in Trib family-induced AML.Methods : G-CSF-induced granulocytic differentiation of 32D cells was assessed morphologically and phenotypically. G-CSF-induced signaling wasassessed by Westernblotting. Results : Overexpression of Trib1 or Trib2 inhibited GCSF-induced granulocytic differentiation of 32D cells, which was accompanied by reduced Akt phosphorylation. Also, an Akt inhibitor API-2 blocked G-CSF-induced granulocytic differentiation independently of C/EBPα degradation. Furthermore, retroviral C/EBPα restoration did not completely abolish the differentiation block caused by Trib1 and Trib2. Conclusion :Trib1 and Trib2 block granulocytic differentiation, at least partially, by suppressing Akt phosphorylation.

造血幹細胞移植患者において、骨粗鬆症の診療として利用される骨代謝マーカーを測定し、移植後の骨量に対する影響と骨量減少に対するビスフォスフォネート製剤介入の有効性の検討を前方視的に行った。

本研究では、多発性骨髄腫(MM)幹細胞を用いて、免疫チェックポイント分子の発現変化と発現調節機序を解析するとともに、同一患者由来の免疫担当細胞の特性を解析することで、MM患者の病態と抗腫瘍免疫との関連を包括的に明らかにすることを目的とする。昨年度はMM細胞集団CD38+138+45-19- (phenotypic MM cell, phMC）を幹細胞マーカーであるCD34の発現の有無によりCD34+, CD34- PhMCに分離し、それぞれにおける免疫チェックポイント分子の発現を網羅的に比較した。その結果CD274 (PDL1), CD155 (TIGIT), CD270 (TNFSFR14), GAL9等の抗腫瘍免疫の抑制分子の発現が、CD34-PhMCと比較してCD34+ PhMCにおいて有意に高いことを見出した。本年度は、これら分子が抗骨髄腫免疫に果たす機能について共培養系を用いて検討した。CD34+ phMC と同一症例から得た樹状細胞, pDC、細胞障害性T細胞, CTLとの共培養の系（Ref. Cancer Cell. 2009; 16: 309-23.）を用いた。各免疫チェックポイント分子の中和抗体を添加することによるCTL活性の変化を、CTLの増殖能、培養上清へのサイトカイン放出能等を評価することで、CTL 活性に及ぼす免疫チェックポイント分子の同定を試みた。その結果、症例ごとにMM 特異的 CD8+ CTL 活性を引き起こす中和抗体は異なり、症例ごとに免疫抑止に関わる分子は異なることが明らかになった。

In this study, we analyzed immune evasion mechanisms of residual chronic myeloid leukemia stem cells (CML-LSCs) during the treatment with tyrosine kinase inhibitors (TKIs). Both expression of immune checkpoint molecule, PDL1 and activation of immunosuppressive enzyme, IDO1 were induced through the activation of CD120a/NF-κB signaling pathway in phenotypically defined CD34+38-120a+225+ cells, which we previously identified as CML-LSC. Furthermore, CML-LSCs suppressed cytotoxic T cell activity and induced a local recruitment of immunosuppressive populations such as regulatory T cells and myeloid-derived suppressor cells, leading to an immunosuppressive bone marrow milieu undergoing TKI therapy.

We isolated myeloma initiating cells from phenotypically defined CD38+ CD 138+ CD 19- CD 45- multiple myeloma (MM) cells (PhMCs) from a set of 54 bone marrow MM patient samples. And we found PhMCs contains a minor CD34+ fraction that possess myeloma-propagating activities in vitro and in vivo, as well as resistance to anticancer drugs. The percent of CD34+ PhMCs was significantly higher in relapse/refractory than in newly diagnosed samples. Gene expression profiling revealed that CD34- PhMCs had a general myeloma cell signature, whereas CD34+ PhMCs exhibited a more immature pre-germinal center like signature. The presence of e cancer stem cells in MM was proposed for a few decades, however the identity of these cells remains controversial. The identification of these MM propagating cells provides a basis for better understanding the pathogenesis of MM and for designing novel therapeutic strategies aimed to eradicate total MM cells.

チロシンキナーゼ阻害剤(TKI)は、受容体チロシンキナーゼ(RTK)に変異を有する腫瘍の治療成績を劇的に改善した。しかしながらTKI単剤では、耐性獲得などにより再発する例が多く、新たな治療法の開発が求められている。 申請者らは、変異RTK を有する白血病細胞に対して、抗精神病薬chlorpromazine (CPZ)がRTKの細胞内局在を変化させることで、特異的な殺細胞効果をもたらすことを見出した。本研究では、この効果がTKI変異を有する様々な固形腫瘍において得られるかを検証するとともに、その分子機構を解析することで、様々な腫瘍におけるTKI耐性克服のための治療戦略基盤を確立することを目的とする。 平成28 年度は、CPZ の固形腫瘍における抗腫瘍効果の検証として、非小細胞肺癌細胞株HCC4006(EGFR活性化変異)、H1437(MET活性化変異)、H1993(MET増幅)、H3122(EML4-ALK)、胃癌細胞株MKN45(MET増幅)を用いて、各阻害剤Gefitinib、Tivantinib、Alectinibとの併用効果について解析した。CPZ を至適血中濃度の範囲0-10μM 添加し、5 日間培養を行った結果、いずれの細胞株もRTKの局在変化により濃度依存的なviabilityの低下を認めた。さらにCPZと各TKIとの併用効果を検討した結果、相乗的な殺細胞効果をもたらすことを見出した。同様の検討を、Gefitinib耐性株HCC827GR、PC-9ZDを用いて検討した結果、EGFRのゲートキーパー変異(T790M)を有するPC-9ZDにおいて、CPZ併用によりTKI感受性が回復し、耐性を克服できる可能性が示唆された。一方HCC827GRでは、過剰発現するMETの細胞内局在がCPZ処理によっても変化せず、Gefitinib耐性が保持されていると考えられた。