TUBB1 dysfunction in inherited thrombocytopenia causes genome instability.

Inherited thrombocytopenia is a genetically heterogeneous disease characterized by varying degrees of thrombocytopenia and risk of haematological malignancy, and the genetic cause of many cases remains unknown. We performed whole-exome sequencing of a family with thrombocytopenia and myeloid malignancy and identified a novel TUBB1 variant, T149P. Screening of other thrombocytopenia pedigrees identified another TUBB1 variant, R251H. TUBB1 encodes the tubulin ß-1 chain, a major component of microtubules abundant in megakaryocytes. Variant TUBB1 disrupted the normal assembly of microtubules and impaired proplatelet formation in vitro. In addition, DNA damage response was severely attenuated by loss of TUBB1. We found that the nuclear accumulation of p53 (also termed TP53) and the expression of pro-apoptotic genes triggered by genotoxic stress were blocked in TUBB1-deficient cells and, accordingly, apoptosis after DNA damage was diminished by knockdown of TUBB1. Thus, we have demonstrated that microtubule dysfunction confers resistance to apoptosis, even in DNA damage-accumulated cells, which explains genome instability in the affected individuals. These studies will lead us to a better understanding of how microtubule dysfunction can contribute to the accumulation of DNA damage, genetic instability and leukaemogenesis.

Prognostic index for chronic- and smoldering-type adult T-cell leukemia-lymphoma.

Adult T-cell leukemia-lymphoma (ATL) has been divided into 4 clinical subtypes: acute, lymphoma, chronic, and smoldering. The aim of this study is to develop a novel prognostic index (PI) for chronic and smoldering ATL. We conducted a nationwide retrospective survey on ATL patients, and 248 fully eligible individuals were used in this analysis. In the univariate analysis, sex, performance status, log10 (soluble interleukin-2 receptor [sIL-2R]), neutrophils count, and lymphadenopathy showed values of P < .05 in training samples. A multivariate analysis was performed on these factors, and only log10 (sIL-2R) was identified as an independent prognostic factor in training samples. Using a regression coefficient of this variable, a prognostic model was formulated to identify different levels of risk: indolent ATL-PI (iATL-PI) = 1.51 × log10 (sIL-2R [U/mL]). The values calculated by iATL-PI were divided into 3 groups using a quartile point. In the validation sample, median survival times (MSTs) were 1.6 years, 5.5 years, and not reached for patients in the high-, intermediate-, and low-risk groups, respectively (P < .0001). To make the scoring system clinically practicable, we simplified iATL-PI according to trichotomizing sIL-2R at 1000 and 6000 U/mL, using a quartile point. Patients with more than 6000 U/mL sIL-2R were categorized into the high-risk group, less than and equal to 1000 U/mL into the low-risk group, and the others into the intermediate-risk group, and MSTs were 1.6 years, not reached, and 5.5 years, respectively (P < .0001). iATL-PI has potential as a novel tool for a risk-adapted therapeutic approach.

Clinical significance of ASXL2 and ZBTB7A mutations and C-terminally truncated RUNX1-RUNX1T1 expression in AML patients with t(8;21) enrolled in the JALSG AML201 study.

We analyzed the clinical significance and genetic features of ASXL2 and ZBTB7A mutations, and the alternatively spliced isoform of the RUNX1-RUNX1T1 transcript, which is also called AML1-ETO9a (AE9a), in Japanese CBF-AML patients enrolled in the JALSG AML201 study. ASXL2 and ZBTB7A genes were sequenced using bone marrow samples of 41 AML patients with t(8;21) and 14 with inv(16). The relative expression levels of AE9a were quantified using the real-time PCR assay in 23 AML patients with t(8;21). We identified ASXL2 (34.1%) and ZBTB7A (9.8%) mutations in only AML patients with t(8;21). ASXL2-mutated patients had a significantly higher WBC count at diagnosis (P = 0.04) and a lower frequency of sex chromosome loss than wild-type patients (33 vs. 76%, respectively, P = 0.01). KIT mutations were the most frequently accompanied with both ASXL2 (36%) and ZBTB7A (75%) mutations. Neither ASXL2 nor ZBTB7A mutations had an impact on overall or event-free survival. Patients harboring cohesin complex gene mutations expressed significantly higher levels of AE9a than unmutated patients (P = 0.03). In conclusion, ASXL2 and ZBTB7A mutations were frequently identified in Japanese AML patients with t(8;21), but not in those with inv(16). Further analysis is required to clarify the detailed biological mechanism of AE9a regulation of the cohesin complex.

Mogamulizumab for relapsed adult T-cell leukemia-lymphoma: Updated follow-up analysis of phase I and II studies.

The present study sought to elucidate the prognosis of adult T-cell leukemia-lymphoma (ATL) patients receiving mogamulizumab, a defucosylated anti-CCR4 monoclonal antibody. Progression-free survival (PFS) and overall survival (OS) of ATL patients enrolled in two studies are herein updated, namely NCT00355472 (phase I study of mogamulizumab in relapsed patients with ATL and peripheral T-cell lymphoma) and NCT00920790 (phase II study for relapsed ATL). Of 13 patients with relapsed aggressive ATL in the phase I study, four (31%) survived >3 years. For 26 relapsed patients with aggressive ATL in the phase II study, median PFS was 5.2 months and 1-year PFS was 26%, whereas median OS was 14.4 months, and 3-year OS was 23%. For patients without a rash or who developed a grade 1 rash only, median PFS was 0.8 months, and 1-year PFS was zero, with a median OS of 6.0 months, and 3-year OS of 8%. In contrast, for patients who developed a rash ≥grade 2, median PFS was 11.7 months, and 1-year PFS was 50%, with a median OS of 25.6 months, and 3-year OS of 36%. Thus, we conclude that mogamulizumab monotherapy may improve PFS and OS in some patients with relapsed aggressive ATL, especially those who develop a skin rash as a moderate immune-related adverse event. Therefore, further investigation is warranted to validate the present observations and to clarify the mechanisms involved in the activity of mogamulizumab.

Treatment and survival among 1594 patients with ATL.

Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature T lymphocytes caused by human T-lymphotropic virus type I. Intensive combination chemotherapy and allogeneic hematopoietic stem cell transplantation have been introduced since the previous Japanese nationwide survey was performed in the late 1980s. In this study, we delineated the current features and management of ATL in Japan. The clinical data were collected retrospectively from the medical records of patients diagnosed with ATL between 2000 and 2009, and a total of 1665 patients' records were submitted to the central office from 84 institutions in Japan. Seventy-one patients were excluded; 895, 355, 187, and 157 patients with acute, lymphoma, chronic, and smoldering types, respectively, remained. The median survival times were 8.3, 10.6, 31.5, and 55.0 months, and 4-year overall survival (OS) rates were 11%, 16%, 36%, and 52%, respectively, for acute, lymphoma, chronic, and smoldering types. The number of patients with allogeneic hematopoietic stem cell transplantation was 227, and their median survival time and OS at 4 years after allogeneic hematopoietic stem cell transplantation was 5.9 months and 26%, respectively. This study revealed that the prognoses of the patients with acute and lymphoma types were still unsatisfactory, despite the recent progress in treatment modalities, but an improvement of 4-year OS was observed in comparison with the previous survey. Of note, one-quarter of patients who could undergo transplantation experienced long survival. It is also noted that the prognosis of the smoldering type was worse than expected.

Comparison of clinicopathological characteristics between T-cell prolymphocytic leukemia and peripheral T-cell lymphoma, not otherwise specified.

OBJECTIVES: T-cell prolymphocytic leukemia (T-PLL) is a very rare, aggressive T-cell neoplasm. Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is also a highly aggressive lymphoma. These two diseases can often be confused with each other; therefore, we aimed to determine the clinical and pathological differences between T-PLL and PTCL-NOS. METHODS: We analyzed 15 T-PLL and 91 PTCL-NOS patients and also compared clinical features between T-PLL and PTCL-NOS with leukemic presentation. Peripheral blood images and biopsy specimens were analyzed, and treatment responses were determined via imaging modalities. The clinicopathological characteristics were statistically compared. RESULTS: T-PLL cells were smaller in size than those of PTCL-NOS with leukemic presentation (P=.0068); moreover, PTCL-NOS cells with leukemic presentation were smaller than those of PTCL-NOS without leukemic presentation (P=.0017). Immunophenotypic patterns in T-PLL and PTCL-NOS were similar. Five-year overall survival rates of T-PLL and all PTCL-NOS patients were 57.5% and 36.8%, respectively. No significant differences were found in clinical manifestations or prognoses; T-PLL and PTCL-NOS with leukemic presentation had essentially equivalent characteristics. CONCLUSION: T-PLL and PTCL-NOS may share common biological and clinical characteristics in Japanese patients.

Galectin-9 as a Predictive Marker for the Onset of Immune-Related Adverse Effects Associated with Anti-CCR4 MoAb Therapy in Patients with Adult T Cell Leukemia.

Adult T-cell leukemia/lymphoma (ATL/ATLL) is one of the most malignant lymphomas with poor prognosis. ATL/ATLL cells express CC chemokine receptor 4, and mogamulizumab (anti-CCR4 monoclonal antibody) exhibits strong cytotoxicity for ATL/ATLL cells. We analyzed plasma samples of 6 patients with ATL/ATLL treated with chemotherapy followed by mogamulizumab therapy (mogatherapy) for changes in the levels of biomarkers in relation to immune-related adverse effects. As treatment is often associated with skin eruptions, we investigated the profiles of inflammatory cytokines, including galectin-9 (Gal-9), which becomes increased in various infectious diseases and allergic patients. Gal-9, soluble interleukin (IL)-2 receptor, tumor necrosis factor-α, and IL-10 levels were increased before chemotherapy, and Gal-9 levels were associated with the sIL-2 receptor, which reflects tumor burden. Inflammatory levels decreased after chemotherapy. After mogatherapy, 5 of 6 patients attained complete remission (CR), whereas 1 patient showed no response (NR) and died. Among 5 patients with CR, the biomarkers remained low during mogatherapy, except for a 3-5-fold increment in Gal-9 (associated with skin eruptions). A skin biopsy showed infiltration by inflammatory cells and Gal-9 synthesis in areas with CD8 cell infiltration. In the patient with NR, increased levels of Gal-9 and the aforementioned biomarkers were noted 3 days after mogatherapy, followed by opportunistic infections resembling immune reconstitution inflammatory syndrome. Therefore, an increased Gal-9 plasma level in ATL/ATLL indicates tumor burden and reflects immune activation by mogatherapy. These findings may indicate that an increase in the Gal-9 level, a novel immune checkpoint molecule, can reflect immune-related adverse effects of various biotherapies.

Dose-intensified chemotherapy alone or in combination with mogamulizumab in newly diagnosed aggressive adult T-cell leukaemia-lymphoma: a randomized phase II study.

This multicentre, randomized, phase II study was conducted to examine whether the addition of mogamulizumab, a humanized anti-CC chemokine receptor 4 antibody, to mLSG15, a dose-intensified chemotherapy, further increases efficacy without compromising safety of patients with newly diagnosed aggressive adult T-cell leukaemia-lymphoma (ATL). Patients were assigned 1:1 to receive mLSG15 plus mogamulizumab or mLSG15 alone. The primary endpoint was the complete response rate (%CR); secondary endpoints included the overall response rate (ORR) and safety. The %CR and ORR in the mLSG15-plus-mogamulizumab arm (n = 29) were 52% [95% confidence interval (CI), 33-71%] and 86%, respectively; the corresponding values in the mLSG15 arm (n = 24) were 33% (95% CI, 16-55%) and 75%, respectively. Grade ≥ 3 treatment-emergent adverse events, including anaemia, thrombocytopenia, lymphopenia, leucopenia and decreased appetite, were observed more frequently (≥10% difference) in the mLSG15-plus-mogamulizumab arm. Several adverse events, including skin disorders, cytomegalovirus infection, pyrexia, hyperglycaemia and interstitial lung disease, were observed only in the mLSG15-plus-mogamulizumab arm. Although the combination strategy showed a potentially less favourable safety profile, a higher %CR was achieved, providing the basis for further investigation of this novel treatment for newly diagnosed aggressive ATL. This study was registered at ClinicalTrials.gov, identifier: NCT01173887.

IDH1 and IDH2 mutations confer an adverse effect in patients with acute myeloid leukemia lacking the NPM1 mutation.

We examined the incidence and prognostic effect of IDH1 and IDH2 mutations in 233 Japanese adults with acute myeloid leukemia (AML). IDH1 R132 mutations were detected in 20 (8.6%) patients with AML. IDH2 mutations were found in 19 (8.2%, 17 R140 and two R172) patients. IDH1 and IDH2 mutations were mutually exclusive and were associated with normal karyotype AML, cytogenetic intermediate-risk group, and NPM1 mutations. Five-year overall survival (OS) rates were significantly lower (15.6%) in patients harboring the IDH mutations than in patients lacking the IDH mutation (32.0%) in the entire cohort of AML (P = 0.005). Among patients aged 59 yr or younger with IDH mutations, 5-yr OS in patients who underwent allogeneic stem cell transplantation (SCT) was significantly higher than that in those not receiving allogeneic SCT (50% vs. 10.6%, P = 0.020). Of 51 patients with NPM1 mutations, there was no significant difference in 5-yr OS rates between patients with and those without the IDH mutations. In contrast, among 175 patients lacking the NPM1 mutations, 5-yr OS rate in patients with IDH mutations was significantly lower than that in those without IDH mutations (0% vs. 34.7%, P = <0.001). These data suggest that IDH mutations have an unfavorable effect in AML, especially AML with the NPM1 wild type and younger AML patients with IDH mutations may benefit from allogeneic SCT.

Amyloid A amyloidosis in a Japanese patient with familial Mediterranean fever associated with homozygosity for the pyrin variant M694I/M694I.

Familial Mediterranean fever (FMF) is an autoinflammatory disease common in eastern Mediterranean populations. The most severe complication is the development of secondary amyloid A (AA) amyloidosis. A 51-year-old Japanese male who had been suffering from periodic fever since in his twenties was referred to our hospital for proteinuria. Histological findings from renal biopsy revealed the deposition of AA amyloid fibrils, suggesting that renal dysfunction was due to AA amyloidosis. Gene analysis of the patient and his mother showed that both were homozygous for the M694I mutation in the MEFV gene. His mother was also a carrier of the SAA1.3 allele, which is not only a univariate predictor of survival but also a risk factor for the association of AA amyloidosis with rheumatoid arthritis in Japanese patients, and the SAA1-13T allele in the 13T/C polymorphism on the 5'-flanking region of the SAA1 gene. The patient was also a carrier of the SAA-13T allele. Colchicine resulted in not only an amelioration of the acute febrile attacks of FMF inflammation, but also an improvement in kidney dysfunction due to AA amyloidosis.

High frequency of IKZF1 genetic alterations in adult patients with B-cell acute lymphoblastic leukemia.

Alterations in the IKZF1 gene are associated with poor prognosis in pediatric B-cell acute lymphoblastic leukemia (B-ALL). We examined the relationship between IKZF1 alterations and clinical findings in 78 adult patients with B-ALL. Aberrant isoforms of IKZF1 were detected using RT-PCR. The copy numbers of IKZF1 exons and fusion genes caused by exon deletions were determined using RQ-PCR and genomic PCR, respectively. We detected aberrant IKZF1 isoforms in 20 of the 78 patients (13 Ik6 and seven Ik10) and deletions of the entire or parts of the IKZF1 gene in 40 of 70 patients. No IKZF1 point mutations were detected by direct sequencing. Nineteen Ik6 and Ik10 isoforms had been generated through genomic exon deletions, but one through aberrant splicing. In total, 41 of the 78 (52.6%) patients harbored IKZF1 alterations, which were identified in 20 of 24 (83.3%) patients with Philadelphia chromosome (Ph)-positive B-ALL compared with 21 of 54 (38.9%) Ph-negative B-ALL (P = 0.0004). IKZF1 alterations are highly involved even in adults with B-ALL. To fully detect IKZF1 alterations, several methods with alternative approaches are required. To elucidate the clinical significance of IKZF1 alterations in adult B-ALL, our study warrants prospective clinical studies with a full analysis of IKZF1 alterations.

Rheumatoid arthritis caused by non-tuberculous mycobacteria infection.

A 72-year-old Japanese woman had right digital flexor tenosynovitis with a non-tuberculous mycobacteria (NTM) infection, which was identified as Mycobacterium marinum in culture. She had been treated at another hospital with clarithromycin, rifampicin, and ethambutol for the non-tuberculous tenosynovitis. However, the swelling of her right hand worsened, and 5 months later, her left hand swelled and she exhibited symmetrical arthritis. Blood tests detected elevated serum C-reactive protein and rheumatoid factor positivity. Although rheumatoid arthritis (RA) was suspected and corticosteroid treatment was started, she came to our hospital because of the insufficient treatment effect. Musculoskeletal ultrasonography showed intra-articular and peritendinous power Doppler signal-positive symmetrical synovitis. A contrast-enhanced magnetic resonance imaging (MRI) evaluation of the left hand without NTM tenosynovitis revealed findings of inflammatory synovitis accompanied by bone marrow oedema. We diagnosed RA and started treatment with weekly low-dose methotrexate pulses and 2 weeks of tocilizumab administration; her symptoms then disappeared within 2 months. This is a rare case of RA manifested with NTM-associated arthritis.

Prospective comparison of 5- and 7-day administration of azacitidine for myelodysplastic syndromes: a JALSG MDS212 trial.

The hypomethylating agent azacitidine (AZA) significantly extends overall survival (OS) in patients with higher risk myelodysplastic syndromes (MDS), when compared with other conventional care regimens, including supportive care and low-dose and intensive chemotherapy. However, the effects of 5- and 7-day treatment schedules of AZA (AZA-5 and AZA-7, respectively) on the OS of MDS patients had not been compared prospectively. We started a phase 3 trial comparing the effects of AZA-7 and AZA-5 on MDS patients with refractory anemia with excess blasts (RAEB) and RAEB in transformation (RAEB-T). However, this trial was prematurely terminated because of poor recruitment. Using all data, there was no significant difference in the OS of patients between AZA-7 (92 patients) and AZA-5 (95 patients), with the 2-year OS rates of AZA-7 and AZA-5 at 36.4% and 25.8%, respectively (P = 0.293). Adverse event profiles were similar between the two groups. Interestingly, data of the centrally diagnosed RAEB and RAEB-T cases showed that AZA-7 significantly prolonged the time to leukemia transformation compared with AZA-5 (P = 0.022), confirmed by multivariate analysis. Although this trial could not provide definite evidence, the results support the use of AZA-7 for RAEB and RAEB-T. (UMIN Clinical Trials Registry UMIN000009633).

HTLV-1 infection promotes excessive T cell activation and transformation into adult T cell leukemia/lymphoma.

Human T cell leukemia virus type 1 (HTLV-1) mainly infects CD4+ T cells and induces chronic, persistent infection in infected individuals, with some developing adult T cell leukemia/lymphoma (ATL). HTLV-1 alters cellular differentiation, activation, and survival; however, it is unknown whether and how these changes contribute to the malignant transformation of infected cells. In this study, we used single-cell RNA-sequencing and T cell receptor-sequencing to investigate the differentiation and HTLV-1-mediated transformation of T cells. We analyzed 87,742 PBMCs from 12 infected and 3 uninfected individuals. Using multiple independent bioinformatics methods, we demonstrated the seamless transition of naive T cells into activated T cells, whereby HTLV-1-infected cells in an activated state further transformed into ATL cells, which are characterized as clonally expanded, highly activated T cells. Notably, the greater the activation state of ATL cells, the more they acquire Treg signatures. Intriguingly, the expression of HLA class II genes in HTLV-1-infected cells was uniquely induced by the viral protein Tax and further upregulated in ATL cells. Functional assays revealed that HTLV-1-infected cells upregulated HLA class II molecules and acted as tolerogenic antigen-presenting cells to induce anergy of antigen-specific T cells. In conclusion, our study revealed the in vivo mechanisms of HTLV-1-mediated transformation and immune escape at the single-cell level.

THP-COP regimen for the treatment of peripheral T-cell lymphoma and adult T-cell leukemia/lymphoma: a multicenter phase II study.

OBJECTIVE: The efficacy of pirarubicin (THP)-COP was previously compared with cyclophophamide + doxorubicin + vincristine + prednisolone (CHOP) in elderly patients with lymphoma. The subset analysis showed that T-cell lymphoma had a significantly better response with THP-COP, whereas no such difference was observed in B-cell lymphoma. The aim of this study is to confirm the efficacy of THP-COP in the treatment of T-cell lymphoma. METHODS: We underwent a multicenter phase II study of THP-COP as a first-line treatment for T-cell lymphoma. The overall response rate, survival period, and toxicity were analyzed. RESULTS: Fifty-three patients were enrolled in this study. Seventeen patients had peripheral T-cell lymphoma (PTCL), including nine of PTCL not otherwise specified (PTCL-NOS) and eight of angioimmunoblastic T-cell lymphoma (AITL). Thirty-six patients had adult T-cell leukemia/lymphoma (ATLL), including 20 of acute type and 16 of lymphoma type. A treatment response was obtained in 35 (66%) patients, including 17 (32%) complete responses. Median overall survival (OS) and progression-free survival (PFS) times were 14.3 months and 5.2 months, respectively. Patients with ATLL showed a tendency to obtain low response rate (61% vs. 77%, P = 0.27) and had a significantly inferior OS (13.3 vs. 28.6 months, P = 0.04) and PFS (4.6 vs. 8.1 months, P = 0.01) in comparison with PTCL. Grade 3 to 4 neutropenia, anemia, and thrombocytopenia occurred in 72%, 34%, and 58% of the patients, respectively. Febrile neutropenia was observed in 51% and grade 3 non-hematological toxicities in 2-9% of the patients. CONCLUSION: The efficacy of THP-COP is equivalent to that of CHOP for the first-line therapy in T-cell lymphoma.

Prognostic impact of immunohistochemical biomarkers in diffuse large B-cell lymphoma in the rituximab era.

We evaluated the usefulness of prognostic markers in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, vincristine, doxorubicin, and prednisolone (CHOP) +/- rituximab (R-CHOP) in Japan. We studied 730 patients with DLBCL; 451 received CHOP and 279 R-CHOP. We analyzed biopsy samples immunohistochemically for markers of germinal center B cells (CD10, Bcl-6), postgerminal center B cells (Multiple myeloma-1), and apoptosis (Bcl-2). The median follow-up period for surviving patients was 56.4 months for the CHOP group and 25.2 months for the R-CHOP group. DLBCL were categorized as germinal center B (GCB) subtype (352/730; 48.2%) or non-GCB subtype (378/730; 51.8%). In the CHOP group, the high expression of CD10 (P = 0.022) or Bcl-6 (P = 0.021), or GCB subtype (P = 0.05) was associated with better overall survival, whereas the high expression of Bcl-2 (P = 0.001) or MUM1 (P = 0.011), or non-GCB subtype (P = 0.05) was associated with worse overall survival. In the R-CHOP group, however, these biomarkers except Bcl-6 were not significant prognostic factors. The patients with non-GCB subtype showed improved survival in the R-CHOP group (P = 0.756). The International Prognostic Index was a useful clinical marker of survival in the CHOP group (P < 0.001) and also in the R-CHOP group (P < 0.001). Results of improved survival with rituximab addition indicate that the relevance of previously recognized prognostic factors should be re-evaluated.

Systemic Lupus Erythematosus-associated Acute Acalculous Cholecystitis Successfully Treated by a Corticosteroid Combined with Azathioprine.

A 69-year-old Japanese woman was transferred to our hospital due to pancytopenia with a fever. She had Murphy's sign, and computed tomography showed pleural effusion and a swollen gallbladder without gallstones. We diagnosed her with systemic lupus erythematosus (SLE)-associated acute acalculous cholecystitis (AAC). Partly because her clinical and laboratory findings were not serious enough to warrant immediate surgical intervention, and partly because her poor general condition made her ineligible for surgery, surgical therapy was not selected. Corticosteroid therapy was performed with azathioprine, and the swelling in her gallbladder improved. As a conservative therapy for SLE-associated AAC, corticosteroid therapy combined with azathioprine might be beneficial.

Deeper molecular response is a predictive factor for treatment-free remission after imatinib discontinuation in patients with chronic phase chronic myeloid leukemia: the JALSG-STIM213 study.

The objective of this prospective clinical trial (JALSG-STIM213, UMIN000011971) was to evaluate treatment-free remission (TFR) rates after discontinuation of imatinib in chronic myeloid leukemia (CML). CML patients who received imatinib treatment for at least 3 years and sustained deep molecular response for at least 2 years were eligible. Molecular recurrence was defined as loss of major molecular response (MMR). Of the 68 eligible patients, 38.2% were women, the median age was 55.0 years, and the median duration of imatinib treatment was 97.5 months. The 12-month TFR rate was 67.6%. Patients who lost MMR were immediately treated with imatinib again; all re-achieved MMR. Three-year treatment-free survival (TFS) was estimated as 64.6% using the Kaplan-Meier method. Undetectable molecular residual disease (UMRD) was defined as no BCR-ABL1 in > 100,000 ABL1 control genes using international scale polymerase chain reaction. UMRD at the study baseline was found to be predictive of continuation of TFR. Our findings suggest that CML patients who meet all the eligibility criteria that have commonly been used in the TFR trials are able to discontinue imatinib use safely. TFR may thus be valuable as a new goal for CML treatment in Japan.

Prognostic analysis according to the 2017 ELN risk stratification by genetics in adult acute myeloid leukemia patients treated in the Japan Adult Leukemia Study Group (JALSG) AML201 study.

Many genetic alterations that are associated with the prognosis of acute myeloid leukemia (AML) have been identified, and several risk stratification systems based on the genetic status have been recommended. The European LeukemiaNet (ELN) first proposed the risk stratification system for AML in 2010 (ELN-2010), and recently published the revised system (ELN-2017). We validated the long-term prognosis and clinical characteristics of each ELN-2017 risk category in Japanese adult AML patients who were treated in the Japan Adult Leukemia Study Group (JALSG) AML-201 study. We demonstrated that the 3-risk category system of the ELN-2017 successfully discriminated the overall survival and complete remission rates in our cohort in comparison with the 4-risk category of the ELN-2010. However, there were still genetic categories in which stratification of patients into favorable or intermediate risk categories was controversial; the low allelic ratio of FLT3-ITD was not necessarily associated with a better prognosis in patients with FLT3-ITD, and cytogenetic abnormalities may affect the prognosis in patients with favorable genetic lesions such as NPM1 and CEBPA mutations. As many molecular targeting agents, such as FLT3 inhibitors, have been developed, we must continue to modify the genetic risk stratification system to match the progression of therapeutic strategies.