Safety and Pharmacokinetics of Quizartinib Combination Therapy With Standard Induction and Consolidation Chemotherapy in Patients With Newly Diagnosed Acute Myeloid Leukemia: Results from Two Phase 1 Trials in Japan and China.

Quizartinib is a potent, oral, second-generation, selective type II FMS-like receptor tyrosine kinase 3 (FLT3) inhibitor. It has shown improved overall survival in a randomized, multinational, Phase 3 (QuANTUM-First) study in patients with FLT3-internal tandem duplication (ITD)-positive newly diagnosed acute myeloid leukemia. We conducted 2 Phase 1b studies in Japan and China to evaluate the safety, pharmacokinetics, and efficacy of quizartinib in combination with standard induction and consolidation chemotherapy in patients with newly diagnosed acute myeloid leukemia. Quizartinib was started at a dose level of 20 mg/day and then escalated to 40 mg/day, the dose used in the Phase 3 study. Seven patients were enrolled according to the 3 + 3 dose-escalation method in each study, including 3 patients who were FLT3-ITD positive. No dose-limiting toxicities were observed at dose levels up to 40 mg/day in both studies. Grade 3 or higher, quizartinib-related, treatment-emergent adverse events included febrile neutropenia, hematologic toxicities, and infections. QT prolongation on electrocardiogram was observed in 5 patients. The pharmacokinetics of quizartinib and its metabolite AC886 were similar between the studies and consistent with previous findings in the United States. We confirmed the tolerability of Japanese and Chinese patients to the dose of quizartinib and chemotherapy regimens used in the QuANTUM-First study.

Impact of a third dose of anti-SARS-CoV-2 vaccine in hematopoietic cell transplant recipients: A Japanese multicenter observational study.

This prospective observational study aimed to assess the serological response and safety after the third booster shot of SARS-CoV-2 mRNA vaccines in 292 hematopoietic cell transplant (HCT) recipients. In our patients, mild systemic reactions were present in 10-40% and GVHD aggravation in 1.1%. Overall, clinically relevant response (>250 U/mL) was observed in 93.1% of allogeneic (allo)-HCT recipients and 70.6% of autologous (auto)-HCT recipients, respectively. Of note, detectable antibody response with any titer following the first two doses was a powerful predictor for adequate response after booster shot in both cohorts. For such patients, 98.8% of allo- and 92.3% of auto-HCT recipients obtained clinically relevant response after dose 3. In addition, continued systemic steroid and/or calcineurin inhibitors at the booster shot significantly correlated with serological response. These findings highlighted that booster vaccination efficiently improved serological response without safety concerns and thus recommended for the majority of HCT recipients.

Japanese subgroup analysis in the Asian phase II study of darinaparsin in patients with relapsed or refractory peripheral T-cell lymphoma.

A Japanese subgroup analysis from the Asian phase II study of darinaparsin in patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) was performed to evaluate the efficacy and safety outcomes of the Japanese population. In this Asian phase II study, darinaparsin was administered to 65 patients, including 37 Japanese patients. In the Japanese population, the histopathological type of PTCL was PTCL, not otherwise specified in 26 patients (70.3%), angioimmunoblastic T-cell lymphoma in 9 patients (24.3%) and anaplastic large cell lymphoma, anaplastic lymphoma kinase (ALK) -negative in 2 patients (5.4%), and the median patient age was 70.0 (range: 43-85). 94.6% and 35.1% of the Japanese population had previously received multi-agent and single-agent regimen, respectively. The efficacy and safety were summarized and compared between the overall and Japanese populations. Based on central assessment, the overall response rate was 22.2% (8/36; 90% confidence interval [CI]: 11.6-36.5) in the Japanese population and 19.3% (11/57; 90% CI: 11.2-29.9) in the overall population. There were no essential differences in the safety profile of darinaparsin between the Japanese population and the overall population. The results of this subgroup analysis indicate that the efficacy and safety profiles of the Japanese subpopulation were broadly consistent with that of the overall population, and that darinaparsin is potentially an effective treatment with a manageable safety profile in Japanese patients with relapse or refractory PTCL.

Immunoreactivity to WT1 peptide vaccine is associated with prognosis in elderly patients with acute myeloid leukemia: follow-up study of randomized phase II trial of OCV-501, an HLA class II-binding WT1 polypeptide.

We previously conducted a randomized phase II trial of OCV-501, a WT1 peptide presented by helper T cells, in elderly AML (acute myeloid leukemia) patients in first remission, indicating no difference in 2-year disease-free survival (DSF) between the OCV-501 and placebo groups. Here, we analyzed 5-year outcome and biomarkers. Five-year DFS was 36.0% in the OCV-501 group (N = 52) and 33.7% in the placebo group (N = 53), with no significant difference (p = 0.74). The peripheral WT1 mRNA levels were marginally suppressed in the OCV-501 group compared with the placebo group. Enhanced anti-OCV-501 IgG response by the 25th week was an independent favorable prognostic factor. Anti-OCV-501 IFNγ responses were less frequent than the IgG reactions. These findings suggest that host immunoreactivity has a significant impact on the prognosis of AML and that further improvement of the WT1 peptide vaccine is needed.

Real-world data from yttrium-90 ibritumomab tiuxetan treatment of relapsed or refractory indolent B-cell non-Hodgkin's lymphoma: J3Zi Study.

Yttrium-90 ibritumomab tiuxetan (90YIT) is a radioimmunotherapy agent in which the radioisotope yttrium-90 is bound to ibritumomab via tiuxetan as a chelating agent, and is used for relapsed or refractory low-grade B-cell non-Hodgkin's lymphoma (rr-B-NHL). We conducted a joint study to evaluate the clinical outcome of 90YIT. The J3Zi study is composed of data from patients receiving 90YIT for rr-B-NHL from the top three institutions with 10 years of 90YIT treatment experience from October 2008 to May 2018 in Japan. The efficacy, prognostic factors and safety of 90YIT were retrospectively evaluated. Data from 316 patients were analyzed; the mean age was 64.6 years and the median number of prior treatments was 2. The median PFS was 3.0 years, the final OS rate was over 60%, and the median OS was not reached during the study period. Significant factors influencing PFS were sIL-2R ≤ 500 (U/mL) and no disease progression within 24 months of first treatment. Significant factors influencing OS were number of prior treatments ≤ 2 and sIL-2R ≤ 500 (U/mL). The PFS and OS rates were found to be significantly higher in the late half era (2013 to 2018) than in the early half era (2008 to 2013) during the study period. Prognosis following 90YIT treatment was improved in the late half era compared to the early half era. As treatment using 90YIT increased, administration of 90YIT shifted to the earlier treatment line. This may have contributed to the improvement of prognosis found in the late era. (UMIN000037105).

Predictors of impaired antibody response after SARS-CoV-2 mRNA vaccination in hematopoietic cell transplant recipients: A Japanese multicenter observational study.

HCT recipients reportedly have a high mortality rate after developing COVID-19. SARS-CoV-2 vaccination is generally useful to prevent COVID-19. However, its safety and efficacy among HCT recipients remain elusive. This large-scale prospective observational study including 543 HCT recipients with 37-months interval from transplant demonstrated high safety profiles of mRNA vaccine: only 0.9% of patients avoided the second dose due to adverse event or GVHD aggravation following the first dose. Regarding the efficacy, serological response with a clinically relevant titer (≥250 BAU/mL) was obtained in 397 (73.1%) patients. We classified the remaining 146 patients as impaired responders and compared the clinical and immunological parameters between two groups. In allogeneic HCT recipients, multivariable analysis revealed the risk factors for impaired serological response as follows: age (≥60, 1 points), HLA-mismatched donor (1 points), use of systemic steroids (1 points), absolute lymphocyte counts (<1000/µL, 1 points), absolute B-cell counts (<100/µL, 1 points), and serum IgG level (<500 mg/dL, 2 points). Notably, the incidence of impaired serological response increased along with the risk scores: patients with 0, 1-3, and 4-7 points were 3.9%, 21.8%, and 74.6%, respectively. In autologous HCT recipients, a shorter interval from transplant to vaccination was the only risk factor for impaired serological response. Our findings indicate that two doses of SARS-CoV-2 vaccine are safe but insufficient for a part of HCT recipients with higher risk scores. To improve this situation, we should consider additional treatment options, including booster vaccination and prophylactic neutralizing antibodies during the SARS-CoV-2 pandemic.

Oral HDAC inhibitor tucidinostat in patients with relapsed or refractory peripheral T-cell lymphoma: phase IIb results.

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 HDAC. 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 : 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 two CR and five 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 (AE) (all grades) were thrombocytopenia, neutropenia, leukopenia, anemia, and diarrhea. The grade ≥3 AE emerging in ≥20% of patients included thrombocytopenia (51%), neutropenia (36%), lymphopenia (22%), and leukopenia (20%). Importantly, most of the AE were manageable by supportive care and dose modification. In conclusion, the favorable efficacy and safety profiles indicate that tucidinostat could be a new therapeutic option in patients with R/R PTCL (clinicaltrials gov. Identifier: NCT02953652).

Oral histone deacetylase inhibitor HBI-8000 (tucidinostat) in Japanese patients with relapsed or refractory non-Hodgkin's lymphoma: phase I safety and efficacy.

OBJECTIVE: HBI-8000 (tucidinostat) is a novel, oral histone deacetylase inhibitor that selectivity inhibits Class I (histone deacetylase 1, 2, 3) and Class II (histone deacetylase 10) with direct anti-tumor activity through various mechanisms of action, including epigenetic reprogramming and immunomodulation. It has been approved in China for the treatment of relapsed or refractory peripheral T-cell lymphoma. METHODS: This multicenter, prospective phase I dose-escalation trial evaluating the safety of twice weekly HBI-8000 was conducted in Japan. Eligible patients had non-Hodgkin's lymphoma and no available standard therapy. The primary endpoint was maximum tolerated dose; secondary endpoints included anti-tumor activity, safety and pharmacokinetics. RESULTS: Fourteen patients were enrolled in the study. Twelve patients were assessed for dose-limiting toxicity: six patients in the 30 mg BIW cohort had no dose-limiting toxicitys; two of six patients in the 40 mg BIW cohort had asymptomatic dose-limiting toxicitys. Treatment was well tolerated; adverse events were predominantly mild to moderate hematologic toxicities and were managed with dose modification and supportive care. Thirteen patients were included in the efficacy analysis. Objective response was seen in five of seven patients in the 40 mg BIW cohort; three partial responders had adult T-cell leukemia-lymphoma. In the 30 mg BIW cohort, three of six patients had stable disease after the first cycle. CONCLUSIONS: Treatment with HBI-8000 30 and 40 mg BIW were well-tolerated and safe, with hematological toxicities as expected from other studies of histone deacetylase inhibitor. The maximum tolerated dose and recommended dosage for phase II studies of HBI-8000 is 40 mg BIW. Preliminary efficacy results are encouraging.

Oral histone deacetylase inhibitor tucidinostat (HBI-8000) in patients with relapsed or refractory adult T-cell leukemia/lymphoma: Phase IIb results.

This multicenter, prospective phase IIb trial evaluating the efficacy and safety of tucidinostat (HBI-8000) in patients with relapsed or refractory (R/R) adult T-cell leukemia/lymphoma (ATLL) was undertaken in Japan. Eligible patients had R/R ATLL and had failed standard of care treatment with chemotherapy and with mogamulizumab. Twenty-three patients received tucidinostat 40 mg orally twice per week and were included in efficacy and safety analyses. The primary end-point was objective response rate (ORR) assessed by an independent committee. The ORR was 30.4% (95% confidence interval [CI], 13.2, 52.9]. Median progression-free survival was 1.7 months (95% CI, 0.8, 7.4), median duration of response was 9.2 months (95% CI, 2.6, not reached), and median overall survival was 7.9 months (95% CI, 2.3, 18.0). All patients experienced adverse events (AEs), which were predominantly hematologic and gastrointestinal. Incidence of grade 3 or higher AEs was 78.3%; most were laboratory abnormalities (decreases in platelets, neutrophils, white blood cells, and hemoglobin). Tucidinostat was well tolerated with AEs that could be mostly managed with supportive care and dose modifications. Tucidinostat is a meaningful treatment option for R/R ATLL patients; further investigation is warranted.

Genomic determinants impacting the clinical outcome of mogamulizumab treatment for adult T-cell leukemia/lymphoma.

In order to identify genomic biomarkers for the outcome of mogamulizumab-containing treatment, an integrated molecular analysis of adult T-cell leukemia/lymphoma (ATL) was conducted on 64 mogamulizumab-naïve patients. Among driver genes, CCR4 and CCR7 alterations were observed in 22% and 11% of the patients, respectively, both consisting of single nucleotide variants (SNV)/insertion-deletions (indels) in the C-terminus. Patients with CCR4 alterations or without CCR7 alterations exhibited a more favorable clinical response (complete response [CR] rate 93%, 13/14; P=0.024, and CR rate 71%, 40/56; P=0.036, respectively). Additionally, TP53, CD28, and CD274 alterations were identified in 35%, 16%, and 10% of the patients, respectively. TP53 alterations included SNV/indels or copy number variations (CNV) such as homozygous deletion; CD28 alterations included SNV, CNV such as amplification, or fusion; CD274 alterations included CNV such as amplification, or structural variants. Univariate analysis revealed that TP53, CD28 or CD274 alterations were associated with worse overall survival (OS) (hazard ratio [HR]: 2.330, 95% confidence interval [CI]: 1.183-4.589; HR: 3.191, 95% CI: 1.287- 7.911; HR: 3.301, 95% CI: 1.130-9.641, respectively) but that CCR4 alterations were associated with better OS (HR: 0.286, 95% CI: 0.087-0.933). Multivariate analysis indicated that in addition to performance status, TP53, CCR4 or CD274 alterations (HR: 2.467, 95% CI: 1.197-5.085; HR: 0.155, 95% CI: 0.031-0.778; HR: 14.393, 95% CI: 2.437-85.005, respectively) were independently and significantly associated with OS. The present study contributes to the establishment of precision medicine using mogamulizumab in ATL patients.

Serum immunoglobulin G as a discriminator of infection in follicular lymphoma patients undergoing chemotherapy with bendamustine in combination with rituximab.

OBJECTIVES: Chemotherapy, including bendamustine, usually causes lymphocytopaenia and hypogammaglobulinaemia as side effects in patients with haematological malignancies. Therefore, the possibility has been considered that these immunological adverse events induced by bendamustine may lead to infectious diseases. However, lymphocytopaenia and/or hypogammaglobulinaemia have not yet been shown to have a statistically significant association with infection in cancer patients who receive bendamustine. METHODS: We retrospectively studied 27 patients with relapsed or refractory indolent follicular lymphoma who were treated with bendamustine and rituximab (BR). In order to elucidate relationships between immune-related laboratory parameters (i.e. peripheral blood leukocyte, neutrophil, lymphocyte and immunoglobulin G [IgG]) and infectious events, receiver operating characteristic (ROC) curve and multivariate logistic regression analyses were performed. RESULTS: Infectious diseases occurred in 11 patients (11/27, 41%), including 3 (3/27, 11%) with severe diseases. The area under the ROC curve (AUC) showed that the lowest IgG level during and after BR discriminated infectious events (cut-off value, 603 mg/dL) with 81.8% sensitivity and 68.8% specificity (AUC, 0.76; 95% CI, 0.52-0.90). Furthermore, a multivariate regression analysis revealed that the minimal serum IgG value during and after BR therapy was the only variable that was significantly associated with infection (odds ratio, 8.29; 95% CI, 1.19-57.62; p value, 0.03). CONCLUSION: Serum IgG ≤603 mg/dL during and after BR therapy was independently associated with an increased risk of infection. The monitoring of serum IgG during chemotherapy may help to predict the development of infection in blood cancer patients undergoing chemotherapy with bendamustine in combination with rituximab.

Long-term outcomes and central nervous system relapse in extranodal natural killer/T-cell lymphoma.

To elucidate the long-term outcomes of non-anthracycline-containing therapies and central nervous system (CNS) events in patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL), the clinical data of 313 patients with ENKTL diagnosed between 2000 and 2013 in a nationwide retrospective study in Japan were updated and analyzed. At a median follow-up of 8.4 years, the 5-year overall survival (OS) and progression-free survival (PFS) were 71% and 64%, respectively, in 140 localized ENKTL patients who received radiotherapy-dexamethasone, etoposide, ifosfamide, and carboplatin (RT-DeVIC) in clinical practice. Nine (6.4%) patients experienced second malignancies. In 155 localized ENKTL patients treated with RT-DeVIC, 10 (6.5%) experienced CNS relapse (median, 12.8 months after diagnosis). In five of them, the events were confined to the CNS. Nine of the 10 patients who experienced CNS relapse died within 1 year after CNS relapse. Multivariate analysis identified gingival (hazard ratio [HR], 54.35; 95% confidence interval [CI], 8.60-343.35) and paranasal involvement (HR, 7.42; 95% CI, 1.78-30.89) as independent risk factors for CNS relapse. In 80 advanced ENKTL patients, 18 received steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) chemotherapy as first-line treatment. Patients who received SMILE as their first-line treatment tended to have better OS than those who did not (p = 0.071). Six (7.5%) advanced ENKTL patients experienced isolated CNS relapse (median, 2.6 months after diagnosis) and died within 4 months of relapse. No second malignancies were documented in advanced ENKTL patients. In the entire cohort, the median OS after first relapse or progression was 4.6 months. 12 patients who survived 5 years after PFS events were disease-free at the last follow-up. Of those, 11 (92%) underwent hematopoietic stem cell transplantation. Our 8-year follow-up revealed the long-term efficacy and safety of RT-DeVIC and SMILE. The risk of CNS relapse is an important consideration in advanced ENKTL.

Comprehensive geriatric assessment as a useful tool in predicting adverse events in elderly patients with diffuse large B-cell lymphoma.

We conducted a multicenter prospective study on whether a comprehensive geriatric assessment (CGA) can predict the adverse events (AEs) of chemotherapy in elderly patients with diffuse large B-cell lymphoma (DLBCL). Patients aged ≥ 65 years with newly diagnosed DLBCL underwent a pretreatment baseline CGA consisting of six assessment tools: activities of daily living (ADL), instrumental ADL (IADL), mood, nutritional status, comorbidities, and cognitive function. An attending physician chose each patient's treatment but was blind to CGA results. Patients were grouped as "dependent" or "independent" according to the CGA. The primary endpoint was to evaluate the association between chemotherapy-induced grade 3-4 toxicity and CGA. Of 86 patients, 78 completed the designated CGA. The median age was 79 years (65-89). Seventy-two patients were treated with a cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP-like) regimen, and six were treated with low-toxicity regimens. Forty-one patients were classified as dependent and 37 as independent. In multivariate analysis, an impairment of IADL was independently associated with grade 3-4 leukopenia (odds ratio [OR] 0.63; 95% confidence interval [CI] 0.43-0.92, p = 0.017) and anemia (OR 0.67; 95% CI 0.50-0.90, p = 0.008). The presence of a comorbidity was also associated with grade 3-4 non-hematological toxicity (OR 2.17; 95% CI 1.37-3.43, p = 0.001). The 4-year survival rate tended to be longer in the independent (72.7%) compared to dependent (56.9%) group. Overall, a CGA may be a useful tool for predicting serious AEs associated with chemotherapy in elderly patients with DLBCL.

Venetoclax plus azacitidine in Japanese patients with untreated acute myeloid leukemia ineligible for intensive chemotherapy.

BACKGROUND: The phase 3 VIALE-A trial (NCT02993523) reported that venetoclax-azacitidine significantly prolonged overall survival compared with placebo-azacitidine in patients with newly diagnosed acute myeloid leukemia ineligible for intensive chemotherapy. Herein, efficacy and safety of venetoclax-azacitidine are analyzed in the Japanese subgroup of VIALE-A patients. METHODS: Eligible Japanese patients were randomized 2:1 to venetoclax-azacitidine (N = 24) or placebo-azacitidine (N = 13). Primary endpoints for Japan were overall survival and complete response (CR) + CR with incomplete hematologic recovery (CRi). Venetoclax (target dose 400 mg) was given orally once daily. Azacitidine (75 mg/m2) was administered subcutaneously or intravenously on Days 1-7 of each 28-day cycle. RESULTS: Median follow-up was 16.3 months (range, 1.0-20.3). Median overall survival was not reached with venetoclax-azacitidine (hazard ratio 0.409 and 95% confidence interval: 0.151, 1.109); overall survival estimate was higher with venetoclax-azacitidine than placebo-azacitidine at 12 (67 and 46%) and 18 months (57 and 31%), respectively. CR and CRi rates were 67% with venetoclax-azacitidine and 15% with placebo-azacitidine. Most common any-grade adverse events were febrile neutropenia (79 and 39%), thrombocytopenia (54 and 77%), constipation (54 and 54%) and decreased appetite (54 and 38%) in the venetoclax-azacitidine and placebo-azacitidine arms, respectively. Only 1 patient in the venetoclax-azacitidine arm, and no patients in the placebo-azacitidine arm, had grade 4 febrile neutropenia that led to treatment discontinuation. CONCLUSIONS: This Japanese subgroup analysis of VIALE-A demonstrates comparable safety and efficacy outcomes compared with the global study and supports venetoclax-azacitidine as first-line standard-of-care for Japanese treatment-naive patients with acute myeloid leukemia who are ineligible for intensive chemotherapy.

Clinical significance of the immunoglobulin G heavy-chain repertoire in peripheral blood mononuclear cells of adult T-cell leukaemia-lymphoma patients receiving mogamulizumab.

'Monitoring of immune responses following mogamulizumab-containing treatment in patients with adult T-cell leukaemia-lymphoma (ATL)' (MIMOGA) is a multicentre prospective clinical study (UMIN000008696). In the MIMOGA study, we found that a lower percentage of CD2- CD19+ B cells in peripheral blood mononuclear cells (PBMC) was a significant unfavourable prognostic factor for overall survival (OS). Accordingly, we then analysed the immunoglobulin G (IgG) heavy-chain repertoire in PBMC by high-throughput sequencing. Of the 101 patients enrolled in the MIMOGA study, for 81 a sufficient amount of PBMC RNA was available for repertoire sequencing analysis. Peripheral IgG B cells in patients with ATL had a restricted repertoire relative to those in healthy individuals. There was a significant positive correlation between the Shannon-Weaver diversity index (SWDI) for the IgG repertoire and proportions of B cells in the PBMC of the patients. Multivariate analysis identified two variables significantly affecting OS: a higher serum soluble interleukin-2 receptor level, and a lower SWDI for the IgG repertoire [hazard ratio, 2·124; 95% confidence interval, 1·114-4·049; n = 44]. The present study documents the importance of humoral immune responses in patients receiving mogamulizumab-containing treatment. Further investigation of strategies to enhance humoral immune responses in patients with ATL is warranted.

Improved survival of patients with aggressive ATL by increased use of allo-HCT: a prospective observational study.

Aggressive adult T-cell leukemia/lymphoma (ATL) is a hematological malignancy that is difficult to treat with chemotherapy alone, and allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy. We conducted a multicenter, prospective, observational study to clarify the treatment outcomes of aggressive ATL in the current era. Between 2015 and 2018, 113 patients aged 70 years or younger with newly diagnosed aggressive ATL were enrolled. The median age at diagnosis was 61 years. Treatment outcomes were compared with those of 1792 ATL patients diagnosed between 2000 and 2013 in our previous retrospective study. The inclusion criteria were the same in both studies. The prospective cohort demonstrated better overall survival (OS) than the retrospective cohort (2-year OS, 45% vs 29%, respectively; P < .001), with a much higher proportion of patients receiving allo-HCT (80% vs 34%, respectively; P < .001) and a shorter interval from diagnosis to allo-HCT (median, 128 vs 170 days, respectively; P < .001). Among the 90 patients who received allo-HCT (cord blood, n = 30; HLA-haploidentical related donors, n = 20; other related donors, n = 14; other unrelated donors, n = 26), the 2-year probabilities of OS, non-relapse mortality (NRM), and disease progression were 44%, 23%, and 46%, respectively. OS and NRM did not differ statistically according to donor type. Our results suggest that increased application of allo-HCT improved the survival of patients with aggressive ATL. The use of cord blood or HLA-haploidentical donors may be feasible for aggressive ATL when HLA-matched related donors are unavailable. This study was registered at the UMIN Clinical Trials Registry as #000017672.