Adult T-cell Leukemia/lymphoma In Japan Research Articles

An update on the developments in the treatment of adult T-cell leukemia-lymphoma: current knowledge and future perspective.

Adult T-cell leukemia-lymphoma is defined as peripheral T-cell lymphoma caused by the human T-cell leukemia virus type I. Adult T-cell leukemia-lymphoma is classified into indolent (favorable chronic or smoldering) or aggressive (acute, lymphoma or unfavorable chronic) types. This review discusses the therapeutic developments for patients with adult T-cell leukemia-lymphoma and unmet issues in treating adult T-cell leukemia-lymphoma. For indolent adult T-cell leukemia-lymphoma, a watchful waiting strategy is recommended until the disease progresses to aggressive adult T-cell leukemia-lymphoma. For aggressive adult T-cell leukemia-lymphoma, multi-agent chemotherapy with or without allogeneic hematopoietic stem cell transplantation has been recommended. However, many patients with adult T-cell leukemia-lymphoma relapse, and their prognosis is poor. Recently, novel agents, including mogamulizumab, lenalidomide, brentuximab vedotin, tucidinostat and valemetostat, have been approved for patients with relapsed or refractory aggressive adult T-cell leukemia-lymphoma, and the combination of mogamulizumab with multi-agent chemotherapy or brentuximab vedotin with cyclophosphamide, doxorubicin and prednisone has been approved for patients with untreated aggressive adult T-cell leukemia-lymphoma in Japan. Importantly, the aging of patients with adult T-cell leukemia-lymphoma has recently been reported, and no standard of care for elderly patients with adult T-cell leukemia-lymphoma has been established. New evidence must be obtained from prospective clinical trials to improve the prognosis of patients with adult T-cell leukemia-lymphoma.

Current and emerging therapeutic strategies in adult T-cell leukemia-lymphoma.

Adult T-cell leukemia-lymphoma (ATL) is classified into four clinical subtypes: acute, lymphoma, chronic, and smoldering. Chronic ATL is further divided into unfavorable and favorable chronic types according to serum lactate dehydrogenase, blood urea nitrogen, and serum albumin values. Acute, lymphoma, and unfavorable chronic types are categorized as aggressive ATL, whereas favorable chronic and smoldering types are categorized as indolent ATL. Intensive chemotherapy alone is not sufficient to prevent relapse of aggressive ATL. Allogeneic hematopoietic stem cell transplantation is a potential therapeutic option to cure aggressive ATL in younger patients. Reduced-intensity conditioning regimens have decreased transplantation-related mortality, and increased donor availability has dramatically improved transplant access. New agents, including mogamulizumab, brentuximab vedotin, tucidinostat, and valemetostat, have recently become available for patients with aggressive ATL in Japan. Here, I provide an overview of recent advances in therapeutic strategies for ATL.

Valemetostat: First approval as a dual inhibitor of EZH1/2 to treat adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is a mature T-cell lymphoma with a poor prognosis. Accumulating trimethylation of histone H3 lysine 27 (H3K27me3) caused by upregulated function of either enhancer of zeste homologue 2 (EZH2) or its homolog EZH1 plays an essential role in the maintenance of transcriptional repression in ATL. Selective inhibition of EZH2 may complementarily induce EZH1 activation, so dual targeting EZH1/2 is a rational strategy in developing potent antitumor agents. Valemetostat is the first dual EZH1/2 inhibitor approved for treatment of aggressive ATL in Japan in September 2022. Several other dual EZH1/2 inhibitors such as HH2853, HM97594, and HM97662 have also demonstrated potential in treating malignant tumors. Dual targeting EZH1/2 may have promising antitumor action in hematological malignancies and solid tumors.

Epidemiology of adult T-cell leukemia-lymphoma in Japan: An updated analysis, 2012-2013.

Adult T‐cell leukemia‐lymphoma (ATL) is a T‐cell malignancy that is endemic to Japan. In this latest nationwide study of ATL, we collected the data from 4 nationwide registries of patients diagnosed in 2012‐2013; the Hematology Blood Disease, the Skin Cancer Society, the Hospital‐Based Cancer Registries, and information from the hospitals that participated in the Japanese nationwide survey of ATL in 2010‐2011. In the present study, 2614 patients with ATL were diagnosed based on the registries, and 117 departments registered 1042 patients. Among these patients, 984 were eligible for analysis. The median age at diagnosis was 69 y. A larger proportion of patients with ATL older than 70 y was diagnosed with the lymphoma subtype, and more than half of the patients with ATL in the metropolitan areas were born in the human T‐cell leukemia virus type I (HTLV‐1)‐endemic areas of Kyushu/Okinawa, which are almost identical to the findings in our 2010‐2011 study. Additionally, we identified that patients with ATL migrated from the endemic areas for HTLV‐1 to the non‐endemic metropolitan areas. The present study was able to reduce the burden of searching each hospital and to update the clinico‐epidemiological characteristics of a large number of patients with ATL in Japan, suggesting the usefulness and feasibility of the novel data collection method. The establishment of a more sophisticated database management system for ATL is necessary for future continuous surveys.

Prognosis of patients with adult T-cell leukemia/lymphoma in Japan: A nationwide hospital-based study.

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.

Epidemiology of HTLV-1 Infection and ATL in Japan: An Update.

Adult T-cell leukemia-lymphoma (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) infection that often occurs in HTLV-1-endemic areas, such as Japan, the Caribbean islands, Central and South America, Intertropical Africa, and the Middle East. In Japan, the nationwide estimation of the number of HTLV-1 carriers was at least 1.08 million in 2006–2007. Furthermore, in 2016, the nationwide annual incidence of newly infected with HTLV-1 was first estimated to be 3.8 per 100,000 person-years based on the age-specific seroconversion rates of blood donors in almost all areas of Japan. The incidence rate was three times higher in women than in men, and it was estimated that at least 4,000 new HTLV-1 infections occur yearly among adolescents and adults in Japan. As well known that HTLV-1 infection alone is not a sufficient condition for ATL to develop. To date, a variety of molecular abnormalities and host susceptibilities have been reported as candidate progression factors for the development of ATL in HTLV-1-carriers. In particular, quite recently in Japan, a variety of immunosuppressive conditions have been recognized as the most important host susceptibilities associated with the development of ATL from HTLV-1-carrier status. Furthermore, in 2013–2016 in Japan, a new nationwide epidemiological study of ATL was conducted targeting patients newly diagnosed with ATL in 2010–2011, from which the most current knowledge about the epidemiological characteristics of Japanese patients with ATL was updated as follows: (1) continuing regional unevenness of the distribution of people with HTLV-1, (2) further aging, with the mean age at diagnosis being 67.5 years, (3) declining M/F ratio, (4) increase of the lymphoma subtype, (5) sex differences in subtype distribution, (6) age differences in subtype distribution, and (7) comorbidity condition. In particular, 32.2% of ATL patients had comorbid malignancies other than ATL. However, the number of deaths due to ATL in Japan has been relatively stable, at around 1,000 patients annually, without significant decline from 1999 to 2017. Because the current epidemiological evidence about HTLV-1 and ATL is insufficient, further epidemiological studies are required.

Improved Overall Survival Among Newly Diagnosed Aggressive Adult T-Cell Leukemia/Lymphoma Patients Treated with Mogamulizumab Plus EPOCH Compared to Mogamulizumab Plus Vcap-AMP-Vecp

Introduction: Adult T-cell leukemia/lymphoma (ATLL) is a rare and quite refractory peripheral T-cell lymphoma. The human T-lymphotropic virus type 1 (HTLV-1) retrovirus causes ATLL. Tax protein produced by HTLV-1 has oncogenic activities, and its peptides can be recognized as tumor antigens by the host immune system. Therefore, some immunological approaches to treat ATLL are effective. Mogamulizumab (Moga), an anti-CCR4 monoclonal antibody, and lenalidomide, an immunomodulator, have been recently approved for newly diagnosed and/or relapsed/refractory aggressive ATLL in Japan. However, to date, satisfactory treatment results have not been obtained with these drugs. Before approval of Moga and lenalidomide, VCAP-AMP-VECP (mLSG15) therapy was one of the standard combination chemotherapies for aggressive ATLL. A randomized phase II study comparing Moga plus mLSG15 and mLSG15 alone showed a higher %CR in Moga plus mLSG15 arm but no significant difference in overall survival (OS) between the two arms. In this study, we compared the outcomes of Moga plus EPOCH with those of Moga plus mLSG15. Methods: Aggressive ATLL patients, who were ineligible for hematopoietic stem cell transplantation (HSCT) and were newly diagnosed after June 2000 in our hospital, were retrospectively analyzed. Results: Table 1 summarizes the patient characteristics. Twenty-two patients were treated with Moga plus EPOCH, and 16 were treated with Moga plus mLSG15. There was no significant difference in gender and disease subtype between the groups. Moga-induced skin disorders, such as rash and erythema, were observed in 14 (64%) patients treated with Moga plus EPOCH group and 9 (56%) patients treated within Moga plus mLSG15; the difference was not significant. Figure 1 shows OS of both groups. There was no significant difference (P=0.3092), but a 30% risk reduction was observed in the Moga plus EPOCH group (hazard ratio [HR]: 0.6859, 95% confidence interval [CI]: 0.3165−1.430), though patients treated with Moga plus EPOCH were significantly older than those treated with Moga plus mLSG15 (Table 1). Figure 2 shows OS of patients with and without Moga-induced skin disorders in both groups. The OS of patients with skin disorders was significantly greater than that of those without skin disorders (P<0.0001, HR: 0.2653, 95% CI: 0.05879−0.3628), as previously reported. Elevation of the Tax-specific cytotoxic T-lymphocytes (CTL) percentage was observed after occurrences of skin disorders in some patients. Representative data are shown in Figure 3. These data suggest that the combination chemotherapy regimen might be irrelevant for patients with Moga-induced skin disorders. Next, the OS of the Moga plus EPOCH group was compared with that of those treated with chemotherapy alone, such as mLSG15 and the CHOP-like regimen, as the historical control (Table 2). There was no statistical difference between the groups, but a 16% risk reduction was observed in the Moga plus EPOCH group (P=0.5885, HR: 0.8401, 95% CI: 0.4491−1.568) (Figure 4), though those treated with Moga plus EPOCH were significantly older than those treated with chemotherapy alone (Table 2). A 36% risk reduction in OS was observed in patients with Moga-induced skin disorders compared to those treated with chemotherapy alone (Figure 5). Conclusion: Improved OS was observed more frequently in the Moga plus EPOCH group than in the Moga plus mLSG15 group. However, to date, Moga plus chemotherapy has not shown a significant impact on OS for newly diagnosed aggressive ATLL patients in non-HSCT settings, except for patients with Moga-induced skin disorders. Elevation of the Tax-specific CTL percentage was observed in some patients with Moga-induced skin disorders. We previously reported in the 2014 ASH annual meeting that several aggressive ATLL patients, who obtained long-time survival using chemotherapy alone, had maintained Tax-specific CTLs for long periods. Therefore, it might be necessary to induce, up-regulate, and maintain ATLL-specific CTLs to obtain long-time survival. Moga is useful, but insufficient, for inducing such CTLs by suppressing regulatory T-cells. No effective method is available to activate an ATLL-specific cellular immune response. Further studies are urgently needed to establish effective methods for attaining ATLL-specific CTLs. Disclosures No relevant conflicts of interest to declare.

Maintenance of long remission in adult T-cell leukemia by Tax-targeted vaccine: A hope for disease-preventive therapy.

Adult T‐cell leukemia/lymphoma (ATL) is an aggressive lymphoproliferative disease caused by human T‐cell leukemia virus type 1 (HTLV‐1). Multi‐agent chemotherapy can reduce ATL cells but frequently allows relapses within a short period of time. Allogeneic hematopoietic stem cell transplantation (allo‐HSCT) following chemotherapy is now a standard therapy for ATL in Japan as it can achieve long‐term remission in approximately one‐third of recipient ATL patients; however, it also has a risk of treatment‐related mortality. Allo‐HSCT often induces HTLV‐1 Tax‐specific cytotoxic T cells (CTL) as well as graft‐versus‐host (GVH) response in ATL patients. This observation led to development of a new therapeutic vaccine to activate Tax‐specific CTL, anticipating anti‐ATL effects without GVH response. The newly developed Tax‐DC vaccine consists of autologous dendritic cells pulsed with Tax peptides corresponding to CTL epitopes that have been identified in post‐allo‐HSCT ATL patients. In a pilot study of Tax‐DC therapy in three ATL patients after various initial therapies, two patients survived for more than 4 years after vaccination without severe adverse effects (UMIN000011423). The Tax‐DC vaccine is currently under phase I trial, showing a promising clinical outcome so far. These findings indicate the importance of patients’ own HTLV‐1‐specific T‐cell responses in maintaining remission and provide a new approach to anti‐ATL immunotherapy targeting Tax. Although Tax‐targeted vaccination is ineffective against Tax‐negative ATL cells, it can be a safe alternative maintenance therapy for Tax‐positive ATL and may be further applicable for treatment of indolent ATL or even prophylaxis of ATL development among HTLV‐1‐carriers.

SY30-3 - The difficulty in establishing clinical evidence of extremely-rare hematological malignancies

Remarkable renovations in standard of care by novel drugs have been made in some hematological malignancies for the past two decades, but not significantly in adult T-cell leukemia/lymphoma (ATL) which is a lymphoid malignancy caused by human T-lymphotropic virus type-I. The main reasons for little progress are its rarity, heterogeneity and aggressiveness. The number of patients of newly-diagnosed ATL is estimated to be less than 1000/year in Japan, and those diagnosed outside Japan are mainly from developing countries. In these 6 years, two drugs, a CCR4 monoclonal antibody, mogamulizumab and an immunomodulatory drug, lenalidomide, have been approved for ATL in Japan as orphan drug. The number of patients involving in the clinical trials for approval was very low, and importantly their background characteristics appeared to be different from those in practice. The substantial number of patients could not be enrolled into the trials due to poor performance status and rapid progression of the disease. On the other hand, if more aggressive patients were enrolled, it is likely to fail to show the efficacy. Well-designed postmarketing study is thereby essential to validate its efficacy and toxicity in the real-world practice. Moreover, most recent clinical trials aiming to develop novel drugs for relapsed/refractory ATL are experiencing a tough time to complete. In addition to rarity of the disease, recommendation by the regulatory agency to target patients only after use of mogamulizumab precludes patients' registration. It is a standard strategy to evaluate new drugs after available drugs are used up as in other cancers, but it is not a case in ATL. Only a few patients who relapse on mogamulizumab or become refractory to it are eligible for clinical trials due to the aggressive nature of ATL. To develop novel treatment and to establish standard of care for ATL is still challenging, but it is a lesson to learn its strategy for rare and very aggressive diseases.

Adult T Cell Leukemia-Lymphoma (ATL): State of the Art.

ATL is a rare and highly aggressive T cell malignancy caused by HTLV-1. We will review the state of the art of ATL epidemiology, pathogenesis, diagnosis, and treatment. Because of population migration, cases of ATL in non-HTLV-1 endemic countries including North America and Europe are increasingly recognized. ATL has diverse clinical manifestations, limited treatment options not widely available globally, and poor prognosis despite therapy. A small subset of patients may achieve prolonged survival with antiviral therapy or allogeneic stem cell transplant. Mogamulizumab, an anti-CCR4 monoclonal antibody, and lenalidomide, an immunomodulatory drug, are approved for ATL in Japan. Molecular studies have identified key alterations in T cell signaling and DNA methylation that may further guide drug development. Patients should be encouraged to enroll in prospective clinical trials when possible. Ongoing, collaborative, international research continues to elucidate disease pathogenesis and contribute to an evolving therapeutic landscape for ATL.

Current Clinico-Epidemiological Characteristics of Adult T-Cell Leukemia-Lymphoma (ATL) Based on the 11th Nationwide Survey in Japan

Introduction: Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-cell lymphomacaused by human T-lymphotropic virus type I (HTLV-1), which is endemic in Japan. Only a small percentage of HTLV-1 carriers infected through breast-feeding develop the disease. Previous nationwide surveys during 1980s-2000s in Japan provided a comprehensive view on the clinio-epidemiological profiles of ATL, including the establishment of the subtype-classification (i.e., the Shimoyama criteria: acute, lymphoma, chronic, and smoldering type) based on the diversity of the clinical features and prognosis. Treatment strategies have been developed by the subtype-classification; watchful waiting for indolent ATL, intensive chemotherapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) for aggressive ATL. The aim of this 11th survey is to characterize the current clinio-epidemiological features of ATL in Japan in the light of previous surveys.Methods: In 2013-14, we conducted an anonymous, cross-sectional, hospital-based survey of patients with ATL who were newly diagnosed during 2010-2011 across Japan. First, we asked 2500 hospitals with departments of hematology and dermatology to participate in this survey, and then we sent questionnaires to 128 participating hospitals to accumulate data of ATL. Skilled five hematologists reviewed the data of each questionnaire sheet, and the agreements of ATL diagnosis including the subtypes between the central review and participating hospitals were evaluated using Kappa statistics. Most of the collected data were analyzed by descriptive statistics.Results: A total of 996 ATL patients were registered; of these, 41 were eliminated because of the insufficient information for the diagnosis of ATL. Overall diagnostic agreement on subtype of ATL was substantial, with a kappa value 0.71 (standard error, 0.021); most of the disagreement was within aggressive/indolent category, acute vs. lymphoma types or acute vs. unfavorable chronic types. Among the 955 evaluable patients (M/F ratio, 1.12), 70% were diagnosed in the southwest region of Japan (Kyusyu/Okinawa) where HTLV-1 is endemic, which was consistent with the past surveys. The mean age at diagnosis was 68.3 years (median 68.8, range 24.7-100.3), which was significantly higher than 60.3 years in 1994-1995 and 57.7 years in 1986-1987. The proportion of ATL patients aged over 65 years was 79 % in this survey (whereas, 48% in the 1990-1991 survey), which indicates that the allo-HSCT is not applicable to the majority of current ATL patients in Japan. The proportion of acute, lymphoma, chronic, and smoldering types was 48, 28, 10 and 13%, respectively. The proportion of smoldering and chronic types tended to be greater than previous surveys (7% and 10% in the 1988-1997 surveys combined). The proportion of subtype by age group in this survey showed that the older in age at diagnosis are, the higher proportion of lymphoma subtype (10% in those aged younger than 40 years, 20% in those 50-59, and 31% in those 70 years or older.Discussion: This 11th survey revealed several clinio-epidemiological features of current ATL in Japan different from those in past two decades. First, a considerably increasing proportion of elderly ATL patients were diagnosed, which may be expected from a recent distribution of nationwide HTLV-1 carriers in Japan (Satake, et al, 2011). Second, there is an increasing tendency in the proportion of indolent types of ATL. This may be partly influenced by participation of the dermatology departments for the first time, because early phase of ATL localized in skin were frequently diagnosed in the dermatology department. Third, the proportion of lymphoma subtype was increased with age, which suggests that aging-related unknown mechanisms may affect the subtype distribution. More detailed analysis and subsequent surveys are planned to further evaluate clinical features and the efficacy of modern therapies on prognosis of ATL. DisclosuresIshizawa:Kyowa Kirin: Speakers Bureau; GSK: Research Funding; Takeda: Research Funding; Celgin: Speakers Bureau; Kyowa Kirin: Research Funding; Celgin: Research Funding; Janssen: Research Funding; Takeda: Speakers Bureau; Pfizer: Speakers Bureau. Ishida:Bristol-Myers Squibb: Honoraria. Ishida:Kyowa Hakko Kirin Co., LTD: Honoraria, Other: Research Funding to my institution; Bayer Pharma AG: Other: Research Funding to my institution; Celgene K.K.: Other: Research Funding to my institution. Tobinai:Gilead Sciences: Research Funding. Watanabe:Daiichi Sankyo Co., Ltd.: Research Funding.

Cytotoxic T-Lymphocyte Analysis of Aggressive Types of Adult T-Cell Leukemia/Lymphoma Patients with Complete Remission after Intensive Combination Chemotherapy

Introduction: Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell malignancy caused by human T-lymphotropic virus type I (HTLV-I). Most ATLL cells are CD4 and CCR4 positive, and CD8 negative. ATLL is classified into 4 clinical subtypes: smoldering, chronic, acute, and lymphoma. Acute and lymphoma type ATLLs, which are aggressive types, have a very poor prognosis. In Japan, aggressive ATLLs are commonly treated by intensive chemotherapies, such as VCAP-AMP-VECP, modified LSG15 therapy, and biweekly CHOP therapy. Recently, an anti-CCR4 monoclonal antibody (mogamulizumab) was approved for relapse and refractory ATLL in Japan. Mogamulizumab induces a highly potent antibody dependent cellular cytotoxicity, suggesting the importance of immuno-cell therapy for treatment of ATLL. We report here the extremely interesting results of aggressive ATLL patients with long-term survival and complete remission (CR) after activation of cellular immunity against ATLL cells following intensive chemotherapies.Patients and Methods: We retrospectively evaluated 46 cases of aggressive ATLLs diagnosed at the Nagasaki Genbaku Hospital between January 2001 and August 2011. Of these, 7 patients had long-term survival greater than 3 years with CR after intensive chemotherapies. Four of these 7 patients had human leukocyte antigen (HLA)-A02:01 or HLA-A24:02, and were investigated using anti-HTLV-I specific cytotoxic T-lymphocyte (CTL) analysis. The HTLV-I provirus load in peripheral blood was also analyzed.Results: Table 1 summarizes the characteristics of 7 aggressive type ATLL patients with long-term survival. Four patients were male and 3 were female. Six patients were classified as lymphoma type and 1 as acute type ATLL. The median age was 68 (range, 60–78) years. The median survival period from the onset of the disease was 111 (range, 36–165) months. In all 7 patients, the CD4/CD8 ratio reversed during, or shortly after, chemotherapy and CD8 predominance continued for more than 1 year (range, 13–165 months, median 24 months). Three patients had herpes virus infection during chemotherapy and reversal of the CD4/CD8 ratio appeared just after herpes virus infection in 2 of these patients. These observations suggested that HTLV-I specific CTLs were induced and contributed to the treatment of ATLL in these patients. An HTLV-I specific CTL analysis currently is available in patients with HLA-A02:01 and HLA-A24:02. Three of 7 aggressive ATLL patients with long-term survival and CR had HLA-A02:01 and 1 had HLA-A24:02. Therefore, HTLV-I specific CTL analysis and HTLV-I provirus load in the peripheral blood were performed in all 4 patients. Each patient was examined twice, once in 2012 and once in 2014. HTLV-I specific CTLs were detected in all patients (Table 2 and Figure 1). Although all patients maintained CR for, HTLV-I proviruses were detected in the peripheral blood in all patients (Table 2). This phenomenon was observed both in 2012 and in 2014 (Table 2 and Figure 1).Conclusions: The findings from this study suggest that HTLV-I specific CTLs can be induced in patients with aggressive types of ATLL. In patients having long survival with CR, these CTLs can contribute to treatment and may play a roll inhibiting the relapse of ATLL. The development of efficacious methods to induce HTLV-I specific CTLs in individual ATLL patients may lead to improved outcomes for aggressive types of ATLL.Table 1Summary of aggressive type ATLL patients with long-term survival and complete remissionPatientNo.GenderAge(year)Survival fromthe onset of ATLL (months)Duration ofCD4/CD8 reversal(months)Herpes virus infection1Male69165165+2Male6814096+3Female717165-4Male6012413+5Female6111118-6Male783613-7Female655624-Table 2A Summary of HTLV-I specific CTL analysis and HTLV-I provirus load in the peripheral bloodPatient No.HLA20122014CTLHTLV-I provirusCTLHTLV-I provirus(%)(copies/1000 cells)(%)(copies/1000 cells)1A02:010.1135.40.1361.92A02:010.7824.41.5614.75A02:011.067.11.3113.37A24:022.0726.43.6427.9 [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Mogamulizumab for the treatment of adult T-cell leukemia/lymphoma

Mogamulizumab for the treatment of adult T-cell leukemia/lymphoma Makoto Yoshimitsu, Naomichi Arima Division of Hematology and Immunology, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan Abstract: Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell lymphoma caused by latent infection of human T-cell lymphotropic virus type 1. The outcome for ATLL is very poor, with a 3-year overall survival of approximately 24% with conventional chemotherapy; thus, there is an unmet need for developing new treatment options. Defucosylated humanized anti-CC chemokine receptor 4 (CCR4) antibody (KW-0761, mogamulizumab) has been clinically available for the treatment of relapsed or refractory ATLL in Japan since 2012, and a Phase II study of mogamulizumab for patients with relapsed CCR4+ ATLL demonstrated a 50% objective response, a 30.8% complete response, and an acceptable safety profile. Allogeneic hematopoietic stem cell transplantation has been used to treat patients with ATLL, and mogamulizumab in combination with allogeneic hematopoietic stem cell transplantation has been used successfully in a limited number of patients to treat refractory or relapsed ATLL. The efficacy of combining mogamulizumab with standard chemotherapy (mLSG15) for patients with ATLL has also been examined, and the results have shown higher rates of complete response with the combined therapy (52%) compared with for chemotherapy alone (33%). Mogamulizumab also has potential application in the treatment of human T-cell lymphotropic virus type 1-associated myelopathy/tropical paraparesis, Epstein–Barr virus-associated T-cell and natural killer-cell lymphoproliferative diseases, and peripheral and cutaneous T-cell lymphomas. Possible adverse events of mogamulizumab have been reported, such as cutaneous adverse reactions (including Stevens–Johnson syndrome), diffuse panbronchiolitis, reactivation of hepatitis B, and opportunistic infections. The treatment outcome of patients with ATLL might be improved by further optimizing the use of mogamulizumab and managing severe adverse events. In this review, we provide an overview of the current treatment options for patients with ATLL and a focused review on the use, application, and adverse events associated with mogamulizumab. Keywords: ATLL, anti-CCR4 antibody, defucosylated antibody, cutaneous adverse reaction

Association between decreasing trend in the mortality of adult T-cell leukemia/lymphoma and allogeneic hematopoietic stem cell transplants in Japan: analysis of Japanese vital statistics and Japan Society for Hematopoietic Cell Transplantation (JSHCT)

Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm with a very poor outcome. However, several studies have shown a progress in the treatment. To evaluate the effect of the progress in the treatment of ATLL in a whole patient population, we used vital statistics data and estimated age-adjusted mortality and trends in the mortality from 1995 to 2009. Since allogeneic hematopoietic stem-cell transplantation (allo-HSCT) has been introduced as a modality with curative potential during study period, we also evaluated the association of the annual number of allo-HSCT and the trend of the mortality of ATLL. Endemic (Kyushu) and non-endemic areas (others) were evaluated separately. Significance in the trend of mortality was evaluated by joinpoint regression analysis. During the study period, a total of 14 932 patients died of ATLL in Japan, and mortality decreased significantly in both areas (annual percent change (95% confidence interval (CI)): Kyushu, −3.1% (−4.3, −1.9); others, −3.4% (−5.3, −1.5)). This decreasing trend in mortality seems to be associated with an increase in the number of allo-HSCTs (Kyushu, R-squared=0.70, P=0.003; and others, R-squared=0.55, P=0.058). This study reveals that the mortality of ATLL is now significantly decreasing in Japan and this decreasing trend might be associated with allo-HSCT.

Epidemiology, clinical features and prevention of HTLV‐I infection

Human T-cell leukemia virus type I (HTLV-I) [1,2] is the main cause of Adult T-cell leukemia ⁄ lymphoma (ATLL) [3] and HTLV-I associated myelopathy ⁄ Tropical spastic paraparesis (HAM ⁄ TSP) [4,5]. From the long-term epidemiological observation, the HTLV-I carriers are clustered in limited groups in the world, i.e., Southwestern Japanese, native Oceanians, Amerindians in Andes and Northeast British Colombia, North Iranians as well as Central Africans and their descendants in the Caribbean basin and South America [6]. According to evidence obtained from a biennial nationwide surveillance of adult T-cell leukemia ⁄ lymphoma (ATLL) carried out in Japan since 1986, the annual incidence is estimated to be 700 within approximately one million HTLV-I carriers in Japan [7]. The affected individuals mainly inhabit the southern and northern ATLL endemic areas. Among 3499 ATLL patients newly diagnosed during the last ten years from 1988 to 1997 [8], approximately 70% were born in the southwestern districts of Kyushu and Shikoku, and 10% in the northern districts of Hokkaido and Tohoku (Fig. 1). This epidemic pattern of ATLL is still continuous up until now. The main reasons of unique geographical clustering of ATLL in Japan might be linked to a history of old Japanese migration with unique geographical clustering of HTLV-I carriers in Japanese archipelago due to the natural transmission routes of mother-to-child through breast milk and man-to-woman through semen [9,10]. In the ATLL endemic areas in Japan a systematic prevention trial against HTLV-I transmission through breast milk from HTLV-I carrying mothers to newborn babies, e.g., strong recommendation to pregnant women with HTLV-I to completely stop breast milk and ⁄ or to raise their babies by short-term breast feeding [11,12]. Clinically contrasting HTLV-I related diseases

Neuro-immunological complications of retroviruses other than the HIV

The aim of this review is to introduce and adjust the recent results of clinical and basic studies of neurological diseases associated with human T-lymphotropic virus type I (HTLV-I) and type 11. HTLV-I and II are type C retroviruses, members of the subfamily Oncoviridae. HTLV-I has been implicated as the causative agent of adult T-cell leukemia/lymphoma (ATL), first proposed as a clinical entity by Takatsuki and colleagues in Japan. This RNA virus was independently isolated from a patient with cutaneous T-cell lymphoma in the United States by Poiesz et al. in 1980 and from a patient with ATL in Japan by Hinuma et al. in 1981. The common causes of neurological complications of ATL were direct tumor cell invasion and hypercalcemia and the manifestations of ATL, including neurological signs and symptoms were variable. Another neurological disease associated with the same HTLV-I has been independently demonstrated in Martinique and Japan. The disease is now known under the combined acronym HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A nationwide survey in Japan found about 700 cases of HAM/TSP. Approximately 450 persons with HAM/TSP have been reported from other countries, including those in the Caribbean basin, South America and Africa. In the Japanese nationwide survey, the mean age at onset of symptoms was 43 years and the male-to-female ratio of occurrence was 1:2.9. The main neurologic features of HAM/TSP are spasticity and/or hyper-reflexia of lower extremities, urinary bladder disturbance, lower extremity muscle weakness and sensory disturbances (mostly with poorly defined thoracic sensory levels). Histopathologic features consisted of chronic inflammatory changes which were most conspicuous in the lower thoracic cord. There is no convincing proof of virus infection in neural cells and immune pathogenesis for HAM/TSP may play a part. Currently, however, it would be too hasty to draw the conclusion that HTLV-1 infection in neural cells is not related to pathogenic mechanisms for the disease. Oral prednisone may have a beneficial effect in some cases, but effects may be transient. In contrast to HTLV-I, HTLV-II has not been associated conclusively with any specific disease.

Adult T-cell Leukemia/Lymphoma (ATL) in Japan

A specific type of lymphoid malignancy, adult T-cell leukemia/ lymphoma(ATL), which is caused by human T-cell leukemia virus type I (HTLV-I), is highly prevalent and there are also many healthy carriers of HTLV-I in the same areas. Three main routes of HTLV-I transmission are recognized: 1) vertical transmission from mother to child mainly through breast milk, 2) horizontal transmission from man to woman through semen, and, 3) parenteral transmission from carrier donor to non-carrier recipient. The annual incidence rate of ATL among HTLV-I carriers is estimated at 2.0 in males and 0.5 in females, and the cumulative risk for ATL in HTLV-I carriers during a 70-year life span is 2-5%. Possible risk factors for ATL in addition to HTLV-Iinfection were considered, i.e. genetic factors, environmental factors, nutritional condition, thymus involution and so on. ATL in Japan is an important subject for study in the field of cancer epidemiology, and several trial intervention programs for the prevention of ATL, such as controls of vertical transmission from mother to child through breast milk, are now in progress in ATL-endemic areas in Japan.

The 4th nation‐wide study of adult T‐cell leukemia/lymphoma (ATL) in Japan: Estimates of risk of ATL and its geographical and clinical features

To estimate the annual incidence of adult T-cell leukemia/lymphoma (ATL) by district in Japan, a large-scale nationwide survey of ATL and of non-Hodgkin's lymphoma was performed in 1988. Questionnaires for the registration of ATL and of T-cell and non-T-cell lymphoma were distributed to the physicians in charge of this survey in 1,287 hospitals with 200 or more beds throughout Japan. From the positive rate of anti-HTLV-I antibody in adults, the annual incidence of ATL was estimated at 697, independently of the present survey. In fact, 657 cases (47% of the estimated number), newly diagnosed during the 2 years January 1986 to December 1987, were registered from 191 general hospitals throughout Japan. Major results obtained from the present survey are as follows: (1) among all ATL cases registered, 51% were from Kyushu and 29% were from metropolitan areas (Kanto, Chubu and Kinki) and most, but not all, patients with ATL in the metropolitan areas had come from the ATL-endemic areas and settled in the metropolitan areas; (2) the estimated annual incidence rates of ATL per million adults were 40.4 in males and 26.4 in females in Kyushu, the overall risk of ATL being 1.5 times as high in males as in females; (3) the age-specific incidence rate in Kyushu increased steeply with age until the age of 70, and then decreased markedly in both sexes; (4) the ratio of T-cell versus non-T-cell lymphomas was 2.9 in Kyushu but 0.5 in other districts of Japan, however, this difference regressed to the average for the whole of Japan if ATL cases were excluded; (5) 26.5% of patients with ATL had a family history of cancer, and among these, 14 (8.2%) were ATL, 21 (12.2%) were lymphoma and 17 (9.9%) were hematopoietic malignancies, the incidence of which was markedly higher than in the general population; (6) with regard to clinicopathological features of ATL, there were more advanced cases in south Kyushu than in other districts, however, these differences were not statistically significant. To clarify the chronological changes and geographical variations in the annual incidence of ATL in Japan, continuous systematic nationwide surveillance is necessary and further nation-wide studies are being prepared.

Malignant lymphomas in Japan: epidemiological analysis of adult T-cell leukemia/lymphoma (ATL).

The incidence of malignant lymphomas in Japan is relatively low compared to that in western European countries and the United States. However, in limited areas in Japan a specific type of lymphoid malignancy called adult T-cell leukemia/lymphoma (ATL), which is caused by human T-cell leukemia virus type I (HTLV-I), is highly prevalent, and there are also many healthy carriers of HTLV-I in the same areas. A cross-sectional seroepidemiological study of HTLV-I showed that the age-specific proportion of healthy HTLV-I carriers in these ATL-endemic areas increased with age, especially over 40, and was higher in females than in males. Three main routes of HTLV-I transmission are recognized: 1) vertical transmission from mother to child mainly through breast milk; 2) horizontal transmission from man to woman through semen, and; 3) parenteral transmission from carrier donor to non-carrier recipient. The annual incidence rate of ATL among HTLV-I carriers is estimated at 2.0 in males and 0.5 in females, and the cumulative risk for ATL in HTLV-I carriers during a 70-year life span is 1%-5%. Possible risk factors for ATL in addition to HTLV-I infection were considered, i.e. genetic factors, environmental factors, nutritional condition, thymus involution etc., but none of these were found to be clearly associated with ATL. To determine whether there exist particularly susceptible hosts for ATL in the ATL endemic areas, HLA types were examined, but no conclusive results on the positive relationships between HLA types and ATL manifestation or HTLV-I infection were obtained. From follow-up studies on the age-specific distribution of HTLV-I carriers in Japan, it is now speculated that the HTLV-I infection rate might have decreased naturally in the more recent generational cohort groups, even in the ATL-endemic areas. However, ATL in Japan is an important subject for study in the field of cancer epidemiology, and several trial intervention programs for the prevention of ATL, such as controls of vertical transmission from mother to child through breast milk, are now ongoing in the ATL-endemic areas of Japan.

Malignant lymphomas in Japan: epidemiological analysis on adult T-cell leukemia/lymphoma.

According to the Vital Statistics Japan Series in 1950-1981, the age-adjusted death rate for malignant lymphomas (ICDs, 200-202) in Japan has increased in recent years. A geographical clustering of malignant lymphomas in the Kyushu districts was observed both in the period 1969-1971 and more recently in 1979-1981. The excessive rate of malignant lymphomas in Kyushu was due to the high incidence of adult T-cell leukemia/lymphoma (ATLL). The distribution of healthy carriers of ATLV, a human retrovirus which is almost identical to HTLV, was closely related to that of patients with ATLL in Japan. Epidemiological features of the infectious mode of ATLV suggested two main routes of natural transmission, one from mother to child and the other from husband to wife. ATLV is considered to be a main causative agent of ATLL from virological and epidemiological evidence, but infection by this virus alone may not result in ATLL because the incidence of ATLL among ATLV carriers was apparently not very high even in endemic areas of ATLL. Thus, some risk factors other than ATLV, such as environmental and genetic factors, may contribute to the development of ATLL.