Adult T-cell Leukemia/lymphoma Patients Research Articles

HTLV-1 viral oncogene HBZ drives bone destruction in adult T cell leukemia.

Osteolytic bone lesions and hypercalcemia are common, serious complications in adult T cell leukemia/lymphoma (ATL), an aggressive T cell malignancy associated with human T cell leukemia virus type 1 (HTLV-1) infection. The HTLV-1 viral oncogene HBZ has been implicated in ATL tumorigenesis and bone loss. In this study, we evaluated the role of HBZ on ATL-associated bone destruction using HTLV-1 infection and disease progression mouse models. Humanized mice infected with HTLV-1 developed lymphoproliferative disease and continuous, progressive osteolytic bone lesions. HTLV-1 lacking HBZ displayed only modest delays to lymphoproliferative disease but significantly decreased disease-associated bone loss compared with HTLV-1-infected mice. Gene expression array of acute ATL patient samples demonstrated increased expression of RANKL, a critical regulator of osteoclasts. We found that HBZ regulated RANKL in a c-Fos-dependent manner. Treatment of HTLV-1-infected humanized mice with denosumab, a monoclonal antibody against human RANKL, alleviated bone loss. Using patient-derived xenografts from primary human ATL cells to induce lymphoproliferative disease, we also observed profound tumor-induced bone destruction and increased c-Fos and RANKL gene expression. Together, these data show the critical role of HBZ in driving ATL-associated bone loss through RANKL and identify denosumab as a potential treatment to prevent bone complications in ATL patients.

Transplant-related complications are impediments to the success of allogeneic hematopoietic stem cell transplantation for adult T cell leukemia patients in non-complete remission.

Outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with adult T cell leukemia/lymphoma (ATL) are not satisfactory, particularly in patients in non-complete remission at transplantation (Pt-non-CR). We conducted a regional retrospective study in the ATL endemic area of Okinawa, Japan. Of 62 ATL patients, 21 received allo-HSCT in CR and 41 in non-CR. The 3-year overall survival (3yOS) rate and median survival time for the whole cohort was 25.6% and 7.7 months, respectively. The 3yOS of Pt-non-CR was significantly lower than that of patients in CR (Pt-CR) (16.8% vs. 43.6%, P = 0.005). Transplant-related mortality (TRM) was significantly higher in Pt-non-CR than in Pt-CR (46.3% vs. 15.7%, P = 0.025), while there was no significant difference in disease-associated mortality (DAM) between Pt-non-CR and Pt-CR. Multivariable analysis for Pt-non-CR revealed that poor performance status (poor-PS) and higher sIL-2R level (high sIL-2R) adversely affected OS. Poor-PS was associated with higher TRM, but not with higher DAM in Pt-non-CR. High sIL-2R did not affect TRM or DAM in Pt-non-CR. Overall, high TRM rates rather than DAM contribute to the poor outcomes of Pt-non-CR, suggesting that not only disease control but also management of transplant-related complications is required for allo-HSCT in ATL patients.

CCR4 is rarely expressed in CCR4-mutated T/NK-cell lymphomas other than adult T-cell leukemia/lymphoma.

CCR4 is expressed on tumor cells of most patients with adult T-cell leukemia/lymphoma (ATL). Gain-of-function mutations of the CCR4 gene in ATL patients may be associated with alterations at the carboxyl terminus, a finding which led to a high efficacy anti-CCR4 antibody, mogamulizumab. Only a few studies have reported CCR4 protein expression and genomic CCR4 mutations in non-ATL T/NK-cell lymphomas. Furthermore, an association between CCR4 protein expression, genomic CCR4 mutations, and transcript CCR4 mutations has not been well analyzed. The T/NK-cell lymphomas (n = 226) enrolled in this study were examined for CCR4 expression by immunohistochemistry. CCR4 mutations in the codons 322-348 were detected by direct sequencing and a SNaPshot Multiplex assay. CCR4 protein expression was positive in 48/52 (92%) and 58/174 (33%) of ATL and non-ATL cases, respectively, and genomic CCR4 mutations were detected in 17/52 (33%) and 6/174 (3.4%), respectively. While all 17 ATL cases with genomic CCR4 mutations were positive for CCR4 protein expression, five of six mutated non-ATL cases were negative for CCR4 protein expression and transcript CCR4 mutations. This study suggests that frequencies of CCR4 expression and genomic CCR4 mutations and an association between the two may be considerably different between ATL cases and non-ATL T/NK-cell lymphomas.

Cutaneous manifestations of adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell lymphoma caused by the human T-lymphotropic virus type-1 (HTLV-1). The skin is affected in approximately half of ATLL patients, and it may be the first manifestation of the disease. The skin lesions of ATLL are polymorphous, and depending on the type of skin eruption, it is possible to predict the prognosis of the disease. Besides specific skin lesions, other non-specific lesions and increased risk of cutaneous and systemic infections are observed. In this article, we describe the different skin lesions of ATLL patients (specific, non-specific, and infectious lesions), the different histopathological patterns, and the association of clinicopathological characteristics with prognosis. Recognition of ATLL skin lesions is essential for the correct management and the search for the virus, even in non-endemic regions, where global migration may bring HTLV-1 infected individuals.

COVER (PMS 180&K) (p/u from previous issue w/updates)

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell lymphoma caused by the human T-lymphotropic virus type-1 (HTLV-1). The skin is affected in approximately half of ATLL patients, and it may be the first manifestation of the disease. The skin lesions of ATLL are polymorphous, and depending on the type of skin eruption, it is possible to predict the prognosis of the disease. Besides specific skin lesions, other non-specific lesions and increased risk of cutaneous and systemic infections are observed. In this article, we describe the different skin lesions of ATLL patients (specific, non-specific, and infectious lesions), the different histopathological patterns, and the association of clinicopathological characteristics with prognosis. Recognition of ATLL skin lesions is essential for the correct management and the search for the virus, even in non-endemic regions, where global migration may bring HTLV-1 infected individuals.

PS1097 ADULT T‐CELL LEUKEMIA/LYMPHOMA: EPIDEMIOLOGY, CLINICAL FEATURES AND OUTCOME OF A CARIBBEAN COHORT FROM GUADELOUPE

Background:Adult T‐cell leukemia/lymphoma (ATLL) is a rare mature T‐cell malignancy first described in Japan in 1977. The causative agent of ATLL has been identified as the human T cell lymphotropic virus type 1 (HTLV‐1) which is endemic in Japan, Caribbean area, Central and South America and parts of sub‐Saharan Africa. Whereas Japanese cohorts of ATLL are commonly described, the studies gathering ATLL in the Caribbean islands are less frequently provided. ATLL is an unfrequent and subsequently unknown in Europa in opposite to the French overseas departments of the caribbean area.Aims:To report and describe ATLL in the lesser Antilles at the modern area of zidovudine and interferon treatment.Methods:We identified ATLL patients diagnosed in our institution between 2014 and 2018. Charts were reviewed to report clinicopathologic features, treatment patterns and outcomes of this Caribbean cohort exclusively diagnosed in Guadeloupe (French West Indies). ATLL diagnosis is based for all patients on the presence of a clonal T cells proliferation along with positivity for HTLV‐1 serology.Results:Among 309 patients positive for HTLV‐1 in this period, 24 developed an ATLL (7.76%). The median age at presentation is of 59 years (27–92). The sex ratio M/F was 11/13 (0.84). Based on the Shimoyama classification, 14 patients (58,9%) had acute subtype, 9 (37,5%) had lymphomatous and 1 (4,1%) chronic/smoldering disease. 22/24 had lymphadenopathy or deep tumoral syndrom at diagnosis whereas 2 patients presented splenomegaly. LDH was elevated in 23 patients (mean rate is 4.36N (0.94 – 28.03)). Hypercalcemia was present in half of the cases (mean value of 2,69 mg/dL (1.46 – 4.22)). Lymphocytosis was present in 7 patients (29%) and typical flower cells in 14 cases. Circulating lymphocyte phenotyping, performed for 19 patients, showed clonal T‐cells in 15 cases. Two third of the available karyotype were complex with abnormalities of the chromosome 14 in 50% of the cases.Most of the patients (n = 22, 91.6%) received first‐line treatment, whereas 8.3% (n = 2) quickly passed away before initiating any specific medication. As first line, 11 patients were treated by zidovudine and pegylated interferon +/‐ corticosteroid, 10 patients received a polychimiotherapy only or associated with zidovudine and peg‐interferon and one received corticosteroid only. Among the 15 patients with relapse or refractory diseases, 6 were able to receive a second line treatment. One patient benefits from haploidentical bone marrow transplantation. Five patients are still alive at last follow‐up : 3 patients in complete response (including the transplanted patient), 2 in partial response. Among them, 4 are still treated with interferon and zidovudine. Mean overall survival is 10.1 months (0.2–58.4). Among the 18 death with available data: 10 were related to ATLL progression, 6 related to infections and 2 patients died with acute respiratory distress syndrome.Summary/Conclusion:We report the first description of ATLL in Guadeloupe island. Compared to Japanese cohorts, we have younger patients and dominance of acute and lymphomatous ATLL subtypes. Cytologic detection of flower cells needs trained biologists and Shimoyama classification requires a very low blood cell count (<1%) for lymphomatous category. Nevertheless, this detection can be improved by immunophenotyping which might be worthly introduced in this classification. Despite large and early use of zidovudine and interferon, with or without chemotherapy, ATLL remains a very poor prognostic disease confirming that innovative therapies are still needed.

Complete sequence of human T cell leukemia virus type 1 in ATLL patients from Northeast Iran, Mashhad revealed a prematurely terminated protease and an elongated pX open reading frame III

To gain insight into the origin, evolution, dissemination and viral factors affecting HTLV-1-associated diseases, knowing the complete viral genome sequences is important. So far, no full-length HTLV-1 genome sequence has been reported from Iran. Here we report the complete nucleotide sequence of HTLV-1 viruses isolated from adult T cell leukemia/lymphoma (ATLL) patients from this region. The genome size of HTLV-1-MhD (Mashhad) was found to be 9036 bp and sequence analysis of the LTR region showed that it belongs to cosmopolitan subtype A. Comparing the sequences with isolates from another endemic area (HTLV-1ATK) revealed variations in the U3 region (~3.4%), while there was 99.1% and 97.0% similarity in R and U5 regions, respectively. The nucleotide sequences of HTLV-1 gag, pro and pol genes had a difference of 1.1% compared with HTLV-1 ATK with 16 nucleotides replaced in the gag and 27 in the pol regions. There was no variability in the amino acid sequences in the p24gag, however three residues were different in the p19gag and one in the p15gag. The nucleotide sequence of env showed a divergence of 1.5% compared to ATK with 22-nucleotide variation. The HTLV-1-MhD Tax, p13, p30, and p12 had 99.1, 100, 98.8, and 98%, respectively similarity with the prototype strain. Four amino acid changes were detected in ORF1 and ORF2 products p12 and p30, respectively, while the p13 region showed 100% conservation. The nucleotide identity between the isolates of Mashhad and those isolated from France, Germany, China, Canada and Brazil was 99.1%, 99.2%, 97.9%, 99% and 99.3%, respectively. Four amino acid changes compared with HTLV-1ATK from Japan were detected in ORF1 and ORF2 products p12 and p30, respectively, while the p13 region showed 100% conservation. This data could provide information regarding the evolutionary history, phylogeny, origin of the virus and vaccine design.

RNA sequencing identifies clonal structure of T-cell repertoires in patients with adult T-cell leukemia/lymphoma

The diversity of T-cell receptor (TCR) repertoires, as generated by somatic DNA rearrangements, is central to immune system function. High-throughput sequencing technologies now allow examination of antigen receptor repertoires at single-nucleotide and, more recently, single-cell resolution. The TCR repertoire can be altered in the context of infections, malignancies or immunological disorders. Here we examined the diversity of TCR clonality and its association with pathogenesis and prognosis in adult T-cell leukemia/lymphoma (ATL), a malignancy caused by infection with human T-cell leukemia virus type-1 (HTLV-1). We analyzed 62 sets of high-throughput RNA sequencing data from 59 samples of HTLV-1−infected individuals—asymptomatic carriers (ACs), smoldering, chronic, acute and lymphoma ATL subtypes—and three uninfected controls to evaluate TCR distribution. Based on these TCR profiles, CD4-positive cells and ACs showed polyclonal patterns, whereas ATL patients showed oligo- or monoclonal patterns (with 446 average clonotypes across samples). Expression of TCRα and TCRβ genes in the dominant clone differed among the samples. ACs, CD4-positive samples and smoldering patients showed significantly higher TCR diversity compared with chronic, acute and lymphoma subtypes. CDR3 sequence length distribution, amino acid conservation and gene usage variability for ATL patients resembled those of peripheral blood cells from ACs and healthy donors. Thus, determining monoclonal architecture and clonal diversity by RNA sequencing might be useful for prognostic purposes and for personalizing ATL diagnosis and assessment of treatments.

Cytological tumour cell characteristics and reactive small lymphocytes influence patient prognosis in acute and lymphoma type adult T-cell leukaemia/lymphoma.

Acute and lymphoma type adult T-cell leukaemia/lymphoma (ATLL) patients show an aggressive clinical course. While some clinical signs indicate good prognosis, definitive cytohistological prognostic factors have yet to be described. We classified 65 ATLL patients into three groups by tumour cell size and nuclear pleomorphism on fine-needle aspiration and tumour touch smear samples. Semi-quantitative analysis of background small lymphocytes, reactive CD20-positive B cells and CD8-positive T cells was performed. Thirty-one patients had pleomorphic lymphoma with predominantly medium-sized cells and coarse granular nuclei. Another 24 patients showed pleomorphic large cell lymphoma with stippled chromatin. The remaining 10 demonstrated monomorphic large lymphoma cells with fine granular chromatin. Patients with pleomorphic lymphoma with medium-sized cells showed significantly higher serum lactate dehydrogenase and lower CD30 and C-MYC expression in lymphoma cells than the other two groups (P = .0216, P < 0.01, respectively). Patients with pleomorphic medium-sized ATLL had few usual small lymphocytes observed on routine morphological examination and showed less concurrent detection of CD20-positive B cells and CD8-positive T cells, both of which were lower than in the other two groups (P = .006, P = .019, respectively). Furthermore, ATLL patients with predominantly medium-sized lymphocytes exhibited a worse prognosis than patients with pleomorphic large cells (P = .0197). Background small lymphocytes and concurrent detection of CD20-positive B cells and CD8-positive T cells may thus be good prognostic factors (P = .011, P = .021, respectively). Morphological features, size of neoplastic cells and background non-neoplastic lymphocyte (B cells and CD8-positive T cells) volume appear to influence the prognosis of patients with aggressive-type ATLL.

COVER (PMS 180&amp;K) (p/u from previous issue w/updates)

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive peripheral T-cell lymphoma caused by the human T-lymphotropic virus type-1 (HTLV-1). The skin is affected in approximately half of ATLL patients, and it may be the first manifestation of the disease. The skin lesions of ATLL are polymorphous, and depending on the type of skin eruption, it is possible to predict the prognosis of the disease. Besides specific skin lesions, other non-specific lesions and increased risk of cutaneous and systemic infections are observed. In this article, we describe the different skin lesions of ATLL patients (specific, non-specific, and infectious lesions), the different histopathological patterns, and the association of clinicopathological characteristics with prognosis. Recognition of ATLL skin lesions is essential for the correct management and the search for the virus, even in non-endemic regions, where global migration may bring HTLV-1 infected individuals.

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.

Adult T-Cell Leukemia/Lymphoma-Related Ocular Manifestations: Analysis of the First Large-Scale Nationwide Survey.

Adult T-cell leukemia/lymphoma (ATL) is a rare and aggressive T-cell malignancy with a high mortality rate, resulting in a lack of information among ophthalmologists. Here, we investigated the state of ophthalmic medical care for ATL and ATL-related ocular manifestations by conducting the first large-scale nationwide survey in Japan. A total of 115 facilities were surveyed, including all university hospitals in Japan that were members of the Japanese Ophthalmological Society and regional core facilities that were members of the Japanese Ocular Inflammation Society. The collected nationwide data on the state of medical care for ATL-related ocular manifestations and ATL-associated ocular findings were categorized, tallied, and analyzed. Of the 115 facilities, 69 (60%) responded. Overall, 28 facilities (43.0%) had experience in providing ophthalmic care to ATL patients. ATL-related ocular manifestations were most commonly diagnosed “based on blood tests and characteristic ophthalmic findings.” By analyzing the 48 reported cases of ATL-related ocular manifestations, common ATL-related ocular lesions were intraocular infiltration (22 cases, 45.8%) and opportunistic infections (19 cases, 39.6%). All cases of opportunistic infection were cytomegalovirus retinitis. Dry eye (3 cases, 6.3%), scleritis (2 cases, 4.2%), uveitis (1 case, 2.1%), and anemic retinopathy (1 case, 2.1%) were also seen. In conclusion, intraocular infiltration and cytomegalovirus retinitis are common among ATL patients, and ophthalmologists should keep these findings in mind in their practice.

Ectonucleosidase CD39 Is Highly Expressed on ATLL Cells and Suppresses the Immune Response through the Adenosine Pathway

Background: Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm, linked to the human T-cell lymphotropic virus, HTLV-1. Patients with ATLL are often at the risk of opportunistic infections. Some studies suggested that ATLL cells originate from HTLV-1-infected regulatory T cells (Tregs). It could be possible that this immunocompromised state is caused by the function of ATLL cells having similar phenotypes with Tregs. In this study, we examined the expression of immunosuppressive molecules associated with Tregs in ATLL cells, and analyzed their roles in the function of ATLL cells.Methods: The protocol of this study was approved by the Investigational Review Board of Osaka University Hospital. Peripheral blood mononuclear cells (PBMCs) were collected from 10 asymptomatic HTLV-1 carriers and 22 ATLL patients (1 with smoldering type, 5 with chronic type, 2 with lymphoma type, and 14 with acute type) after getting informed consent. PBMCs from 3 ATLL patients were separated into CD4+ CD7- CADM1+ATLL cells and adjacent CD4+CD7+ CADM1-normal T cells using Fluorescence-activated Cell Sorter (FACS), and cells in each fraction were subjected to total RNA sequencing experiments. Based on the results, we examined the expression patterns of CD39 and CD73 in HTLV-1 carriers or each type of ATLL patients, and also analyzed the immune functions of these molecules in ATLL tumor cells.Results: We compared whole transcriptome of ATLL cells and normal CD4+cells. Bioinformatic analyses showed that many genes associated with immunosuppressive functions were elevated or downregulated in ATLL cells. Among these genes we focused on CD39, CD73 and CD26, because they have recently been reported to be strongly associated with the functions of Tregs. CD39, expressed on normal Tregs, and extrinsic CD73 have immunosuppressive potential by catalyzing adenosine from extracellular ATP, and CD26 has opposite potential by resolving adenosine, which have a strong anti-inflammatory function and plays major role in Treg-mediated immunosuppression. We found that all of 4 ATLL cell lines (MJ, MT1, MT2, MT4) expressed CD39, but not CD73 just as human effector Tregs. Tumor cells from 12 acute ATLL patients (86%) and 2 chronic ATLL patients (40%) expressed CD39, but the expressions of CD73 were various. Also in asymptomatic carriers, we could detect CD39 and/or CD73 positive in CD7- CADM1+ abnormal fraction of CD4+cells. On the other hand, CD26, normally expressed on human CD4+Th cells other than effector Tregs, was negative in ATLL cell lines and primary ATLL cells except for cells in abnormal fraction of one asymptomatic carrier. CD39 negative cases in chronic/smoldering type tended to show slower disease progression after the blood collection. Next, the role of CD39 and/or CD73 in ATLL cells was assessed in vitro and in vivo. As expected, CD39+ ATLL cells converted significantly more extracellular ATP than CD39- ATLL cells, and mass spectrometry analysis of AMP/adenosine concentration identified the AMPase activity of CD73+ ATLL cells. Furthermore, we established CD39 knockout (KO) cells from ATL cell-line MJ using CRISPR/Cas9 system, and performed in vitro suppression assays for assessment of immunosuppressive function. Although wild type MJ suppressed the growth of normal CD4+ and CD8+ T cells, KO MJ did little. Next, we analyzed the role of CD39 in the progression of tumor cells in vivo. We transplanted mouse T-cell lymphoma cell-line EG7-OVA artificially expressing CD39 or mock into mice subcutaneously. The coinjection of immunoadjuvant poly(I:C) significantly suppressed the tumor growth of mock cells, but the tumor sizes of CD39 expressing cells were almost the same as those of mock cells without poly(I:C) injection (Figure).Conclusion: In this study, we reported that most of ATLL cells in acute type patients express CD39+ CD26- just as Tregs, and that CD39- KO of ATLL cell line cancelled its immunosuppressive effects, and forcibly expressed CD39 on tumor cells rejected the anti-tumor immunity in vivo. From these data, we clarified the pathological mechanism of immunosuppressive function in ATLL cells, and also showed that CD39 expression could be used as a prognostic clue and be a new therapeutic target of ATLL. [Display omitted] DisclosuresEzoe:TAIHO Phamaceutical Co., Ltd.: Research Funding. Yokota:Celgene: Research Funding; Bristol-Myers Squibb: Research Funding; Pfizer Inc.: Research Funding; CHUGAI PHARMACEUTICAL CO., LTD.: Research Funding; MSD K.K.: Research Funding. Ichii:Novartis Pharma K.K.: Speakers Bureau; Kowa Pharmaceutical Co.,LTD.: Speakers Bureau; Celgene K.K.: Speakers Bureau. Shibayama:Novartis Pharma K.K.: Honoraria, Research Funding; Celgene K.K.: Honoraria, Research Funding; Takeda Pharmaceutical Co.,LTD.: Honoraria, Research Funding; Fujimoto Pharmaceutical: Honoraria, Research Funding; Jansen Pharmaceutical K.K: Honoraria; Ono Pharmaceutical Co.,LTD: Honoraria, Research Funding; Mundipharma K.K.: Honoraria, Research Funding; Bristol-Meyer Squibb K.K: Honoraria, Research Funding. Oritani:Novartis Pharma: Speakers Bureau. Kanakura:Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding.

Tax-Targeting Dendritic Cell Therapy for ATL: A Phase Ia/Ib Clinical Study

Background: Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive peripheral T-cell neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). Although most patients respond to initial therapy, relapse is inevitable and the overall prognosis is dismal. Therefore, we developed a novel immune therapy consisting of autologous dendritic cells (DC) pulsed with Tax peptides (ATL-DC-101) to prevent relapse. The used peptides are corresponding to the major epitopes of HTLV-1 Tax-specific cytotoxic T lymphocytes (CTLs) that potentially act as anti-ATL effectors. Mogamulizumab is an anti-CCR4 antibody, which binds to ATL cells and regulatory T cells. A preceding pilot study suggested the safety of ATL-DC-101 monotherapy, and then we conducted a phase Ia/Ib study to investigate safety and efficacy of ATL-DC-101 combined with mogamulizumab.Methods: ATL patients pretreated and stable for at least 4 weeks were enrolled. Peripheral blood mononuclear cells were obtained by apheresis and differentiated into DC, which was pulsed with Tax-peptides. The study consisted of 2 cohorts, i.e., Ia and Ib phase, in which patients were assigned ATL-DC-101 monotherapy and ATL-DC-101 combined with mogamulizumab, respectively. The protocol consisted of three subcutaneous injections of ATL-DC-101 at 2-week intervals. Mogamulizumab was administered once before ATL-DC-101 in Ib phase. The primary endpoint of the study was to evaluate safety and feasibility of ATL-DC-101. The secondary endpoints were anti-tumor effects, progression-free survival (PFS), overall survival (OS), and time to next treatment, estimated by Kaplan-Meier method. The safety and disease status were accessed at day 56 and followed until 2 years.Results: Six aggressive ATL patients who were in stable condition by previous therapies were enrolled in this study from 2015 to 2016. Frequent DC- related toxicities were mild injection site reaction (n=5, 83.3%), decreased WBC count (n=3, 50%), and liver damage (n=2, 33.3%), all of which were grade 1 or 2. Notably, 2 patients (1 in each cohort) with partial response (PR) after chemotherapy were converted into complete response (CR) after ATL-DC-101. The 2-year PFS and OS were both 83.3%. All three patients who received ATL-DC-101 monotherapy (Ia) maintained CR for more than two years. Although one patient in phase Ib developed progressive disease after one year, the other two patients remained in CR. Interestingly ATL cells in a relapsed case harbored deletion of Tax gene, which resulted in the loss of the target peptide presentation. After a median follow-up of 29 months, 5/6 patients are alive without any additional chemotherapy after ATL-DC-101.Conclusions: ATL-DC-101 was well tolerated and successfully maintained CR more than 2 years in 5/6 patients irrespective of additional mogamulizumab, indicating that this therapy could be a safe and effective long-lasting maintenance therapy even for elderly ATL patients. Currently, we are preparing Phase II trial to confirm anti-tumor effects of ATL-DC-101 monotherapy. DisclosuresShiratsuchi:Kyowa Hakko Kirin Co.Ltd: Research Funding; Chugai Pharmaceutical Co.Ltd: Research Funding; Daiichi Sankyo Co.Ltd: Research Funding. Fukuda:Chugai Pharmaceutical: Speakers Bureau. Ishida:Kyowa Hakko Kirin Co.Ltd: Honoraria, Research Funding; Celgene K.K: Honoraria, Research Funding; Bayer AG: Research Funding; Mundiparma K: Honoraria. Akashi:Ono Pharmaceutical: Research Funding; MSD: Research Funding; Taiho Pharmaceutical: Research Funding; sanofi: Research Funding; Celgene: Research Funding, Speakers Bureau; Eli Lilly Japan: Research Funding; Novartis pharma: Research Funding; Kyowa Hakko Kirin: Research Funding, Speakers Bureau; Bristol-Myers Squibb: Research Funding, Speakers Bureau; Otsuka Pharmaceutical: Research Funding; Eisai: Research Funding; Pfizer: Research Funding; Astellas Pharma: Research Funding; Asahi-kasei: Research Funding; Chugai Pharma: Research Funding. Matsuoka:Bristol Myers Squibb: Research Funding. Suehiro:Kyowa Hakko Kirin: Research Funding; Ono Pharmaceutical: Research Funding; Chugai Pharmaceutical: Research Funding; Takeda Pharmaceutical: Research Funding.

DA-Edoch Regimen As First-Line Treatment Could Significantly Improve the Early Efficacy of Adult T-Cell Leukemia/Lymphoma

OBJECTIVE: Adult T-cell leukemia/lymphoma (ATLL) is a rare and unique T cell malignancy with generally inferior clinical response to current chemotherapy and extremely poor prognosis. Optimizing chemotherapy is considered as the key to improve the efficacy. This study attempted to use DA-EDOCH regimen (etoposide, dexamethasone, vincristine, cyclophosphamide, doxorubicin) as the first-line chemotherapy regimen to treat ATLL patients. Efficacy and safety was evaluated and those curative impact factors were analyzed.METHODS: The ATLL patients, who visited Fujian Medical University Union Hospital and received at least one course of DA-EDOCH regimen from December 2014 to July 2018, were enrolled. The clinical characteristics, clinical response and adverse events were collected for analyzing the efficacy and safety of DA-EDOCH regimen.RESULTS: A total of 16 patients were enrolled, including 14 patients treated with DA-EDOCH regimen as first-line treatments and 2 patients as second-line treatments. The male-female ratio was 3:2 and the median age was 53 (28-65) years. There were 11 cases of acute type and 5 cases of lymphoma type. Of the 16 patients, 1 was unevaluable, and the remaining 15 patients were available for efficacy assessment. The objective response rate (ORR) was 86.7% (13/15), of which the complete remission (CR) rate was 40.0% (6/15) and the partial response rate (PR) was 46.7% (7/15), which was similar to the modified LSG(mLSG) regimen in Japan (CR rate is 40.0%). The median overall survival (OS) time of the 16 patients was 12.3 (0.9-43.4) months, and the 1-year OS rate and progression-free survival (PFS) rate were 53.8% and 47.1%, respectively; the 3-year OS and PFS was 44.9% and 37.7%, respectively, which produced preferable prognosis compared to the mLSG regimen (median survival time was 12.7 months and 3-years OS was 24.0%). It showed no statistically distinguished prognosis between lymphoma type and acute type (P=0.709), which the median OS time at 12.7 (0.9-40.3) months and 11.8 (1.2-43.4) months, respectively, and the 3-year OS at 60.0% and 40.4%, respectively. 4 of the 6 patients reaching CR underwent hematopoietic stem cell transplantation(HSCT). Three of them underwent allogeneic HSCT and were currently still alive with a median OS time of 43.0 (18.2-43.4) months. The rest 1 patient received autogenetic HSCT, but relapsed 1 month after the transplantation and died two months after recurrence. 9 of the 15 patients with ORR relapsed, with the recurrence rate of 60.0% (9/15). The recurrence may be related to the untimely treatment due to not following medical advice. During chemotherapy, grade 4 neutropenia, grade 4 thrombocytopenia, and grade 3 or 4 infection rates were 62.5% (10/16), 18.8% (3/16), and 75.0% (12/16), respectively. No serious liver, kidney or heart function damage happened while treatment and disease progression related death occurred in 2 patients.Conclusion: The DA-EDOCH regimen could improve the early efficacy of patients with ATLL. Further allogeneic hematopoietic stem cell transplantation after CR may bring better long-term outcomes to patients. DisclosuresNo relevant conflicts of interest to declare.

Aberrant Regional DNA Hypermethylation As a Preventive and Therapeutic Target for Adult T-Cell Leukemia-Lymphoma

Aberrant DNA methylation profiles in various types of cancer have highlighted the importance of DNA methylation in human carcinogenesis and opened the prospect of targeting aberrant DNA methylation with demethylating agents as a therapy for cancer. Adult T-cell leukemia-lymphoma (ATL) is an aggressive hematological malignancy derived from CD4 (+) T-cells transformed by human T-cell lymphotropic virus-1 (HTLV-1). Although it has been estimated that 20 million people are infected with HTLV-1 worldwide, most HTLV-1 infected individuals have no symptoms and only 3-7% of HTLV-1 positive carriers develop ATL in their life time. HTLV-1 infected cells undergo multistep leukemogenesis and there are four clinical subtypes of ATL, smoldering type, chronic type, acute type, and lymphoma type. It takes several decades to acquire aggressive phenotypes through the accumulation of genetic and epigenetic abnormalities. In this study, we aimed to elucidate the contribution of aberrant DNA methylation to ATL leukemogenesis and the anti-ATL effects of DNA demethylating agents.Since the expression profiles of CADM1 and CD7 in CD4 (+) T-cells reflect ATL disease progression, fractions of HTLV-1 infected cells and normal T-cells were isolated from ATL patients, HTLV-1 carriers, and healthy volunteers using the expression statuses of CADM1 and CD7. Comprehensive genome-wide profiling of DNA methylation was performed by quantitative array-based methylation analysis at the single-CpG-site level using the Infinium HumanMethylation450 BeadChip array. Anti-ATL effects of four DNA demethylating agents were investigated in in vitro experiments using ATL-related cell lines and a xenograft mouse model.Unsupervised hierarchical clustering analysis was first conducted using the DNA methylation profiles of 20,000 CpG probes, which were randomly picked from 470,870 probes. Global DNA hypomethylation was detected in HTLV-1 infected cells at the asymptomatic carrier stage. To identify differentially methylated positions (DMPs) that specifically reflect ATL disease status, the DNA methylation profiles of a normal cell subpopulation were compared with those of a HTLV-1 infected subpopulation. We identified 12,025 hypermethylated and 33,581 hypomethylated DMPs that were specific to the HTLV-1 infected subpopulation. Importantly, the methylation profiles of hypermethylated DMPs, but not those of hypomethylated DMPs, were different between the aggressive and indolent types of ATL and could be used to distinguish them. Therefore, we next extracted and analyzed 1,207 hypermethylated CpG sites located in TSS200 CpG islands (CGIs) in hypermethylated DMPs, since TSS200 CGIs are widely recognized to regulate gene expression in a methylation dependent manner. We found the DNA methylation profiles of 1,207 probes tended to correlate with ATL disease status.Since regional DNA hypermethylation appears to be associated with ATL disease progression, we tested the anti-leukemia activities of two novel decitabine prodrugs, OR-21 and OR-12, and compared their efficacies with those of clinically available AZA and DAC. OR-21 and OR-12 showed enhanced oral bioavailability and sustained release of decitabine and decitabine 5'-monophosphate, respectively. In ATL-related T-cell lines cultured in the presence of each DNA demethylating compound, DAC and OR-21 significantly suppressed cell growth and decreased DNA methylation at LINE-1 repeat regions, which are used as a biomarker for the monitoring of global changes in DNA methylation.To establish a xenograft mouse model, cells of the HTLV-1-transformed T-cell line, MT-2, were inoculated into the subcutaneous tissue of immunodeficient Balb/c Rag-2-/- Jak3-/- mice, which lack mature T and B lymphocytes and NK cells. A visible tumor appeared 10 days after inoculation and DAC or OR-21 was injected intraperitoneally twice a week, because they were rapidly degraded in the stomach acidic environment and could not be administered orally. The AUC-guided dosing of OR21 (3.39mg/kg) suppressed tumor growth, which was comparable with that obtained with 1.25 mg/kg DAC, while OR21 showed less hematotoxicity than DAC. DisclosuresWatanabe:OHARA Pharmaceutical Co., Ltd.: Research Funding. Ureshino:OHARA Pharmaceutical Co., Ltd.: Research Funding. Kurahashi:OHARA Pharmaceutical Co., Ltd.: Employment. Fukuda-Kurahashi:OHARA Pharmaceutical Co., Ltd.: Employment. Kimura:OHARA Pharmaceutical Co., Ltd.: Research Funding.

Differentiating Lung Involvement in Adult T-Cell Leukemia Lymphoma (ATLL) Versus HTLV Infection: Results from a Large Single-Center Cohort with Implications for Staging and Response Criteria

Introduction: Human T-cell lymphotropic virus (HTLV) is a retrovirus that has been associated with adult-T cell leukemia/lymphoma (ATLL) and other inflammatory conditions. Pulmonary involvement has not been widely associated to HTLV infection; however, high rates of imaging abnormalities in patients with and without ATLL have been reported. Okada reported 30%, 69% and 94% of abnormalities in HTLV1 carriers, ATLL and patients that transformed into ATLL. Whether these abnormalities follow a pattern related to each condition individually has not been defined. Hence, we undertook a retrospective study in ATLL and HTLV infected patients to determine the lung abnormalities which could be due to ATLL involvement rather than HTLV infection.Objectives: To compare the CT pulmonary findings among patients with HTLV infection with and without ATLL diagnosed at Montefiore Medical Center between 2004 and 2017.Methods: Patients diagnosed with HTLV infection by ICD9 were identified using the software Clinical Looking Glass and those with an available chest CT scan were selected. Data regarding demographics, smoking history, prior pulmonary conditions, HTLV and ATLL-associated characteristics was collected by chart review. CT chest was reviewed by an expert radiologist who was unaware of the patient diagnosis (ATLL versus non-ATLL) and findings were compared among groups. The staging CT scan was used to determine baseline pulmonary findings in patients with ATLL and the first CT chest around HTLV diagnosis was used for HTLV patients.Results: A total of 97 patients (72 with ATLL and 25 with HTLV alone) were identified. Mean age at HTLV diagnosis was 58.4 years (range: 33-88), 54.6% were females, 72.2% were Black Non-Hispanics while 27.8% were Hispanic. 88.3% were from Caribbean origin. Smoking history was similar between ATLL and non-ATLL groups (12% vs 8%, p=0.07) with no cases of prior active TB infection. Abnormal CT chest findings were present in 92.8%, 94.4% and 88% for the total cohort, ATLL and non-ATLL patients.Among patients with ATLL, 52.1% had acute and 43.7% had lymphomatous types; while only 1.4% and 2.8% had smoldering and chronic type. The most common CT chest findings were lymphadenopathy (50, 69.4%); followed by 3-10 mm nodules (32, 44.4%), ground-glass opacity, pleural effusion (31, 43.1% each), centrilobular nodules (28, 39.4%), thickening of interlobular septum (23, 31.9%) and bronchiectasis (18, 25%). Compared to the acute subtype, patients with lymphomatous subtype had higher rates of lymphadenopathy (83.9% vs 64.9, p=0.07) and lower rates of bronchiectasis (16.1% vs 35.1%, p=0.07).Among patients with non-ATLL, HTLV infection was diagnosed at an older age (63.8 vs. 56.6 years, p=0.03); HTLV-associated comorbidities were found in 16 cases (64%). Of these, myelopathy was the most frequent (10, 40%), followed by strongyloides (4, 16%). After HTLV diagnosis, CT chest was indicated in 28% patients for otherwise unexplained respiratory symptoms and to evaluate lung nodules or other chest X-ray abnormalities in 24% of cases. Bronchiectasis was the most common finding (12, 48%) followed by pleural thickening (11, 44%), ground-glass opacity and thickening of interlobular septum (10, 40%, each). Persistent abnormalities on follow-up imaging were present in 86.7% of the cases. Among patients with HTLV infection, those with ATLL were more likely to have nodules and lymphadenopathy (41.7% vs 20%, p=0.05 and 69.4% vs 24%, p<0.001, respectively) while bronchiectasis and pleural thickening was more likely in patients without ATLL (48% vs 25%, p=0.03 and 44% vs 23.6%, p=0.05; respectively).Conclusions: Pulmonary findings are highly prevalent in CT chest of patients with HTLV infection with and without ATLL. Bronchiectasis and pleural thickening was more frequently encountered in non-ATLL patients while lymphadenopathy and nodules were common finding in patients with ATLL. Pulmonary involvement in lymphoma is usually characterized by nodules and lymphadenopathy but patients with ATLL had a higher incidence of findings including ground glass opacities, bronchiectasis and interlobular septal thickening possibly due to their underlying HTLV infection. Based on this data, nodules and lymphadenopathy should be classified as ATLL involvement of the lung while other findings described here could be due to HTLV infection. These findings are important in staging and response criteria for ATLL. [Display omitted] DisclosuresJanakiram:Seatle Genetics: Membership on an entity's Board of Directors or advisory committees.

Absence of FLT3 mutations in Iranian adult T-cell leukemia/lymphoma patients.

Background: Adult T cell leukemia lymphoma (ATLL) is a rare disease, significantly linked to the infection by the human T-cell lymphotropic virus 1(HTLV-1). ATLL is typically preceded by decades of clinical latency during which infected cells accumulate selectable traits leading to a malignant transformation. Amongst all the HTLV-1 infected carriers only about 3-5% will develop ATLL. Despite the intensive attempt to improve the overall survival, ATLL remains one of worse prognosis among the hematologic malignancies. FMS like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations are mutations which are frequent among leukemic patients. We aimed to investigate the frequency of FLT3 mutation status in patients with acute type of ATLL which has not been studied yet. Methods: In this case control study 38 patients with acute type of ATLL were retrospectively analyzed between February 2015 and February 2017. Forty HTLV-1 positive patients were also used as control cases. Genomic DNA was extracted according to phenolchloroform protocol and two restriction fragment length polymorphism (RFLP) PCR reactions were set up to detect FLT3/ ITD and FLT3/TKD mutations. Differences between variables were evaluated by the chi-square test and t test for categorical and continuous variables, respectively. SPSS software v. 15 was used for statistical analysis. All P values were two sided and values less than 0.05 were considered to be significant. Results: No FLT3 mutations were detected in acute type of ATLL patients. So far, not many studies have shown the frequency of FLT3 mutation in ATLL patients Conclusion: Therefore, we conclude that although FLT3 mutations are rather unusual in the acute type of ATLL patients, but other alternative mechanisms associated with ATLL remain to be further investigated. This study was a novel project regarding the analysis of FLT3 mutation in the field of ATLL research.

Metabolic abnormalities in adult T-cell leukemia/lymphoma and induction of specific leukemic cell death using photodynamic therapy

Adult T-cell leukemia/lymphoma (ATL) is an aggressive T-cell neoplasm caused by human T-cell leukemia virus type I (HTLV-I). Therapeutic interventions have not been associated with satisfactory outcomes. We showed that the porphyrin metabolic pathway preferentially accumulates the endogenous photosensitive metabolite, protoporphyrin IX (PpIX) in ATL, after a short-term culture with 5-aminolevulinic acid (ALA). PpIX accumulated 10–100-fold more in ATL leukemic cells when compared to healthy peripheral blood mononuclear cells (PBMCs). Patient specimens showed dynamic changes in flow cytometry profiles during the onset and progression of ATL. Furthermore, 98.7% of ATL leukemic cell death in the ATL patient specimens could be induced with 10 min of visible light exposure, while 77.5% of normal PBMCs survived. Metabolomics analyses revealed that a specific stage of the metabolic pathway progressively deteriorated with HTLV-I infection and at the onset of ATL. Therefore, this method will be useful in diagnosing and identifying high-risk HTLV-I carriers with single cell resolutions. Photodynamic therapy in the circulatory system may be a potential treatment due to its highly-specific, non-invasive, safe, simultaneous, and repeatedly-treatable modalities.

Outcome of allogeneic hematopoietic cell transplantation in patients with adult T-cell leukemia.

Adult T‐cell leukemia/lymphoma (ATL) is an aggressive peripheral T‐cell neoplasm, and the outcome of patients with ATL after chemotherapy is poor. Allogeneic hematopoietic stem‐cell transplantation (allo‐HSCT) is a curative treatment modality for ATL, and four factors, namely, age > 50 years, male recipient, lack of complete remission at transplantation, and transplantation of cord blood, were previously shown to be associated with poor survival. We retrospectively analyzed the outcome of 21 patients with ATL who had undergone allo‐HSCT at our hospital during a 3‐year period. Of 21 patients, all had at least one of the above risk factors, and 18 had two or more. With a median follow‐up of 19.7 months for living patients, the 1‐ and 2‐year overall survival (OS) rates after transplantation were 34% and 27%, respectively. All relapse/progression events occurred within 1 year after allo‐HSCT, and the cumulative incidence of relapse/progression at 1 year after allo‐HSCT was 46.9%. The 100‐day and 1‐year nonrelapse mortality (NRM) rates were 19% and 42%, respectively. No significant difference in OS was observed between myeloablative and reduced‐intensity conditioning regimens. The 3‐year OS (27%) of ATL patients who received allo‐HSCT and who had at least one adverse factor was somewhat poorer than the 3‐year OS of 33% identified in a nationwide study of allo‐HSCT in ATL patients in Japan. The high relapse/progression and NRM rates are major problems to be solved to achieve better outcome.