Advanced Cutaneous T-cell Lymphoma Research Articles

013 - Antibiotics inhibit tumor and disease activity in cutaneous T cell lymphoma

It has been proposed that CD4 T-cell responses to Staphylococcus aureus (SA) can inadvertently enhance neoplastic progression in models of skin cancer and cutaneous T-cell lymphoma (CTCL). In this prospective study, we explored the effect of transient antibiotic treatment on tumor cells and disease activity in 8 patients with advanced-stage CTCL. All patients experienced significant decrease in clinical symptoms in response to aggressive, transient antibiotic treatment. In some patients, clinical improvements lasted for more than 8 months. In 6 of 8 patients, a malignant T-cell clone could be identified in lesional skin, and a significant decrease in the fraction of malignant T cells was observed following antibiotics but an otherwise unchanged treatment regimen. Immunohistochemistry, global messenger RNA expression, and cell-signaling pathway analysis indicated that transient aggressive antibiotic therapy was associated with decreased expression of interleukin-2 high-affinity receptors (CD25), STAT3 signaling, and cell proliferation in lesional skin. In conclusion, this study provides novel evidence suggesting that aggressive antibiotic treatment inhibits malignant T cells in lesional skin. Thus, we provide a novel rationale for treatment of SA in advanced CTCL.

031 - Single-cell lymphocyte heterogeneity in advanced cutaneous T-cell lymphoma

031 - Single-cell lymphocyte heterogeneity in advanced cutaneous T-cell lymphoma

Argx-110 for Treatment of CD70-Positive Advanced Cutaneous T-Cell Lymphoma in a Phase 1/2 Clinical Trial

Argx-110 for Treatment of CD70-Positive Advanced Cutaneous T-Cell Lymphoma in a Phase 1/2 Clinical Trial

Antibody-Based Therapies for Cutaneous T-Cell Lymphoma.

Cutaneous T-cell lymphomas (CTCLs) are a group of non-Hodgkin's lymphomas that present in the skin. In early-stage disease, the course is generally chronic and indolent; however, in advanced stages of disease, therapies rarely provide long-lasting responses, and the only potential curative therapy is allogeneic hematopoietic stem-cell transplantation. This has led to the search for novel targeted therapies to better treat more advanced stages of CTCLs that cannot be controlled by typical treatment regimens. One area of advancement has been the development of antibodies specifically targeted to cell types that are known to be involved in CTCL. At present, brentuximab vedotin, an antibody-drug conjugate composed of an anti-cluster of differentiation (CD)-30 antibody covalently linked to monomethyl auristatin E, is approved for the treatment of CD30+ lymphoproliferative disorders [lymphomatoid papulosis (LyP) and primary cutaneous-anaplastic large-cell lymphoma (pc-ALCL)] as well as transformed CD30+ mycosis fungoides (MF). Additionally, mogamulizumab, an anti-chemokine receptor 4 (CCR4) monoclonal antibody, is approved for patients with MF or Sézary syndrome (SS) for whom one prior systemic therapy has failed. Trials are underway looking into the use of immune checkpoint inhibitors in the treatment of CTCLs. As we continue to research CTCL, and as antibody-based therapies continue to advance, more antibody-specific targeted therapy could provide alternative treatment regimens for patients with advanced CTCL.

IL-10 is overexpressed in human cutaneous T-cell lymphoma and is required for maximal tumor growth in a mouse model

A crucial question pertains to a role of IL-10 as a tumorigenic factor, or just a marker of advanced disease in cutaneous T-cell lymphoma (CTCL). Herein, we measured significantly elevated IL-10 mRNA in a cohort of skin samples of patients with CTCL. Increased IL-10 was also detected in the tumor microenvironment of an established inflammation-dependent murine model of using MBL2 T lymphoma cells. Conditioned media from MBL2 cells was able to stimulate IL-10 production in bone marrow-derived macrophages in an IL-4-dependent manner. Implanted MBL2 T-cell lymphomas in IL-10KO mice were 50% smaller, accompanied by decreased numbers of infiltrating macrophages and reduced efficiency of M2-polarization compared with wild-type mice. With anti-IL-10R mAb treatment, both wild-type tumor-bearing mice and IL-10KO mice exhibited a further growth inhibition. Our data indicate that targeting IL-10 signaling with neutralizing antibodies to IL-10 or its receptor may have a great potential for advanced CTCL therapy.

PCN203 - HEALTHCARE RESOURCE USE IN PATIENTS WITH END-STAGE ADVANCED CUTANEOUS T-CELL LYMPHOMA (CTCL): RESULTS OF SEVEN SEMI-STRUCTURED INTERVIEWS ACROSS LEADING UK CENTRES

To estimate the healthcare resource use burden for patients with advanced stage cutaneous T-cell lymphoma (CTCL) who have exhausted all systemic treatment options, have progressed and whose symptoms are being managed until end of life in the UK. Semi-structured interviews were conducted with clinical experts from six of the seven supra-regional centres for CTCL in England and a leading Welsh centre between March 2018 and June 2018. Each respondent was responsible for end stage patient management within their catchment area. Interviews were guided by a questionnaire capturing resource use associated with pain, anxiety/depression, itch relief, pharmacological support, and skin care and wound management. The greatest burden was associated with dressings and wound care, which necessitated frequent and lengthy nurse visits (up to two hours) and constant therapies to control infection, pain and intractable pruritus. The questionnaire found that 100% of these patients needed expensive specialised dressings of which up to 20-25% required full-body coverage of dressings, with the remaining 75%-80% requiring localised coverage. Due to the frailty of skin, specialised (non-adhesive borders) dressings are needed, costing up to £63.64 per dressing. Multiple interventions were reported to be given in an attempt to alleviate the symptoms of pruritus, including anti-histamines and anti-epileptics/anti-depressants. In addition, patients are treated with oral opioids for background pain with episodes of breakthrough pain requiring subcutaneous injections of morphine on average reported monthly. The weekly cost of resource use for these patients was up to £2,095 per patient. A striking feature of end-stage management of CTCL compared to the management of other cancers at this stage is the frequency of visits and touch-points with multiple healthcare providers, all the way until death. This is likely due to the “double nature” of CTCL which requires both oncologic relief and extensive skin care, which requires daily attention and management.

PO-455 Epigenetic insights: resminostat regulates targets associated with the pathogenesis of cutaneous T cell lymphoma (CTCL)

IntroductionCutaneous T cell lymphoma (CTCL) is a heterogeneous group of extra-nodal non-Hodgkin lymphomas arising from transformation and clonal expansion of skin-homing T cells. Epigenetics alterations have been described for the molecular pathogenesis of CTCL. Resminostat is a potent, orally bioavailable histone deacetylase (HDAC) inhibitor targeting class I, IIb and IV and is currently in phase II of clinical development. Resminostat showed anti-tumoral in vitro efficacy by inhibiting proliferation of CTCL cell lines. The aim of this study was to elucidate resminostat’s molecular mechanism of action in CTCL using a genome-wide approach.Material and methodsResminostat’s mechanism of action was analysed using a set of established CTCL cell lines representing different types of CTCL. Global lysine acetylation was evaluated by flow cytometry and specific histone H3 acetylation at lysine residue 27 (H3K27ac) was mapped genome-widely by chromatin immunoprecipitation followed by sequencing (ChIP-seq). Resminostat’s effect on global gene expression was analysed by RNA-seq focusing on CTCL-relevant pathways and genes.Results and discussionsResminostat increased total lysine acetylation in CTCL cell lines. The active epigenetic mark H3K27ac dose-dependently accumulated on a genome-wide level as detected by ChIP-seq analysis. Global gene expression profiling revealed both gene induction and repression by resminostat. First data showed a regulation of T helper (Th) 1 and 2 specific genes implying that resminostat normalises the Th1/Th2 imbalance in CTCL which is discussed to be associated with disease progression. Moreover, expression of skin-homing receptor genes was reduced by resminostat indicating a potential effect of resminostat on the cutaneous tropism of malignant T cells. Furthermore, the pruritus mediator IL-31 was downregulated by resminostat suggesting an attenuation of itching and thus indicating an important benefit for CTCL patients regarding their health-related quality of life.ConclusionFirst results from a genome-wide study suggest a promising impact of resminostat on different targets relevant for the pathogenesis of CTCL. These data broaden our understanding of resminostat’s molecular mechanism of action in CTCL and support our current clinical phase II trial evaluating resminostat for maintenance treatment of patients with advanced stage CTCL (RESMAIN, NCT02953301).

'It's a traumatic illness, traumatic to witness': a qualitative study of the experiences of bereaved family caregivers of patients with cutaneous T-cell lymphoma.

Cutaneous T-cell lymphomas (CTCL) are rare cancers, which can be difficult to diagnose, are incurable and adversely affect quality of life, particularly in advanced disease. Families often provide care, but little is known about their experiences or needs while caring for their relative with advanced disease or in bereavement. To explore the experiences of bereaved family caregivers of patients with CTCL. Single, semi-structured qualitative interviews were conducted with bereaved family caregivers of patients with CTCL recruited via a supra-regional CTCL clinic. Transcribed interviews were analysed thematically, focusing on advanced disease, the approach of death and bereavement. Fifteen carers of 11 deceased patients participated. Experiences clustered under four themes: (1) complexity of care and medical intervention; (2) caregiver roles in advanced CTCL; (3) person-centred vs. organization-centred care in advanced CTCL and (4) knowing and not knowing: reflections on dying, death and bereavement. Caregivers often had vivid recollections of the challenges of caring for their relative with advanced CTCL and some took on quasi-professional roles as a result. Advanced disease made high demands on both organizational flexibility and family resources. For many caregivers, seeing disease progression was a prolonged and profoundly traumatic experience. The extent to which they were prepared for their relative's death and supported in bereavement was highly variable. Sub-themes within each theme provide more detail about caregiver experiences. Family caregivers should be considered part of the wider healthcare team, acknowledging their multiple roles and the challenges they encounter in looking after their relative with CTCL as the disease progresses. Their experiences highlight the importance of organizational flexibility and of good communication between healthcare providers in advanced CTCL.

Interleukin-25 is involved in cutaneous T-cell lymphoma progression by establishing a T helper 2-dominant microenvironment.

Interleukin (IL)-25 is a member of the IL-17 family, which can promote and augment T-helper (Th) type 2 responses. The expression of IL-25 and its cognate receptor, IL-25 receptor (IL-25R), is upregulated and correlated with disease activity in Th2-associated diseases. To examine the expression and function of IL-25 in cutaneous T-cell lymphoma (CTCL). Expression and location of IL-25 in lesional skin was investigated with immunohistochemistry. The effect of various cytokines on IL-25 production from normal human epidermal keratinocytes was assessed by quantitative reverse-transcription real-time polymerase chain reaction. Serum IL-25 levels were measured by enzyme-linked immunosorbent assay. The direct effect of IL-25 on tumour cells was also examined using CTCL cell lines and peripheral blood mononuclear cells in patients with Sézary syndrome. IL-25 expression was increased in epidermal keratinocytes in lesional skin of CTCL. Th2 cytokines, IL-4 and IL-13, and periostin induced IL-25 expression by normal human epidermal keratinocytes. Serum IL-25 levels were increased in patients with advanced CTCL and correlated with serum lactate dehydrogenase levels. MyLa cells expressed IL-25R and its expression was augmented by stimulation with IL-25. IL-25 enhanced IL-13 production from MyLa cells via phosphorylation of signal transducer and activator of transcription 6. Peripheral blood mononuclear cells from one patient with Sézary syndrome expressed IL-25R and showed increase of IL-13 production by IL-25. Th2 cytokines highly expressed in CTCL lesional skin induce IL-25 production by epidermal keratinocytes, which may, in turn, lead to formation of a Th2-dominant microenvironment through the direct induction of IL-13 by tumour cells.

Systemic Treatment Options for Advanced-Stage Mycosis Fungoides and Sézary Syndrome.

Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma. Globally, the most common subtypes of CTCL are mycosis fungoides and Sézary syndrome. CTCL can confer significant morbidity and even mortality in advanced disease. Here we review the current and potential future treatments for advanced-stage CTCL. Heterogeneity of treatment choice has been demonstrated both in US and non-US centers. Systemic treatment choice is currently guided by prognostic features, incorporating stage, immunophenotypic and molecular findings, and patient-specific factors such as age and comorbidities. Randomized controlled studies are uncommon, and the literature is composed predominantly of retrospective, cohort, and early-phase studies. International consensus guidelines are available; however, the lack of comparative trials means that there is no clear algorithmic approach to treatment. This review article reports on the systemic treatment options in current use for advanced CTCL, and on the possible future therapies, acknowledging that an algorithmic approach is not yet forthcoming to guide treatment prioritization.

Allogeneic hematopoietic stem cell transplantation in Primary Cutaneous T Cell Lymphoma.

In our retrospective study, 16 patients affected by advanced cutaneous T cell lymphoma (CTCL) underwent allogeneic hematopoietic stem cell transplantation (HSCT). Two patients (12.5%) were in complete remission (CR), nine (56.3%) in partial remission (PR), and five (31.2%) with active disease. The patients were transplanted from an HLA-identical (n = 7) from a mismatched (n = 1) or haploidentical (n = 1) sibling, from matched unrelated donor (n = 5), or from a single cord blood unit (n = 2). Conditioning regimen was standard myeloablative in 6 patients and at reduced intensity in 10. Seven patients died from non relapse mortality (NRM) and four patients relapsed or progressed, three of them achieved a second CR after donor lymphocyte infusion (DLI) or chemotherapy plus DLI. To date, with a median follow-up of 76months (range 6-130), nine patients are alive, eight in CR, and one with active disease. Overall survival (OS) and disease-free survival (DFS) at 1 and 10years are 61% (95% CI 40-91%) and 54% (95% CI 33-86%), 40% (95% CI 22-74%), and 34% (95% CI 16-68%), respectively. The time from diagnosis to transplant seems to influence negatively both OS (log-rank p < 0.04) and DFS (log-rank p < 0.05). Our results confirm on a long follow-up that CTCL appears particularly susceptible to the graft versus lymphoma (GVL) effect, so that allogeneic HSCT represents a possibility of cure for advanced CTCL. The timing of HSCT in the clinical course of disease remains an open issue.

An exploratory cost-effectiveness analysis of systemic treatments for cutaneous T-cell lymphoma

Purpose: To conduct an exploratory cost-effectiveness analysis of systemic treatment options for more advanced cutaneous T-cell lymphoma (CTCL).Methods: A cost-effectiveness model compared systemic bexarotene, denileukin diftitox, interferon-α, methotrexate, pralatrexate, romidepsin, vorinostat, and extracorporeal photopheresis (ECP) treatment of CTCL. Treatment effectiveness data were extracted from published studies and/or US product labeling. Overall response, the primary effectiveness measure, was defined as the proportion of patients achieving complete or partial response. Costs were based on wholesale acquisition cost (medications) and Medicare reimbursement rates (ECP, medication administration, adverse drug effect treatment). The perspective of the study was from that of a payer.Results: Methotrexate was the lowest cost option [mean $436; standard deviation (SD) $284], followed by interferon-α (mean $32,174; SD $27,582), denileukin difitox (mean $40,107; SD $18,598), and ECP (mean $40,985; SD $45,633). Other treatments had costs greater than $50,000, ranging from vorinostat ($65,958; SD $40,637) to bexarotene ($239,424; SD $178,881). The incremental cost-effectiveness ratio per successfully treated patient was $396,725 (interferon) and $213,416 (ECP). Denileukin diftitox, romidepsin, and vorinostat were less effective and cost more than methotrexate.Conclusion: Methotrexate is the most cost-effective option for CTCL; however, its low cost is offset by its limited effectiveness in advanced stages of CTCL. ECP and interferon appear the next most cost-effective therapies.

Histone Deacetylase Inhibitors Downregulate CCR4 Expression and Decrease Mogamulizumab Efficacy in CCR4-Positive Mature T-Cell Lymphomas

Background: Histone deacetylase inhibitors (HDACis) are promising agents for various T-cell lymphomas, including cutaneous T-cell lymphoma (CTCL), peripheral T-cell lymphoma (PTCL), and adult T-cell lymphoma/leukemia (ATLL). CCR4 is an important therapeutic target molecule because mogamulizumab, an anti-CCR4 antibody, has shown promising efficacy against CTCL, PTCL, and ATLL. However, their combined effects and interactions have not been examined thus far. We previously showed that CCR6, a chemokine receptor, is overexpressed in cutaneous T-cell lymphomas (Ito et al., 2014 Blood). Moreover, we recently demonstrated that HDACis downregulate CCR6 expression in advanced cutaneous T-cell lymphomas (Abe et al., 2017 Oncotarget). These reports lead us to hypothesize that HDACis might also downregulate CCR4 in various T-cell lymphomas. In this study, we clarify the effect of the combined use of mogamulizumab and HDACis on various T-cell and NK-cell lymphomas. Based on our findings, we discuss what benefits or adverse effects might be assumed for patients if these molecular targeting agents are used in clinical practice.Methods: We evaluated changes in CCR4 expression and antibody-dependent cell-mediated cytotoxicity (ADCC) activities against mogamulizumab- and HDACi-treated T-cell and NK-cell lymphoma lines and primary cases. To determine which HDAC mainly regulated CCR4 expression, we used isoform-specific HDACis and induced knockdown of respective HDACs for T-cell lymphoma cell lines. To examine the effect of CCR4 downregulation by HDACis in clinical cases, we examined the CCR4 expression of CTCL skin samples, which were obtained from the same patients before and after HDACi treatment (n = 6).Results: We first examined the expression of CCR4 for 15 T-cell and NK-cell lymphoma cell lines and a peripheral blood mononuclear cell (PBMC) sample derived from healthy donors to investigate the effect of vorinostat, a pan-HDACi, on CCR4 expression. The expression of CCR4 was mostly expressed in the (11 out of 15) cell lines: ATLL (MT-1, MT-2, MT-4, and TL-Su), CTCL (My-La, HH, and MJ), and NK/T-cell lymphoma cell lines (Kai3, SNK6, HANK1, and SNK10). We found that vorinostat decreases mRNA expression and surface expression of CCR4 except for the cell lines without CCR4 expression. Next, we used isoform-specific HDACis to examine which isoform of HDAC is involved in the regulation of CCR4. We used the following class-specific HDACis: romidepsin as a class I selective HDACi, CI-994 as an HDAC1/HDAC2-selective inhibitor, RGFP966 as an HDAC3-selective inhibitor, ricolinostat as an HDAC6-selective inhibitor, and PCI-34051 as an HDAC8-selective inhibitor. When these drugs were exposed to T-cell lymphoma cells, romidepsin and CI-994 strongly suppressed CCR4 expression. These results suggest that class I HDACs might controls CCR4 expression. We further performed knockdown experiments using siRNAs against HDAC1, HDAC2, and HDAC3. When we compared the expression change of CCR4 in HDAC-knockdown cells, HDAC2 knockdown cells showed the most significantly decreased expression of CCR4. These results suggest that class I HDACs, especially HDAC2, might be deeply involved in CCR4 expression regulation. When we examined the CCR4 expression in skin samples from primary CTCL, obtained from the same patients before and after vorinostat treatment, we found that CCR4 expression was greatly reduced after vorinostat treatment. Finally, when we conducted an ADCC assay with mogamulizumab by using various lymphoma cell lines and primary T-cell lymphoma samples, we found that the efficacy of mogamulizumab was significantly reduced by pre-treatment with vorinostat.Conclusion: Our results suggest that the primary use of HDACis before treatment of mogamulizumab might not be suitable to obtain synergistic effects. Moreover, these results provide potential implications for optimal therapeutic sequences in various CCR4 positive T-cell and NK-cell lymphomas. DisclosuresKitadate:Kyowa Kirin: Research Funding; Fujimoto: Research Funding; Eisai: Research Funding; Otsuka: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Asahi Kasei: Research Funding; Chugai: Research Funding; Toyama kagaku: Research Funding. Abe:Kyowa Kirin: Research Funding; Fujimoto: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Otsuka: Research Funding; Toyama Kagaku: Research Funding; Chugai: Research Funding; Asahi Kasei: Research Funding; Eisai: Research Funding. Tagawa:TaNeDS (Daiichi Sankyo): Research Funding.

Synergy of BCL2 and histone deacetylase inhibition against leukemic cells from cutaneous T-cell lymphoma patients

AbstractThe presence and degree of peripheral blood involvement in patients with cutaneous T-cell lymphoma (CTCL) portend a worse clinical outcome. Available systemic therapies for CTCL may variably decrease tumor burden and improve quality of life, but offer limited effects on survival; thus, novel approaches to the treatment of advanced stages of this non-Hodgkin lymphoma are clearly warranted. Mutational analyses of CTCL patient peripheral blood malignant cell samples suggested the antiapoptotic mediator B-cell lymphoma 2 (BCL2) as a potential therapeutic target. To test this, we developed a screening assay for evaluating the sensitivity of CTCL cells to targeted molecular agents, and compared a novel BCL2 inhibitor, venetoclax, alone and in combination with a histone deacetylase (HDAC) inhibitor, vorinostat or romidepsin. Peripheral blood CTCL malignant cells were isolated from 25 patients and exposed ex vivo to the 3 drugs alone and in combination, and comparisons were made to 4 CTCL cell lines (Hut78, Sez4, HH, MyLa). The majority of CTCL patient samples were sensitive to venetoclax, and BCL2 expression levels were negatively correlated (r = −0.52; P = .018) to 50% inhibitory concentration values. Furthermore, this anti-BCL2 effect was markedly potentiated by concurrent HDAC inhibition with 93% of samples treated with venetoclax and vorinostat and 73% of samples treated with venetoclax and romidepsin showing synergistic effects. These data strongly suggest that concurrent BCL2 and HDAC inhibition may offer synergy in the treatment of patients with advanced CTCL. By using combination therapies and correlating response to gene expression in this way, we hope to achieve more effective and personalized treatments for CTCL.

Frequency, cell lineage, and clinical correlates of lymphopenia in untreated T-cell lymphomas (TCL).

e19023 Background: Pre-treatment lymphopenia (Lp) independently predicts survival in TCL. However, lack of knowledge about the lineage of the decreased lymphocyte subset(s) prevents hypothesis formulation on pathophysiology of Lp and its effect on survival. Methods: We retrospectively identified 331 adult patients (pts) with biopsy-proven, newly diagnosed TCL between 2001-2016 at OSU. Pts had no prior chemotherapy or immunosuppressive treatment (tx). Clinical data including flow cytometry (FC) at diagnosis were abstracted from the EMR. Lp was defined as absolute lymphocyte count (ALC) &lt;1,000/µL. Cutaneous TCL (CTCL) stage was defined according to modified EORTC/ISLC criteria. Lymphocyte subsets were defined by FC and reported as proportions of ALC. We examined group differences with Fisher’s Exact or the Wilcoxon Rank Sum tests. Survival was analyzed using Cox regression models. Results: Of 331 pts with TCL, 102 were excluded due to prior tx or incomplete data. Of the 229 pts included, 67 had peripheral TCL (PTCL) and 162 had CTCL; 112 mycosis fungoides/sezary syndrome; 99 (61%) early stage (Stage IA-B), 22 (13%) advanced stage (Stage IIB-IVB), and 41 (26%) cutaneous CD30+ lymphoproliferative disorder (CD30+ LPD). Lp was present in 10% of CTCL, 8% in early stage, 22% in late stage, 12% of CD30+LPD, and 34% of PTCL, with overall frequency of 17%. After median follow up of 1,105 days, Lp was associated with worse progression-free survival (PFS) in CTCL pts with an unadjusted hazard ratio of 3.19 (p=0.19). Adjusting for stage and albumin level on multivariate analysis, Lp retained statistical significance for PFS (HR 3.46, p=.04). For the entire cohort, lymphopenia was associated with inferior OS (p=.0027). Analysis of lymphocyte subsets in late stage CTCL compared to early stage showed a significant decrease in B (CD19+) p=.014, NK (CD56+) p=.012, and CD8+ (p=.0045) cell populations. Conclusions: Lp was prevalent (10-34%) in our cohort of newly diagnosed TCL pts and was associated with worse OS. Lp was more prevalent and lymphocyte subsets were significant altered in pts with advanced stage CTCL. These findings will inform further investigations into mechanisms of Lp in TCL, and its potential as predictive biomarker.

Hematopoietic stem cell transplantation in advanced cutaneous T‐cell lymphoma

We retrospectively reviewed data pertaining to five patients with cutaneous T-cell lymphoma (CTCL) who had received hematopoietic stem cell transplantation (HSCT) between 2004 and 2015 at Kurume University Hospital, along with their clinical data until March 2016. For patients with advanced CTCL eligible for HSCT, autologous HSCT was performed when they responded well to chemotherapy, and allogeneic HSCT was selected for patients with advanced mycosis fungoides (MF)/Sézary syndrome (SS) and CTCL other than MF/SS with poor chemosensitivity. Two patients (primary cutaneous anaplastic large cell lymphoma and primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma) who responded well to chemotherapy received autologous HSCT: one patient was alive in partial remission and the other died due to therapy-related acute myeloid leukemia without disease relapse. In the remaining three patients with MF or SS, allogeneic HSCT was performed. Although one patient with MF died due to disease progression, the remaining two patients were alive in complete remission. Although there were two deaths in this study, the outcomes were considered satisfactory.

BCL11B-Mediated Epigenetic Repression Is a Crucial Target for Histone Deacetylase Inhibitors in Cutaneous T-Cell Lymphoma

The treatment options for advanced cutaneous T-cell lymphoma (CTCL) are limited because of its unclear pathogenesis. Histone deacetylase (HDAC) inhibitors (HDACis) are recently developed therapeutics approved for refractory CTCL. However, the response rate is relatively low and unpredictable. Previously, we discovered that BCL11B, a key T-cell development regulator, was aberrantly overexpressed in mycosis fungoides, the most common CTCL, as compared with benign inflammatory skin. In this study, we identified a positive correlation between BCL11B expression and sensitivity to HDACi in CTCL lines. BCL11B suppression in BCL11B-high cells induced cell apoptosis by de-repressing apoptotic pathways and showed synergistic effects with suberoylanilide hydroxamic acid (SAHA), a pan-HDACi. Next, we identified the physical interaction and shared downstream genes between BCL11B and HDAC1/2 in CTCL lines. This interaction was essential in the anti-apoptosis effect of BCL11B, and the synergism between BCL11B suppression and HDACi treatment. Further, in clinical samples from 46 mycosis fungoides patients, BCL11B showed increased but varied expression in advanced tumor stage. Analysis of four patients receiving SAHA treatment suggested a positive correlation between BCL11B expression and favorable response to SAHA treatment. In conclusion, BCL11B may serve as a therapeutic target and a useful marker for improving HDACi efficacy in advanced CTCL.

New Targeted Treatments for Cutaneous T-cell Lymphomas.

Cutaneous T-cell lymphomas (CTCLs) represent a group of rare and heterogeneous diseases that are very difficult to treat at advanced stages. The development of monoclonal antibodies is a new hope for the treatment of these diseases. Alemtuzumab (Campath) is a humanized IgG1 kappa monoclonal antibody specific for CD52, an antigen expressed by most T and B lymphocytes. Alemtuzumab may frequently induce long-term remissions in patients with Sezary syndrome but high-dose treatments lead to severe cytopenia, immune depletion, and opportunistic infections. This treatment is less efficient in mycosis fungoides (MF). Brentuximab vedotin is a chimeric anti-CD30 monoclonal antibody conjugated to monomethyl auristatin E, a cytotoxic antitubulin agent. Brentuximab vedotin is a very interesting new treatment for advanced tumor MF, Sezary syndrome, and primary cutaneous CD30+ lymphoproliferative disorders. The main limiting adverse event is neurosensitive peripheral neuropathy. Mogamulizumab is a humanized anti-C-C chemokine receptor Type 4 monoclonal antibody with a defucosylated Fc region leading to increased antibody-dependent cellular cytotoxicity. Mogamulizumab is very efficient on aggressive peripheral T-cell lymphomas, particularly adult T-cell leukemia/lymphoma and CTCLs, especially on the blood component of tumor cells. The main limiting events are related to the concomitant depletion of regulatory T-cells. IPH4102 is a humanized monoclonal antibody that targets the immune receptor KIR3DL2/CD158k. Preclinical results with this antibody offer proofs of concept for the clinical development of IPH4102 to treat patients with advanced CTCL.

Placental Growth Factor and Vascular Endothelial Growth Factor Together Regulate Tumour Progression via Increased Vasculature in Cutaneous T-cell Lymphoma.

Angiogenesis is regarded as an essential step in supporting tumour growth and metastasis. In haematological malignancies, including cutaneous T-cell lymphoma (CTCL), angiogenesis is increased and serum levels of some pro-angiogenic markers are elevated. The aim of this study was to investigate expression levels of placental growth factor (PlGF) and vascular endothelial growth factor (VEGF)-A in lesional skin and sera in patients with CTCL, and to assess the association of these factors with development of CTCL. A further aim was to investigate the effect of PlGF on lymphoma cell growth in vivo using a tumour inoculation model. Expression of PlGF and VEGF-A were significantly elevated in CTCL skin. Tumour cells expressed PlGF in some cases. Serum PlGF levels were increased in patients with advanced CTCL and correlated with disease markers. Moreover, PlGF enhanced lymphoma cell growth in vivo through increasing tumour vasculature. These findings suggest that angiogenesis plays a role in the progression of CTCL and raises the possibility of using inhibitors of PlGF in CTCL therapy.

Histone deacetylase inhibitors inhibit metastasis by restoring a tumor suppressive microRNA-150 in advanced cutaneous T-cell lymphoma.

Tumor suppressive microRNA (miR)-150 inhibits metastasis by combining with the C-C chemokine receptor 6 (CCR6) “seed sequence” mRNA of the 3′-untranslated region (3′-UTR) in advanced cutaneous T-cell lymphoma (CTCL). Because the histone deacetylase inhibitor (HDACI) vorinostat showed excellent outcomes for treating advanced CTCL, HDACIs may reduce the metastasis of CTCL by targeting miR-150 and/ or CCR6. To examine whether these candidate molecules are essential HDACI targets in advanced CTCL, we used the My-La, HH, and HUT78 CTCL cell lines for functional analysis because we previously demonstrated that their xenografts in NOD/Shi-scid IL-2γnul mice (CTCL mice) induced multiple metastases. We found that pan- HDACIs (vorinostat and panobinostat) inhibited the migration of CTCL cells and downregulated CCR6. The miRNA microarray analysis against CTCL cell lines demonstrated that these pan-HDACIs commonly upregulated 161 miRNAs, including 34 known tumor suppressive miRNAs such as miR-150. Although 35 miRNAs possessing the CCR6 “seed sequence” were included in these 161 miRNAs, miR-150 and miR-185-5p were downregulated in CTCL cells compared to in normal CD4+ T-cells. The transduction of 12 candidate miRNAs against CTCL cells revealed that miR-150 most efficiently inhibited their migration capabilities and downregulated CCR6. Quantitative reverse transcriptase-polymerase chain reaction demonstrated that miR-150 was downregulated in advanced but not early CTCL primary cases. Finally, we injected miR-150 or siCCR6 into CTCL mice and found that mouse survival was significantly prolonged. These results indicate that miR-150 and its target, CCR6, are essential therapeutic targets of pan-HDACIs in advanced CTCL with metastatic potential.