XPO1 blockade with KPT-330 promotes apoptosis in cutaneous T-cell lymphoma by activating the p53-p21 and p27 pathways

Dysregulated nuclear-cytoplasmic trafficking has been shown to play a role in oncogenesis in several types of solid tumors and hematological malignancies. Exportin 1 (XPO1) is responsible for the nuclear export of several proteins and RNA species, mainly tumor suppressors. KPT-330, a small molecule inhibitor of XPO1, is approved for treating relapsed multiple myeloma and diffuse large B-cell lymphoma. Cutaneous T-cell lymphoma (CTCL) is an extranodal non-Hodgkin lymphoma with an adverse prognosis and limited treatment options in advanced stages. The effect of therapeutically targeting XPO1 with KPT-330 in CTCL has not been established. We report that XPO1 expression is upregulated in CTCL cells. KPT-330 reduces cell proliferation, induces G1 cell cycle arrest and apoptosis. RNA-sequencing was used to explore the underlying mechanisms. Genes associated with the cell cycle and the p53 pathway were significantly enriched with KPT-330 treatment. KPT-330 suppressed XPO1 expression, upregulated p53, p21WAF1/Cip1, and p27Kip1 and their nuclear localization, and downregulated anti-apoptotic protein (Survivin). The in vivo efficacy of KPT-330 was investigated using a bioluminescent xenograft mouse model of CTCL. KPT-330 blocked tumor growth and prolonged survival (p < 0.0002) compared to controls. These findings support investigating the use of KPT-330 and next-generation XPO1 inhibitors in CTCL.

Modulation of the skin microbiome in cutaneous T-cell lymphoma delays tumour growth and increases survival in the murine EL4 model

Cutaneous T-cell lymphomas (CTCL) are a group of lymphoproliferative disorders of skin-homing T cells causing chronic inflammation. These disorders cause impairment of the immune environment, which leads to severe infections and/or sepsis due to dysbiosis. In this study, we elucidated the host-microbial interaction in CTCL that occurs during the phototherapeutic treatment regime and determined whether modulation of the skin microbiota could beneficially affect the course of CTCL. EL4 T-cell lymphoma cells were intradermally grafted on the back of C57BL/6 mice. Animals were treated with conventional therapeutics such as psoralen + UVA (PUVA) or UVB in the presence or absence of topical antibiotic treatment (neomycin, bacitracin, and polymyxin B sulphate) as an adjuvant. Microbial colonisation of the skin was assessed to correlate with disease severity and tumour growth. Triple antibiotic treatment significantly delayed tumour occurrence (p = 0.026), which prolonged the survival of the mice (p = 0.033). Allocation to phototherapeutic agents PUVA, UVB, or none of these, along with antibiotic intervention, reduced the tumour growth significantly (p = 0.0327, p ≤ 0.0001, p ≤ 0.0001 respectively). The beta diversity indices calculated using the Bray-Curtis model showed that the microbial population significantly differed after antibiotic treatment (p = 0.001). Upon modulating the skin microbiome by antibiotic treatment, we saw an increase in commensal Clostridium species, e.g., Lachnospiraceae sp. (p = 0.0008), Ruminococcaceae sp. (p = 0.0001)., Blautia sp. (p = 0.007) and a significant reduction in facultative pathogens Corynebacterium sp. (p = 0.0009), Pelomonas sp. (p = 0.0306), Streptococcus sp. (p ≥ 0.0001), Pseudomonas sp. (p = 0.0358), and Cutibacterium sp. (p = 0.0237). Intriguingly, we observed a significant decrease in Staphylococcus aureus frequency (p = 0.0001) but an increase in the overall detection frequency of the Staphylococcus genus, indicating that antibiotic treatment helped regain the microbial balance and increased the number of non-pathogenic Staphylococcus populations. These study findings show that modulating microbiota by topical antibiotic treatment helps to restore microbial balance by diminishing the numbers of pathogenic microbes, which, in turn, reduces chronic inflammation, delays tumour growth, and increases survival rates in our CTCL model. These findings support the rationale to modulate the microbial milieu during the disease course of CTCL and indicate its therapeutic potential.

Adrenal Insufficiency after Long-term use of Topical Glucocorticoids in Patients with Advanced Cutaneous T-cell Lymphomas: A Case Series

Abstract is missing (Short communication)

Changes to Registered and Pivotal Clinical Trials after the 2011 Tri-Societies Guidelines for Clinical Endpoints and Response Criteria in Mycosis Fungoides and Sézary Syndrome

Guidelines for mycosis fungoides and Sézary syndrome clinical trials were published in 2011 to standardize endpoint criteria and trial design. Our retrospective cohort study of mycosis fungoides/Sézary syndrome clinical trials registered on ClinicalTrials.gov and pivotal trials supporting drug approvals and label extensions evaluates adherence to these guidelines. Sixty-three trials met our inclusion criteria. In a subpopulation of trials, mean adherence to the guidelines was approximately 60%. When comparing trials that began in the first 6 years after their publication with those that started after, we found no difference in mean adherence (4.12 vs 3.41) (P = .15). Among the 8 pivotal trials supporting new mycosis fungoides or Sézary syndrome systemic therapies from 1990 to 2020, systemic trials published after 2011 were more likely to randomize patients (100 vs 0%, P = .036), perform superiority testing (100 vs 0%, P = .036), and use an intention-to-treat analysis (100 vs 0%, P = .036). The design of trials registered on Clinicaltrials.gov did not change significantly between the first 6 years after the publication of the guidelines and after. This demonstrates that the guidelines are still not consistently implemented across all trials. However, registrational trials were more likely to implement the recommendations.

The Role of Cytokines in Cutaneous T Cell Lymphoma: A Focus on the State of the Art and Possible Therapeutic Targets

Cutaneous T cell lymphomas (CTCLs), encompassing mycosis fungoides (MF) and Sézary syndrome (SS), present a complex landscape influenced by cytokines and cellular responses. In this work, the intricate relationship between these inflammatory proteins and disease pathogenesis is examined, focusing on what is known at the clinical and therapeutic levels regarding the most well-known inflammatory mediators. An in-depth look is given to their possible alterations caused by novel immunomodulatory drugs and how they may alter disease progression. From this narrative review of the actual scientific landscape, Interferon-gamma (IFN-γ) emerges as a central player, demonstrating a dual role in both promoting and inhibiting cancer immunity, but the work navigates through all the major interleukins known in inflammatory environments. Immunotherapeutic perspectives are elucidated, highlighting the crucial role of the cutaneous microenvironment in shaping dysfunctional cell trafficking, antitumor immunity, and angiogenesis in MF, showcasing advancements in understanding and targeting the immune phenotype in CTCL. In summary, this manuscript aims to comprehensively explore the multifaceted aspects of CTCL, from the immunopathogenesis and cytokine dynamics centred around TNF-α and IFN-γ to evolving therapeutic modalities. Including all the major known and studied cytokines in this analysis broadens our understanding of the intricate interplay influencing CTCL, paving the way for improved management of this complex lymphoma.

GATA-3-dependent Gene Transcription is Impaired upon HDAC Inhibition

PURPOSE

Many peripheral and cutaneous T-cell lymphoma (CTCL) subtypes are poorly responsive to conventional chemotherapeutic agents and associated with dismal outcomes. The zinc finger transcription factor GATA-3 and the transcriptional program it instigates are oncogenic and highly expressed in various T-cell neoplasms. Posttranslational acetylation regulates GATA-3 DNA binding and target gene expression. Given the widespread use of histone deacetylase inhibitors (HDACi) in relapsed/refractory CTCL, we sought to examine the extent to which these agents attenuate the transcriptional landscape in these lymphomas.

EXPERIMENTAL DESIGN

Integrated GATA-3 chromatin immunoprecipitation sequencing and RNA sequencing analyses were performed in complementary cell line models and primary CTCL specimens treated with clinically available HDACi.

RESULTS

We observed that exposure to clinically available HDACi led to significant transcriptional reprogramming and increased GATA-3 acetylation. HDACi-dependent GATA-3 acetylation significantly impaired both its ability to bind DNA and transcriptionally regulate its target genes, thus leading to significant transcriptional reprogramming in HDACi-treated CTCL.

CONCLUSIONS

Beyond shedding new light on the mechanism of action associated with HDACi in CTCL, these findings have significant implications for their use, both as single agents and in combination with other novel agents, in GATA-3-driven lymphoproliferative neoplasms.

Efficacy of single-agent chemotherapy with pegylated liposomal doxorubicin or gemcitabine in a diverse cohort of patients with recalcitrant cutaneous T-cell lymphoma

There is a need for updated studies regarding the efficacy of single-agent chemotherapy for Black patients with cutaneous T-cell lymphoma. This study evaluates outcomes of single-agent chemotherapy for cutaneous T-cell lymphoma in a large and diverse cohort of patients. Both gemcitabine and pegylated liposomal doxorubicin had promising response rates and time to next treatment, including in Black patients with recalcitrant cutaneous T-cell lymphoma.

Clinical and Real-World Effectiveness of Mogamulizumab: A Narrative Review

Mogamulizumab (MOG) is an antibody targeting the CCR4 receptor, authorized for relapsed or refractory peripheral T-cell (PTCL) and cutaneous T-cell lymphomas (CTCL). Its adoption in guidelines and endorsement by FDA and EMA established it as a systemic treatment, especially for advanced disease stages due to its comparatively lower toxicity. Clinical trials and real-world evidence have underscored its efficacy in advanced CTCLs, including mycosis fungoides and Sézary syndrome; PTCLs; and adult T-cell leukemia/lymphoma (ATLL), showcasing positive outcomes. Notably, the drug has demonstrated significant response rates, disease stability, and extended periods of progression-free survival, suggesting its applicability in cases with multiple treatment lines. Its safety profile is generally manageable, with adverse events (AEs) primarily related to the skin, infusion-related reactions, drug eruptions, autoimmune diseases, and skin disorders. The latter seem to appear as CCR4 can promote the skin-specific homing of lymphocytes, and MOG is directed against this receptor. While combination with immunostimulatory agents like interferon alpha and interleukin 12 has shown promising results, caution is urged when combining with PD1 inhibitors due to the heightened risk of immune-mediated AEs. The introduction of MOG as a systemic treatment implies a significant advancement in managing these diseases, supported by its favorable safety profile and complementary mechanisms.

What's New in Cutaneous T-Cell Lymphoma-Associated Pruritus

Cutaneous T-cell lymphomas are a heterogenous group of lymphomas that cause various skin manifestations. Severe pruritus occurs frequently in cutaneous T-cell lymphoma and negatively impacts patients' quality of life. The pathophysiology of cutaneous T-cell lymphoma-associated itch is complex and involves various immune cells, inflammatory cytokines, and neuroimmune interactions. Treating cutaneous T-cell lymphoma pruritus can be challenging, and there have been few randomized controlled studies evaluating the use of antipruritic treatments in these patients. Systemic therapies targeting the disease have also been shown to have some antipruritic effects. Furthermore, although biologic therapy has revolutionized the treatment of other pruritic skin conditions, the use of biologics in cutaneous T-cell lymphoma remains controversial.

An update on mechanisms of pruritus and their potential treatment in primary cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas (CTCL), which include mycosis fungoides (MF) and Sézary syndrome (SS), are a group of lymphoproliferative disorders characterized by clonal accumulation of neoplastic T-lymphocytes in the skin. Severe pruritus, one of the most common and distressing symptoms in primary CTCL, can significantly impair emotional well-being, physical functioning, and interpersonal relationships, thus greatly reducing quality of life. Unfortunately, effectively managing pruritus remains challenging in CTCL patients as the underlying mechanisms are, as of yet, not fully understood. Previous studies investigating the mechanisms of itch in CTCL have identified several mediators and their corresponding antagonists used for treatment. However, a comprehensive overview of the mediators and receptors contributing to pruritus in primary CTCL is lacking in the current literature. Here, we summarize and review the mediators and receptors that may contribute to pruritus in primary CTCL to explore the mechanisms of CTCL pruritus and identify effective therapeutic targets using the PubMed and Web of Science databases. Studies were included if they described itch mediators and receptors in MF and SS. Overall, the available data suggest that proteases (mainly tryptase), and neuropeptides (particularly Substance P) may be of greatest interest. At the receptor level, cytokine receptors, MRGPRs, and TRP channels are most likely important. Future drug development efforts should concentrate on targeting these mediators and receptors for the treatment of CTCL pruritus.

Embelin inhibits viability of cutaneous T cell lymphoma cell lines HuT78 and H9 by targeting inhibitors of apoptosis

Cutaneous T cell lymphoma (CTCL) is a varied group of neoplasms that affects the skin. Acquired resistance against chemotherapeutic drugs and associated toxic side effects are limitations that warrant search for novel drugs against CTCL. Embelin (EMB) is a naturally occurring benzoquinone derivative that has gained attention owing to its anticancer pharmacological actions and nontoxic nature. We assessed the anticancer activity of EMB against CTCL cell lines, HuT78, and H9. EMB inhibited viability of CTCL cells in a dose-dependent manner. EMB activated extrinsic and intrinsic pathways of apoptosis as shown by the activation of initiator and executioner caspases. EMB-induced apoptosis also involved suppression of inhibitors of apoptosis, XIAP, cIAP1, and cIAP2. PARP cleavage and upregulation of pH2AX indicated DNA damage induced by EMB. In conclusion, we characterized a novel apoptosis-inducing activity of EMB against CTCL cells, implicating EMB as a potential therapeutic agent against CTCL.

A Case Series on the Use of Brentuximab Vedotin for the Treatment of Mycosis Fungoides

BACKGROUND

Brentuximab vedotin (BV) is an anti-CD30 monoclonal antibody that appears to be more effective against CD30-expressing cutaneous T-cell lymphoma (CTCL) compared to current standard-of-care treatments.   Objective: To determine the real-world efficacy and adverse effects of BV use in patients with mycosis fungoides (MF) who were treated with BV at Atrium Health Wake Forest Baptist Medical Center.

METHODS

Study staff performed a retrospective chart review of patients diagnosed with MF who were prescribed BV at Atrium Health Wake Forest Baptist Comprehensive Cancer Center.

RESULTS

  Regardless of their response to BV, all patients in our cohort had higher CD30 positivity on subsequent biopsies compared to their initial skin biopsy.  Conclusions: Improved understanding of appropriate CD30 testing and evaluation will allow for quicker invention of patients with BV responsive CTCL.  J Drugs Dermatol. 2023;22(12):e33-e34.    doi:10.36849/JDD.6981e.

EORTC consensus recommendations for the treatment of mycosis fungoides/Sézary syndrome - Update 2023

On behalf of the EORTC Cutaneous Lymphoma Tumours Group (EORTC-CLTG) and following up on earlier versions published in 2006 and 2017 this document provides an updated standard for the treatment of mycosis fungoides and Sézary syndrome (MF/SS). It considers recent relevant publications and treatment options introduced into clinical practice after 2017. Consensus was established among the authors through a series of consecutive consultations in writing and a round of discussion. Treatment options are assigned to each disease stage and, whenever possible and clinically useful, separated into first- and second line options annotated with levels of evidence. Major changes to the previous version include the incorporation of chlormethine, brentuximab vedotin, and mogamulizumab, recommendations on the use of pegylated interferon α (after withdrawal of recombinant unpegylated interferons), and the addition of paragraphs on supportive therapy and on the care of older patients. Still, skin-directed therapies are the most appropriate option for early-stage MF and most patients have a normal life expectancy but may suffer morbidity and impaired quality of life. In advanced disease treatment options have expanded recently. Most patients receive multiple consecutive therapies with treatments often having a relatively short duration of response. For those patients prognosis is still poor and only for a highly selected subset long term remission can be achieved with allogeneic stem cell transplantation. Understanding of the disease, its epidemiology and clinical course, and its most appropriate management are gradually advancing, and there is well-founded hope that this will lead to further improvements in the care of patients with MF/SS.

In vitro evaluation of Neosetophomone B inducing apoptosis in cutaneous T cell lymphoma by targeting the FOXM1 signaling pathway

BACKGROUND

Cutaneous T cell lymphoma (CTCL) is a T cell-derived non-Hodgkin lymphoma primarily affecting the skin, with treatment posing a significant challenge and low survival rates.

OBJECTIVE

In this study, we investigated the anti-cancer potential of Neosetophomone B (NSP-B), a fungal-derived secondary metabolite, on CTCL cell lines H9 and HH.

METHODS

Cell viability was measured using Cell counting Kit-8 (CCK8) assays. Apoptosis was measured by annexin V/PI dual staining. Immunoblotting was performed to examine the expression of proteins. Applied Biosystems' high-resolution Human Transcriptome Array 2.0 was used to examine gene expression.

RESULTS

NSP-B induced apoptosis in CTCL cells by activating mitochondrial signaling pathways and caspases. We observed downregulated expression of BUB1B, Aurora Kinases A and B, cyclin-dependent kinases (CDKs) 4 and 6, and polo-like kinase 1 (PLK1) in NSP-B treated cells, which was further corroborated by Western blot analysis. Notably, higher expression levels of these genes showed reduced overall and progression-free survival in the CTCL patient cohort. FOXM1 and BUB1B expression exhibited a dose-dependent reduction in NSP-B-treated CTCL cells.FOXM1 silencing decreased cell viability and increased apoptosis via BUB1B downregulation. Moreover, NSP-B suppressed FOXM1-regulated genes, such as Aurora Kinases A and B, CDKs 4 and 6, and PLK1. The combined treatment of Bortezomib and NSP-B showed greater efficacy in reducing CTCL cell viability and promoting apoptosis compared to either treatment alone.

CONCLUSION

Our findings suggest that targeting the FOXM1 pathway may provide a promising therapeutic strategy for CTCL management, with NSP-B offering significant potential as a novel treatment option.

Use of Pegylated Interferon Alpha-2a in Cutaneous T-cell Lymphoma: A Retrospective Case Collection

Mycosis fungoides and Sézary syndrome are rare and largely incurable types of cutaneous T-cell lymphoma with limited therapeutic options. In 1984 Bunn et al. reported that interferon alpha is an efficient monotherapy in cutaneous T-cell lymphoma and 14 years later it was shown in a prospective, randomized trial that a combination of interferon alpha and psoralen plus ultraviolet A therapy (PUVA) is most efficient in the treatment of cutaneous T-cell lymphoma. Since then interferon alpha as single agent or, most often, in combination with phototherapy and/or retinoids has been integrated as standard of care in cutaneous T-cell lymphoma guidelines worldwide. However, production of interferon alpha was discontinued recently worldwide and pegylated interferon alpha-2a (PEG-IFNα) has been used as an alternative therapy. In contrast to numerous interferon alpha studies, only a few studies focusing on PEG-IFNα are available. Therefore, the aim of this study was to conduct a retrospective data collection to report on the efficacy, adverse events and therapy regimens of PEG-IFNα in cutaneous T-cell lymphoma. In 28 patients with cutaneous T-cell lymphoma treated in Germany and in the Netherlands, 36% of patients achieved complete remission, 36% partial remission and 29% stable disease. Eighteen percent of patients developed adverse events during therapy, which led to the discontinuation of PEG-IFNα therapy in 2 patients. The most common concomittant therapies were oral PUVA phototherapy and local radiotherapy. In conclusion, PEG-IFNα, especially in combination with skin-directed therapies, is an effective treatment option for cutaneous T-cell lymphoma in clinical practice.

Overall survival in the UK in mycosis fungoides or Sézary syndrome cutaneous T-cell lymphoma: comparative effectiveness of mogamulizumab versus current standard of care

Aim: Due to extensive treatment switching in the MAVORIC trial, lack of UK regulatory licence for the comparator, overall survival (OS) with mogamulizumab was compared with patients with previously treated advanced mycosis fungoides/Sézary syndrome (MF/SS) in real-world setting. Design, setting & participants: Data were from the Hospital Episode Statistics database (all patients in NHS secondary care system in 2009-2019). Patients were selected according to trial inclusion criteria, then trial and HES samples were matched on selected variables with significant imbalance. Outcomes: The analysis indicated significant improvement in OS for mogamulizumab treatment compared with UK clinical practice (hazard ratio: 0.36, 95% CI: 0.24, 0.53). Conclusion: Results suggest an OS advantage for patients with advanced MF/SS treated with mogamulizumab in MAVORIC trial compared with UK clinical practice.

Clinical efficacy of recombinant canine interferon-gamma therapy in dogs with cutaneous epitheliotropic T-cell lymphoma

BACKGROUND

The antitumour effects of interferon-gamma (IFN-γ) in humans with cutaneous epitheliotropic T-cell lymphoma (CETCL) have been described; however, the efficacy of IFN-γ in dogs has not been investigated.

HYPOTHESIS/OBJECTIVES

The aim of this study was to evaluate the efficacy of recombinant canine IFN-γ (rCaIFN-γ) therapy in dogs with CETCL.

ANIMALS

Twenty dogs with CETCL recruited from seven veterinary clinics were enrolled in the study.

MATERIALS AND METHODS

Fifteen dogs were treated with rCaIFN-γ, and five control dogs were treated with prednisolone. We evaluated survival time, skin lesions (erythema, nodules, ulcers and bleeding), pruritus and general condition (sleep, appetite and body weight). In the rCaIFN-γ group, a questionnaire regarding the therapy was administered to owners after the dogs died.

RESULTS

No significant differences existed in the median survival time between the rCaIFN-γ and control groups (log-rank test: p = 0.2761, Wilcoxon's rank sum test: p = 0.4444). However, there were significant differences in ulcer, bleeding, pruritus, sleep, appetite and body weight between the groups (Wilcoxon-Mann-Whitney U-test: p = 0.0023, p = 0.0058, p = 0.0005, p = 0.0191, p = 0.0306 and p = 0.0306, respectively). Two (40%) of five dogs were euthanised in the control group, compared with none in the rCaIFN-γ group. Fourteen questionnaires were collected, and owners reported that they were satisfied with the rCaIFN-γ treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Although the median survival time was not prolonged, rCaIFN-γ could be helpful in maintaining good quality of life for dogs with CETCL.

Endolysin Inhibits Skin Colonization by Patient-Derived Staphylococcus Aureus and Malignant T-Cell Activation in Cutaneous T-Cell Lymphoma

Staphylococcus aureus is suspected to fuel disease activity in cutaneous T-cell lymphomas. In this study, we investigate the effect of a recombinant, antibacterial protein, endolysin (XZ.700), on S. aureus skin colonization and malignant T-cell activation. We show that endolysin strongly inhibits the proliferation of S. aureus isolated from cutaneous T-cell lymphoma skin and significantly decreases S. aureus bacterial cell counts in a dose-dependent manner. Likewise, ex vivo colonization of both healthy and lesional skin by S. aureus is profoundly inhibited by endolysin. Moreover, endolysin inhibits the patient-derived S. aureus induction of IFNγ and the IFNγ-inducible chemokine CXCL10 in healthy skin. Whereas patient-derived S. aureus stimulates activation and proliferation of malignant T cells in vitro through an indirect mechanism involving nonmalignant T cells, endolysin strongly inhibits the effects of S. aureus on activation (reduced CD25 and signal transducer and activator of transcription 5 phosphorylation) and proliferation (reduced Ki-67) of malignant T cells and cell lines in the presence of nonmalignant T cells. Taken together, we provide evidence that endolysin XZ.700 inhibits skin colonization, chemokine expression, and proliferation of pathogenic S. aureus and blocks their potential tumor-promoting effects on malignant T cells.

Dimethyl fumarate treatment in relapsed and refractory cutaneous T-cell lymphoma: a multicenter phase 2 study

Targeted therapies for cutaneous T-cell lymphoma (CTCL) are limited and curative approaches are lacking. Furthermore, relapses and drug induced side effects are major challenges in the therapeutic management of patients with CTCL, creating an urgent need for new and effective therapies. Pathologic constitutive NF-κB activity leads to apoptosis resistance in CTCL cells and, thus, represents a promising therapeutic target in CTCL. In a preclinical study we showed the potential of dimethyl fumarate (DMF) to block NF-κB and, specifically, kill CTCL cells. To translate these findings to applications in a clinical setting, we performed a multicentric phase 2 study evaluating oral DMF therapy in 25 patients with CTCL stages Ib to IV over 24 weeks (EudraCT number 2014-000924-11/NCT number NCT02546440). End points were safety and efficacy. We evaluated skin involvement (using a modified severity weighted assessment tool [mSWAT]), pruritus, quality of life, and blood involvement, if applicable, as well as translational data. Upon skin analysis, 7 of 23 (30.4%) patients showed a response with >50% reduction in the mSWAT score. Patients with high tumor burden in the skin and blood responded best to DMF therapy. Although not generally significant, DMF also improved pruritus in several patients. Response in the blood was mixed, but we confirmed the NF-κB-inhibiting mechanism of DMF in the blood. The overall tolerability of the DMF therapy was very favorable, with mostly mild side effects. In conclusion, our study presents DMF as an effective and excellently tolerable therapeutic option in CTCL to be further evaluated in a phase 3 study or real-life patient care as well as in combination therapies. This trial was registered at www.clinicaltrials.gov as #NCT02546440.

Treating relapsed/refractory mature T- and NK-cell neoplasms with tislelizumab: a multicenter open-label phase 2 study

Patients with relapsed/refractory (R/R) mature T- and natural killer (NK)-cell neoplasms lack effective treatments after failure of standard therapies. This phase 2 study evaluated the efficacy and safety of the programmed cell death protein 1 inhibitor tislelizumab in these patients. Seventy-seven patients were treated with 200 mg tislelizumab every 3 weeks. Twenty-two patients with extranodal NK-/T-cell lymphomas were enrolled in cohort 1; 44 patients with peripheral T-cell lymphoma (PTCL) were enrolled in cohort 2 (21 patients had PTCL not otherwise specified, 11 patients had angioimmunoblastic T-cell lymphoma, and 12 patients had anaplastic large-cell lymphoma). Cohort 3 comprised 11 patients with cutaneous T-cell lymphoma, of which 8 patients had mycosis fungoides (MF) and 3 had Sézary syndrome. Of the 77 patients, 76.6% had advanced-stage disease, 51.9% had refractory disease, and 49.4% received ≥3 prior systemic regimens. Promising efficacy was observed in cohort 3 (median follow-up [FU], 16.6 months; overall response rate [ORR], 45.5%; complete response [CR], 9.1%; median duration of response [DOR], 11.3 months; median progression-free survival, 16.8 months; median overall survival, not reached). Modest efficacy was observed in cohort 1 (median FU, 8.4 months; ORR, 31.8%; CR, 18.2%; median DOR, not reached) and cohort 2 (median FU, 9.3 months; ORR, 20.5%; CR, 9.1%; median DOR, 8.2 months). Most treatment-related adverse events were grade 1 or 2, and the safety profile was consistent with the known safety profile of tislelizumab. In conclusion, tislelizumab was well tolerated, achieving modest efficacy in R/R mature T- and NK-cell neoplasms, with some long-lasting remissions. This trial was registered at www.clinicaltrials.gov as #NCT03493451.

Brentuximab-vedotin in combination with cyclophosphamide, doxorubicin, prednisolone for the treatment of aggressive CD30-positive cutaneous T-cell lymphomas

Aggressive CD30-positive cutaneous T-cell lymphomas (CD30+CTCL) are associated with unfavorable prognosis. Anthracycline-based polychemotherapy (CHOP) and brentuximab-vedotin (BV) monotherapy are related to poor outcomes in case of extracutaneous involvement or rapidly-progressing disease. Our objective was to assess the effectiveness of BV + CHP in aggressive CD30+CTCL. We included 7 patients treated with BV + CHP from April 2015 to January 2022: 4 had mycosis fungoides with large-cell transformation, 2 had primary cutaneous anaplastic large-cell lymphoma, and 1 harbored a primary cutaneous aggressive epidermotropic CD8-positive T-cell lymphoma. After a median [IQR] follow-up of 17.2 [13.2-21.0] months, 6/7 patients achieved an ORR lasting ≥4 months. The median [IQR] duration of response was 9.5 [5.9-11.1] months and the median [IQR] progression free survival was 14.9 [11.6-16.4] months. Four patients displayed progression with a median (range) time to next treatment of 15.8 (6.5-16.3) months. Two grade-3 adverse events were reported: febrile neutropenia and thromboembolic event. BV + CHP displayed substantial antitumor activity and favorable safety profile in 7 patients with aggressive CD30+CTCL.

Cost-utility analysis of mogamulizumab in advanced mycosis fungoides and Sézary syndrome cutaneous T-cell lymphoma

Aim: This study assessed the cost-utility of mogamulizumab, a novel monoclonal antibody, versus established clinical management (ECM) in UK patients in previously treated advanced mycosis fungoides (MF)/Sézary syndrome (SS). Materials & methods: Lifetime partitioned survival model based on overall survival, next treatment-free survival and the use of allogeneic stem cell transplant was developed. Inputs were from the pivotal MAVORIC trial, real-world evidence and published literature. Extensive sensitivity analyses were conducted. Results: Discounted incremental quality-adjusted life years (QALYs), costs and incremental cost-effectiveness ratio were 3.08, £86,998 and £28,233. Results were most sensitive to the survival extrapolations, utilities and costs after loss of disease control. Conclusion: Mogamulizumab is a cost-effective alternative to ECM in UK patients with previously treated advanced MF/SS.

Cost-Effectiveness of Brentuximab Vedotin Versus Physician's Choice of Methotrexate or Bexarotene for the Treatment of Cutaneous T-cell Lymphoma in Canada

INTRODUCTION

Brentuximab vedotin versus physician's choice of methotrexate (MTX) or bexarotene (BEX) significantly improved progression-free survival (PFS) (median PFS, 16.7 vs. 3.5 months) and delayed time to subsequent treatment (8.4 vs. 3.7 months), with similar overall survival in patients with CD30-expressing mycosis fungoides (MF) or primary cutaneous anaplastic large cell lymphoma (pcALCL), two types of cutaneous T-cell lymphomas. We assessed the cost-effectiveness of brentuximab vedotin versus MTX or BEX from a Canadian healthcare payer perspective in the indicated population.

METHODS

A 5-state partitioned survival model [pre-progression, non-stem cell transplant (SCT) post-progression, SCT, SCT relapse, death] with a weekly cycle length and 45-year lifetime horizon has been developed. Health-state occupancies, utility estimates, and treatment duration were informed by ALCANZA. Other inputs and costs came from the literature or clinician experts. Scenario analyses varied key parameters and tested assumptions.

RESULTS

Brentuximab vedotin versus MTX or BEX was cost-effective; the incremental cost-effectiveness ratio was CAN$43,790 per quality-adjusted life year (QALY) gained. Brentuximab vedotin was more effective (incremental life years: 0.15; QALYs: 0.25) and total treatment costs were slightly higher (incremental costs: $11,105) than MTX or BEX. Key model drivers included end-stage care duration, SCT eligibility, and brentuximab vedotin retreatment rates.

CONCLUSION

Brentuximab vedotin compared with MTX or BEX was cost-effective for CD30-expressing MF and pcALCL. Brentuximab vedotin's higher drug costs versus MTX or BEX were offset by decreased post-progression and end-stage management costs, and showed a 0.25 QALY gain versus MTX or BEX, and increased the proportion of patients eligible for potentially curative SCT.

Single-cell RNA sequencing unveils the communications between malignant T and myeloid cells contributing to tumor growth and immunosuppression in cutaneous T-cell lymphoma

Cutaneous T cell lymphoma (CTCL) is characterized by the accumulation of malignant T cells in the skin. However, advanced CTCL pathophysiology remains elusive and therapeutic options are limited due to the high intratumoral heterogeneity and complicated tumor microenvironment (TME). By comparing the single-cell RNA-seq (scRNA-seq) data from advanced CTCL patients and healthy controls (HCs), we showed that CTCL had a higher enrichment of T/NK and myeloid cells. Subpopulations of T cells (CXCR3+, GNLY+, CREM+, and MKI67+ T cells), with high proliferation, stemness, and copy number variation (CNV) levels, contribute to the malignancy of CTCL. Besides, CCL13+ monocytes/macrophages and LAMP3+ cDC cells were enriched and mediated the immunosuppression via inhibitory interactions with malignant T cells, such as CD47-SIRPA, MIF-CD74, and CCR1-CCL18. Notably, elevated expressions of S100A9 and its receptor TLR4, as well as the activation of downstream toll-like receptor and NF-κB pathway were observed in both malignant cells and myeloid cells in CTCL. Cell co-culture experiments further confirmed that the interaction between malignant CTCL cells and macrophages contributed to tumor growth via S100A9 upregulation and NF-kb activation. Our results showed that blocking the S100A9-TLR4 interaction using tasquinimod could inactivate the NF-κB pathway and inhibit the growth of CTCL tumor cells, and trigger cell apoptosis. Collectively, our study revealed a landscape of immunosuppressive TME mediated by interactions between malignant T cells and myeloid cells, and provided novel targets and potential treatment strategies for advanced CTCL patients.

Advanced stage cutaneous T-cell lymphoma treated with high-dose external beam radiation therapy: A case report

INTRODUCTION

The treatment for advanced-stage or refractory cutaneous T-cell lymphoma (CTCL) is largely palliative. Due to the rarity of the disease, there are few randomized controlled trials and large-scale prospective studies. Therefore, the treatment of advanced-stage CTCL remains challenging.

PATIENT CONCERNS AND DIAGNOSIS

A 64-years-old man who had received narrowband UVB phototherapy for several years presented with a generalized rash with widespread polycyclic erosions and painful ulcers on his hands and feet. We restaged him as stage III CTCL.

INTERVENTIONS AND OUTCOMES

He was treated with high-dose radiation for curative purposes and 3-dimensional conformal radiation therapy to both hands and feet. At the 2-year follow-up after the end of radiotherapy, the irradiated skin had recovered to normal soft, smooth skin with localized fibrosis and hypopigmented skin. He reported an excellent quality of life, and his hands and feet were free to move.

CONCLUSION

CTCL at an advanced stage could require dose escalation with local radiotherapy for curative purposes. High-dose 3-dementional conformal radiation therapy could be effective and has tolerable toxicities.

Blocking STAT3/5 through direct or upstream kinase targeting in leukemic cutaneous T-cell lymphoma

Leukemic cutaneous T-cell lymphomas (L-CTCL) are lymphoproliferative disorders of skin-homing mature T-cells causing severe symptoms and high mortality through chronic inflammation, tissue destruction, and serious infections. Despite numerous genomic sequencing efforts, recurrent driver mutations have not been identified, but chromosomal losses and gains are frequent and dominant. We integrated genomic landscape analyses with innovative pharmacologic interference studies to identify key vulnerable nodes in L-CTCL. We detected copy number gains of loci containing the STAT3/5 oncogenes in 74% (n = 17/23) of L-CTCL, which correlated with the increased clonal T-cell count in the blood. Dual inhibition of STAT3/5 using small-molecule degraders and multi-kinase blockers abolished L-CTCL cell growth in vitro and ex vivo, whereby PAK kinase inhibition was specifically selective for L-CTCL patient cells carrying STAT3/5 gains. Importantly, the PAK inhibitor FRAx597 demonstrated encouraging anti-leukemic activity in vivo by inhibiting tumor growth and disease dissemination in intradermally xenografted mice. We conclude that STAT3/5 and PAK kinase interaction represents a new therapeutic node to be further explored in L-CTCL.

"Knock Me Out": The Challenges of Managing Pain Due to Cutaneous T Cell Lymphomas: A Case Report

Cutaneous T cell lymphomas are associated with distressing symptoms, including pain and pruritus that negatively impact quality of life. Early involvement of palliative care can provide relief of symptoms and address multifaceted distress. This case highlights the complex management of cutaneous T cell lymphoma pain and associated symptoms, including existential and psychosocial distress. Our patient required frequent titration and rotation of high-dose opioids and adjuvant analgesics, ultimately requiring transfer to the intensive care unit for analgosedation. Total skin loss and disease complications led to his death after a compassionate withdrawal of life support. Cutaneous T cell lymphoma pain can be successfully managed with an interdisciplinary approach, early palliative care, and aggressive pain management. Complications from advanced disease, superinfection, and multidimensional distress complicate the efficacy of a multimodal analgesic approach. Further research is needed to deepen our understanding of how to optimally alleviate suffering within this vulnerable population.

Mogamulizumab and bexarotene are a promising association for the treatment of advanced cutaneous T-cell lymphomas: a case series

BACKGROUND

Treatment choices for patients with advanced-stage mycosis fungoides (MF) or Sézary syndrome (SS) who have failed first-line systemic therapies can be challenging, as several options are available. However, most evidence is based on observational and early phase studies due to the rarity of the disease. Mogamulizumab has recently been approved for the treatment of adult patients with MF or SS who have received at least one prior systemic therapy; it has a good tolerability profile prompting its use in combination with other agents. This article aims at describing the role of the concomitant use of bexarotene with mogamulizumab in this setting.

CASES PRESENTATION

To add information in the field, we describe our experience with four patients with MF/SS who failed first- and second-line treatments and started the combination mogamulizumab in addition to bexarotene. The combination of bexarotene with mogamulizumab in patients with advanced MF/SS after the failure of bexarotene alone obtained a response in all the four patients observed. The response was maintained longer than expected.

CONCLUSIONS

The combination is promising and deserves further study.

CD20-positive subcutaneous panniculitis-like T-cell lymphoma presenting as polycranial neuropathy: A CARE-compliant case report and literature review

BACKGROUND

Subcutaneous panniculitis-like T-cell lymphoma(SPTCL) is a very rare cytotoxic T-cell skin lymphoma involving subcutaneous tissue, and mainly affects young females. T-cell phenotype is characterized by CD3+, CD8+, and CD4-. SPTCT with polycranial neuropathy has rarely been described. SPTCL is believed to show an indolent clinical course unless patients develop haemophagocytic syndrome or sudden respiratory failure. Its treatment has not been established yet.

CASE PRESENTATION

We report a case of intractable SPTCT in a 66-year-old woman with multiple cranial nerve palsies and diabetes. She showed involvement of the bilateral facial nerve, left trigeminal nerve, left auditory nerve, and right oculomotor nerve. The single inconspicuous skin lesion in the trunk presented with an erythematous nodule with a diameter of <5 cm and a slightly pink infiltrated plaque. Electromyography revealed bilateral damage to the facial nerve. Differential immunohistochemical characteristics were observed. Immunohistochemistry demonstrated diffuse CD20 positivity. Cerebral spinal fluid analysis revealed elevated protein levels of 0.92 (0.15-0.45) g/L. Her condition regressed severely over time. She was treated with chemotherapy but died 10 months later, the probable cause of death was lung involvement.

CONCLUSION

The patient's involvement with the central nervous system may be associated with positivity for CD20. Molecular biomarkers may act as therapeutic targets for SPTCL.

Extracorporeal Photopheresis and Its Use in Clinical Dermatology in Canada

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy that has been used for over 35 years to treat numerous conditions. ECP was initially approved by the US FDA in 1988 for the treatment of Sézary syndrome, a leukemic form of cutaneous T-cell lymphoma (CTCL). Although CTCL remains the only FDA-approved indication, ECP has since been used off-label for numerous other conditions, including graft-versus-host disease (GvHD), systemic sclerosis, autoimmune bullous dermatoses, Crohn's disease, and prevention of solid organ transplant rejection. In Canada, ECP is mainly used to treat CTCL, acute and chronic GvHD, and in some instances systemic sclerosis. Herein, we review the current concepts regarding ECP mechanism of action, treatment considerations and protocols, and efficacy.

Efficacy and Safety of Topical Hypericin Photodynamic Therapy for Early-Stage Cutaneous T-Cell Lymphoma (Mycosis Fungoides): The FLASH Phase 3 Randomized Clinical Trial

Importance

Given that mycosis fungoides-cutaneous T-cell lymphoma (MF/CTCL) is chronic, there is a need for additional therapies with minimal short- and long-term adverse effects. Topical synthetic hypericin ointment, 0.25%, activated with visible light is a novel, nonmutagenic photodynamic therapy (PDT).

Objectives

To determine the efficacy and safety of topical synthetic hypericin ointment, 0.25%, activated with visible light as a nonmutagenic PDT in early-stage MF/CTCL.

Design, Settings, and Participants

This was a multicenter, placebo-controlled, double-blinded, phase 3 randomized clinical trial (FLASH study) conducted from December 2015 to November 2020 at 39 academic and community-based US medical centers. Participants were adults (≥18 years) with early-stage (IA-IIA) MF/CTCL.

Interventions

In cycle 1, patients were randomized 2:1 to receive hypericin or placebo to 3 index lesions twice weekly for 6 weeks. In cycle 2, all patients received the active drug for 6 weeks to index lesions. In cycle 3 (optional), both index and additional lesions received active drug for 6 weeks.

Main Outcomes and Measures

The primary end point was index lesion response rate (ILRR), defined as 50% or greater improvement in modified Composite Assessment of Index Lesion Severity (mCAILS) score from baseline after 6 weeks of therapy for cycle 1. For cycles 2 and 3, open label response rates were secondary end points. Adverse events (AEs) were assessed at each treatment visit, after each cycle, and then monthly for 6 months. Data analyses were performed on December 21, 2020.

Results

The study population comprised 169 patients (mean [SD] age, 58.4 [16.0] years; 96 [57.8%] men; 120 [72.3%] White individuals) with early-stage MF/CTCL. After 6 weeks of treatment, hypericin PDT was more effective than placebo (cycle 1 ILRR, 16% vs 4%; P = .04). The ILRR increased to 40% in patients who received 2 cycles of hypericin PDT (P < .001 vs cycle 1 hypericin) and to 49% after 3 cycles (P < .001 vs cycle 1 hypericin). Significant clinical responses were observed in both patch and plaque type lesions and were similar regardless of age, sex, race, stage IA vs IB, time since diagnosis, and number of prior therapies. The most common treatment-related AEs were mild local skin (13.5%-17.3% across cycles 1-3 vs 10.5% for placebo in cycle 1) and application-site reactions (3.2%-6.9% across cycles 1-3 vs 4% for placebo in cycle 1). No drug-related serious AEs occurred.

Conclusion and Relevance

The findings of this randomized clinical trial indicate that synthetic hypericin PDT is effective in early-stage patch and plaque MF/CTCL and has a favorable safety profile.

Trial Registration

ClinicalTrials.gov Identifier: NCT02448381.

Chlormethine Gel for Patients with Mycosis Fungoides Cutaneous T Cell Lymphoma: A Review of Efficacy and Safety in Clinical Trial and Real-World Settings

Mycosis fungoides (MF) is a rare disease and is the most common form of cutaneous T cell lymphoma. Topical chlormethine (CL) gel is the first cytotoxic chemotherapy gel that was specifically developed for treatment of MF. In this review, we provide an overview of all available data on the use of CL gel for treatment of patients with MF. On the basis of the current data collected, CL gel is highly effective, with good response rates observed both in clinical trial and real-world settings. While the gel is approved for monotherapy, it is also used in combination with concomitant skin-directed or systemic therapies in clinical practice. Responses to CL gel treatment can be rapid, but they also frequently occur with a delayed onset of up to 6 months. This indicates that continued treatment with CL gel is important. CL gel has a manageable safety profile, with most adverse events being mild and skin related. Contact dermatitis is one of the more common skin-related adverse events to occur with CL gel treatment that can potentially lead to treatment discontinuation. The data from the literature indicate that patients being treated with CL gel should be monitored carefully, and that dermatitis must be managed effectively to allow patients to continue treatment and achieve the best possible response to treatment.

Genomic and Single-Cell Landscape Reveals Novel Drivers and Therapeutic Vulnerabilities of Transformed Cutaneous T-cell Lymphoma

ABSTRACT

Cutaneous T-cell lymphoma (CTCL) is a rare cancer of skin-homing T cells. A subgroup of patients develops large cell transformation with rapid progression to an aggressive lymphoma. Here, we investigated the transformed CTCL (tCTCL) tumor ecosystem using integrative multiomics spanning whole-exome sequencing (WES), single-cell RNA sequencing, and immune profiling in a unique cohort of 56 patients. WES of 70 skin biopsies showed high tumor mutation burden, UV signatures that are prognostic for survival, exome-based driver events, and most recurrently mutated pathways in tCTCL. Single-cell profiling of 16 tCTCL skin biopsies identified a core oncogenic program with metabolic reprogramming toward oxidative phosphorylation (OXPHOS), cellular plasticity, upregulation of MYC and E2F activities, and downregulation of MHC I suggestive of immune escape. Pharmacologic perturbation using OXPHOS and MYC inhibitors demonstrated potent antitumor activities, whereas immune profiling provided in situ evidence of intercellular communications between malignant T cells expressing macrophage migration inhibitory factor and macrophages and B cells expressing CD74.

SIGNIFICANCE

Our study contributes a key resource to the community with the largest collection of tCTCL biopsies that are difficult to obtain. The multiomics data herein provide the first comprehensive compendium of genomic alterations in tCTCL and identify potential prognostic signatures and novel therapeutic targets for an incurable T-cell lymphoma. This article is highlighted in the In This Issue feature, p. 1171.

Downregulation of miR-26 promotes invasion and metastasis via targeting interleukin-22 in cutaneous T-cell lymphoma

It has been reported that certain microRNAs (miRNA) are associated with the pathogenesis of lymphoma. We have previously demonstrated that histone deacetylase inhibitors restore tumor-suppressive miRNAs, such as miR-16, miR-29, miR-150, and miR-26, in advanced cutaneous T-cell lymphoma (CTCL). Among these, the function of miR-26 remains unclear. In this study, we aimed to reveal the function of miR-26 in CTCL oncogenesis. First, we confirmed that the miR-26 family was markedly dysregulated in CTCL cell lines and primary samples. In vivo analysis using miR-26a-transduced CTCL cells injected into immunodeficient NOG mice demonstrated the significant prolonged survival of the mice, suggesting that the miRNA had a tumor-suppressive function. We performed gene expression assays and identified 12 candidate miR-26 targets, namely RGS13, FAM71F1, OAF, SNX21, CDH2, PTPLB, IL22, DNAJB5, CASZ1, CACNA1C, MYH10, and CNR1. Among these, IL22 was the most likely candidate target because the IL-22-STAT3-CCL20-CCR6 cascade is associated with tumor invasion and metastasis of advanced CTCL. In vitro analysis of IL22 and IL22RA knockdown and miR-26 transduction demonstrated inhibited CTCL cell migration. In particular, IL22 knockdown induced cell apoptosis. Finally, we conducted in vivo inoculation analysis of mice injected with shIL22-transfected CTCL cells, and found no tumor invasion or metastasis in the inoculated mice, although the control mice showed multiple tumor invasions and metastases. These results, along with our previous data, demonstrated that miR-26 is a tumor suppressor that is associated with tumor invasion and the metastasis of advanced CTCL by regulating the IL-22-STAT3-CCL20 cascade. Therefore, a IL-22-targeting therapy could be a novel therapeutic strategy for advanced CTCL.

Epigenetics of Cutaneous T-Cell Lymphomas

Epigenetic modifications rarely occur in isolation (as single “epigenetic modifications”). They usually appear together and form a network to control the epigenetic system. Cutaneous malignancies are usually affected by epigenetic changes. However, there is limited knowledge regarding the epigenetic changes associated with cutaneous lymphomas. In this review, we focused on cutaneous T-cell lymphomas such as mycosis fungoides, Sézary syndrome, and anaplastic large cell lymphoma. With regard to epigenetic changes, we summarize the detailed chemical modifications categorized into DNA methylation and histone acetylation and methylation. We also summarize the epigenetic modifications and characteristics of the drug for cutaneous T-cell lymphoma (CTCL). Furthermore, we discuss current research on epigenetic-targeted therapy against cutaneous T-cell lymphomas. Although the current method of treatment with histone deacetylase inhibitors does not exhibit sufficient therapeutic benefits in all cases of CTCL, epigenetic-targeted combination therapy might overcome this limitation for patients with CTCL.

Survival and Prognostic Factors in Patients with Aggressive Cutaneous T-cell Lymphomas

Aggressive primary cutaneous T-cell lymphomas include advanced-stage mycosis fungoides (stage ≥ IIB mycosis fungoides), Sézary syndrome, gamma/delta cutaneous lymphoma, nasal type lymphoma, aggressive epidermotropic CD8+ T-cell lymphoma and some cutaneous lymphomas not otherwise specified. To evaluate their long-term prognosis, we conducted a retrospective cohort study of 85 patients diagnosed between 2005 and 2020 with advanced-stage mycosis fungoides (n = 48), Sézary syndrome (n = 28) or aggressive non-mycosis fungoides/Sézary syndrome subtypes (n = 9). The median survival times in these 3 groups were 118.7, 45.7 and 11.2 months, respectively, and the 5-year survival rates were 55.3%, 27.8% and 33.3%, respectively. Multivariate analyses in patients with mycosis fungoides/Sézary syndrome identified age ≥ 70 years, Eastern Cooperative Oncology Group Performance Status ≥ 2, and the high-risk group according to the Cutaneous Lymphoma International Consortium prognostic model, as adverse prognostic factors. Seven patients in this mycosis fungoides/Sézary syndrome group were in complete long-term remission after treatment with bexarotene, including 4 patients living without any treatment for 16–101 months.

Bexarotene-induced central hypothyroidism assessed by TRH stimulation test in cutaneous T-cell lymphoma patients

Bexarotene-induced central hypothyroidism (CH), for which levothyroxine (LT4) replacement is recommended, has been shown to be caused by pituitary but not hypothalamic disorder experimentally, though the underlying mechanism in humans remains unclear. Here, the pathophysiology of bexarotene-induced CH was examined using a TRH stimulation test in cutaneous T-cell lymphoma (CTCL) patients. In this retrospective longitudinal observational study, serum TSH and free T4 (F-T4) levels were measured in 10 euthyroid patients with CTCL during 24 weeks of bexarotene treatment. TRH stimulation testing was performed following CH diagnosis, with LT4 replacement dosage adjusted to maintain F-T4 at the pre-treatment level. After one week of bexarotene administration, all 10 patients developed CH, based on combined findings of low or low-normal F-T4 with low or normal TSH levels. TSH peak response after a stimulation test at one week was reached at 30 minutes. However, that was <4 μIU/mL in all patients, indicating a blunted though not exaggerated and delayed TSH response. In eight who continued bexarotene for 24 weeks, median LT4 replacement dosage was 125 (range, 75-150) μg/day. TSH level at 30 as well as 15, 60, 90, and 120 minutes after TRH stimulation was significantly correlated with LT4 replacement dosage (ρ = -0.913, p = 0.002), whereas TSH and F-T4 basal levels at one week were not. These results suggest that pituitary hypothyroidism is responsible for bexarotene-induced CH, while TSH levels after TRH stimulation precisely reflect residual pituitary-thyroid function in patients receiving bexarotene.

[Preclinical and clinical researches of Denileukin Diftitox (Genetical Recombination) (Remitoro®), a novel agent for T-cell lymphoma]

Denileukin Diftitox (DD) is a recombinant fusion protein of diphtheria toxin (DT) fragments and human interleukin-2 (IL-2). DD binds to IL-2 receptor (IL-2R) expressed on tumor cells and is taken up into the cells. Subsequently, DT fragments with adenosine diphosphate ribosylation enzyme inhibit protein synthesis, then ultimately trigger cell death. DD binds to both high- and intermediate-affinity IL-2Rs via IL-2 domain and inhibits growth of human T-cell lymphomas cell lines. E7777, which contains DD as an active component, has improved purity and an increased percentage of active monomer compared with the approved drug E7272 (ONTAK in the US, not approved in Japan). In the phase I clinical study in Japanese patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL), the maximum tolerated dose and recommended dose of E7777 were 9 μg/kg/day (administered on Days 1-5 of each cycle) based on the evaluation of dose-limiting toxicity. In the phase II clinical study, the objective response rate was 36.1%, showing comparable efficacy to existing therapies. E7777 showed anti-tumor activity observed across the range of CD25 expression. Grade 3 or higher adverse events (AE) occurred in 94.6%, and serious AE such as capillary leak syndrome and rhabdomyolysis were reported. Therefore, safety monitoring activities have been continued along with alerting related events. Based on these results, E7777 obtained a new drug approval in Japan in March 2021 for the indication of relapsed or refractory PTCL/CTCL.

Functional Depletion of HSP72 by siRNA and Quercetin Enhances Vorinostat-Induced Apoptosis in an HSP72-Overexpressing Cutaneous T-Cell Lymphoma Cell Line, Hut78

Histone deacetylase inhibitors (HDACis) are one of the therapeutic options for cutaneous T-cell lymphoma (CTCL), but they have limited effects. We previously demonstrated that HSP72 overexpression is associated with chemoresistance to HDACis in lymphoma cells. The purpose of this study was to investigate whether the functional depletion of HSP72 enhances the effect of the HDACi vorinostat. First, we established a stable HSP72-knockdown CTCL cell line and confirmed the influence of HSP72 reduction on the antitumor effects of vorinostat. Next, we studied the effect of quercetin, an inhibitor of HSP72, on the antineoplastic effects of vorinostat. In five CTCL cell lines examined, HSP72 expression was highest in Hut78 cells, and HSP72 knockdown enhanced vorinostat-induced apoptosis in these cells. Low-dose quercetin reduced HSP72 expression, increased HDAC activity, and enhanced vorinostat-induced suppression of Hut78 cell proliferation. A single low dose of quercetin induced G2 arrest and only slightly increased the sub-G1 cell fraction. Quercetin also significantly enhanced vorinostat-induced apoptosis, caspase-3, caspase-8, and caspase-9 activity, and the loss of mitochondrial membrane potential. HSP72 knockdown enhanced vorinostat-induced apoptosis in an HSP72-overexpressing CTCL cell line, and thus, quercetin may be a suitable candidate for combination therapy with vorinostat in clinical settings.

A Rare Case of Cutaneous Intravascular NK/T-Cell Lymphoma

BACKGROUND

Cutaneous intravascular NK/T cell lymphoma (CIVNKTC) is a rare form of extranodal non-Hodgkin's lymphoma with its unique histological and immunophenotypic characteristics.

METHODS

We report a case presenting with an over 2-month history of nodules on the extremities and trunk with intermittent fever. Skin biopsy was taken from the patient and a histopathological examination was made from the material.

RESULTS

The histopathological examination showed some expanding vessels filled with atypical lymphoid cells in the dermis and subcutaneous tissue. The tumor cells had large nuclei and one or two small nucleoli, with the expression of CD3, cytotoxic protein, and Epstein-Barr virus (EBV)-encoded messenger RNAs (EBER), and without the expression of tumor cytokeratin (CK), CD20, CD79A, CD4, and CD8. After being diagnosed as CIVNKTC and treated with a CHOP regimen 6 times, the patient died of this disease 1 year later.

CONCLUSIONS

The clinical course is dangerous and the prognosis is extremely poor.