Sézary Syndrome Research Articles

Health-related quality of life and economic burden in Chinese patients with cutaneous T-cell lymphoma.

e19533 Background: Cutaneous T-cell lymphoma (CTCL) is a rare type of non-Hodgkin lymphoma. As described in European Organization for Research and Treatment of Cancer Consensus, the subtypes of mycosis fungoides (MF) and Sézary Syndrome (SS) comprised roughly 55% and 5% of CTCL, respectively. The clinical presentations of MF and SS include skin lesion, tumors, ulcerations, systemic involvements and even death. This study aimed to measure the overall HRQoL and economic burden of MF and SS patients in China. Methods: A cross-sectional survey was conducted from 21 July 2022 to 24 October 2022. Eligible adult participants with a pathologically confirmed diagnosis of either MF or SS were recruited from specialty or general hospitals across China. All participants were asked to complete a questionnaire that assessed HRQoL and annual economic burden. Validated instruments in Chinese, specifically the EuroQoL Group’s five-level QoL five-dimensional questionnaire (EQ-5D-5L), Functional Assessment of Cancer Therapy-General (FACT-G), and Skindex-29, were used to assess general, cancer and skin-related HRQoL. All HRQoL outcomes were calculated using the scoring system provided by the institutions, and EQ-5D utility scores were mapped using the China time trade-off value sets. As for economic burden, it was investigated from the societal perspective, as the direct medical costs, direct non-medical costs, and productivity loss were all calculated. Results: A total of 61 patients were recruited and completed the survey. Patients resided in 38 cities of 21 provinces across China. 56 patients (92%) were diagnosed with MF and 5 (8%) with SS. 56% were male, with a mean age of 39 years. Half of the patients had early-stage disease (defined as less than stage IIB, patch or plaque), with the remainder having late-stage disease. Among the recruited patients, 43 (70%) received skin-directed therapy, and 55 (90%) received systemic therapy. As for HRQoL measures, EQ-5D utility score was 0.79 (±0.18), FACT-G score was 61.3 (±12.4), and the Skindex-29 score was 43.4 (±24.2). Comparison between patients with early-stage disease and late-stage is presented in the table. As for economic burden, the annual per capita cost for MF and SS patients was CNY 86,729 (USD 12,428), which greatly exceeded the annual disposable income in 2022 (CNY 36,883, equals USD 5,440). Conclusions: This was the first study investigating economic burden and HRQoL using patient-reported outcomes conducted in mainland China. The findings suggested that MF and SS has significantly compromised patients’ HRQoL and posed substantial economic burden. [Table: see text]

SOHO State-of-the-Art Updates and Next Questions: A Modern Approach to the Systemic Treatment of Advanced CTCL.

The term cutaneous T-cell lymphoma (CTCL) is a general term for T-cell lymphomas that are found primarily in skin. The most common CTCL entities, mycosis fungoides and Sezary syndrome are incurable diseases with a plethora of conventional treatment options. In the past treatment options have been selected primarily according to stage. Given newer targeted therapies with varied response in different body compartments, we suggest a compartment-guided algorithm that may enhance response rates directing the selection of the most efficacious treatment options.

A CASE SERIES OF PATIENTS WITH CUTANEOUS T‐CELL LYMPHOMA TREATED WITH COMBINATION MOGAMULIZUMAB AND OTHER THERAPIES AFTER SINGLE AGENT MOGAMULIZUMAB

Introduction: Mogamulizumab (moga) is an anti-CCR4, monoclonal antibody approved as monotherapy for the treatment of relapsed/refractory mycosis fungoides (MF) and Sezary syndrome (SS). Combination therapies are frequently utilized in cutaneous T-cell lymphoma (CTCL), in part due to the variation in response across blood, nodal, and skin compartments. Little is known about moga in combination with other therapies. Methods: We conducted a single institution retrospective analysis of MF/SS patients who were treated with moga in combination with other systemic therapies, including peginterferon alpha-2a (IFNα), bexarotene, extracorporeal photopheresis (ECP), and oral methotrexate between March 2019 and March 2023. Baseline characteristics and clinical outcomes were recorded and summarized. Responses were assessed by Olsen staging criteria (Olsen et al., 2022). Results: We identified 9 patients treated with moga combination therapy at our institution (Table 1). Six of 7 patients transitioned from mono to combination therapy due to progressive disease or stable disease with uncontrolled symptom burden. Median time to next treatment was 157.5 days (range 42-330) for moga monotherapy. The best response observed in the 8 patients to single agent moga was classified as: 4 (50%) partial responses (PR), 3 (37.5%) stable disease (SD), and 1 (12.5%) progressive disease (PD). We identified a total of 7 different treatment combinations in our 9 patients (6 systemic therapies and 2 skin-directed), which included IFNα (n = 4), bexarotene (2), ECP (2), total skin electron beam radiation (TSEB) (2), narrow band ultraviolet-B therapy (NBUVB) (1), IFNα + ECP (2), and oral methotrexate (1). Multiple patients received more than one combination treatment. Among the combination therapies, the median time to next treatment was 137 days (range 24-224 days) with 2 out of 6 patients having ongoing responses to moga + IFNα +/- ECP. The patient with PR on moga + IFNα received 7 prior therapies. His skin involvement improved from T4 to T1 but significant disease in the blood persisted (B2). He continues moga + IFNα now 846 days later. Conclusions: Mogamulizumab has improved outcomes for MF/SS patients, but global complete responses are rare with the best responses seen in blood. In our series, the addition of IFNα provided clinical benefits to patients with SD or PD on single agent moga. One patient achieved a lengthy partial response despite persistent disease seen in peripheral blood samples. We speculate the combination of moga + IFNα may augment antibody-dependent cellular cytotoxicity thereby improving efficacy of moga. Additionally, combinatorial approaches may improve responses in skin, nodes, and viscera where lower responses are observed to single agent moga. Further investigations of moga combinations are needed. Keywords: Combination Therapies, Cutaneous non-Hodgkin lymphoma No conflicts of interests pertinent to the abstract.

PCR73 Health-Related Quality of Life and Economic Burden in Chinese Patients with Cutaneous T-Cell Lymphoma (CTCL) – Results from Interim Analysis

Little is known about health-related quality of life (HRQoL) and economic burden in Chinese patients with cutaneous T-cell lymphoma (CTCL). This study aimed to measure the overall HRQoL and economic burden of CTCL patients with mycosis fungoides (MF) and Sezary syndrome (SS) subtypes in China.

CCR4-IL2 bispecific immunotoxin is more effective than brentuximab for targeted therapy of cutaneous T-cell lymphoma in a mouse CTCL model.

Cutaneous T-cell lymphoma (CTCL) encompasses two main subtypes: mycosis fungoides and Sezary syndrome. Global response rates for the systemic treatment of mycosis fungoides and Sezary syndrome are approximately 30% and none of these treatments are thought to be curative. C-C chemokine receptor type 4 (CCR4) and CD25 are encouraging targets for the treatment of CTCL and are individually targeted by mogamulizumab and denileukin diftitox, respectively. We developed a novel CCR4-IL2 bispecific immunotoxin (CCR4-IL2 IT) targeting both CCR4 and CD25. CCR4-IL2 IT demonstrated superior efficacy against CCR4+ CD25+ CD30+ CTCL in an immunodeficient NSG mouse tumor model. Investigative New Drug-enabling studies of CCR4-IL2 IT are ongoing, including Good Manufacturing Practice production and toxicology studies. In this study, we compared the in vivo efficacy of CCR4-IL2 IT versus the US Food and Drug Administration-approved drug, brentuximab, using an immunodeficient mouse CTCL model. We demonstrated that CCR4-IL2 IT was significantly more effective in prolonging survival than brentuximab, and combination treatment of CCR4-IL2 IT and brentuximab was more effective than brentuximab or CCR4-IL2 IT alone in an immunodeficient NSG mouse CTCL model. Thus, CCR4-IL2 IT is a promising novel therapeutic drug candidate for CTCL treatment.

Primary cutaneous lymphomas: exploration of 10-year data from supraregional mutlidisciplinary team meetings in Glasgow, UK.

Primary cutaneous lymphomas (PCLs) are non-Hodgkin lymphomas, presenting in the skin. They are classified into cutaneous B-cell lymphomas (CBCLs) or cutaneous T-cell lymphomas (CTCLs). The most common CTCL subtypes are mycosis fungoides (MF) and Sézary syndrome (SS). All patient's cases should be discussed at a specialist multidisciplinary team (MDT) meeting. This is the first published review, to our knowledge, of PCL MDT case discussion in the UK. Patient cases between 2008 and 2019 were reviewed to assess: frequency of PCL subtype, documentation of CTCL staging and management of MF/SS. Of 356, 103 (29%) were CBCLs and the majority (n = 200, 56%) were CTCLs. MF/SS was the diagnosis in 120 (34%). Staging was documented in 44% (n = 53) of patients with MF/SS. Management largely followed guidelines for MF/SS, topical corticosteroids were the most common treatment (n = 93, 78%). Frequency of PCL subtype is largely comparable with previously published data. Documentation of CTCL staging is low, but higher than other reports. Our work begins to address the gap in real-world data on CTCLs. A standardized approach to data collection would inform clinical practice.

Mycosis fungoides and Sézary syndrome.

Mycosis fungoides (MF) and Sézary syndrome (SS) are a distinct disease entity of cutaneous T-cell lymphoma with heterogenous clinical features and prognosis. MF mainly involves skin and usually shows an indolent and favorable clinical course. In patients with advanced-stage disease, extracutaneous involvement including lymph nodes, viscera, and blood, or large cell transformation may be observed. SS is a leukemic form of advanced-stage MF, characterized by generalized erythroderma. Early-stage MF can be treated with skin-directed therapy. However, patients with refractory or advanced-stage disease are associated with severe symptoms or poor prognosis, requiring systemic therapy. Recent progress in understanding the pathogenesis of MF/SS has contributed to advances in the management of these rare diseases. This review aims to describe the clinical manifestations, diagnosis, risk stratification, and treatment strategy of MF/SS, focusing on the recent updates in the management of these diseases.

Spatially Guided and Single Cell Tools to Map the Microenvironment in Cutaneous T-Cell Lymphoma

Mycosis fungoides (MF) and Sézary syndrome (SS) are two closely related clinical variants of cutaneous T-cell lymphomas (CTCL). Previously demonstrated large patient-to-patient and intra-patient disease heterogeneity underpins the importance of personalized medicine in CTCL. Advanced stages of CTCL are characterized by dismal prognosis, and the early identification of patients who will progress remains a clinical unmet need. While the exact molecular events underlying disease progression are poorly resolved, the tumor microenvironment (TME) has emerged as an important driver. In particular, the Th1-to-Th2 shift in the immune response is now commonly identified across advanced-stage CTCL patients. Herein, we summarize the role of the TME in CTCL evolution and the latest studies in deciphering inter- and intra-patient heterogeneity. We introduce spatially resolved omics as a promising technology to advance immune-oncology efforts in CTCL. We propose the combined implementation of spatially guided and single-cell omics technologies in paired skin and blood samples. Such an approach will mediate in-depth profiling of phenotypic and molecular changes in reactive immune subpopulations and malignant T cells preceding the Th1-to-Th2 shift and reveal mechanisms underlying disease progression from skin-limited to systemic disease that collectively will lead to the discovery of novel biomarkers to improve patient prognostication and the design of personalized treatment strategies.

263 SLFN11 is a possible biomarker of sensitivity to DNA-targeted regents in CD30-positive mycosis fungoides and Sezary syndrome

263 SLFN11 is a possible biomarker of sensitivity to DNA-targeted regents in CD30-positive mycosis fungoides and Sezary syndrome

266 Analysis of novel sezary syndrome genes in mycosis fungoides reveals genes common across stages and those associated with advanced stages

266 Analysis of novel sezary syndrome genes in mycosis fungoides reveals genes common across stages and those associated with advanced stages

Mycosis fungoides and Sézary syndrome: clinical presentation, diagnosis, staging, and therapeutic management.

Mycosis fungoides (MF) and Sézary syndrome (SS) are cutaneous T-cell lymphomas. MF is the most common cutaneous lymphoma, and it is classified into classic Alibert-Bazin MF, folliculotropic MF, pagetoid reticulosis, and granulomatous slack skin, each with characteristic clinical presentation, histopathological findings, and distinct clinical behaviors. SS is an aggressive leukemic variant of cutaneous lymphoma, and it is characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by malignant cells. There is a wide range of dermatological manifestations of MF/SS, and prompt recognition is essential for early diagnosis. Skin biopsy for histopathology and immunohistochemical analysis is imperative to confirm the diagnosis of MF/SS. Histopathology may also provide information that may influence prognosis and treatment. Staging follows the TNMB system. Besides advanced stage, other factors associated with poorer prognosis are advanced age, male gender, folliculotropism in histopathology of patients with infiltrated plaques and tumors in the head and neck region, large cell transformation, and elevated lactate dehydrogenase. Treatment is divided into skin-directed therapies (topical treatments, phototherapy, radiotherapy), and systemic therapies (biological response modifiers, targeted therapies, chemotherapy). Allogeneic bone marrow transplantation and extracorporeal photopheresis are other treatment modalities used in selected cases. This review discusses the main clinical characteristics, the histopathological/immunohistochemical findings, the staging system, and the therapeutic management of MF/SS.

New Molecular and Biological Markers in Cutaneous T Cell Lymphoma: Therapeutic Implications.

Cutaneous T cell lymphomas (CTCLs) exhibit a wide variety of clinical features, histologic characteristics, and genetic drivers. We review novel molecular findings that inform our understanding of the pathogenesis of CTCL, with a focus on the tumor microenvironment (TME). There is increasing evidence challenging the model of TCM:mycosis fungoides (MF) and TEM:Sézary syndrome (SS) phenotype. Phylogenetic analysis performed using whole-exome sequencing (WES) raises the possibility that MF can arise without a common ancestral T cell clone. The detection of ultraviolet (UV) marker signature 7 mutations in the blood of patients with SS raises questions about the role of UV exposure in CTCL pathogenesis. There is also increasing interest on the role of the TME in CTCL. Existing therapies such as the RXR retinoid bexarotene and the anti-CCR4 monoclonal antibody mogamulizumab may act through the CTCL TME by impacting the CCL22:CCR4 axis, while cancer-associated fibroblasts (CAFs) in the CTCL TME contribute to drug resistance, as well as a Th2 milieu and tumor growth via secretion of pro-tumorigenic cytokines. Staphylococcus aureus (SA) is a frequent cause of morbidity among CTCL patients. SA may positively select for malignant T cells through adaptive downregulation of alpha-toxin surface receptors and promotion of tumor growth via upregulation of the JAK/STAT pathway. Recent molecular advancements have contributed to our understanding of the pathogenesis of CTCL and shed light into the potential mechanisms of existing therapies. Further understanding of the CTCL TME may fuel the discovery of novel therapies for CTCL.

Abstract 464: AAC-11 survival pathways as therapeutic target in cancer: AAC-11 leucine-zipper domain derived peptides exert potent antitumor effects and exhibit favorable stability, pharmacokinetic and toxicology profiles

Abstract Background: Due to their basal stress phenotype associated to transformation, cancer cells are addicted to non-mutated, non-oncogenic proteins that do not bear such vital functions in normal cells, a phenomenon referred as Non-Oncogenic Addiction (NOA). Targeting these NOAs could therefore induce selective killing of cancer cells, opening several therapeutic opportunities. Recent data suggest that the stress-related scaffold protein AAC-11 (anti-apoptosis clone 11, also known as Api5) is critically involved in cancer cells resistance to chemotherapies, metastatic potential and escape from the immune system. Methods: We have developed inactivating peptides based on the fusion of a cell penetrating sequence and portions of the leucine-zipper domain of AAC-11, which functions as a protein-protein interaction module. These peptides induce cancer cells death, through the inhibition of protein-protein interactions between AAC-11 and its partners, while sparing normal cells. We now describe further characterization of our lead peptide, JRT39, which contains residues 377 to 379 of AAC-11 linked to the cell-penetrating peptide “penetratin”. Results: In vitro, JRT39 causes cell death in a wide spectrum of cancer cell lines with IC50 ranging from 5 µM to 30 µM depending on tumor cell type. In particular, JRT39 showed selective efficacy towards primary cells from Acute Myeloid Leukemia (AML), Acute Lymphocytic Leukemia (ALL) or Sézary syndrome (SS) patients, while sparing normal hematopoietic cells, with an IC50 of 5-15 µM. Mechanistically, JRT39 induces membranolysis of cancer cells through binding to p21-activated kinase 1 (PAK1) in AML or SS cells plasma membrane, where PAK1 is overexpressed. In addition, JRT39 exerted potent anti-tumor activity in vivo in disseminated or subcutaneous AML, APL (Acute Promyelocytic Leukemia) and SS-patient derived preclinical murine models. Preliminary pharmacokinetic studies revealed that JRT39 is stable in human serum and has a plasma half-life of ~1.5-2.5 hours after intravenous (IV) administration to dogs or cynomolgus monkeys, with concentration-time data fitting 2-compartment model. Finally, JRT39 was well tolerated at 5 and 10 mg/kg after single or repeated (daily) IV injections. Conclusions: Combined, our preclinical data confirm that interfering with AAC-11-related survival pathways is a promising novel anticancer strategy and support the development of JRT39 for the treatment of cancer. Citation Format: Louise Jeammet, Emile Adicéam, Justine Habault, Anna Kaci, Jeannig Berrou, Mélanie Dupont, Nicolas Thonnart, Ewa Pasquereau-Kotula, Anne Marie-Cardine, Armand Bensussan, Marika Pla, Hervé Dombret, Claude Gardin, Martine Bagot, Jean-Christophe Rain, Hélène Sicard, Jérôme Tiollier, Thorsten Braun, Jean-Luc Poyet. AAC-11 survival pathways as therapeutic target in cancer: AAC-11 leucine-zipper domain derived peptides exert potent antitumor effects and exhibit favorable stability, pharmacokinetic and toxicology profiles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 464.

Challenges in commissioning the "TSET" technique: A new approach towards monitor unit calculation and beam profile measurements.

Total skin electron beam therapy, commonly known as TSET, is a good choice of treatment for patients suffering from mycosis fungoides. The aim of this study was to introduce a new approach to the beam profile measurement using diodes and to calculate the monitor units required for the TSET treatment by the use of a simple setup of output measurement. Dosimetric measurements required for the treatment were taken to establish the Stanford technique in the department, and the measured data was compared with the published data. High-energy Linear Accelerator Clinac-DHX, Varian medical system, Palo Alto, CA, was commissioned for TSET. The output of the machine was measured by the use of a Parallel-Plate Chamber (PPC40) as per the TRS 398 recommendation. Diode dosimeters (EDD2 and EDD5) were used for beam profile measurements due to easy setup and to reduce the measurement time. Homogeneous dose distribution within a field size of 80 cm x160 cm was observed with the variation of -5.0% on the horizontal axis and -5.4% on the vertical axis. The calculated monitor unit to deliver 200 cGy per fraction per field at the source to surface (SSD) of 416 cm was 489 MU. The technique described for the output measurements is simple and accurate. Results of the absorbed dose and MU measured were within good agreement compared to the published literature.

Complete Response to tenalisib and romidepsin with long-term maintenance using tenalisib monotherapy in a patient with relapsed and refractory sézary syndrome.

Mycosis fungoides (MF) and Sézary Syndrome (SS) are the most common subtypes of cutaneous T cell lymphomas (CTCL). Advanced-stage MF/SS have poor prognoses and may be refractory to multiple systemic treatments. These cases can be difficult to achieve and maintain complete response and there is a need for novel therapeutics. Inhibition of the phosphatidylinositol 3-kinase (PI3K) pathway by Tenalisib presents one such emerging drug. We report a relapsed/refractory SS patient achieving complete remission using the combination of Tenalisib and Romidepsin and subsequently maintaining long-duration CR with Tenalisib monotherapy.

Clinical and biological analysis of Sézary syndrome: A report of four cases

Background: Sézary syndrome (SS) is a rare and aggressive type of cutaneous T cell lymphoma characterized by an intensely pruritic, exfoliative rash, known as erythroderma, with cutaneous and systemic dissemination of clonal CD4+ T cells into the blood and lymph nodes. We report through a series of 4 cases, the experience of the hematology laboratory in the diagnosis of the syndrome of Sézary. Methods: Four patients with SS were identified retrospectively among patients with cutaneous T-cell lymphoma followed up in the dermatology department and diagnosed in the hematology laboratory of the Avicenne military hospital in Marrakesh. Results: Four patients with SS were described: three men and one woman, mean age at diagnosis 62 years (55-71). All the patients showed generalized dry erythroderma, pruritus and lymphadenopathy. Palmo-plantar hyperkeratosis, nail lesions and alopecia were also present. The white blood cell count was elevated (>10,000 WBC/ mm3) in all 4 patients with a mean value of 17,276 and one patient among these showed an elevation of eosinophils (> 500/ µl). The blood smear showed the presence of 65% of small to medium-sized cells with a high nucleocytoplasmic ratio and cerebriform nuclei typical of Sézary cells and suggests the diagnosis of SS. Conclusion: Sézary syndrome is a rare subtype of cutaneous T-cell lymphoma characterized by erythroderma, circulating neoplastic T cells, and poor prognosis. Microscopic findings must be correlated with the clinical presentation to make the diagnosis.

A CASE REPORT: TRANSFORMATION OF ERYTHRODERMIC PSORIASIS TO CUTANEOUS T-CELL LYMPHOMA

Background: Erythrodermic psoriasis (EP) is a severe type of psoriasis, a chronic inflammatory disease characterized by general erythematous condition with thick scale all around the body. The treatment of EP consists systemic medications like cyclosporine or methotrexate and biologic agents, which lately suggested related to the development of cutaneous T-cell lymphoma (CTCL) in severe psoriasis patients.
 Case Report: A 45-year old, Javanese male was diagnosed previously with EP that transformed to CTCL. His previous history, he was histologically confirmed as psoriasis vulgaris since 2014 and was treated regularly with methotrexate. After 5 years, he gradually suffered several episodes of erythrodermic condition and was diagnosed with erythrodermic psoriasis with unusual pruritic hyperkeratotic plaques and ulcers on his trunks without any general lymph nodes enlargement. Peripheral blood smear showed Sezary cell and histopathology result confirmed CTCL. He was treated with combination of radiotherapy, phototherapy and topical regiments with a good result and acceptable.
 Discussion: Several studies suggested that severe psoriasis had increased the susceptibility of CTCL, especially with the use of cyclosporine, methotrexate or biologic agents as the treatment. In this case, methotrexate might play role in the development of CTCL or enhanced the transformation of EP to CTCL. Combination of localized radiation therapy, NBUVB and topical therapy gave a quiet good result for the skin condition and increased patient’s quality of life.
 Conclusion: Erythrodermic psoriasis might transform or develop to CTCL which in this case was probably related to the use of methotrexate.
 

Nb-UVB and PUVA therapy in treating early stages of Mycosis Fungoides: A single-center cross-sectional study.

Mycosis fungoides (MF) and Sezary Syndrome are the most common forms of cutaneous T-cell lymphoma. Early-stage MF is known to have an indolent behavior, and the EORTC guidelines recommend treating patients with skin-directed therapies, such as phototherapy, instead of systemic therapies. Phototherapy is a popular therapeutic option, with two commonly used light sources-PUVA and narrow band-nb UVB. PUVA is less commonly used due to its potential carcinogenic role, but it has systemic effects, while nb-UVB has mostly skin-limited effects. There is ongoing debate regarding the role of UVB light, and in 2021, the Cutaneous Lymphoma Italian Study Group reached a consensus on technical schedules for NB-UVB and PUVA for MF. This study aims to analyze and compare the efficacy of the two phototherapy options in treating early-MF patients. The study included patients diagnosed with stage IA/B MF in the last 10 years, who had at least 12 months of follow-up data and a minimum of 24 phototherapy sessions (PUVA or nb UVB) and treated with topical steroids apart from phototherapy. Results showed that the two phototherapy options were similarly effective in treating early MF, with no significant differences in clinical response, although PUVA was associated with more adverse effects. The study provides valuable insights into the use of phototherapy in early MF, and the results can be used to guide treatment decisions and improve patient outcomes.

Ultrahypofractionated Low-Dose Total Skin Electron Beam in Advanced-Stage Mycosis Fungoides and Sézary Syndrome

To assess the safety and efficacy of ultra-hypofractionated low-dose total skin electron beam therapy (TSEBT) regimen in patients with advanced mycosis fungoides (MF) or Sézary syndrome (SS). In this multicenter observational study from five German centers, 18 total patients with MF/SS underwent TSEBT with a total dose of 8 Gy in two fractions. The primary endpoint was the overall response rate (ORR). 15 of 18 patients with stage IIB-IV MF or SS were heavily pre-treated with a median of four prior systemic therapies. The ORR was 88.9% (95%-confidence interval (CI): 65.3-98.6), with three complete responses (17%). At a median follow-up period of thirteen months, the median time to next treatment (TTNT) was 12 months (95%-CI: 8.2-15.8), and the median progression-free survival was 8 months (95%-CI: 2-14). Asignificant reduction in the modified severity-weighted assessment tool (mSWAT), total Skindex-29 score (Bonferroni-corrected P-value < 0.005), and all subdomains (Bonferroni-corrected P-values < 0.05) was observed after TSEBT. Half of the irradiated patients (N=9) developed grade 2 acute and subacute toxicities. One patient had confirmed grade 3 acute toxicity. Chronic grade 1 toxicity has been observed in 33% of patients. Patients with erythroderma/SS or prior radiation therapy appear at higher risk of skin toxicities. TSEBT with 8 Gy in 2 fractions achieves good disease control and symptom palliation with acceptable toxicity, greater convenience, and fewer hospital visits.

CARD11 gain-of-function mutation drives cell-autonomous accumulation of PD-1+ ICOShigh activated T cells, T-follicular, T-regulatory and T-follicular regulatory cells.

Germline CARD11 gain-of-function (GOF) mutations cause B cell Expansion with NF-κB and T cell Anergy (BENTA) disease, whilst somatic GOF CARD11 mutations recur in diffuse large B cell lymphoma (DLBCL) and in up to 30% of the peripheral T cell lymphomas (PTCL) adult T cell leukemia/lymphoma (ATL), cutaneous T cell lymphoma (CTCL) and Sezary Syndrome. Despite their frequent acquisition by PTCL, the T cell-intrinsic effects of CARD11 GOF mutations are poorly understood. Here, we studied B and T lymphocytes in mice with a germline Nethyl-N-nitrosourea (ENU)-induced Card11M365K mutation identical to a mutation identified in DLBCL and modifying a conserved region of the CARD11 coiled-coil domain recurrently mutated in DLBCL and PTCL. Our results demonstrate that CARD11.M365K is a GOF protein that increases B and T lymphocyte activation and proliferation following antigen receptor stimulation. Germline Card11M365K mutation was insufficient alone to cause B or T-lymphoma, but increased accumulation of germinal center (GC) B cells in unimmunized and immunized mice. Card11M365K mutation caused cell-intrinsic over-accumulation of activated T cells, T regulatory (TREG), T follicular (TFH) and T follicular regulatory (TFR) cells expressing increased levels of ICOS, CTLA-4 and PD-1 checkpoint molecules. Our results reveal CARD11 as an important, cell-autonomous positive regulator of TFH, TREG and TFR cells. They highlight T cell-intrinsic effects of a GOF mutation in the CARD11 gene, which is recurrently mutated in T cell malignancies that are often aggressive and associated with variable clinical outcomes.