Allogeneic hematopoietic stem cell transplantation for advanced mycosis fungoides and Sézary syndrome. An updated experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation

Breaking Down the Barriers for Patients With Cutaneous T-Cell Lymphoma: Current Controversies and Challenges for Radiation Oncologists in 2024

Cutaneous T-cell lymphomas (CTCL) are a rare collection of diseases, frequently associated with diagnostic challenges and complex management dilemmas. The multidisciplinary team is vital for accurate clinico-pathological diagnoses and for collaborative therapeutic decisions throughout the management journey, which frequently involves multiple lines of therapy. Radiotherapy (RT) is a highly effective skin-directed therapy for CTCL, commonly delivered as localised fields or as total skin electron beam therapy (TSEBT). Mycosis fungoides (MF) is the most common of the CTCL, and patients typically experience high rates of morbidity and long natural histories of relapse and progression. Patients with MF typically present with incurable disease; in these patients, RT has an established role in symptom- and disease-control, achieving excellent response rates and proven therapeutic benefits. The role of RT continues to evolve, with modern practices favouring lower doses to reduce toxicity risks and allow for re-irradiation. Less commonly, there are situations where RT has an integral role in the potential cure of patients with MF: firstly, in the setting of unilesional MF where localised RT alone may be curative, and secondly, in the setting of preconditioning prior to curative-intent allogeneic hematopoietic stem cell transplant for patients with advanced MF/Sezary syndrome, where conventional-dose TSEBT is indicated as the most effective single agent for maximal debulking of skin disease. Radiotherapy also has an important role in the management of the less common CTCL, including the curative treatment of localised primary cutaneous anaplastic large cell lymphoma. Despite proven efficacy and quality of life benefits, disparity exists in access to RT and TSEBT. World-wide, stronger multidisciplinary collaborations and greater patient advocacy are required to increase access to RT and improve equity of care for our patients with CTCL.

The role of stem cell transplant (auto and allo) in PTCL and CTCL

In contrast to B-cell lymphoma, the advent of modern targeting drugs and immunotherapeutics has not led to major breakthroughs in the treatment of peripheral T-cell lymphoma (PTCL) to date. Therefore, both autologous and allogeneic hematopoietic cell transplantation (HCT) continue to play a central role in the management of PTCL. Focusing on the most common entities (PTCL not otherwise specified, angioimmunoblastic T-cell lymphoma, and ALK-negative anaplastic large cell lymphoma), we summarize evidence, indications, and points to consider for transplant strategies in PTCL by treatment line. Although cutaneous T-cell lymphomas (CTCLs) are biologically and clinically distinct from the aforementioned PTCL, both disease groups appear to be susceptible to the graft-versus-lymphoma effects conferred by allogeneic HCT (alloHCT), setting the stage for alloHCT as a potentially curative treatment in otherwise incurable CTCL, such as mycosis fungoides/Sezary syndrome. Nevertheless, specific aspects regarding indication and prerequisites for alloHCT in CTCL need to be considered. Given the inherent toxicity of alloHCT and the significant risk of relapse after transplant, only intelligent strategies embedding alloHCT in current PTCL/CTCL treatment algorithms in terms of patient selection, timing, pretransplant preparation, and posttransplant maintenance provide optimal results. New targeted and cellular therapies, either complementary or competitive to HCT, are eagerly awaited in order to improve PTCL/CTCL outcomes.

ASTCT and USCLC Clinical Practice Recommendations for Allogeneic Stem Cell Transplant in Mycosis Fungoides and Sézary Syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of cutaneous T-cell lymphoma (CTCL). While MF generally follows an indolent course, a subset of patients will experience progressive and/or treatment-refractory disease; Sézary syndrome is an aggressive lymphoma associated with high morbidity and mortality. Although allogeneic hematopoietic cell transplant (allo-HCT) is the only currently available potentially curative treatment modality for MF/SS there is no published guidance on referral criteria, transplant timing orallo-HCT approach. To develop consensus clinical practice recommendations, we performed a Delphi survey of 32 specialists in dermatology (n = 9), transplant hematology/oncology (n = 10), non-transplant hematology/oncology (n = 8), and radiation oncology (n = 5) from across the United States. Consensus required agreement of ≥75% of participants. Sixteen consensus statements were generated on four topics: (1) criteria for referral for consideration for allo-HCT, (2) allo-HCT preparative regimens and procedures (3) disease status at the time of allo-HCT, and (4) multidisciplinary management in the pre- and post-transplant settings. These clinical practice guidelines provide a framework for decision-making regarding allo-HCT for MF/SS and highlight areas for future prospective investigation.

Multidisciplinary and personalized approach to the management of mycosis fungoides with chlormethine gel: a collection of clinical experiences

Topical chlormethine (CL) gel formulation was approved by the EMA in 2017 for the treatment of adult patients with mycosis fungoides (MF). To expand the knowledge on the management of MF, this paper provides an overview of clinical practice evidence about the MF diagnostic phase and a collection of clinical experiences to better characterize the use of CL gel in daily practice. Collected cases underline the importance of the concomitant biopsy and clinical evaluation in the diagnostic phase, with the contribution of a multidisciplinary team, and support the use of CL gel as a first-line or adjuvant treatment in selected patients.

Allogeneic hematopoietic stem cell transplantation after mogamulizumab in T-cell lymphoma patients: a retrospective analysis

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an important therapy for patients with T-cell lymphomas, including cutaneous T-cell lymphoma (CTCL), adult T-cell lymphoma (ATL), and peripheral T-cell lymphoma (PTCL). Mogamulizumab is an anti-CCR4 antibody that has been associated with an increased risk of transplant-related complications in retrospective analyses of ATL, particularly when administered within 50 days before transplantation. This post hoc analysis of 3 clinical trials examined safety and outcome data for 32 patients with CTCL (n = 23), ATL (n = 7), or PTCL (n = 2) who underwent allo-HSCT after mogamulizumab treatment. Overall, 22 patients (69%) were known to have graft-versus-host disease (GVHD), 8 patients (25%) did not report GVHD, and 2 patients (6%) had unknown GVHD status. Fourteen patients with known GVHD underwent transplantation between 50 and 365 days after their last dose of mogamulizumab, while 2 underwent transplantation within 50 days after treatment. Based on this limited evidence, GVHD was not associated with the time interval from last mogamulizumab dose to transplantation.

Long term outcomes of nonmyeloablative allogeneic stem cell transplantation with TSEB TLI and ATG for Mycosis Fungoides and Sezary Syndrome

Advanced stage (IIB-IVB) Mycosis Fungoides (MF) and Sezary Syndrome (SS) have a poor prognosis with median survival <5 years. We report long-term outcomes of a non-myeloablative allogeneic stem cell transplantation regimen consisting of total skin electron beam therapy, total lymphoid irradiation and antithymocyte globulin. Our prospective cohort consisted of 41 patients with a higher proportion of MF (34MF, 7SS). Acute GVHD Grade 2 to 4 was seen in 31.7% and chronic GVHD Grade 2 to 4 in 24%. The cumulative incidence of non-relapse mortality was 9.8% at 1 year and 12.6% at 2 years. At Day +90 post-transplant 66% of patients had a complete response (CR). With a median post-transplant follow up of 5.27 years, the 5-year overall survival rate was 37.7% (MF 36.7%, SS 57.1%). The 5-year cumulative incidence of progressive disease or relapse was 52.7% in all patients but only 20.8% in those with CR at transplant compared to 70.6% in those not in CR at transplant (p = 0.006). Long term survival is possible in advanced MF and SS with non-myeloablative transplantation and outcomes are improved in patients with CR at transplant.

Allogeneic stem cell transplant for treatment of mycosis fungoides and Sezary syndrome: a systematic review and meta-analysis

Allogeneic hematopoietic stem cell transplant (allo-HSCT) has been noted to be a potential curative treatment in cases of advanced-stage mycosis fungoides (MF) or Sezary syndrome (SS). To assess outcomes of allo-HSCT for MF/SS we performed a systematic review and meta-analysis including 15 manuscripts and 557 patients, published from 2010-2023. Meta-analysis revealed 1-year and 3+year overall survival (OS) of 51% (95% CI 39-64%) and 40% (32-49%). Progression-free survival at 1 year and 3+years were 42% (31-53%) and 33% (25-42%). Non-relapse mortality was 18% (13-23%). Relapse occurred in of 47% (40-53%) with a median time to relapse of 7.9 months (range 1.6-24 months). Rates of acute and chronic graft-versus-host disease (GVHD) were 45% (35-55%) and 40% (33-48%). Reduced-intensity conditioning (RIC) was associated with superior OS compared to myeloablative conditioning (MAC) (58% vs. 30%, p < 0.001). Of patients with relapse after allo-HSCT, 46% treated with donor lymphocyte infusion (DLI) achieved complete remission. These data support use of allo-HSCT for treatment of advanced-stage MF/SS and suggest superiority of RIC over MAC. Rates of GVHD were comparable to allo-HSCT in general. The improved OS for RIC and high rate of CR with DLI underscore the importance of the graft-versus-lymphoma effect in allo-HSCT for MF/SS.

Allogeneic transplantation and cellular therapies in cutaneous T-cell lymphoma

INTRODUCTION

Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of cutaneous T-cell lymphoma. Although many available treatments offer temporary disease control, allogeneic hematopoietic stem cell transplant (allo-HSCT) is the only curative treatment option for advanced stage MF and SS. CAR T-cell therapy is a promising new avenue for treatment.

AREAS COVERED

In this review, we discuss the evidence supporting the use of allo-HSCT for the treatment of MF/SS, including disease status at the time of transplant, conditioning regimen, total body irradiation (TBI), and donor lymphocyte infusion (DLI). We also address the potential role for CAR T-cell therapy in CTCL.

EXPERT OPINION

Allo-HSCT is an effective treatment for patients with advanced MF and SS. However, significant research is required to determine optimal treatment protocols. Data support the use of reduced-intensity conditioning regimens and suggests that the use of TBI for debulking of skin disease may result in more durable remissions. Donor lymphocyte infusions (DLI) appear to be particularly effective in inducing complete remission in MF/SS patients with relapsed or residual disease. Challenges with CAR-T therapies in T-cell lymphoma include T-cell fratricide due to shared antigens on malignant and nonmalignant T-cells, penetrance into the skin compartment, and CAR-T cell persistence.

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.

International study of treatment efficacy in SS shows superiority of combination therapy and heterogeneity of treatment strategies

Despite increasing availability of therapies, patients with Sezary syndrome (SS) commonly endure multi-line treatment journeys, mostly with partial responses of short duration. Measuring clinical benefit is challenging; time-to-next-treatment (TTNT) provides a robust, objective measurement of efficacy. This international observational study examines patterns of clinical care and therapeutic benefit as measured by TTNT. TTNT was calculated for monotherapies and combination therapies, with consideration to treatment line. 178 patients with SS (73% de novo, 27% secondary) were included, receiving 721 lines of systemic therapy, with median follow-up of 56.9 months. Across all lines, 58 different therapeutic regimens were prescribed (54 were systemic therapies) and classified into 17 treatment groups. The most common first-line treatments were extracorporeal photopheresis (ECP)-containing combination therapy (20%) and retinoid monotherapy (19%). Median TTNT for all first-line therapies was short (5.4 months). First-line, combination therapies had longer median TTNT than monotherapies, 10.0 vs 5.0 months (P = .004), respectively. Later delivery of combination therapies was associated with shorter clinical benefit, with median TTNT reduced to 6.2 and 2.2 months for mid-line (2nd-4th line) and late-line (≥5th line), respectively (P < .001). First-line ECP-containing treatments were associated with longer median TTNT than non-ECP-containing treatments, 9.0 vs 4.9 months (P = .007). For both ECP-monotherapy and ECP-containing combination therapy, significant reductions in TTNT were seen in later lines. These data suggest therapeutic benefit from first-line delivery of combination therapy for SS and favor early inclusion of ECP in the treatment algorithm for those who can access it.

What Is New in Cutaneous T Cell Lymphoma?

PURPOSE OF REVIEW

This review focuses on updates in prognosis, pathogenesis, and treatment of cutaneous T cell lymphoma (CTCL).

RECENT FINDINGS

Cohort studies indicate imaging may be necessary in early-stage CTCL. Risk factors for progression of CTCL have been identified. Interactions between malignant cells and the tumor microenvironment (TME) and the skin microbiome advance the understanding of pathogenesis and tumor cell dissemination. Studies support a hypothesis of circulating malignant tumor cells. MicroRNA (miR) influence tumor progression and prognosis; the IL22-STAT3-CCL20 cascade may be a novel target. IL-4, IL-5, and IL-31 cytokines are relevant for pruritus and could be targets for therapeutic interventions. Systemic therapies, such as JAK inhibitors, targeted antibodies, and checkpoint inhibitors, show promise in advanced stages. Allogenic hematopoietic stem cell transplantation provides a potential curative option for patients. Further investigations of prognosis and translational research are necessary to improve stratification of patients for treatment.

Functional heterogeneity of human skin-resident memory T cells in health and disease

The human skin is populated by a diverse pool of memory T cells, which can act rapidly in response to pathogens and cancer antigens. Tissue-resident memory T cells (TRM ) have been implicated in range of allergic, autoimmune and inflammatory skin diseases. Clonal expansion of cells with TRM properties is also known to contribute to cutaneous T-cell lymphoma. Here, we review the heterogeneous phenotypes, transcriptional programs, and effector functions of skin TRM . We summarize recent studies on TRM formation, longevity, plasticity, and retrograde migration and contextualize the findings to skin TRM and their role in maintaining skin homeostasis and altered functions in skin disease.

Allogeneic transplantation in advanced cutaneous T-cell lymphomas (CUTALLO): a propensity score matched controlled prospective study

BACKGROUND

Advanced-stage cutaneous T-cell lymphomas (CTCLs) are rare, usually refractory, and fatal diseases. Case series have suggested that allogeneic haematopoietic stem cell transplantation (HSCT) might improve the prognosis of advanced-stage CTCLs. The objective of this study was to investigate the effect of allogeneic HSCT compared with non-HSCT therapy on the outcome of individuals with advanced-stage CTCLs.

METHODS

In this prospective, multicentre, matched controlled trial, conducted at 30 hospitals, participants with advanced CTCLs were allocated treatment: if they had an available compatible related donor they were assigned to allogeneic HSCT, or if not they were allocated to non-allogeneic HSCT therapy. Key inclusion criteria were participants aged 18-70 years, with advanced stage mycosis fungoides or Sézary syndrome, and at least one poor prognostic criteria. Participants were excluded if they were not in complete or partial remission of the disease. Propensity score 1:1 matching with replacement (ie, that each participant treated with HSCT was matched to the participant with the closest propensity score treated with non-HSCT therapy, even if they had already been matched) was used to handle confounding factors, with the balance of covariate distribution between HSCT and non-HSCT groups assessed using standardised mean differences. The primary endpoint was progression-free survival in the matched intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02520908), and is currently active but not recruiting.

FINDINGS

From June 1, 2016, to March 3, 2022, total of 99 participants were enrolled at 17 centres in France. Participants with a sibling or matched unrelated donor were assigned to allogeneic HSCT (HSCT group, n=55 [56%]) and participants without a donor were assigned to non-allogeneic HSCT treatment (non-HSCT group, n=44 [44%]). The median follow-up among survivors was 12·6 months (IQR 11·0-35·2). In the HSCT group, 51 participants (93%) were 1:1 matched to participants from the non-HSCT group. In the intention-to-treat analysis, median progression-free survival was significantly longer in the HSCT group (9·0 months [95% CI 6·6-30·5]) than in the non-HSCT group (3·0 months [2·0-6·3]), with a hazard ratio of 0·38 (95% CI 0·21-0·69; p<0·0001). In the per-protocol population, 40 participants (78%) in the HSCT group had 101 serious events and 29 participants (67%) in the non-HSCT group had 70 serious adverse events. The most common serious adverse event other than graft-versus-host disease in both groups was infections, occurring in 30 participants (59%) in the HSCT group and in 19 participants (44%) in the non-HSCT group.

INTERPRETATION

Allogeneic HSCT was associated with significantly longer progression-free survival in participants with advanced-stage CTCLs. These results indicate that allogeneic HSCT treatment should be made available to individuals with high-risk, advanced-stage mycosis fungoides or Sézary syndrome who achieve pre-transplant disease remission.

FUNDING

French Ministry of Health, National Cancer Institute, Programme Hospitalier de Recherche Clinique en Cancérologie.

Are we there yet? cellular therapies for cutaneous T cell lymphoma

Cutaneous T cell lymphomas (CTCLs) are a heterogenous group of skin-involved T-cell non-Hodgkin lymphoma which Mycosis Fungoides and Sezary Syndrome are the most common variants. Despite considerable progress in distinguishing the pathophysiology, the treatment options are still limited for advanced-stage disease. Recent approval of novel agents such as vorinostat, brentuximab vedotin and mogamulizumab paved a way. Allogeneic hematopoietic stem cell transplantation has been shown to be a feasible option in selected advanced-stage CTCL patients. Chimeric antigen receptor (CAR) T cells have been promising for the treatment of B-cell tumors and have been approved for second-line treatment in non-Hodgkin's lymphoma. Although several obstacles still need to be addressed, CAR T cell treatment for CTCLs seems not far off. This review discusses new discoveries in pathophysiology, the state of cellular therapies in current practice, challenges for cellular treatment in advanced CTCL, and how to overcome these challenges.

Integrating novel agents into the treatment of advanced mycosis fungoides and Sézary syndrome

Agents targeting the unique biology of mycosis fungoides and Sézary syndrome are quickly being incorporated into clinical management. With these new therapies, we are now capable of inducing more durable responses and even complete remissions in advanced disease, outcomes which were exceedingly rare with prior therapies. Yet, even this new generation of therapies typically produce objective responses in only a minority of patients. As our therapeutic options increase, we are now challenged with selecting treatments from a growing list of options. To gain the full benefit of these novel agents, we must develop strategies to match treatments for the patients most likely to benefit from them. Here, we consider both the current approaches to treatment selection based on clinical features and the future of molecular biomarker-guided therapy for patients with this heterogeneous disease.

Cutaneous T-cell lymphomas: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or the blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Brentuximab vedotin in the treatment of cutaneous T-cell lymphomas: Data from the Spanish Primary Cutaneous Lymphoma Registry

BACKGROUND

Brentuximab vedotin (BV) has been approved for CD30-expressing cutaneous T-cell lymphoma (CTCL) after at least one previous systemic treatment. However, real clinical practice is still limited.

OBJECTIVES

To evaluate the response and tolerance of BV in a cohort of patients with CTCL.

METHODS

We analysed CTCL patients treated with BV from the Spanish Primary Cutaneous Lymphoma Registry (RELCP).

RESULTS

Sixty-seven patients were included. There were 26 females and the mean age at diagnosis was 59 years. Forty-eight were mycosis fungoides (MF), 7 Sézary syndrome (SS) and 12 CD30+ lymphoproliferative disorders (CD30 LPD). Mean follow-up was 18 months. Thirty patients (45%) showed at least 10% of CD30+ cells among the total lymphocytic infiltrate. The median number of BV infusions received was 7. The overall response rate (ORR) was 67% (63% in MF, 71% in SS and 84% in CD30 LPD). Ten of 14 patients with folliculotropic MF (FMF) achieved complete or partial response (ORR 71%). The median time to response was 2.8 months. During follow-up, 36 cases (54%) experienced cutaneous relapse or progression. The median progression free survival (PFS) was 10.3 months. The most frequent adverse event was peripheral neuropathy (PN) (57%), in most patients (85%), grades 1 or 2.

CONCLUSIONS

These results confirm the efficacy and safety of BV in patients with advanced-stage MF, and CD30 LPD. In addition, patients with FMF and SS also showed a favourable response. Our data suggest that BV retreatment is effective in a proportion of cases.

Allogeneic Hematopoietic Stem Cell Transplantation For Heavily Pretreated Patients With Mycosis Fungoides and Sezary Syndrome

Allogeneic hematopoietic stem cell transplantation (AHSCT) is a promising strategy for treatment of heavily pretreated mycosis fungoides/Sezary syndrome (MF/SS). Herein, we aimed to evaluate the outcomes of AHSCT for heavily pretreated patients with MF/SS retrospectively. This analysis included consecutive 19 patients with MF/SS who received 20 AHSCT between 2012-2021 in our transplant center. Eight patients have been previously reported. Fifteen patients had diagnosis of MF and referred to SS in five patients. In our cohort, all cases had advanced disease (stages IIB: n = 1, IIIA: n = 7; IIIB: n = 4, IVA: n = 4, IVB: n = 3). Nine patients (47.4%) had developed large cell transformation. Only two patients received AHSCT in complete response (CR), one very good partial response (VGPR) and two partial response (PR) while the others had progressive disease (PD) (n = 15) before transplant. Seven (35%) patients were alive at the time of analysis, with a median follow up of 10.5 months (range, 0.3-113 months) after AHSCT. Nine patients (47.4%) died without disease relapse or progression. NRM was 35.9% at 1 year and 26.9% at 3 years and therafter. For all patients the probability of OS was 48.5% and 32.3% at 1- and 5- year post-transplant, respectively. AHSCT for MF/SS resulted in an estimated PFS of 45.4% at 1 year. Given the poor prognosis of patients not receiving transplants and in the absence of curative non-transplantation therapies, our results support that AHSCT is able to effectively rescue 32.3% of the population of transplant eligible, heavily pretreated patients in 5 years. This article is protected by copyright. All rights reserved.

Macrophage-derived CXCL9 and CXCL11, T-cell skin homing and disease control in mogamulizumab-treated CTCL patients

Cutaneous T-cell lymphoma (CTCL) is a malignancy of skin-homing T-cells. Long-term remissions are rare in CTCL, and the pathophysiology of long-lasting disease control is unknown. Mogamulizumab is a defucosylated anti-human CCR4 antibody that depletes CCR4-expressing CTCL tumor cells and peripheral blood memory regulatory T cells. Prolonged remissions and immune side effects have been observed in mogamulizumab-treated CTCL patients. We report that mogamulizumab induced skin rashes in 32% of 44 CTCL patients. These rashes were associated with long-term CTCL remission, even in the absence of specific CTCL treatment. CTCL patients with mogamulizumab-induced rash had significantly higher overall survival (hazard ratio, 0.16 (0.04-0.73, p=0.01)). Histopathology and immunohistochemistry of the rashes revealed granulomatous and lichenoid patterns with CD163 macrophagic and CD8 T-cell infiltrates. Depletion of skin CTCL cells was confirmed by high-throughput sequencing analysis of TCRβ genes and in blood by flow cytometry. New reactive T-cell clones were recruited in skin. Gene expression analysis showed overexpression of CXCL9 and CXCL11, two chemokines involved in CXCR3-expressing T-cell homing to skin. Single-cell RNA sequencing analysis in skin of CTCL patients confirmed that CXCL9 and CXCL11 were primarily macrophage-derived and that skin T-cells expressed CXCR3. Finally, patients with rashes had a significantly higher proportion of exhausted reactive blood T-cells expressing TIGIT and PD1 at baseline compared to patients without rash, which decreased under mogamulizumab treatment, consistent with an activation of the antitumor immunity. Together, these data suggest that mogamulizumab may induce long-term immune control in CTCL patients by activation of the macrophagic and T-cell immune responses.

Case Report: Graft Versus Tumor Effect After Non-Myeloablative Allogeneic Stem-Cell Transplantation in a Patient With Brentuximab-Vedotin Refractory Sezary Syndrome

Sezary Syndrome (SS) is a rare leukemic variant of primary cutaneous T-cell lymphoma. Relapsed or refractory disease is generally considered incurable by conventional therapeutic approaches, although durable responses can be achieved with novel monoclonal antibodies. Allogeneic hematopoietic stem cell transplantation (alloHSCT) may have potential value by inducing graft vs-lymphoma (GvL) effects, but there is currently no consensus regarding the timing of alloHSCT or type of conditioning regimen. Here we present the case of a male patient who achieved a complete remission (CR) of primary refractory SS after non-myeloablative alloHSCT. Patient: Two years prior to HSCT, the patient had been refractory to CHOEP-based chemotherapy, interferon, extracorporeal photopheresis (ECP), and bexarotene. Directly prior to alloHSCT brentuximab-vedotin (BV) was applied resulting in a partial remission of the skin compartment and overall in a stable disease. Prior to HSCT, flow cytometry of the bone marrow and peripheral blood showed an infiltration with T-cells positive for CD5, CD4, low CD3, low CD2 and negative for CD7, CD38, HLA-DR and CD8. The trephine biopsy showed a 7% infiltration of SS cells. The CD4:CD8 ratio in peripheral blood (pb) was massively increased at 76.67, with 63.5% of white blood cells expressing a SS immune phenotype. The conditioning regimen included 30 mg/m2 fludarabine on days -5, -4 and -3 and total body irradiation with 2 Gy on day -1. Immunosuppression consisted of cyclosporine A from day-1 and mycophenolate mofetil from day 0. The patient received 6.55x106 CD34+ cells and 1.11x108 CD3+ cells/kg body weight. Bone marrow evaluation on day 28 still showed persistent SS cells by flow cytometry. After tapering immunosuppression until day 169, the CD4:CD8 ratio in pb normalized. CR was documented on day 169 after alloHSCT and is now ongoing for almost 3 years after alloHSCT. Conclusions: We confirm that an alloHSCT can be a curative option for refractory patients with SS. The achievement of a CR after tapering the immunosuppressive therapy indicates a significant role of the GvL effect. In present treatment algorithms for patients with SS, the timing of an alloHSCT and the intensity of conditioning should be further explored.

Cutaneous T-cell lymphomas: 2021 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multi-disciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Cutaneous T cell lymphoma

Primary cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphomas that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. CTCL subtypes demonstrate a variety of clinical, histological, and molecular features, and can follow an indolent or a very aggressive course. The underlying pathogenetic mechanisms are not yet entirely understood. The pathophysiology of CTCL is complex and a single initiating factor has not yet been identified. Diagnosis is based on clinicopathological correlation and requires an interdisciplinary team. Treatment decision is made based on short-term and long-term goals. Therapy options comprise skin-directed therapies, such as topical steroids or phototherapy, and systemic therapies, such as monoclonal antibodies or chemotherapy. So far, the only curative treatment approach is allogeneic haematopoietic stem cell transplantation. Novel therapies, such as chimeric antigen receptor T cells, monoclonal antibodies or small molecules, are being investigated in clinical trials. Patients with CTCL have reduced quality of life and a lack of effective treatment options. Further research is needed to better identify the underlying mechanisms of CTCL development and course as well as to better tailor treatment strategies to individual patients.

Multicentric EORTC retrospective study shows efficacy of brentuximab vedotin in patients who have mycosis fungoides and Sézary syndrome with variable CD30 positivity

BACKGROUND

Brentuximab vedotin (BV) was approved as a therapy for mycosis fungoides (MF) based on the ALCANZA trial. Little real-world data, however, are available.

OBJECTIVES

To evaluate the efficacy and safety of BV in patients with MF/Sézary Syndrome (SS) with variable CD30 positivity in a real-world cohort and to explore potential predictors of response.

METHODS

Data from 72 patients with MF/SS across nine EORTC (European Organization for Research and Treatment of Cancer) centres were included. The primary endpoint was to evaluate the proportion of patients with: overall response (ORR), ORR lasting over 4 months (ORR4), time to response (TTR), response duration (RD), progression-free survival (PFS) and time to next treatment (TTNT). Secondary aims included a safety evaluation and the association of clinicopathological features with ORR, RD and TTNT.

RESULTS

All 72 patients had received at least one systemic treatment. ORR was achieved in 45 of 67; ORR4 in 28 of 67 with a median TTR of 8 weeks [interquartile range (IQR) 5·5-14] and with a median RD of 9 months (IQR 3·4-14). Median PFS was 7 months (IQR 2-12) and median TTNT was 30 days (6-157·5). Patient response, RD, PFS and TTNT were not associated with any clinicopathological characteristics. In the MF group, patients with stage IIB/III vs. IV achieved longer PFS and had a higher percentage of ORR4. There was a statistically significant association between large-cell transformation and skin ORR (P = 0·03). ORR4 was more frequently achieved in patients without lymph node involvement (P = 0·04).

CONCLUSIONS

BV is an effective option for patients with MF/SS, including those with variable CD30 positivity, large-cell transformation, SS, longer disease duration and who have been treated previously with several therapies.