Effectiveness of mogamulizumab in patients with Mycosis Fungoides or Sézary syndrome: A multicentre, retrospective, real-world French study.

BACKGROUND: Efficacy and safety of mogamulizumab, a monoclonal antibody directed against C-C chemokine receptor 4, were demonstrated in a previous multinational clinical trial conducted in patients with previously treated cutaneous T-cell lymphoma (CTCL): Sézary syndrome (SS) or Mycosis Fungoides (MF). OBJECTIVES: The real-world French OMEGA study aimed to describe effectiveness and tolerability of mogamulizumab in adult patients with CTCL, overall and according to the disease (SS or MF). METHODS: In this retrospective study, patients treated with mogamulizumab for SS or MF were included from 14 French expert centres. The overall response rate (ORR) under treatment was described (primary criterion), as well as treatment use and safety data. RESULTS: The 122 analysed patients (69 SS, 53 MF) were aged 66.6 ± 12.1 years at mogamulizumab initiation, and their median disease duration was 2.5 years (IQR: 1.3-5.6). Prior to treatment start, they received a median of three systemic CTCL therapies (2-5). Overall, 77.8% of patients suffered from advanced disease (Stage IIB-IVB), with frequent blood (B1/B2) involvement (67.5%). Over the treatment period (median: 4.6 months, 2.1-7.2), 96.7% of patients received all the planned mogamulizumab infusions. Among the 109 patients evaluable for effectiveness, ORR was 58.7% (95% CI [48.9-68.1]) overall, 69.5% [56.1-80.8] in SS and 46.0% [31.8-60.7] in MF. Compartmental response in the blood was observed in 81.8% [69.1-90.9] of SS patients. Skin responses were observed in 57.0% [47.0-66.5] of patients overall, 66.7% [52.9-78.6] in SS and 46.0% [31.8-60.7] in MF. The most common serious adverse drug reactions were rash (8.1% of patients) and infusion-related reactions (2.4%) which led to treatment discontinuation in 7.3% and 0.8% of patients, respectively. One patient with SS died from mogamulizumab-related tumour lysis syndrome. CONCLUSIONS: This large French study confirmed the effectiveness and tolerability of mogamulizumab in SS and MF patients in routine medical practice.

Neutrophilic dermatoses.

Neutrophilic dermatoses (ND) are a group of inflammatory skin conditions characterized by a neutrophilic infiltrate on histopathology with no evidence of infection. ND are classified based upon the localization of neutrophils within the skin and clinical features. Recent findings suggest that ND are due to two main mechanisms: i) a polyclonal hereditary activation of the innate immune system (polygenic or monogenic); or ii) a clonal somatic activation of myeloid cells such as encountered in myelodysplastic syndrome or VEXAS syndrome. ND belong to internal medicine as a great number of patients with ND suffer from an underlying condition (such as hematological malignancy, inflammatory bowel disease, auto-immune and auto-inflammatory diseases). ND are diagnoses of exclusion and physicians should always consider differential diagnoses, particularly skin infections. Here, we review the pathophysiology and classification of the main ND (i.e., subcorneal pustular dermatosis (Sneddon-Wilkinson Disease) and Intercellular IgA dermatoses, aseptic pustulosis of the folds, Sweet syndrome, neutrophilic eccrine hidradenitis, pyoderma gangrenosum, erythema elevatum diutinum, neutrophilic urticarial dermatosis and neutrophilic panniculitis), their clinical and histopathological features, and we highlight the investigations that are useful to identify ND-associated diseases and to exclude the differential diagnoses.

Recent advances on cutaneous lymphoma epidemiology.

BACKGROUND: Primary cutaneous lymphomas are a group of T- (CTCL) and B-cell (CBCL) malignancies. These diseases have different clinical presentations and prognosis. Our knowledge on their epidemiology is limited. Aim of this review was to summarize recent findings on the incidence of CTCL and CBCL, how they change over time, and to describe possible causes and consequences. We found that although there are important differences in the epidemiology of cutaneous lymphomas in different countries, the relative frequency of certain, especially rare lymphomas remains stable. Several studies described growing incidences of both CTCL and CBCL. The emergence of new diagnostic criteria, a more precise definition of the entities and new biomarkers enable a better classification of cases.

Lymphomatoid papulosis types D and E: a multicentre series of the French Cutaneous Lymphomas Study Group.

BACKGROUND: Lymphomatoid papulosis (LyP) type D (LyP D) and type E (LyP E) have recently been described in small series of cases or isolated case reports. AIM: To further describe the clinical and histological features of LyP D and E based on a retrospective multicentre study. METHODS: The clinical and histopathological features of 29 patients with an initial diagnosis of LyP D or LyP E were retrospectively assessed using standardized forms. RESULTS: After exclusion of 5 cases, 24 patients (14 LyP D, 10 LyP E) were enrolled in the study. The median follow-up was 2.5 years (range 1 month to 13 years). LyP D was characterized by multiple recurrent self-regressing small papules that developed central erosion or necrosis, whereas LyP E presented as papulonodular lesions that rapidly evolved into necrotic eschar-like lesions > 10 mm in size. Epidermal changes were more frequent in LyP D, whereas dermal infiltrates were deeper in LyP E. Anaplastic cytology was rare and the DUSP22 rearrangement was never observed. Two patients (8%) had an associated cutaneous lymphoma. CONCLUSION: LyP D and E have distinct clinical findings and may be associated with other cutaneous lymphomas.

Image-guided lymph node core-needle biopsy predicts survival in mycosis fungoides and Sézary syndrome.

BACKGROUND: The prognosis of Sézary syndrome (SS) and mycosis fungoides (MF) depends on lymph node (LN) involvement. The usefulness of LN image-guided core-needle biopsies (CNBs), instead of surgical sampling, has been poorly evaluated. OBJECTIVES: To determine the prognostic value of LN CNB in MF/SS. METHODS: A retrospective search was conducted to identify all LN biopsy specimens of MF/SS between 2008 and 2019. Biopsies were staged according to the International Society for Cutaneous Lymphomas/European Organisation for Research and Treatment of Cancer (ISCL/EORTC) criteria. We performed immunolabelling and determined the tumour clone frequency (TCF) by high-throughput sequencing of the T-cell receptor beta locus. RESULTS: We included 119 consecutive biopsies from 100 patients, 45 with MF and 55 with SS. N1, N2 and N3 stages were diagnosed in 34 (29%), 26 (22%) and 59 (49%) cases, respectively. The TCF, Ki67 index, and percentage of cells positive for thymocyte selection-associated high mobility group box protein (TOX), programmed cell death protein 1 (PD1), killer cell immunoglobulin-like receptor 3DL2 (KIR3DL2) and cluster of differentiation (CD)30 were all positively correlated with the N stage. Median overall survival (OS) for N1/N2 vs. N3 patients was 42 months (range 26-not reached) vs. 14 months (range 5-30), respectively (P < 0·001). In univariate analyses, an age > 75 years, LN short-axis diameter > 15 mm, N3 stage, presence of large-cell transformation, TOX > 60%, PD1 > 25%, Ki67 > 30%, KIR3DL2 > 15%, CD30 > 10% and TCF > 25% were identified as adverse prognostic factors. In multivariate analyses, only an age > 75 years and Ki67 index > 30% were associated with reduced OS. We developed a new prognostic index associating the N stage and the Ki67 index, which better discriminates N3 patients with poor prognosis. CONCLUSIONS: CNB allows an objective assessment of the LN involvement in MF/SS, relevant for staging and prognosis.

The value of five blood markers in differentiating mycosis fungoides and Sézary syndrome: a validation cohort.

BACKGROUND: Clinical and histological diagnosis of Sézary syndrome (SS) and mycosis fungoides (MF) is challenging in clinical routine. OBJECTIVES: We investigated five blood markers previously described for SS (T-plastin, Twist, KIR3DL2, NKp46 and Tox) in a prospective validation cohort of patients. METHODS: We included 447 patients in this study and 107 patients were followed up for prognosis. The markers were analysed by reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) on peripheral blood leucocytes and CD4+ T cells in a cohort of consecutive patients with early MF, erythrodermic MF and SS and compared with patients presenting with benign inflammatory dermatoses (BID) and erythrodermic BID. The markers were assessed in parallel to gold standard values such as CD4/CD8 ratio, loss of CD7 and CD26 membrane expression and CD4 absolute values. Sensitivity and specificity were analysed by receiver operator characteristic curves. The prognostic value of selected markers was analysed on a subset of patients. This study was conducted in one centre. RESULTS: We defined cut-off values for each marker. T-plastin, Twist and KIR3DL2 had the best validity. SS may be overrepresented. The combination of T-plastin and Twist was able to differentiate between erythrodermic MF or BID and SS. The additional analysis of KIR3DL2 may be useful to predict the prognosis. CONCLUSIONS: We propose T-plastin, Twist and KIR3DL2 measured by RT-qPCR as new diagnostic markers for Sézary syndrome.

Epidemiological changes in cutaneous lymphomas: an analysis of 8593 patients from the French Cutaneous Lymphoma Registry.

BACKGROUND: Primary cutaneous lymphomas (PCLs) are a heterogeneous group of T-cell (CTCL) and B-cell (CBCL) malignancies. Little is known about their epidemiology at initial presentation in Europe and about potential changes over time. OBJECTIVES: The aim of this retrospective study was to analyse the frequency of PCLs in the French Cutaneous Lymphoma Registry (GFELC) and to describe the demography of patients. METHODS: Patients with a centrally validated diagnosis of primary PCL, diagnosed between 2005 and 2019, were included. RESULTS: The calculated incidence was unprecedently high at 1·06 per 100 000 person-years. The number of included patients increased yearly. Most PCL subtypes were more frequent in male patients, diagnosed at a median age of 60 years. The relative frequency of rare CTCL remained stable, the proportion of classical mycosis fungoides (MF) decreased, and the frequency of its variants (e.g. folliculotropic MF) increased. Similar patterns were observed for CBCL; for example, the proportion of marginal-zone CBCL increased over time. CONCLUSIONS: Changes in PCL frequencies may be explained by the emergence of new diagnostic criteria and better description of the entities in the most recent PCL classification. Moreover, we propose that an algorithm should be developed to confirm the diagnosis of PCL by central validation of the cases.

Revisiting the initial diagnosis and blood staging of mycosis fungoides and Sézary syndrome with the KIR3DL2 marker.

BACKGROUND: The early diagnosis of Sézary syndrome (SS) is challenging. Loss of CD7 and CD26 expression on CD4+ T cells is the currently used criterion in the initial diagnosis and staging of patients with SS. OBJECTIVES: Our aim was to evaluate the respective value of CD26, CD7 and KIR3DL2 expression on CD4+ T cells and total lymphocytes at initial diagnosis of SS. METHODS: This prospective study included 254 patients with clinical features consistent with cutaneous T-cell lymphoma seen at our institution between March 2014 and February 2019. Peripheral blood analysis by flow cytometry was performed for each patient at the time of diagnosis and during follow-up. The diagnosis of SS was based on ISCL/EORTC criteria. RESULTS: The presence of KIR3DL2+ Sézary cells (SCs) ≥ 200 µL-1 correlated with the diagnosis of SS, with sensitivity of 88·6% and specificity of 96·3%. All 154 patients with either inflammatory skin disease or other haematological disease had KIR3DL2+ cells < 200 µL-1 , while eight of them had CD4+ CD26- T cells ≥ 1000 µL-1 . Of five patients with SS and lymphopenia, four had CD4+ CD7- T cells < 1000 µL-1 and three had CD4+ CD26- T cells < 1000 µL-1 . However, all of them had KIR3DL2+ CD4+ T cells ≥ 200 µL-1 . Among patients with available samples during evolution, all B1-staged patients with ≥ 200 µL-1 KIR3DL2+ SCs at diagnosis evolved to B2 stage within 7 months. CONCLUSIONS: KIR3DL2 expression on T cells is highly specific and helps the early diagnosis of SS, especially in those patients with lymphopenia. What's already known about this topic? In the ISCL/EORTC cutaneous T-cell lymphoma (CTCL) categorization of blood involvement (B0-B2), B2 is defined as a T-cell receptor clonal rearrangement in blood, associated with high blood-smear Sézary cell (SC) count. Flow cytometry was developed to circumvent interobserver variability of SC manual counts; however, it mostly relies on detection of cells lacking CD7 and/or CD26 expression. We previously reported the reliability of KIR3DL2 as the first positive SC marker. What does this study add? Based on our analysis of 254 patients, we propose that KIR3DL2 be added to the ISCL/EORTC criteria for initial diagnosis of Sézary syndrome (SS) and B2 staging. This marker improved sensitivity of SS B2-stage CTCL diagnosis with a specificity > 95%, especially for patients with lymphopenia. We found KIR3DL2 helped early diagnosis of SS and was more reliable than CD26 in assessing blood tumour burden during therapy. What is the translational message? SC quantification is the major means of staging at initial diagnosis and monitoring blood tumour burden in a clinical trials setting. We recommend using a threshold value of KIR3DL2+ SCs ≥ 200 µL-1 or KIR3DL2+ SCs/lymphocytes ≥ 10% in the diagnostic criteria of SS and propose a novel algorithm for CTCL B2 blood staging.