CD39 is expressed by a wide range of cutaneous T-cell lymphomas.

CD39, an ectoenzyme in the immunosuppressive CD39/CD73/adenosine pathway, known to promote solid tumour outgrowth and spreading, was investigated in both skin and blood compartments of cutaneous T cell lymphomas. CD39 was overexpressed by peripheral blood T-cells in Sezary syndrome and mycosis fungoides, and in skin-infiltrating lymphocytes of Sezary syndrome, mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma and primary cutaneous CD30-positive lymphoproliferation. Our study emphasizes the interest in using CD39/CD73/adenosine pathway blocking agents for cutaneous T cell lymphomas treatment.

Real-world study on the use of pegylated interferon alpha-2a for treatment of mycosis fungoides/Sézary syndrome using Time to Next Treatment as a measure of clinical benefit: An EORTC CLTG study.

INTRODUCTION: Mycosis fungoides (MF) and Sézary syndrome (SS) are chronic malignant diseases that typically necessitate diverse strategies to achieve remission. Systemic interferon alpha (IFN-α, subtypes 2a and 2b) has been used for MF/SS since 1984, however its production was recently stopped and so the recombinant pegylated (PEG) form of IFN α-2a remains as single IFN alternative treatment, even though not approved for MF/SS. OBJECTIVE: To assess effectiveness and safety of PEG IFN α-2a in monotherapy and in combination with other treatments using time to next treatment (TTNT) as a measure of clinical therapeutic benefit in real world setting. METHODS: We conducted an international and multicenter retrospective study of patients with MF and SS at any stage, treated with PEG IFN α-2a, from July 2012 to February 2022. Patients were included across 11 centers in 10 countries. Primary endpoints were to determine TTNT of PEG IFN α-2a and the adverse events (AE) in MF/SS. RESULTS: In total 105 patients were included, mean age was 61 (22-86 years); 42 (40%) with disease stage IA-IIA, 63 (60%) with stage IIB-IVB. PEG IFN α-2a was combined with other therapies in 67 (64%) patients, usually with extracorporeal photopheresis (36%) and bexarotene (22%). Fifty-seven percent of stage I-IIA patients achieved ORR, whereas 51% of stage IIB-IVB. Combination therapy showed a TTNT of 10.4 months, while 7 months in monotherapy (p=0.0099). Overall, TTNT was 9.2 months, ORR was 53% (56/105), CR and PR were 13% and 40%, respectively.AE were described in 69% (72) of the patients. Flu-like symptoms (27%), lymphopenia (23%) and elevated liver function (10%) were the most frequently reported. Grade 3-4 adverse events were reported in 23 (21%) patients, which were mostly related to myelosuppression. LIMITATIONS: retrospective data analysis and unrestricted number of combination therapies. CONCLUSIONS: PEG IFN α-2a for MF/SS showed ORR of 53%, TTNT of 9.2 months, superiority of combination regimens in comparison to monotherapy and doses of 180 mcg/weekly related to higher ORR.

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.

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.

Bone involvement in primary cutaneous diffuse large B-cell lymphoma, leg-type.

Primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT) is an aggressive cutaneous lymphoma. Bone involvement is rare and poorly described. We present five cases of PCDLBCL-LT with bone localization. In four cases, the bone involvement was diagnosed during the initial staging with positron emission tomography (PET) or computed tomography (CT) scan, and in the fifth case after tibial fracture during treatment with rituximab (RTX) and polychemotherapy (PCT). PCDLBCL-LT can be asymptomatic and involve bone sites distant from cutaneous lesions. None had other extracutaneous involvement. In our series, all patients received RTX-PCT as first-line chemotherapy and all had early relapses or progression. Second-line treatments had poor efficacy. Our series shows that bone involvement seems to be associated with poor prognosis in PCDLBCL-LT. Bone localization is not diagnosed with initial thoracic-abdominal-pelvic CT when asymptomatic and affecting the limbs only. If there is a suspicion of PCDLBCL-LT, patients should undergo systematic investigation with alternative imaging techniques, including PET, both at baseline and if there is any concern during follow-up.

Clinical Features, Histological Characteristics, and Disease Outcomes of Mycosis Fungoides in Children and Adolescents: A Nationwide Multicentre Cohort of 46 Patients.

BACKGROUND: Our objective was to describe the clinical, histological characteristics, and disease outcome of a cohort of mycosis fungoides (MF) diagnosed during childhood including disease status at adulthood. METHODS: This is a retrospective multicentre survey of patients aged under 18 years at diagnosis with histologically confirmed MF. Patients' clinical and histological characteristics, treatments, and disease outcome (for patients followed for more than 12 months) were analysed. RESULTS: Forty-six patients were included (median age at diagnosis: 11 years; M:F sex ratio: 3:1) with 39 (85%) followed for at least 12 months. Thirty-nine patients (85%) had stage I MF. Hypopigmented patches were observed in 48% and folliculotropism in 43% patients. Immunophenotype of the skin infiltrate was predominantly CD8+ in 17% of patients. Initial management included a wait-and-see strategy in 6/39 (15%), skin-directed treatment in 27 (69%), and systemic treatment in 6 (15%) patients, respectively, with partial or complete clinical response (PR or CR) observed in 28 patients (72%). 14/39 patients (36%) relapsed after initial response. After a median follow-up period of 54 months, disease status at last news was PR or CR in 31/39 (79%), stable disease in 6 (15%), and progression in 2 (5%) patients. Histological transformation was observed in 3/39 (8%). Of the 15 patients followed until adulthood, 13 (87%) had persistent MF. DISCUSSION: This survey confirms the high frequency of hypopigmented and folliculotropic lesions and of CD8+ immunophenotype compared to adult MF patients. The long-term course is usually indolent but transformation may occur sometimes long after disease onset and the disease may persist during adulthood.

Validation of AAC-11-Derived Peptide Anti-Tumor Activity in a Single Graft Sézary Patient-Derived Xenograft Mouse Model.

Sézary syndrome (SS) is an aggressive cutaneous T cell lymphoma with poor prognosis mainly characterized by the expansion of a tumor CD4+ T cell clone in both skin and blood. So far, the development of new therapeutic strategies has been hindered by a lack of reproducible in vivo models closely reflecting patients' clinical features. We developed an SS murine model consisting of the intravenous injection of Sézary patients' PBMC, together with a mixture of interleukins, in NOD-SCID-gamma mice. Thirty-four to fifty days after injection, mice showed skin disorders similar to that observed in patients, with the detection of epidermis thickening and dermal tumor T cell infiltrates. Although experimental variability was observed, Sézary cells could be tracked in the blood stream, confirming that our model could efficiently exhibit both skin and blood involvement. Using this model, we evaluated the therapeutic potential of RT39, a cell-penetrating peptide derived from the survival protein anti-apoptosis clone 11 (AAC-11), that we previously characterized as specifically inducing apoptosis of Sézary patients' malignant clone ex vivo. Systemic administration of RT39 led to cutaneous tumor T cells depletion, demonstrating efficient malignant cells' targeting and a favorable safety profile. These preclinical data confirmed that RT39 might be an innovative therapeutic tool for Sézary syndrome.