56 | first-line extracorporeal photopheresis plus interferon-α in sézary syndrome: Real-world survival and exploratory blood biomarkers

Background. Sézary syndrome (SS) is a rare and aggressive leukemic variant of cutaneous T-cell lymphoma, characterized by erythroderma, peripheral blood involvement by malignant Sézary cells¹˒² Management usually requires multimodal strategies. Extracorporeal photopheresis (ECP), alone or combined with interferon-α (IFN-α), is widely used as a first-line option in erythrodermic CTCL, although outcomes are heterogeneous and reliable prognostic biomarkers remain insufficiently defined. The aim is evaluate overall survival (OS) in patients with SS treated with first-line ECP plus IFN-α, and to explore whether blood clonality and Sézary cell immunophenotype are associated with distinct survival patterns.Materials and Methods. We conducted a retrospective single-center survival analysis of 72 consecutive patients with SS treated with first-line ECP plus IFN-α between 2000 and 2023. Patients were stratified according to extreme survival outcomes. Blood tumor burden was assessed by flow cytometry using a TCR Vβ repertoire kit combined with anti-CD3 and anti-CD4 antibodies. When applicable, Sézary cells were also identified by the aberrant immunophenotypic profile.³ Results. The cohort included 72 patients, with a median age at diagnosis of 69 years; 39 were female and 33 male. Median treatment duration with ECP plus IFN-α was 18 months. Kaplan–Meier analysis showed a median OS of 59 months and a 5-year survival rate of 44.9%. Thirteen long survivors, defined by OS >80 months, and 13 poor survivors, defined by OS