Benefit of Allogeneic Haematopoietic Stem Cells in Cutaneous T-cell Lymphomas Epidermotropic With Advanced Stage and Poor Prognosis

Inclusion Criteria: * Age ≥ 18 and ≤ 65 years * Histopathologically confirmed diagnosis of International Society for Cutaneous Lymphomas (ISCL) / European Organisation for Research and Treatment of Cancer (EORTC) stage IIB, III, IVA or IVB ETCL * Complete or partial response of the lymphoma (as defined by the international ISCL-EORTC criteria at the time of inclusion * Written informed consent given by the patient * Contraception in women of childbearing age * Hematopoietic stem cell donor search underway And at least one of the three following criteria: * Refractoriness or early relapse (i.e. within one year) after at least one line of systemic chemotherapy (not including skin-directed therapies, methotrexate, interferon-alpha, and oral retinoids) * Early histological large-cell transformation, i.e. within two years following ETCL diagnosis * Histologically proven nodal (ISCL / EORTC N3) or extra-cutaneous visceral involvement by the lymphoma Exclusion Criteria: * Prior allogeneic HSCT * Other progressive neoplastic disease * Progressive psychotic disease * Left ventricular ejection fraction \< 50% (as determined by trans-thoracic echocardiography) * Pulmonary disease with FEV1, FVC or DLCO \<30% of expected corrected for hemoglobin. * Creatinine clearance \<50 ml/min or requiring dialysis * Transaminases or bilirubin \>two-fold the normal value in the absence of liver involvement by the lymphoma * Pregnant or breastfeeding woman * Patient with no health coverage * Patient under guardianship or curatorship * HTLV-1 lymphoma