TSEB and Brentuximab for Treatment of Mycosis Fungoides & Sezary Syndrome

Inclusion Criteria: * Histologically confirmed CD30-positive (defined in this study as ≥ 1% expression) Mycosis Fungoides (including large cell transformation variant) or Sezary Syndrome who have either: * Received prior systemic therapy (for whom commercial supply of brentuximab vedotin is available) OR * Not received prior systemic therapy (who will receive brentuximab vedotin free of charge) * Any of the disease stages listed below * Stage IB disease that meets one of the following criteria: * Plaque disease (ie,T2b staging) * Diffuse skin involvement with indication for TSEB (plaque disease with or without patches) * Not appropriate for treatment with focal therapies * One prior course of low-dose TSEB or one prior course of systemic chemotherapy regimens (excluding brentuximab) * Stage IIA, IIB, or IIIA that meets ONE or BOTH of the following criteria: * Patient is a candidate for treatment with low-dose TSEB * Patient is a candidate for systemic therapy * IIIB or IVA disease requiring systemic therapy * Transformed CTCL * Candidate for TSEB based on investigator determination * Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, 2, or 3, if the performance status of 3 is due to skin disease involvement * Adequate bone marrow function as defined below: * Absolute neutrophil count (ANC) ≥ 1000/mm3 * Platelets \> 75,000/mm3 * Hemoglobin ≥ 9 g/dL * Note: Patients requiring transfusion to meet the hemoglobin requiremen…