Patients with mature T cell lymphomas not included above will be enrolled in a fourth arm. These include but are not exclusively limited to: Enteropathy-type T cell lymphoma; Hepatosplenic T-cell lymphoma; Subcutaneous panniculitis-like T cell lymphoma; Angioimmunoblastic T-cell lymphoma; Anaplastic large cell lymphoma. Patients must have experienced disease progression after receiving prior standard treatment. There will be no limit on the number of prior regimens. Primitive T cell neoplasms and T cell leukemias will not be enrolled.