Phase II Study of the Efficacy and Toxicity of Ontak(Registered Trademark) (Denileukin Diftitox) in the Therapy of Adult T-Cell Leukemia

Inclusion Criteria

• •Patients must have serum antibodies directed to human T-lymphotropic virus type 1 (HTLV-I).
• •All patients must have a histologically confirmed diagnosis of adult T-cell leukemia/lymphoma and more than 10% of the malignant cells must express cluster of differentiation 25 (CD25).
• •All stages of Tac-expressing adult T cell leukemia except smoldering are eligible: patients with chronic, lymphomatous or acute adult T-cell leukemia (ATL) are eligible. (See appendix 2 for characteristics of patients with the various stages of ATL)
• •Patients must have measurable disease. All patients with greater than 10% abnormal (i.e. TAC homogenous strongly expressing) peripheral blood mononuclear cells (PBMC) in the peripheral blood will be deemed to have measurable disease.
• •The patient must have a granulocyte count of at least 1000/mm\^3 and a platelet count of greater than or equal to 50,000/mm\^3.
• •Patients must have a creatinine of less than 2.0 mg/dl.
• •Omission of cytotoxic chemotherapy for ATL for 3 weeks prior to entry into the trial is required. However, patients receiving corticosteroids will be eligible.
• •Patients must have a life expectancy of greater than 2 months.
• •Eligible patients must be greater than or equal to 18 years old. There is no upper age limit.
• •Patients must have serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) value less than or equal to 2.5 times the upper limit of normal and bilirubin less than or equal to 3.0/dl. If a liver function test is judged to be elevated due to the underlying ATL, this parameter will be considered an unevaluable parameter for toxicity determinations.
• •Patients must have a serum albumin greater than or equal to 2.5 g/dl
• •Patients must be able to understand and sign an Informed Consent form.
• •All patients must use adequate contraception during participation in this trial and for three months after completing therapy.