Dexamethasone Followed by Denileukin Diftitox in Treating Patients With Persistent or Recurrent T-Cell Lymphoma

DISEASE CHARACTERISTICS: Diagnosis of persistent or recurrent cutaneous T-cell lymphoma (CTCL) and suitable for denileukin diftitox therapy

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Not specified Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Albumin at least 3.0 mg/dL Renal: Not specified Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception for at least 28 days prior to and during study No known hypersensitivity to denileukin diftitox or its components (e.g., diphtheria toxin, interleukin-2, or its excipients) or to dexamethasone No concurrent serious, uncontrolled infection that would preclude study

PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics No prior denileukin diftitox (DAB389-interleukin-2) or DAB486-interleukin-2 No concurrent interferon Chemotherapy: No concurrent chemotherapy* No concurrent extracorporeal photochemotherapy* No concurrent systemic or combination cytotoxic chemotherapy No concurrent topical chemotherapy *For remission induction of CTCL Endocrine therapy: No other concurrent corticosteroids Radiotherapy: No concurrent electron beam radiotherapy and/or photophoresis Surgery: Not specified Other: At least 21 days since any prior anticancer therapy and recovered No other concurrent anticancer therapy for CTCL No concurrent experimental drugs or approved drugs tested in an investigational setting No concurrent topical therapy* No concurrent phototherapy* No concurrent cyclosporine No concurrent systemic retinoids *For remission induction of CTCL