Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of 1 of the following:

- Melanoma

- Kidney cancer

- Metastatic disease

- Measurable disease

- Documented disease progression while receiving standard therapy

- No resectable local or regional disease

PATIENT CHARACTERISTICS:

Age

- 16 and over

Performance status

- ECOG 0-2

Life expectancy

- More than 3 months

Hematopoietic

- WBC ≥ 3,000/mm^3

- Platelet count ≥ 90,000/mm^3

- Lymphocyte count ≥ 500/mm^3

- No concurrent coagulation disorders

Hepatic

- Bilirubin ≤ 2.0 mg/dL (< 3.0 mg/dL for patients with Gilbert's syndrome)

- AST and ALT < 3 times normal

- Albumin ≥ 2.5 g/dL

- Hepatitis B surface antigen negative

- Hepatitis C antibody negative

Renal

- Creatinine ≤ 2.0 mg/dL

Cardiovascular

- Normal thallium stress test*

- No prior myocardial infarction

- No history of severe coronary artery disease

- No major medical illness of the cardiovascular system NOTE: *For patients > 50 years
of age OR who have a history of cardiovascular disease

Pulmonary

- No major medical illness of the respiratory system

Immunologic

- HIV negative

- No active systemic infection

- No presence of opportunistic infections

- No primary or secondary immunodeficiency

- No autoimmune disease

- No other known immunodeficiency

Other

- No sensitivity to denileukin diftitox or any of its components (e.g., diphtheria
toxin, interleukin-2, or excipients)

- Willing to undergo leukapheresis

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Prior treatment with interleukin-2 allowed provided the patient's disease status
required this therapy

Chemotherapy

- Recovered from prior chemotherapy

Endocrine therapy

- No concurrent systemic steroids

Radiotherapy

- Recovered from prior radiotherapy

Surgery

- Not specified

Other

- More than 3 weeks since prior systemic anticancer therapy

- No other concurrent systemic anticancer therapy