RATIONALE: Interleukin-12 may kill tumor cells by stopping blood flow to the tumor and by stimulating a person's white blood cells to kill cancer cells. Interferon alfa may interfere with the growth of the cancer cells. Combining interleukin-12 and interferon alfa may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of combining interleukin-12 and interferon alfa in treating patients who have metastatic malignant melanoma.

OBJECTIVES:

• Determine the clinical response rate in patients with metastatic malignant melanoma treated with interleukin-12 and interferon alfa.
• Determine the progression-free survival of patients treated with this regimen.

OUTLINE: This is a multicenter study.

Patients receive interleukin-12 IV over 5-15 seconds on day 1 and interferon alfa subcutaneously on days 2-6. Treatment repeats every 2 weeks in the absence of unacceptable toxicity. Patients are reassessed after 6 courses. Patients with a complete response receive 2 additional courses. Patients with a partial response or stable disease continue treatment in the absence of disease progression.

Patients are followed every 3 months for 1 year and then every 6 months for 1 year.

PROJECTED ACCRUAL: A total of 30-60 patients will be accrued for this study within 6-12 months.

• Biological: recombinant interferon alfa
• Biological: recombinant interleukin-12

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed cutaneous melanoma

  • Clinically evident distant, metastatic, unresectable regional lymphatic, or extensive in transit recurrent disease

• At least 1 unidimensionally measurable lesion

  • At least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan

  • The following are not considered measurable:

    • Bone lesions
    • Leptomeningeal disease
    • Ascites
    • Pleural/pericardial effusion
    • Inflammatory breast disease
    • Lymphangitis cutis/pulmonis
    • Abdominal masses not confirmed and followed by imaging techniques
    • Lytic lesions
    • Lesions in a previously irradiated area
• No brain metastases or other CNS disease

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-1

Life expectancy:

• Not specified

Hematopoietic:

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin greater than 9 g/dL (transfusion or epoetin alfa allowed)
• No hemolytic anemia

Hepatic:

• Hepatitis B surface antigen negative

Renal:

• Not specified

Cardiovascular:

• No uncontrolled or severe cardiovascular disease

Pulmonary:

• No pulmonary disease

Other:

• HIV negative
• No prior peripheral neuropathy
• No active or unresolved severe peptic ulcer disease or gastrointestinal bleeding
• No history of or active autoimmune disease
• No concurrent infection
• No diabetes
• No other major active illness
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior interleukin-12
• No prior interferon alfa for metastatic disease
• Prior adjuvant interferon alfa allowed provided patient is disease-free for at least 12 months after last treatment
• No prior cytokine therapy for metastatic disease (e.g., high-dose interleukin-12)

Chemotherapy:

• At least 3 weeks since prior chemotherapy
• No more than 1 prior chemotherapy regimen

Endocrine therapy:

• At least 3 weeks since prior anti-hormonal therapy

Radiotherapy:

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy

Surgery:

• Not specified