Combination of interleukin-2 and interferon-alpha in renal cell carcinoma and malignant melanoma: a phase II clinical trial.

A total of 22 patients with metastatic renal cell carcinoma or malignant melanoma were treated in a phase II study to assess the safety and efficacy of combination therapy of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha). 3 x 10(6) U/m2/day recombinant human (rh)IL-2 was given in repetitive cycles by continuous 24-h infusion from day 1 to day 4; 6 x 10(6) U/m2/day rhIFN-alpha was given subcutaneously on days 1 and 4. There was one complete remission and two partial remissions in the renal cell carcinoma group and two partial remissions in the malignant melanoma group, giving an overall response rate of 24% in 21 evaluable patients with a median response duration of 5+ months. Toxicity was moderate, with hypotension, fever, chills, nausea, neurotoxicity, and dermatitis as prominent side effects. Measurement of circulating cytokine levels showed increased serum tumor necrosis factor-alpha (TNF), interferon-tau, and soluble interleukin-2 receptor levels during each cycle with a tendency to higher concentrations of TNF in responders as compared to nonresponders. With regard to therapeutic efficacy and tolerance, our approach might represent an alternative to the high-dose protocols and the labor- and cost-intensive strategies of adoptive immunotherapy.