Treatment of patients with metastatic renal carcinoma with a combination of subcutaneous interleukin-2 and interferon alfa with or without fluorouracil. Groupe Français d'Immunothérapie, Fédération Nationale des Centres de Lutte Contre le Cancer.

Purpose: Subcutaneous recombinant interleukin-2 (rIL-2) and recombinant interferon alfa-2a (rIFNalpha-2a) have been used extensively in the treatment of metastatic renal cancer. Most results, coming from noncontrolled phase II trials, showed inconsistent rates of response. More recently, the addition of fluorouracil (FU) was proposed to improve the efficacy of these regimens.

Patients And Methods: The role of a subcutaneous combination of rIL-2 and rIFNalpha-2a with or without FU was investigated. Patients were randomly assigned to receive a combination of rIL-2 and rIFNalpha-2a at weeks 1, 3, 5, and 7 or the same combination together with a continuous infusion of FU at weeks 1 and 5. The major end points of this multicenter, randomized trial were progression-free survival, response rate, and toxicity. Overall survival was a secondary end point. Tumor responses were reviewed by an independent committee. Analysis of the results was performed on an intention-to-treat basis.

Results: One hundred thirty-one patients were enrolled. There was no difference in toxicity between the arms, and no toxic death was observed. One partial response was observed in arm A and five in arm B. Progression-free survival did not differ between the arms, and rates at 1 year were 12% and 15% in arms A and B, respectively. No statistically significant differences were detected in any end point.

Conclusion: The subcutaneous combination of rIL-2 and rIFNalpha-2a with or without FU does not benefit patients with metastatic renal carcinoma. Neither of these regimens can be recommended as standard treatment. The results of the subcutaneous cytokine regimen seem disappointing.