Recombinant Human Interleukin-2, Recombinant Human Interferon Alfa-2a, or Both in Metastatic Renal-Cell Carcinoma

Background Recombinant human interleukin-2 (aldesleukin) and recombinant human interferon alfa can induce notable tumor regression in a limited number of patients with metastatic renal-cell carcinoma. We conducted a multicenter, randomized trial to determine the effect of each cytokine independently and in combination, and to identify patients who are best suited for this treatment. Methods Four hundred twenty-five patients with metastatic renal-cell carcinoma were randomly assigned to receive either a continuous intravenous infusion of interleukin-2, subcutaneous injections of interferon alfa-2a, or both. The main outcome measure was the response rate; secondary outcomes were the rates of event-free and overall survival. Predictive factors for response and rapid progression were identified by multivariate analysis. Results Response rates were 6.5 percent, 7.5 percent, and 18.6 percent (P