Purpose: To update response duration and survival data for patients with metastatic renal cell carcinoma treated with high-dose interleukin (IL)-2.
Patients and methods: Two hundred fifty-five assessable patients were entered onto seven phase II clinical trials. Recombinant IL-2 600,000 or 720,000 IU/kg was administered by 15-minute intravenous infusion every 8 hours for up to 14 consecutive doses over 5 days as clinically tolerated with maximal support. A second, identical cycle of treatment was scheduled following 5 to 9 days of rest, and courses could be repeated every 6 to 12 weeks in stable or responding patients. All data were updated as of December 1998, with report forms completed by the clinical investigators. These data had last been updated as part of the Food and Drug Administration reporting requirements in 1996.
Results: Objective responses previously have been reported in 37 of 255 patients (15%) with 17 complete responses (7%) and 20 partial responses (8%). These data remain unchanged from previous reports. Median response duration for all objective responders remains unchanged at 54 months, but the range now extends from 3 to > 131 months. Median duration for all complete responses has not yet been reached, but was at least 80 months (range, 7- > 131 mo) at the time of this analysis. Median duration for all partial responses remains 20 months (range, 3- > 126 mo). Median survival time for all 255 patients remains 16.3 months, with 10% to 20% of patients estimated to be alive 5 to 10 years after treatment with high-dose IL-2.
Conclusion: With prolonged follow-up, treatment with high-dose recombinant IL-2 remains extremely effective for a subset of patients with metastatic renal cell carcinoma.