A comparison of 2 modes of administration of recombinant interleukin-2: continuous intravenous infusion alone versus subcutaneous administration plus interferon alpha in patients with advanced renal cell carcinoma.

PURPOSE To compare 2 treatment modalities with recombinant Interleukin-2 (rIL-2) for patients with advanced Renal Cell carcinoma (RCC): continuous intravenous infusion (CIV) alone versus subcutaneous (s/c) rIL-2 + Interferon-alpha (IFN-alpha). PATIENTS AND METHODS Data have been collected on 425 patients with RCC, treated CIV rIL-2 alone, (225 patients), or rIL-2 by the s/c route (200 patients). Patients receiving s/c rIL-2 also received s/c IFN-alpha both drugs being administered on an outpatient basis. Patients receiving CIV rIL-2 were treated as inpatients. Patient eligibility criteria were similar on all studies, and included patients with progressive, advanced disease, but with an ambulatory performance status. RESULTS The overall response rate for the CIV schedules was not significantly different from the s/c regimens: 15% (95% confidence limits (CL) 10-20%) vs 20% (95%CL 14-26%) with 4% CR in both approaches. Durable responses were seen in both CIV and s/c schedules and there was no evidence of a significant difference in survival in multivariate analysis. There was however an important shift in the toxicity profile. The s/c regimens do not induce a clinically detectable capillary leak syndrome, which is the dose limiting toxicity for CIV regimens. CONCLUSION Although the introduction of CIV regimens of rIL-2 was a major step forward compared to high-dose bolus, because most patients could be treated in a normal oncology ward, the s/c schedule of rIL-2 + IFN-alpha offers the possibility of outpatient (home) therapy, with no evidence of a reduction in efficacy.