RESULTS OF TREATMENT OF 255 PATIENTS WITH METASTATIC RENAL-CELL CARCINOMA WHO RECEIVED HIGH-DOSE RECOMBINANT INTERLEUKIN-2 THERAPY

Purpose: To determine the efficacy and toxicity of a high-dose interle ukin-2 (IL-2) regimen in patients with metastatic renal cell carcinoma . Patients and Methods: Two hundred fifty-five assessable patients wer e entered onto seven phase II clinical trials. Proleukin (aldesleukin; Chiron Corp, Emeryville, CA) 600,000 or 720,000 IU/kg was administere d by 15-minute intravenous (IV) infusion every 8 hours for up to 14 co nsecutive doses over 5 days as clinically tolerated with maximum suppo rt, including pressors. A second identical cycle of treatment was sche duled following 5 to 9 days of rest, and courses could be repeated eve ry 6 to 12 weeks in stable or responding patients. Results: The overal l objective response rate was 14% (90% confidence interval [CI], 10% t o 19%), with 12 (5%) complete responses (CRs) and 24 (9%) partial resp onses (PRs). Responses occurred in all sites of disease, including bon e, intact primary tumors, and visceral metastases, and in patients wit h large tumor burdens or bulky individual lesions. The median response duration for patients who achieved a CR has not been reached, but was 19.0 months for those who achieved a PR. Baseline Eastern Cooperative Oncology Group (ECOG) performance status (PS) was the only predictive prognostic factor for response to IL-2. While treatment was associate d with severe acute toxicities, these generally reversed rapidly after therapy was completed. However, 4% of patients died of adverse events judged to be possibly or probably treatment-related. Conclusion: High -dose IL-2 appears to benefit some patients with metastatic renal cell carcinoma by producing durable CRs or PRs. Despite severe acute treat ment-associated toxicities, IL-2 should be considered for initial ther apy of patients with appropriately selected metastatic renal cell carc inoma. (C) 1995 by American Society of Clinical Oncology.