Phase I/II trial of human recombinant interferon gamma in renal cell carcinoma.

Recombinant interferon gamma (IFN-gamma) was given to 13 patients with metastatic renal cell carcinoma in a Phase I/II trial. Patients were treated twice weekly by a 4-h intravenous infusion. Three patients were each entered at escalating dose levels. Doses were also escalated in each patient until an individual maximum tolerated dose was reached. Pharmacokinetics, toxicity, and tumor response are reported. Blood levels were related to dose and were detected in 6/7 patients receiving 30-75 MU/m2. The t1/2 was approximately 60 min in the higher dose patients, although detectable serum levels in some patients were observed at 24 h. The maximum tolerated dose was 75 MU/m2. Toxicity was limited to the symptom complex of anorexia, fever, and malaise. The latter two were dose-related and quite severe in high-dose patients. No minor or partial responses were observed in any patient.