Phase II study of recombinant human interferon gamma (S-6810) on renal cell carcinoma. Summary of two collaborative studies. Recombinant Human Interferon Gamma (S-6810) Research Group on Renal Cell Carcinoma.

Seventeen institutions in Japan evaluated the antitumor activity of recombinant human interferon gamma (S-6810) as a new modality for advanced renal cell carcinoma. The response rate for 32 evaluable patients who received continuous daily administration of 8 X 10(6) U/m2 to 12 X 10(6) U/m2 of interferon for 4 weeks was 9.4%. Six of 30 patients (20%) were demonstrated responders in the case of the intermittent administration of 40 X 10(6) U/m2 of interferon on each of days 1 to 5, 15 to 19, 29, 31, 33, 43, 45, and 47 over an 8-week period. One of the responders achieved a complete response (CR). The patients tolerated this dose of interferon gamma well. Sites that responded to treatment were the lungs, lymph nodes, and brain. Major adverse effects included fever (86.8% of patients), anorexia (67.1%), fatigue (53.9%), and leukopenia (42.1%). No life-threatening side effects appeared. High doses of recombinant human interferon gamma have an antitumor activity against renal cell carcinoma.