Phase II study of recombinant interferon alpha-2a and vinblastine in advanced renal cell carcinoma.

A total of 66 patients with advanced renal cell cancer received a combination of recombinant interferon alpha-2a (18 times 10(6) units subcutaneously 3 times weekly) and vinblastine (0.1 mg. per kg. intravenously every 3 weeks). Four patients were ineligible and 6 were inevaluable for response but evaluable for toxicity. There were no complete and 9 partial responses among the 56 evaluable patients, for a response rate of 16 per cent. Median duration of response was 26 weeks, with a range of 8 to 50 weeks. Responses were observed predominantly in patients with lung and soft tissue metastases. Patients who had undergone nephrectomy did not show a better response rate than those who had not. Almost all patients had a flu-like syndrome, fatigue and anorexia. Other side effects included leukopenia, nausea, vomiting, liver function disturbances and neurotoxicity. Most of the side effects were World Health Organization grade 1 or 2; no grade 4 toxicity was observed. Antibodies against interferon developed in 6 patients during the course of treatment. However, there was no relationship between the appearance of antibodies and disease progression. The combination of recombinant interferon alpha-2a and vinblastine has modest but definite activity in patients with advanced renal cell carcinoma, although the role of vinblastine is unclear.