Recombinant alpha‐lnterferon and vinblastine in metastatic renal cell carcinoma: Efficacy of low doses

Abstract

Twenty‐six patients with metastatic renal cell carcinoma (RCC) were treated in a phase I‐II trial with recombinant interferon alpha‐2b (α‐IFN) and vinblastine (VBL) in combination. Patients received IFN at a starting dose of 3 × 10⁶ IU/m² subcutaneously three times a week and VBL 0.1 mg/kg intravenously every 3 weeks, with dose modification for toxicity. All patients were evaluable for toxicity; 18 patients were evaluable for efficacy. An objective response rate of 44% was observed (eight of 18 patients, with one complete response and seven partial responses). The median duration of response was 5 months. The actuarial survival of responding patients was significantly longer than that of nonresponding patients. In general, the toxicity was tolerable; the subjective toxicity and fever were similar to that reported for the same doses of IFN alone. Only a mild neurotoxicity, usually mixed polyneuropathy, occurred with increased frequency. Alpha‐IFN and VBL administered at low doses in combination demonstrated the highest response rate so far reported in RCC without significant toxicity.