Prospective Randomized Trial of Interferon Alfa-2a Plus Vinblastine Versus Vinblastine Alone in Patients With Advanced Renal Cell Cancer

PURPOSE: The combination of interferon alfa-2a (IFNα2a) plus vinblastine (VLB) induces objective tumor responses in patients with advanced renal cell cancer. However, no prospective randomized trial has shown that this treatment prolongs overall survival. We compared overall survival after treatment with IFNα2a plus VLB versus VLB alone in patients with advanced renal cell cancer. PATIENTS AND METHODS: We prospectively randomized 160 patients with locally advanced or metastatic renal cell cancer to receive either VLB alone or IFNα2a plus VLB for 12 months or until progression of disease. In both groups, VLB was administered intravenously at 0.1 mg/kg every 3 weeks, and in the combination group IFNα2a was administered subcutaneously at 3 million units three times a week for 1 week, and 18 million units three times a week thereafter for the second and subsequent weeks. For patients unable totolerate IFNα2a at 18 million units per injection, the dose was reduced to 9 million units. RESULTS: Median survival was 67.6 weeks for the 79 patients receiving IFNα2a plus VLB and 37.8 weeks for the 81 patients treated with VLB (P = .0049). Overall response rates were 16.5% for patients treated with IFNα2a plus VLB and 2.5% for patients treated with VLB alone (P = .0025). Treatment with the combination was associated with constitutional symptoms and abnormalities in laboratory parameters, but no toxic deaths were reported. CONCLUSION: The combination of IFNα2a plus VLB is superior to VLB alone in the treatment of patients with locally advanced or metastatic renal cell carcinoma. This is the first study to demonstrate that survival can be prolonged by using IFNα2a for these patients.