The management of metastatic renal cell carcinoma (RCC) constitutes a therapeutic challenge and no standard therapy has yet been established. This phase II study aimed to verify the efficacy and tolerability of subcutaneous low dose recombinant interleukin-2 (IL-2) plus alpha interferon (IFN) and vinblastine (VLB) in patients with metastatic RCC. Twenty-three evaluable adult patients were enrolled in the study. A total of 19 patients were previously subjected to radical nephrectomy and four had been treated with adjuvant immunotherapy. The I-nest frequent metastatic sites were lung/pleura, bone, liver, lymph nodes, and abdominal mass. The following treatment schedule was administered: VLB at 6 mg/m(2) on day 1: IL-2 at 4.5 million IU twice daily from day 1 to 5 and day 8 to 12; IFN at 3 million IU three times weekly intramuscularly. The therapy was recycled every 21 days, except for the IFN which was administered continuously. Five patients demonstrated remission (21.6%) including one complete response persisting for 6 months, and four partial responses with a duration of 41+, 20, 8, and 18+ months. Moreover, 15 patients (65%) showed stable disease for 4-20 months (median 6 months), and three patients progressed. Overall median survival of the 23 patients was 11 months, with 27+ months for responders, 11 months for patients with stable disease, and 8 months for patients with rapid progression. Regressions occurred in lung, pleura, bone, and abdominal mass. Treatment was relatively well tolerated and easily manageable. This study was mainly administered as outpatient care. This study confirms the manageability and tolerability of subcutaneous IL-2 used in association with IFN alpha and chemotherapy. Even though a minority of patients responded, the duration of responses and the high percentage of long stable diseases represent the most interesting aspect of this study.
