LIMITED EFFICACY OF INTERFERON-ALPHA AND VINBLASTINE AS 2ND LINE BIOCHEMOTHERAPY REGIMEN IN PATIENTS WITH PROGRESSIVE METASTATIC RENAL-CELLCARCINOMA

We report on thirty-four patients with metastatic renal cell carcinoma who were treated with a combination of subcutaneous recombinant inter feron-alpha and intravenous vinblastine upon progression after previou s antineoplastic therapy. Pretreatment included chemotherapy (n=3), ho rmonal therapy (n=6) and immunotherapy (interleukin-2/interferon-alpha , n=25). In this study, treatment courses consisted of subcutaneous do ses thrice weekly of recombinant interferon-alpha at 6 million U/m2 (2 0 patients, group 2), respectively. Treatment was given over 8 consecu tive weeks. Additionally, in all patients, vinblastine was administere d intravenously at a dose of 6 mg/m2 in weeks 2, 5 and 8. Of 14 patien ts treated in group 1, one had a partial response for 6 months (overal l response rate 714%; 95% confidence interval, 0.18-33.87%), and four had disease stabilization (median duration, 5.0 months). Of 20 patient s treated in group 2, there was one patient who achieved a complete re sponse (response duration, 34+ months); in addition, two patients had a partial response (median response duration, 10.5+ months; overall re sponse rate, 15%; 95% confidence interval 3.21-37.89%), and 13 patient s exhibited disease stabilization (median duration 5.9+ months). Respo nse rates showed no significant differences when comparing treatment r esults in patients in group 1 vs group 2. In contrast, significantly l ess patients treated in group 2 had progressive disease (p = 0.024), a s compared to patients in group 1. This treatment combination was over all well tolerated with low to moderate systemic toxicity. In addition , there were no significant differences in frequency or intensity of t herapy-related systemic toxicities when comparing patients in group 1 and group 2, respectively. We conclude that the combination of subcuta neous recombinant interferon-a and intravenous vinblastine has limited efficacy as second line biochemotherapy in pretreated progressive met astatic renal cell cancer patients.