Renal function in advanced renal cell carcinoma patients treated with sorafenib: Subset analyses of post-marketing surveillance in Japan with over 3,200 consecutive cases.

Abstract

518 Background: Patients with advanced renal cell carcinoma (RCC) are predisposed to impaired renal function due to prior nephrectomy and existing renal mass. Moreover, treatment with molecular targeted agents may also affect renal function. We retrospectively analyzed post marketing all-patients surveillance to assess the effect of sorafenib on the renal function of advanced renal cell carcinoma (RCC) in real-world use. Methods: We have collected safety/efficacy data of over 3,200 consecutive Japanese patients with advanced RCC treated with sorafenib under daily medical practice (1). Using this database, the effect of sorafenib on renal function was analyzed in a post-hoc manner, by calculating estimated glomerular filtration rate (eGFR) from age, gender, and serum creatinine at each time point. Results: The eGFRs at baseline (n=2,943), 12 months after sorafenib treatment (n=636, and the time of discontinuation (n=1712) of all patients were 54 ± 21, 57 ± 24, and 59.6 ± 31.8 mL/min/1.73 mm2, respectively, and showed no significant differences. The mean eGFRs of each segment at baseline and 12 months were 110 ± 26 and 96 ± 39 in G1(eGFR ≥90), 70 ± 8 and 73 ± 23 in G2 (eGFR ≥60 and <90), 52 ± 4 and 57 ± 15 in G3a (eGFR ≥45 and <60), 39 ± 4 and 43 ± 11 in G3b (eGFR ≥30 and <45), 24 ± 4 and 30 ± 10 in G4 (eGFR ≥15 and <30), 7 ± 3 and 11 ± 12 in G5 (eGFR <15), respectively. The median daily dose were 726mg (G1), 522mg (G2), 524mg (G3a), 517mg (G3b), 483mg (G4), and 400mg (G5). The incidence of renal AEs seemed to be higher in G4 and G5 (14% and 6%, respectively) than the other groups. The objective response rate ranged from 29.2% in G3a to 18.3% in G5, and the overall survival were higher in G3a and G3b (1 year survival rate: 81.5% and 78.4%, respectively), and lower in G1 (1 year survival rate: 50.2%). Conclusions: This study demonstrated that little impact on renal function of advanced RCC patients treated with sorafenib during observational period with sufficient clinical response and safety irrespective of the baseline eGFR value.