Little impact on renal function in advanced renal cell carcinoma patients treated with sorafenib-analyses of postmarketing surveillance in Japan in over 3, 200 consecutive cases

Background: To assess the effect of sorafenib on renal function in patients with advanced renal cell carcinoma (RCC) included in a postmarketing surveillance. Methods: All patients in Japan with advanced RCC treated with sorafenib between February 2008 and September 2009 were followed for 12 months. Baseline characteristics, renal function, survival, safety, and dosage were stratified according to baseline estimated glomerular filtration rate (eGFR):G1 (eGFR≥90), G2 (eGFR≥60- <90), G3a (eGFR≥45-<60), G3b (eGFR≥30-<45), G4 (eGFR≥15-<30), and G5 (eGFR<15). A total of 3, 255 and 3, 171 patients were included in this analysis for safety and efficacy, respectively. Results: The mean eGFRs (mL/min/1.73 m²) were not substantially changed for each group at baseline and 12 months, respectively. Median daily doses of sorafenib were 726mg (G1), 522mg (G2), 524mg (G3a), 517mg (G3b), 483mg (G4), and 400mg (G5). Renal failure, reported as an adverse event, occurred more frequently in the G4and G5 groups (9% and 3%, respectively) than in other groups. Objective response rates for each subgroup were as follows: G1, 23%; G2, 28%; G3a, 29%; G3b, 26%; G4, 24%; and G5, 18%. Oneyear survival was higher in the G3a and G3b groups (82% and 78%, respectively) and lower in the G1 group (50%). Conclusions: This study demonstrated little impact of sorafenib on renal function in advanced RCC patients during the observational period. Patients showed sufficient clinical response and safety irrespective of baseline eGFR value.