ABSTRACT Background Surgical resection alone may fail to cure high-risk RCC. Progression to metastatic recurrence directly relates to tumor size in subjects with clinically localized RCC, and 25–50% of subjects treated for localized disease eventually experience recurrence. Sunitinib is an oral, multitargeted tyrosine kinase inhibitor approved in 2006 for the treatment of advanced RCC based on robust results from randomized clinical trials. Sunitinib led to metastatic deposit size reduction in most cases. These observations provided the rationale to investigate sunitinib as an adjuvant monotherapy in subjects at high risk of recurrence after nephrectomy for clinically localized RCC. Methods In this ongoing prospective, double-blind, placebo-controlled, randomized, multicenter, phase III study, eligible subjects have histologically confirmed, predominantly (>50%) clear cell RCC diagnosed by the UISS staging system and are at high risk of recurrence, with no evidence of residual macroscopic disease. Within 12 weeks after nephrectomy, subjects will be randomized 1:1 to oral sunitinib 50 mg/day on Schedule 4/2 (4 weeks on/2 weeks off) or placebo, for 1 year (9 cycles). Dose reduction to 37.5 mg/day but not to 25 mg/day is permitted. Subjects will be followed for disease recurrence every 12 weeks for 1–3 years and every 6 months thereafter, until final analysis. Safety and efficacy data are under review by an independent data monitoring committee (IDMC). The primary objective is to compare disease-free survival (DFS) for sunitinib vs. placebo based on independent blinded review. Other objectives include safety monitoring, overall survival (OS) and health-related quality of life (EORTC QLQ-C30 and EQ-5D). Results 900 subjects were screened and 630 have been randomized (reasons for screening failures will be presented). The trial is currently ongoing; enrolment closed worldwide in April 2011, except in China. 615 subjects have completed 1 year of treatment and are in follow-up for DFS and/or OS. At last review, there were no unexpected toxicity warnings and the IDMC recommended continuing the trial. NCT00375674 Disclosure A. Ravaud: Advisory relationship with Pfizer, Novartis, Bayer Schering, GSK, Astellas, Dendreon. Honoraria from Pfizer, Novartis, Bayer Schering, Roche, GSK, Astellas, Dendreon. Research funding from Pfizer, Novartis. Travel renumeration from Pfizer and Novartis. R.J. Motzer: Advisory relationship with Pfizer. Research funding from Pfizer. M. Staehler: Advisory relationship with Pfizer. Honoraria from Pfizer. Research Funding from Pfizer. Expert testimony for Pfizer. D.J. George: Advisory relationship with Pfizer. Honoraria to disclose from Pfizer. Research funding from Pfizer. A. Pantuck: Advisory relationship with Pfizer. A. Patel: Advisory relationship with Pfizer; Global S-TRAC Steering Committee Member. Travel Reimbursement for Steering Committee Meetings. P. Gerletti: Compensated employment with Pfizer. Pfizer stock ownership. L. Chen: Compensated employment with Pfizer. Pfizer stock ownership. J. Patard: Advisory relationship with Pfizer, Bayer and Novartis. Honoraria from Pfizer, Bayer, Novartis and Baxter. All other authors have declared no conflicts of interest.