Background: Treatment of RCC has improved due to better understanding of its biology. New targeted therapies have improved time to progression and overall survival but the optimal sequencing of agents is unknown. Currently drugs are given sequentially, usually starting with sunitinib and often followed by an mTOR inhibitor or another VEGFR-targeted therapy, but resistance to both drugs eventually occurs probably due to host adaptive responses. We hypothesize that resistance might be delayed by planned alternation of treatments. Methods: EVERSUN is a single-arm, two-stage, multicenter, phase II clinical trial aiming to determine the activity and safety of an alternating regimen of two therapies with different targets (sunitinib and everolimus) in patients with advanced RCC. Key eligibility criteria: RCC with a clear cell component; metastatic or locally advanced disease not suitable for resection; ECOG performance status 0-1; low or intermediate MSKCC prognostic score. The primary endpoint is the status of being alive and progression-free (RECIST 1.1) 6 months after registration. Target accrual of 55 subjects gives 95% power and 95% confidence to distinguish between 6-month progression free survival rates of 64% or lower vs 84% or higher using a Simon 2-stage minimax design. The criteria for further evaluation come from the pivotal trial of single agent sunitinib as first line therapy for RCC, in which the 6-month progression free survival rate was 74%. Trial treatment is administered in 12-week (wk) cycles consisting of 4 wks of sunitinib (50 mg daily) followed by 2 wks rest, followed by 5 wks of everolimus (10 mg daily) followed by 1 wk rest. Disease progression is interpreted as failure of the most recent drug taken. Participants who stop one drug because of toxicity or disease progression, on or before the 6 month assessment, will continue the other drug until subsequent progression or prohibitive toxicity on the second drug. EVERSUN is an ANZUP Cancer Trials Group Ltd. trial coordinated by the NHMRC Clinical Trials Centre. Accrual commenced in September 2010 with 38/55 participants recruited as of the 31-Jan-12 from 17 Australian sites (ACTRN12609000643279).