SWITCH: A randomized sequential open-label study to evaluate efficacy and safety of sorafenib (SO)/sunitinib (SU) versus SU/SO in the treatment of metastatic renal cell cancer (mRCC).

393 Background: The sequential use of SO and SU has been investigated retrospectively in patients with mRCC. We report here results from the first randomized study to prospectively compare SO/SU versus SU/SO. Methods: Pts with mRCC unsuitable for cytokines without prior systemic therapy, ECOG PS 0/1, MSKCC score low or intermediate, and ≥1 measurable lesion were randomized to receive open-label SO/SU (arm A) or SU/SO (arm B) in standard dosage. Primary endpoint: total PFS (T-PFS) from randomization to event during 2nd line therapy. Therapy continued until progression or intolerability. The study was powered to detect a 47% increase in T-PFS with SO/SU compared to SU/SO using log-rank testingand Cox proportional hazard regression model. (NCT00732914). Results: A total of 365 pts were enrolled: 182 arm A, 183 arm B.The two arms were well balanced: median age (A/B): 64/65 yrs; prior nephrectomy: 74/65%; MSKCC intermediate: 59/51%, low: 39/45%; clear cell histology: 90/84%. At time of final T-PFS analysis 22...