835PUPDATED OS ANALYSIS, MULTIVARIATE AND QTWIST ANALYSIS OF A RANDOMIZED SEQUENTIAL OPEN-LABEL STUDY (SWITCH) TO EVALUATE EFFICACY AND SAFETY OF SORAFENIB (SO) / SUNITINIB (SU) VERSUS SU/SO IN THE TREATMENT OF METASTATIC RENAL CELL CANCER (MRCC)

Abstract Aim: Results of the sequential randomized phase III SWITCH study comparing SO/SU and SU/SO have been reported previously (ASCO GU 2014, abstract 393) showing no significant difference in the primary endpoint total PFS (T-PFS, Hazard Ratio [HR] 1.01) nor the secondary endpoints overall survival (OS, HR 1.0) and 1st-line PFS (HR 1.19). We report here the results of an updated overall survival (OS) analysis, a multivariate analysis and QTWIST analysis (all post-hoc). NCT00732914. 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. The updated OS analysis was performed with data cut-off 14 JAN 2014 (database closure) using 150 events. A multivariate logistic regression analysis was performed to identify patient factors to reach a second-line therapy. QTWIST analysed the number of days without certain grade 3/4 according to CTCAE v 3.0 (HFSR; fatigue, diarrhea, nausea, rash) from randomisation to disease progression or death. Results: The updated OS analyses revealed a median OS for SO/SU of 30 months (95%CI 23.3-34.7) and for SU/SO of 27.4 mos (22.3-35.9), HR 0.985 (one-sided 95%CI