Comparative effectiveness of everolimus (EVE) and axitinib (AXI) for second-line treatment of metastatic renal cell carcinoma (mRCC) in the United States: A retrospective chart review.

500 Background: EVE and AXI are approved as 2nd-line TTs for mRCC. This study compares OS and PFS among mRCC patients treated with EVE and AXI following 1st TKI. The extent to which the duration of 1st TKI can inform optimal selection of a 2nd-line TT is of interest. Methods: A retrospective patient chart review study was conducted. Medical oncologists or hematologists/oncologists who treated ≥3 mRCC patients in the past year were recruited from a national panel. Patient eligibility criteria included: 1) aged ≥18 years; 2) initiated and discontinued 1st TKI (sunitinib or pazopanib) for medical reasons; 3) initiated 2nd TT between 2/1/2012 and 1/31/2013. OS was defined as time from initiation of 2nd TT to death. PFS was defined as time from initiation of 2nd TT to physician/chart reported progression or death, whichever occurred first. Multivariable Cox proportional hazards models were used to estimate the hazard ratio (HR) for OS and PFS between EVE and AXI, adjusting for age, gender, type and duration of...