Clinical outcomes in patients with metastatic renal cell carcinoma receiving everolimus or temsirolimus after sunitinib

Introduction: There are little data on the clinical activity of temsirolimus (TM) and everolimus (EV) when used as second-line therapy after sunitinib (SU) in patients with metastatic renal cell carcinoma (mRCC). Methods: Patients with mRCC treated with EV or TM after SU were included in this retrospective analysis. Progression-free survival (PFS), time to sequence failure (TTSF) from the start of SU to disease progression with EV/TM and overall survival (OS) were estimated using Kaplan-Meier method and compared across groups using the log-rank test. Cox proportional hazards models were applied to investigate predictors of TTSF and OS. Results: In total, 89 patients (median age 60.0 years) were included. At baseline 43% were classified as MSKCC good-risk, 43% as intermediate- risk and 14% as poor-risk. Median OS was 36.3 months and median TTSF was 17.2 months. Sixty-five patients received SU-EV and 24 patients SU-TM. Median PFS after the second-line treatment was 4.3 months in the EV group and 3.5 months in the TM group (p = 0.63). Median TTSF was 17.0 and 18.9 months (p = 0.32) and the OS was 35.8 and 38.3 months (p = 0.73) with SU-EV and SU-TM, respectively. The prognostic role of initial MSKCC was confirmed by multivariable analysis (hazard ratio 1.76, 95% confidence interval 1.08-2.85. p = 0.023). Conclusions: This study did not show significant differences in terms of disease control and OS between EV and TM in the secondline setting. EV remains the preferred mTOR inhibitor for the treatment of mRCC patients resistant to prior tyrosine kinase inhibitor treatment.