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 second-line setting. EV remains the preferred mTOR inhibitor for the treatment of mRCC patients resistant to prior tyrosine kinase inhibitor treatment.