Efficacy of everolimus in second- and third-line therapy for metastatic renal cell carcinoma: a registry-based analysis.
The aim of the present study was to describe the efficacy and safety of everolimus in the treatment of metastatic renal cell carcinoma (mRCC) after administration of 1 vs. 2 prior tyrosine kinase inhibitors (TKIs). A national renal information system database was used as the data source for the retrospective study. There were 483 patients who received everolimus as the second (n = 350) or the third (n = 112) targeted agent following TKIs. Median progression-free survival (PFS) from the start of everolimus in the second or the third line of targeted therapy was 6.1 months for both subgroups (P = 0.863). Median total PFS from the start of the first targeted agent to progression on the third targeted agent for patients receiving 3 lines of therapy with TKI-TKI-everolimus (n = 112) and TKI-everolimus-TKI (n = 27) sequences was 28.3 months vs. 31.3 months, respectively (P = 0.16), and there was no significant difference in overall survival. PFS on everolimus was associated with PFS on previous TKIs in patients receiving 1 but not 2 previous TKIs. Only 13% of 352 patients starting targeted therapy for mRCC in 2010 had received 3 sequential targeted agents by the data cutoff in March 2013. PFS on everolimus correlated with PFS on TKIs in patients pretreated with 1 but not 2 TKIs. Everolimus can be deferred to the third line without loss of efficacy or increased toxicity. However, only a minority of patients with mRCC starting targeted treatment can be expected to receive third-line therapy.