Clinical outcomes in patients receiving three lines of targeted therapy for metastatic renal cell carcinoma: results from a large patient cohort.

Aim: A number of targeted therapies (TTs) are effective in metastatic renal cell carcinoma (mRCC) but clinical outcomes with the sequential use of three TTs have been poorly investigated, this study evaluates their outcome.

Methods: Patients with clear cells mRCC treated with three TTs were retrospectively studied. Therapies were classified as vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor (VEGFR) or mammalian target of rapamycin inhibitors (mTORi). Progression free survival (PFS), overall survival (OS) and total PFS (tPFS)--defined as the time from start of first-line to progression on third-line treatment--were estimated using the Kaplan-Meier method and curves were compared with log-rank test.

Results: A total of 2065 patients with mRCC were consecutively treated with first-line TT in 23 centres in Italy. Overall 281/2065 patients (13%) were treated with three TTs. Median OS and tPFS were 44.7 and 34.1 months, respectively and were longer in patients receiving the sequence vascular endothelial growth factor inhibitors (VEGFi)-VEGFi-mTORi compared with those receiving VEGFi-mTORi-VEGFi with a statistical difference in OS (50.7 versus 37.8 months, p = 0.004; 36.5 versus 29.3 months, p = 0.059, respectively).

Conclusions: Few patients received three lines of TTs. The sequence VEGFi-VEGFi-mTORi was associated with improved survival with respect to VEGFi-mTORi-VEGFi and primary resistance to first-line was a negative predictive and prognostic factor.