Sequential treatment with sorafenib and sunitinib in metastatic renal cell carcinoma: clinical outcomes from a retrospective clinical study.

Sorafenib and sunitinib are inhibitors of receptor protein tyrosine kinases (TKIs) and are approved for the treatment of metastatic renal cell carcinoma (mRCC). Although the mTOR inhibitor everolimus is effective for the treatment of patients who have failed TKI therapy, it is important to consider all available treatment options before switching therapy mode of action. Herein, we report outcomes in patients with mRCC switched to sorafenib following disease progression on sunitinib treatment. The medical records of 35 patients treated between November 2006 and November 2009 at two large referral centers in Greece were retrospectively analyzed for time-to-progression (TTP), overall survival (OS), and tolerability of sorafenib after sunitinib. Median TTP and OS on sorafenib were 4.9 and 11.5 months, respectively. Among 33 patients evaluable for tumor response, three had a partial response and 17 achieved disease stabilization (objective response rate 8.5%; total clinical benefit rate 57%). Sorafenib was well tolerated, with mostly grade 1/2 adverse events and no treatment-related deaths. Sorafenib was effective and well tolerated in this group of patients. The TTP with sorafenib following sunitinib was comparable to outcomes reported previously, providing further support that TKIs should be used in sequence before switching to an mTOR inhibitor.