Sequential Use of the Tyrosine Kinase Inhibitors Sorafenib and Sunitinib in Metastatic Renal Cell Carcinoma: A Retrospective Outcome Analysis

Background: To date, few data are available about the sequential use of the tyrosine kinase inhibitors (TKI) sorafenib and sunitinib in metastatic renal cell carcinoma (mRCC). Objective: To investigate the effectiveness of the use of sunitinib after progression under sorafenib in mRCC. Design, setting, and participants: A retrospective analysis of 30 patients with progressive mRCC, treated with sorafenib between May 2005 and February 2008. When radiologic progression was diagnosed, treatment was switched to sunitinib and continued until a further tumour progression occurred. Measurements: Radiologic evaluation of the treatment results was performed every 3 mo according to the criteria for Response Evaluation Criteria in Solid Tumors (RECIST). Adverse effects and therapeutic abnormalities (eg, dose reduction) were documented during regular visits. Results and limitations: Of the patients, 50% benefited from the secondary use of sunitinib. In detail, a radiologically confirmed new disease stabilisation or partial response was observed in seven and eight patients, respectively. Median progression-free survival was 8.7 mo and 10.3 mo under sorafenib and sunitinib, respectively. Overall, the median time from the initialisation of the first TKI until progression under therapy with the second TKI was 17.3 mo. To our knowledge, this is the second largest study reporting results of sequential therapy from sorafenib followed by sunitinib. However, the number of patients is still not extensive enough to settle this important question conclusively. Conclusions: This study supports the hypothesis that sequential TKI therapy with the sorafenib followed by sunitinib has clinical validity in some patients with advanced renal cell carcinoma when progressive disease occurs under the initial TKI therapy.