TOKIO rationale and protocol: a phase II study to evaluate the activity and safety of third -line tyrosine kinase inhibitor after 2 tyrosine kinase inhibitors in patients with metastatic renal cell carcinoma

Aims and background: The introduction of agents targeting vascular endothelial growth factor has radically changed the approach to metastatic renal cell carcinoma (mRCC): sunitinib and pazopanib are now the standard first -line therapy in mRCC. At sunitinib failure, second -line axitinib or everolimus or sorafenib should be considered to improve the clinical outcome. No data are available for a third -line tyrosine kinase inhibitor (TKI) after 2 previous lines of therapy with TKIs. At pazopanib failure, no prospective data are available. Study design: The TOKIO study was designed to evaluate progression -free survival, safety, and efficacy of third -line therapy with TKI in 44 patients already treated with 2 previous lines of TKIs in 10 Italian centers, and relapsed from sunitinib-axitinib (group A) or pazopanib-sorafenib (group B). Standard treatment is sorafenib in group A and sunitinib in group B, administered until disease progression or unacceptable toxicity. Secondary endpoints include the evaluation of overall survival, safety, and quality of life.