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.