Efficacy of fourth-line targeted therapy in patients with metastatic renal cell carcinoma: a retrospective analysis.

Introduction: Evidence for sequencing targeted therapy (TT) in patients with metastatic renal cell carcinoma (mRCC) beyond third line is limited. Treatment decisions for these sequence options are largely based on individual preferences and experience. The aim of this study was to describe the efficacy and toxicity of fourth-line TT.