Abstract
There have been significant advances in the treatment of metastatic renal cell carcinoma (mRCC), with immunotherapy (IO)-based combinations as the standard-of-care treatment in the front-line setting. IO in this setting is paired with another IO agent or with a vascular endothelial growth factor receptor (VEGF-R) tyrosine kinase inhibitor (TKI). One IO/IO combination and four IO/TKI combinations are currently approved. However, the role of the salvage IO in patients with disease progression on TKI monotherapy is uncertain. Here, we present a case series of five patients who were on single-agent TKI therapy for treatment-refractory mRCC and upon disease progression had an IO agent added to their TKI. The median duration of TKI monotherapy was 11.2 months (range, 1.7-31.1 months), and the median duration of response after the addition of IO was 4 months (range, 2.8-10.5 months). Although IO salvage therapy has a plausible rationale, this case series did not show a clear benefit to this approach. Further clinical trials are needed to determine the clinical utility of IO salvage therapy in mRCC.