A comparison of combined immune checkpoint inhibitors (IO) versus vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI) in the treatment of advanced clear cell renal cell carcinoma.

692 Background: IO and VEGFR/TKI are approved treatment options, either alone or combination, in advanced clear cell RCC. Currently, there is a lack of evidence comparing efficacy and safety outcomes amongst these therapies. We sought to compare the published data for the various options with respect to efficacy and safety. Methods: A literature search using PubMed, clinicaltrials.gov, ASCO and ESMO meeting abstract databases from January 1, 2015 to June 30, 2019 to identify eligible clinical trials in advanced clear cell RCC involving at least one immunotherapy agent was performed. Due to small sample sizes in the various cohorts, descriptive statistics were provided. Weighting of estimates was based on sample size of the intervention arms. Results: 14 studies involving 6,197 pts were identified. The median age was 62 years (54.8, 64), men constituting median of 75%, and prior TKI receipt in 63%. There were 7 studies in each treatment arm. The efficacy outcomes did not demonstrate statistical differences. In the safety analyses, IO + VEGFR/TKI demonstrated the highest serious adverse event rate, correlating with treatment discontinuation rates. Conclusions: IO + IO and IO + VEGFR/TKI showed comparable efficacy and toxicity outcomes in the treatment of advanced clear cell RCC. There is a non-significant trend towards increased efficacy in some outcomes with IO + VEGFR/TKI, with possibly increased adverse events. Further studies with patient level data, cross-comparative trials, and predictive biomarkers are needed to establish a therapeutic matrix for RCC pts.[Table: see text]