Real world outcomes of nivolumab and cabozantinib in metastatic renal cell carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC).

615 Background: The immuno-oncology (IO) checkpoint inhibitor nivolumab and the tyrosine kinase inhibitor (TKI) cabozantinib have both been shown in phase III clinical trials to be effective in metastatic renal cell carcinoma (mRCC) after progression on first-line therapy. We sought to explore the real-world efficacy of these therapies in second-line mRCC. Methods: Using the IMDC database, a retrospective analysis was performed on mRCC patients treated with second-line nivolumab or cabozantinib. Baseline characteristics and IMDC risk factors were collected. Overall survival (OS), time to treatment failure (TTF), and response rates were determined for each therapy. Multivariable Cox regression analysis was performed to determine survival differences. Results: 225 patients were treated with nivolumab and 53 with cabozantinib. There was no significant difference in OS identified, with a mOS for nivolumab of 22.1 months (95% CI 17.18 – NR) and 23.7 months (95% CI 15.52 vs. NR) for cabozantinib, p = 0.6053. The TTF was also similar, with 6.90 months (95% CI 4.60 – 9.20) for nivolumab versus 7.39 months (95% CI 5.52 – 12.85) for cabozantinib, p = 0.1983. The adjusted hazard ratio (HR) for nivolumab vs. cabozantinib was 1.297 (95% CI – 0.728 – 2.312), p = 0.3775. Conclusions: Nivolumab and cabozantinib appear to have similar efficacy in terms of OS and TTF in this real-world patient population, thus both novel agents are reasonable therapeutic options for patients progressing after initial first-line therapy. [Table: see text]