Background: While studies have demonstrated survival benefits of first-line regimens including immuno-oncology agents (IO) in advanced renal cell carcinoma (aRCC), optimal treatment following IO is unknown. In the phase 3 METEOR trial, cabozantinib improved progression-free survival (PFS), objective response rate (ORR), and overall survival (OS) versus everolimus in patients (pts) with aRCC, after VEGFR-TKI therapy. The Japanese phase II C2001 study (NCT03339219), targeting a population similar to that of METEOR, showed similar efficacy and safety results. Here, we present a post-hoc pooled analysis of pts who had received prior IO therapy from METEOR and C2001. Methods: A pooled analysis was performed in pts who received 60mg/day of oral cabozantinib once daily enrolled in the METEOR or C2001. Patients were divided into two groups with previous IO treatment (pre-w/ IO subgroup) or without previous IO treatment (pre-w/o IO subgroup). Analyses of ORR, PFS, OS, and safety were performed as measures of clinical outcome in each subgroup. Results: 365 pts (pre-w/ IO subgroup: 33 pts, pre-w/o IO subgroup:332 pts) were included for efficacy analysis and 366 pts (pre-w/ IO subgroup: 33 pts, pre-w/o IO subgroup:333 pts) for safety analysis. Minor differences in baseline characteristics were noted between the analysis subgroups but are not expected to substantially affect efficacy outcomes. The ORR was 21.2% (95% CI: 9.0-38.9%) for pre-w/ IO subgroup, and 17.2% (95% CI: 13.3-21.7%) for pre-w/o IO subgroup. PFS rate and OS rate at 6 months pre-w/ IO was 65.5%, 90.8% and pre-w/o IO was 58.3%, 90.6%, respectively. Although there were some differences in the safety profile, almost all AEs were manageable by dose modifications. There were no differences in AEs associated with IO treatment, such as pneumonitis, endocrinolopathy or infusion related reaction. No new safety signals were noted in any subgroups. Conclusions: Safety and treatment efficacy of cabozantinib were maintained in the pooled analysis of pts from METEOR and C2001 irrespective of prior IO treatment. Funded by Takeda Pharmaceutical Company Limited, Tokyo, Japan. Clinical trial information: NCT03339219, NCT01865747.