35: Real-world (RW) outcomes of nivolumab plus ipilimumab (N+I) versus pembrolizumab plus axitinib (P+A) for first-line (1L) treatment of advanced renal cell carcinoma (aRCC)

Background: RW data describing clinical outcomes of aRCC patients treated with immuno-oncology combinations are important for clinicians and patients. In the absence of head-to-head trials, this study aimed to evaluate RW outcomes of aRCC patients treated with 1L N+I or P+A.

Methods: This retrospective, physician-abstracted medical chart review included patients with aRCC who received 1L N+I (N=225) or P+A (N=130) between May-2018 and June-2021. Inverse probability of treatment weighting (IPTW) was performed, providing balance of baseline characteristics including age, gender, race, insurance, risk score, ECOG, comorbidities, and laboratory values. Outcomes assessed included overall response rate (ORR), complete response (CR), duration of response (DOR), treatment-free interval (TFI), progression-free survival (PFS), overall survival (OS), and immune-related adverse events (irAEs).

Results: After weighting, each cohort was ~60% male, 65 years old on average, and 90% intermediate/poor risk at 1L initiation. Median follow-up post-1L initiation was 22.4 months for N+I and 19.0 months for P+A. ORR was not significantly different between N+I vs P+A cohorts, while more patients in the N+I vs P+A cohort had CR (Table). DOR and TFI were longer in the N+I vs P+A cohort. Median PFS and OS were not significantly different between cohorts; however, the N+I cohort trended toward longer PFS and OS estimates. Cumulative irAE incidence rate was initially higher in the N+I cohort but rates were similar at the end of the follow up.

Conclusions: This RW analysis suggests that beyond 12 months, effectiveness and safety between N+I and P+A cohorts were similar. Although differences in some endpoints were seen, additional follow-up is necessary.