A real-world comparison of nivolumab plus cabozantinib and pembrolizumab plus lenvatinib focusing on safety outcomes in metastatic renal cell carcinoma: results from the JK-FOOT consortium

Purpose: Immune checkpoint inhibitor (ICI)-based combination therapy is a standard first-line treatment for metastatic renal cell carcinoma (mRCC), with combinations such as nivolumab plus cabozantinib (Nivo + Cabo) and pembrolizumab plus lenvatinib (Pem + Len) demonstrating favorable oncologic outcomes. However, no direct comparisons between these two regimens have been conducted. This study aimed to compare the safety and oncologic outcomes of Nivo + Cabo and Pem + Len in patients with mRCC. Methods: This retrospective study included 185 patients with mRCC treated with Nivo + Cabo (n = 81) or Pem + Len (n = 104) between January 2018 and June 2025 across multiple institutions. The primary outcome was a comparison of treatment-related adverse events (TrAEs). Oncologic outcomes, including objective response rate (ORR), progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS), were compared using one-to-one propensity score matching. Results: Any-grade TrAEs occurred in 90% of patients in the Nivo + Cabo group and 92% in the Pem + Len group (p = 0.6). Severe TrAEs (grade ≥ 3) were more frequent in the Pem + Len group (44%) than in the Nivo + Cabo group (30%, p = 0.048). Tyrosine kinase inhibitor dose reduction and treatment discontinuation rates were similar between groups. In the matched cohort (Nivo + Cabo: n = 74; Pem + Len: n = 74), ORRs were comparable (66% vs. 71%, p = 0.6). With a median follow-up of 17 months, no significant differences were observed in PFS (p = 0.4), CSS (p = 0.9), or OS (p = 0.5). Conclusions: Nivo + Cabo and Pem + Len demonstrated similar oncologic efficacy as first-line treatments for mRCC. However, Pem + Len was associated with more severe TrAEs. Careful toxicity management and shared decision-making are essential when selecting ICI-based combinations.