Efficacy and safety of cabozantinib plus nivolumab in advanced non-clear cell renal cell carcinoma: a nationwide multicenter study.

Non-clear cell renal cell carcinoma (nccRCC) represents a biologically heterogeneous group of tumors for which optimal systemic treatment strategies remain poorly defined despite recent therapeutic advances. To address this gap, we evaluated the clinical activity and safety of cabozantinib plus nivolumab in patients with advanced nccRCC. In this nationwide, multicenter retrospective cohort study conducted in the Republic of Korea, 62 patients received the combination across multiple lines of therapy, with most treated in the first-line setting. Papillary RCC was the most common histologic subtype (50.0%), followed by FH-deficient (22.6%), TFE3-rearranged (9.7%), chromophobe (6.5%), collecting duct (6.5%), and unclassified tumors (4.8%). With a median follow-up of 22.2 months (95% confidence interval [CI], 15.4-29.1), the objective response rate (ORR) was 45.2% (95% CI, 32.4-57.9) and the disease control rate (DCR) was 93.6% (95% CI, 87.3-99.8). Responses were seen across histologic subtypes (ORR = 48.4% in papillary, 50.0% in FH-deficient, 50.0% in TFE3-rearranged, 25.0% in chromophobe, 25.0% in collecting duct, and 33.3% in unclassified tumors; P = 0.876). Median progression-free and overall survival were 9.7 months (95% CI, 7.7-11.6) and 22.0 months (95% CI, 15.2-28.7), respectively. Grade 3-4 treatment-emergent adverse events occurred in 46.8% of patients, and treatment discontinuation due to toxicity was reported in 6.5%. These findings demonstrate that cabozantinib plus nivolumab provides clinically meaningful and durable antitumor activity with manageable toxicity across diverse histologic subtypes in advanced nccRCC, supporting further prospective evaluation of cabozantinib plus nivolumab in advanced nccRCC.