Real-world evidences on adjuvant Pembrolizumab for renal cell carcinoma: results from the multicenter real-world ARON-1 study

Background: Pembrolizumab has demonstrated efficacy in improving disease-free survival (DFS) and overall survival (OS) as adjuvant therapy in clear cell renal cell carcinoma (ccRCC) at a higher risk of recurrence. However, real-world data on its effectiveness and safety remain limited. This study evaluates DFS, OS and severe adverse events (SAEs) associated with adjuvant pembrolizumab in a multicenter international cohort. Methods: This retrospective analysis included 311 ccRCC patients treated with adjuvant pembrolizumab across 40 hospitals in 12 countries from the ARON-1 dataset. Eligible patients had histologically confirmed ccRCC with high relapse risk and received up to 17 cycles of pembrolizumab. The primary objective was DFS, with OS and safety as secondary objectives. Kaplan-Meier survival estimates, Cox proportional hazards models and log-rank tests were used for statistical analysis. Results: At a median follow-up of 15.4-month, 2-year OS and DFS rates were 95% and 69%, respectively. Recurrence occurred in 20% of patients, primarily in the lungs (11%) and bones (5%). DFS was significantly impaired in patients < 65 years (HR 2.14, p = 0.005), N1 disease (HR 5.42, p = 0.004) and sarcomatoid dedifferentiation (HR 2.54, p = 0.007). SAEs led to 19% treatment discontinuation, with colitis (4%), hypertransaminasemia (4%) and nephritis (3%) as the most common events. The study's retrospective nature and short follow-up limit long-term outcome assessments. Conclusions: This large real-world study confirms pembrolizumab's effectiveness and manageable safety profile in the adjuvant setting for intermediate-high and high-risk ccRCC. Further research is needed to refine patient selection strategies and evaluate long-term outcomes.