BACKGROUND: Real-world data on adjuvant pembrolizumab after surgery for renal cell carcinoma (RCC) are limited. OBJECTIVE: To clarify the real-world outcomes of adjuvant pembrolizumab for patients with RCC with a high risk of recurrence. PATIENTS AND METHODS: We retrospectively evaluated the clinicopathological data of 53 patients who received pembrolizumab as an adjuvant therapy after curative surgery for RCC on the basis of the criteria of the KEYNOTE-564 trial. The efficacy and safety profiles were assessed. The potential of PD-L1 expression as a biomarker of recurrence was evaluated in 35 RCC samples using the combined positive score (CPS). RESULTS: The median follow-up period was 18.9 months. On the basis of the KEYNOTE-564 criteria, 45 patients (85%) were categorized into the intermediate-to-high-risk group. A total of 11 patients (21%) experienced recurrence, with a 12-month disease-free survival (DFS) rate of 90.5%. Patients with high PD-L1 CPS (≥ 10) had a higher recurrence rate than those with low PD-L1 CPS (< 10) (44% versus 5%, p = 0.0130). DFS was shorter in patients with high PD-L1 expression than in those with low PD-L1 expression (median: 24.0 months versus not reached, p = 0.0116). Grade ≥ 3 adverse events occurred in 13 patients (25%), and treatment discontinuation was required in 11 patients (21%). CONCLUSIONS: Adjuvant pembrolizumab exhibited feasible efficacy and manageable safety profiles for high-risk RCC in a real-world population. Further studies with longer follow-up periods and larger sample sizes are needed to confirm overall survival benefit, long-term toxicity, and the potential role of PD-L1 as a prognostic biomarker.
Ishihara et al. (2026) studied this question.