Real-world Implementation of Adjuvant Pembrolizumab for High-risk Clear-cell Renal Cell Carcinoma After Surgery

<h3>Background/Aim:</h3> Adjuvant pembrolizumab is an important postoperative treatment option for selected patients with high-risk clear-cell renal cell carcinoma. However, the implementation of adjuvant pembrolizumab in routine clinical practice remains incompletely characterized. This study evaluated the real-world use of adjuvant pembrolizumab after its approval in Japan. <h3>Patients and Methods:</h3> We retrospectively reviewed patients who underwent surgery for renal tumors at our Institution between September 2018 and December 2025. After exclusion of those with benign tumors, non-clear-cell renal cell carcinoma, or renal metastasis from another primary malignancy, and patients treated with perioperative systemic therapy for metastatic disease, 29 patients were considered eligible for adjuvant pembrolizumab. Of these, 21 underwent surgery after pembrolizumab approval in Japan; 16 received adjuvant pembrolizumab and five did not. Clinicopathological characteristics, treatment exposure, discontinuation, safety, and disease-free survival (DFS) were evaluated. <h3>Results:</h3> Among the 21 post-approval patients, the reasons for not receiving adjuvant pembrolizumab included patient preference (n=2), renal function (n=1), age and dementia (n=1), and prioritization of treatment for another malignancy (n=1). Among the treated patients, the median treatment duration was 7.3 months; six completed 1 year of treatment, four remained on treatment at the data cutoff, and six discontinued treatment. Grade ≥3 adverse events occurred in five (31.3%) patients. Median DFS was not reached in the pembrolizumab-treated group and was 18.3 months in the non-pembrolizumab-treated group (<i>p</i>=0.170). <h3>Conclusion:</h3> Adjuvant pembrolizumab was incorporated into real-world clinical practice for patients with high-risk clear-cell renal cell carcinoma after surgery, although not all eligible patients received treatment. Treatment discontinuation and grade ≥3 adverse events were not uncommon. Larger studies with longer follow-up are warranted to better define the real-world effectiveness and tolerability of adjuvant pembrolizumab in this setting.