Real-World Occurrence of Adverse Events Associated With Adjuvant Pembrolizumab Therapy for Renal Cell Carcinoma: A Multicenter Retrospective Study.

BACKGROUND

Pembrolizumab is indicated as adjuvant therapy after nephrectomy in patients with high-risk renal cell carcinoma (RCC). However, data regarding the occurrence of treatment-related adverse events (TRAEs) associated with pembrolizumab in real-world clinical settings in Japanese patients remain limited. In this study, we aimed to assess the clinical safety of adjuvant pembrolizumab therapy in Japan.

METHODS

This multicenter, retrospective, observational study enrolled patients who received adjuvant pembrolizumab therapy for RCC at five facilities in Japan between August 2022 and March 2025. The primary endpoint was the occurrence of TRAEs, which were classified by grade according to the Common Terminology Criteria for Adverse Events version 5.0. Secondary endpoints focused on disease-free survival (DFS) and overall survival (OS).

RESULTS

This study enrolled 35 patients and had a median follow-up period of 7.0 months (interquartile range: 2.0-14.0). TRAEs occurred in 13 patients (37.1%), including two (5.7%) with grade ≥ 3 events. Five patients (14.3%) discontinued pembrolizumab treatment because of TRAEs, and no treatment-related deaths were observed. Grade ≥ 3 TRAEs included one case each of erythema multiforme, myocarditis, gastrointestinal perforation, and myasthenia gravis. During follow-up, no disease recurrence or death was observed, and the median DFS and OS were not achieved.

CONCLUSIONS

The safety profile of pembrolizumab as an adjuvant therapy was found to be acceptable in Japanese patients with high-risk RCC. Therefore, postoperative adjuvant pembrolizumab following surgical intervention may be recommended as a treatment option for eligible patients in clinical practice.