Efficacy and safety of adjuvant nivolumab after radical surgery for high-risk urothelial carcinoma: a preliminary report of real-world data from a single institution

The phase 3 CheckMate 274 trial demonstrated superiority of adjuvant nivolumab over placebo after radical surgery in patients with high-risk urothelial carcinoma (UC). However, real-world data on the efficacy and safety profile of adjuvant nivolumab in Japan have not been reported.

This retrospective study enrolled patients with high-risk UC who received adjuvant nivolumab therapy following radical surgery between 2022 and 2024 at our institution. We evaluated immune-related adverse events (irAEs) according to the Common Terminology Criteria for Adverse Events, version 5.0. Kaplan–Meier curves were used to assess disease-free survival (DFS) and overall survival (OS).

Thirty-three patients with high-risk UC receiving adjuvant nivolumab therapy following radical surgery were identified, and median follow-up was 11 months. Three patients experienced grade 3 irAEs, and 8 discontinued adjuvant nivolumab therapy due to irAEs. No grade 4 or 5 irAEs were observed. Eight patients have completed 1 year of treatment, and nine are currently on treatment. Nine patients had recurrences and one died of cancer. Of the nine patients with recurrences, six relapsed while on adjuvant nivolumab therapy, two relapsed after completing 1 year of treatment, and one relapsed after discontinuation of irAE. The 1- and 2-year OS rates were 100% and 90%, respectively, and median OS was not reached. The 1- and 2-year DFS rates were 70% and 60%, respectively, and median DFS was 26 months.

Adjuvant nivolumab appears to have some efficacy in Japanese patients. Since this is a postoperative adjuvant therapy, careful patient selection is warranted.