Additionally, the new analysis showed a median disease-free survival (DFS) of 25.6 months for those receiving nivolumab, compared to just 8.5 months for the placebo.

Despite these promising results, Dr. Elizabeth Plimack pointed out that only 15% of patients in the study received nivolumab as a standard-of-care treatment following radical surgery.

Plimack also highlighted the importance of identifying biomarkers to avoid over-treatment and to better select patients who would benefit most from nivolumab, suggesting the potential role of circulating tumor DNA (ctDNA) in clinical decision-making.

The study involved 709 patients with stage II to IVa muscle invasive urothelial cancer who had undergone radical surgery within the last 120 days and were disease-free at the time of randomization.

For patients who did not receive prior neoadjuvant chemotherapy, the median overall survival (OS) with nivolumab was not reached, in contrast to 37.7 months for the placebo group, demonstrating statistical significance with a hazard ratio of 0.67.

At the American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium 2025 in San Francisco, Dr. Matthew I. Milowsky presented significant findings on the efficacy of nivolumab in treating muscle invasive urothelial cancer.

Among patients with PD-L1 expression of 1% or more, the median DFS for nivolumab was not reached, while it was 10.8 months for the placebo, with a hazard ratio of 0.53 and a p-value of less than 0.001.

However, the treatment was not without risks; adverse events of grade 3 or higher occurred in 17% of nivolumab patients compared to 6% in the placebo group, with treatment discontinuation due to adverse events at 2% for nivolumab and 1% for placebo.