Perioperative pembrolizumab fails to significantly improve event-free survival in muscle-invasive bladder cancer

Prof Jens Bedke talks to ecancer at ESMO 2026 about results from the phase III KEYNOTE-866 trial, which evaluated perioperative pembrolizumab alongside neoadjuvant gemcitabine and cisplatin chemotherapy in patients with muscle-invasive bladder cancer (MIBC).

The study randomised 907 patients to receive pembrolizumab or placebo alongside chemotherapy, followed by radical cystectomy and adjuvant treatment.

After a median follow-up of 60.9 months, pembrolizumab did not significantly improve event-free survival (HR 0.88; P = 0.1366) or demonstrate an overall survival benefit (HR 1.00).

Although pathological complete response rates were higher with pembrolizumab (44.4% versus 35.8%), the primary endpoint was not met.

The findings suggest that adding perioperative pembrolizumab to cisplatin-based chemotherapy and surgery does not provide a significant clinical benefit in this patient population.