Pembrolizumab significantly improves DFS for urothelial cancer
Results from the open-label, randomised AMBASSADOR trial reveal that disease-free survival (DFS) was doubled with adjuvant pembrolizumab therapy compared with observation in patients with locally advanced muscle-invasive urothelial cancer. Thus, patients can live a disease-free existence for 15 additional months with pembrolizumab compared with observation. The AMBASSADOR study is the first trial in urothelial cancer to show a positive benefit for pembrolizumab as adjuvant therapy in this cancer type. The late-breaking data were presented at the recent ASCO GI conference. The trial randomised 702 patients to receive either pembrolizumab (200 mg intravenously every 3 weeks for up to 18 cycles) or observation. After a median follow-up of 22.3 months, pembrolizumab demonstrated a clinically meaningful improvement in one of the study primary endpoints of DFS, reducing the risk of recurrence or death by 31%. The median DFS was an impressive 29 months for pembrolizumab compared with only 14 months for observation, regardless of tumour PD-1 expression levels. Overall survival (additional primary endpoint) was not statistically significant at the time of interim analysis, with comparable levels noted between the pembrolizumab and observation arms (50.9 versus 55.8 months, respectively). This trial highlights the potential of using pembrolizumab after surgery for patients with locally advanced or high-risk urothelial cancer. Pembrolizumab therapy in earlier stages of resectable muscle-invasive bladder cancer enables patients to stay disease-free for twice as long following surgery.