The Alliance for Clinical Trials in Oncology recently announced that the Alliance Data and Safety Monitoring Board (DSMB) determined that the Phase 3 AMBASSADOR (A031501) trial met one of its dual primary endpoints of disease-free survival (DFS) for the adjuvant treatment of patients with localized muscle-invasive urothelial carcinoma (MIUC) and locally advanced urothelial carcinoma.
At a pre-specified interim analysis review, pembrolizumab demonstrated a statistically significant and clinically meaningful improvement in DFS versus observation in these patients after surgery. The trial will continue to evaluate its other dual primary endpoint of overall survival (OS). Detailed results from the trial will be presented at an upcoming scientific meeting and discussed with regulatory authorities.
“Patients with muscle-invasive bladder cancer after radical surgery are at high risk of disease recurrence and metastases. Pembrolizumab versus observation significantly reduced the risk of disease recurrence for these patients,” said Andrea B. Apolo, MD, study chair for the AMBASSADOR trial and head of the Bladder Cancer Section of the Genitourinary Malignancies Branch and director of the Bladder Cancer and Genitourinary Tumors Multidisciplinary Clinic in the Center for Cancer Research of the National Cancer Institute. “This is long-awaited data in the bladder cancer community, and we are thrilled with the positive results of the AMBASSADOR study and what this means for our patients with bladder cancer.”
Significance of the AMBASSADOR trial results
The safety profile of pembrolizumab in this trial was consistent with that observed in previously reported studies, and no new safety signals were identified.
"The AMBASSADOR trial provides critically important data to contextualize the role of adjuvant immune checkpoint blockade in the treatment of patients with muscle-invasive urothelial cancer once again demonstrating the clinical and scientific impact of the National Cancer Institute's National Clinical Trials Network Treatment Studies," noted Matthew Galsky, MD, professor of medicine at the Icahn School of Medicine at Mount Sinai and associate director for Translational Research at The Tisch Cancer Institute.
AMBASSADOR (A031501) is a randomized, open-label Phase 3 trial evaluating pembrolizumab versus observation for the adjuvant treatment of localized MIUC and locally advanced urothelial carcinoma. The dual primary endpoints are OS and DFS, and secondary endpoints include OS and DFS in PD-L1 positive and negative patients.
The trial enrolled 702 patients who were randomized to receive pembrolizumab (200 mg intravenously every three weeks for up to 18 cycles) or undergo observation.
“Cancer recurrence after surgery can be a devastating event for patients. In this study, pembrolizumab treatment led to a significant improvement in disease-free survival compared to observation, without any new safety signals,” said Jonathan Rosenberg, MD, chief of Genitourinary Oncology Service in the Division of Solid Tumor Oncology at Memorial Sloan Kettering Cancer Center and co-chair the Genitourinary Committee for the Alliance. “These results will help us further understand the role of immune checkpoint blockade in this patient population.”
- This press release was originally published on The Alliance for Clinical Trials in Oncology website