Results from a post-hoc exploratory subgroup analysis from the NIAGARA Phase III trial showed AstraZeneca’s Imfinzi (durvalumab), administered perioperatively in combination with neoadjuvant chemotherapy, demonstrated improvements in event-free survival (EFS) and overall survival (OS) versus neoadjuvant chemotherapy with radical cystectomy alone in patients with or without a pathologic complete response (pCR) in muscle-invasive bladder cancer (MIBC). Patients were treated with four cycles of Imfinzi in combination with neoadjuvant chemotherapy before radical cystectomy (surgery to remove the bladder) followed by eight cycles of Imfinzi monotherapy.

These new data were presented today at the 2025 American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU) in San Francisco, California (abstract #659).

In NIAGARA, treatment with the Imfinzi perioperative regimen improved EFS and OS versus the comparator arm both in patients who achieved pCR and those who did not. This regimen reduced the risk of disease progression, recurrence, not undergoing surgery, or death by 42% in patients who achieved pCR and by 23% in those who did not; and reduced the risk of death by 28% in patients who achieved pCR and by 16% in those who did not (see data table below for details).

The Imfinzi perioperative regimen also improved metastasis-free survival (MFS) and disease-specific survival (DSS), two secondary endpoints, versus the comparator arm in the intent-to-treat (ITT) population. This regimen reduced the risk of developing distant metastases or death by 33% and the risk of death specifically due to bladder cancer by 31% versus the comparator arm (see data table below for details).

Matthew ND. Galsky, Lillian and Howard Stratton Professor of Medicine, Director of Genitourinary Medical Oncology, The Tisch Cancer Institute at the Icahn School of Medicine at Mount Sinai, New York, and NIAGARA Investigator and Steering Committee member, said: “These NIAGARA data confirm the compelling efficacy of the durvalumab perioperative regimen in muscle-invasive bladder cancer, and importantly, show this regimen improved outcomes regardless of whether patients achieved a pathologic complete response. This insight, together with the data showing the durvalumab perioperative regimen extended the time patients live before distant metastases develop, is favourable news for patients with muscle-invasive bladder cancer who are in need of better treatment options.”

Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer, AstraZeneca, said: “NIAGARA was the first Phase III trial of a perioperative immunotherapy regimen in muscle-invasive bladder cancer to show statistically significant and clinically meaningful improvements in event-free and overall survival. The 33 per cent reduction in the risk of distant metastases, which are associated with a poorer prognosis, further reinforces the potential of perioperative Imfinzi to become a new standard of care in this setting.”

These new data build on findings presented at the European Society for Medical Oncology (ESMO) Congress and published in The New England Journal of Medicine which showed NIAGARA met the primary endpoint of EFS and the key secondary endpoint of OS. In the ITT population, patients treated with the Imfinzi perioperative regimen showed a 32% reduction in the risk of disease progression, recurrence, not undergoing surgery, or death versus the comparator arm, as well as a 25% reduction in the risk of death. There was also a 10% improvement in the pCR rate versus the comparator arm.