- In the first year of treatment, the number of high-risk disease events and Bacillus Calmette-Guérin (BCG)-unresponsive recurrences in the IMFINZI plus BCG arm was almost half the number in the BCG-only arm
- IMFINZI plus BCG improved time to cystectomy and cystectomy-free survival, with fewer patients undergoing bladder removal surgery
These new data were presented at the 2026 American Urological Association Annual Meeting (AUA) in Washington, DC.
In the first year of treatment, the number of high-risk disease events and BCG-unresponsive recurrences in the IMFINZI plus BCG arm was almost half the number in the BCG-only arm. Across additional analyses, IMFINZI improved the secondary endpoint of time to cystectomy, as well as cystectomy-free survival, with fewer patients in the IMFINZI arm undergoing bladder removal surgery compared to patients treated with BCG alone (see data table below for details).
In subgroups of patients with any papillary tumors (with or without carcinoma in situ [CIS]) or with papillary tumors only (without CIS), the IMFINZI plus BCG regimen reduced the risk of high-risk disease recurrence, progression or death by 39% and 44%, respectively, compared to BCG alone (based on DFS hazard ratios [HR] of 0.61 and 0.56, respectively; 95% confidence interval [CI] 0.43-0.84 and 0.37-0.84 [P=0.0046], respectively).
Neal Shore, MD, FACS, Director of START Carolinas / Head of the Carolina Urologic Research Center and co-principal investigator in the trial, said: “Nearly 40 percent of patients with high-risk non-muscle-invasive bladder cancer who relapse become unresponsive to BCG therapy and face a higher likelihood of bladder removal surgery. These new data from POTOMAC show that adding one year of durvalumab to BCG induction and maintenance therapy can reduce early high-risk recurrences and BCG-unresponsive recurrences, extending the time that patients live with their bladder intact and adding further compelling evidence for the benefit of this regimen for this group of patients.”Leora Horn, Senior Vice President, Late Development Oncology, Oncology R&D, AstraZeneca, said: “These new analyses reinforce the benefit of IMFINZI plus BCG for patients with high-risk non-muscle-invasive bladder cancer, with data showing that this potential new treatment option reduces recurrences within the first year of treatment and decreases the risk of cystectomy. The results of POTOMAC build on the impact IMFINZI is having in muscle-invasive bladder cancer, further validating our approach to bring novel therapies into earlier-stage settings where they can have the greatest impact on patients’ lives.”
These new data build on findings presented at the European Society for Medical Oncology (ESMO) Congress 2025 and simultaneously published in The Lancet, which showed POTOMAC met the primary endpoint of disease-free survival (DFS). In the intent-to-treat (ITT) population, patients treated with the IMFINZI regimen showed a 32% reduction in the risk of high-risk disease recurrence, progression or death versus the comparator arm (based on a DFS HR of 0.68; 95% CI 0.50-0.93; P=0.0154). Estimated median DFS was not yet reached for either arm. An estimated 87% of patients treated with the IMFINZI regimen remained alive and disease-free at two years compared to 82% in the comparator arm.
Summary of prespecified and post-hoc exploratory analyses (ITT): POTOMAC
The safety and tolerability of IMFINZI plus BCG induction and maintenance therapy was consistent with the known safety profiles of the individual medicines, with no new safety signals identified, with a median follow-up of more than five years for DFS.
Regulatory submissions based on the POTOMAC data are under review in the US, European Union (EU), Japan and several other countries.
Yesterday, positive high-level results from the VOLGA Phase III clinical trial were announced, showing that perioperative IMFINZI plus neoadjuvant enfortumab vedotin (EV) demonstrated statistically significant and clinically meaningful improvements in event-free survival (EFS) and overall survival (OS) in patients with MIBC who are not eligible for or had declined cisplatin-based chemotherapy. IMFINZI plus IMJUDO® (tremelimumab-actl) in combination with neoadjuvant EV demonstrated a statistically significant and clinically meaningful improvement in EFS and a favorable trend for OS; however, the OS data were not statistically significant at this planned interim analysis and will be formally reassessed at a subsequent analysis.
IMFINZI is approved in over 40 countries for patients with cisplatin-eligible MIBC, based on the NIAGARA Phase III trial, and continues to be investigated in locally advanced or metastatic disease in the NILE Phase III trial.
Data will also be presented at AUA on May 16 from the US-based, open-label, single-arm PATAPSCO Phase IIIb trial, which will provide additional safety data for IMFINZI in patients with BCG-naïve, high-risk NMIBC (abstract #PD09-07).
Source: AstraZeneca. (2026). IMFINZI® (Durvalumab) Regimen Reduced Early Disease Recurrence Among High-Risk Non-Muscle-Invasive Bladder Cancer Patients in POTOMAC Phase III Trial Exploratory Analyses [Press release]. https://www.astrazeneca-us.com/media/press-releases/2026/IMFINZI-durvalumab-regimen-reduced-early-disease-recurrence-among-high-risk-non-muscle-invasive-bladder-cancer-patients-in-POTOMAC-Phase-III-trial-exploratory-analyses.html.