Durvalumab plus BCG significantly improves DFS in NMIBC

Treatment for 1 year with durvalumab (Imfinzi) plus standard-of-care BCG induction and maintenance therapy was associated with a statistically significant and clinically meaningful improvement in disease-free survival (DFS) high-risk non–muscle invasive bladder cancer (NMIBC) vs BCG induction and maintenance alone, AstraZeneca announced.¹

The results represent "a significant advance," according to Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer, AstraZeneca.

According to the company, although the phase 3 POTOMAC trial (NCT03528694) was not statistically powered to formally evaluate overall survival, “a descriptive analysis demonstrated no detriment.”

“These exciting data show that adding 1 year of durvalumab to the current standard treatment significantly extends the time patients live without high-risk disease recurrence or progression. While most patients with non-muscle invasive bladder cancer are treated with curative intent, 80% see their disease return and almost half may require life-altering surgery to remove the bladder, underscoring the urgent need to improve treatment,” said POTOMAC principal investigator Maria DeSantis, MD, head of the Interdisciplinary Uro-Oncology Section at Charité Universitätsmediz in Berlin, Germany, in a news release about the data.

Added Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer, AstraZeneca, “The positive results for Imfinzi in the POTOMAC trial represent a significant advance that will potentially allow more patients with early-stage bladder cancer to benefit from this important immunotherapy. Building on the NIAGARA data, this outcome demonstrates our strategy of bringing novel therapies to patients with early-stage disease where there is the greatest potential for long-term benefit.”

The POTOMAC trial is a randomized, open-label, multi-center, global phase 3 study evaluating durvalumab plus BCG for patients with high-risk, BCG-naïve NMIBC who have undergone transurethral resection of the bladder tumor prior to randomization. A total of 1018 patients were randomly assigned in a 1:1:1 fashion to receive durvalumab plus BCG induction and maintenance therapy or durvalumab plus BCG induction-only therapy vs standard-of-care BCG induction and maintenance therapy.

More than 120 sites across 12 countries participated in POTOMAC. The primary end point of the study was DFS, which was defined as “time from randomization to date of first recurrence of high-risk disease or death from any cause,” for the durvalumab plus BCG induction and maintenance vs BCG induction and maintenance therapy alone arms. DFS for durvalumab plus BCG induction-only therapy vs BCG induction and maintenance therapy alone, overall survival at 5 years, and safety in both experimental arms comprised secondary end points.

Regarding adverse events, AstraZeneca reported that the safety and tolerability of durvalumab plus BCG “was consistent with the known safety profiles of the individual medicines, with no new safety concerns identified. The addition of Imfinzi did not compromise patients' ability to complete BCG induction and maintenance therapy.”

In the durvalumab plus BCG induction-therapy vs BCG induction and maintenance therapy alone component of the study, the end point of DFS was not reached.

The FDA recently approved the treatment regimen of neoadjuvant durvalumab in combination with gemcitabine and cisplatin, followed by adjuvant durvalumab monotherapy following radical cystectomy, for adult patients with muscle invasive bladder cancer, based on results of the phase 3 NIAGARA study.²

AstraZeneca said the POTOMAC data will be presented at an upcoming scientific meeting and shared with global regulatory authorities. Other trials of durvalumab include VOLGA (NCT04960709), evaluating durvalumab in patients with muscle-invasive bladder cancer who are ineligible for or refuse cisplatin, and NILE (NCT03682068), evaluating durvalumab in patients with locally advanced or metastatic bladder cancer.¹

REFERENCES

1. Patients lived significantly longer without high-risk disease recurrence or progression after one year of Imfinzi treatment plus Bacillus Calmette-Guérin (BCG) induction and maintenance therapy vs. BCG alone. News release. AstraZeneca. May 9, 2025. Accessed May 9, 2025. https://www.astrazeneca.com/media-centre/press-releases/2025/imfinzi-improved-dfs-in-early-bladder-cancer.html

2. FDA approves durvalumab for muscle invasive bladder cancer. News release. US Food & Drug Administration. March 28, 2025. Accessed May 9, 2025. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-durvalumab-muscle-invasive-bladder-cancer