AstraZeneca announced promising top-line results from its Phase III POTOMAC trial, showing that one year of treatment with Imfinzi (durvalumab) combined with standard-of-care Bacillus Calmette-Guérin (BCG) induction and maintenance therapy significantly improved disease-free survival (DFS) for patients with high-risk non-muscle-invasive bladder cancer (NMIBC), compared to BCG therapy alone.
Although the trial was not statistically powered to formally assess overall survival (OS), a descriptive analysis showed no detriment to OS.
Bladder cancer is one of the most common cancers worldwide, with over 70% of cases diagnosed as NMIBC—an early-stage disease where tumors are confined to the bladder lining and have not penetrated the muscle wall. Approximately half of NMIBC patients are considered high-risk for disease progression or recurrence due to factors such as tumor grade, stage, and specific pathological features.
Dr. Maria De Santis, Head of the Interdisciplinary Uro-Oncology Section at Charité Universitätsmedizin Berlin and principal investigator of the POTOMAC trial, commented:
“These exciting data show that adding one year of durvalumab to current standard treatment significantly extends the time patients remain free from high-risk disease recurrence or progression. While most NMIBC patients are treated with curative intent, 80% experience disease recurrence, and nearly half may ultimately require bladder removal—a life-changing surgery. This underscores the urgent need to improve treatment outcomes.”
Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer at AstraZeneca, added:
“The positive results from the POTOMAC trial represent a major advancement, potentially enabling more early-stage bladder cancer patients to benefit from this important immunotherapy. Combined with the earlier NIAGARA trial results, this outcome reflects our strategy of introducing innovative treatments where they can offer the greatest long-term impact.”
The safety and tolerability of Imfinzi combined with BCG induction and maintenance were consistent with the known safety profiles of each treatment, with no new safety signals identified. Importantly, adding Imfinzi did not hinder patients’ ability to complete BCG therapy.
However, the trial’s second experimental arm, which evaluated Imfinzi plus BCG induction-only therapy (without maintenance) compared to BCG induction and maintenance alone, did not achieve the DFS endpoint.
Detailed results will be presented at an upcoming medical meeting and shared with regulatory authorities worldwide.
Imfinzi is already approved in the US and several other countries for the treatment of muscle-invasive bladder cancer (MIBC) based on the NIAGARA Phase III trial results. The drug continues to be studied across both early and late-stage bladder cancer, including in the VOLGA trial (for MIBC patients ineligible or unwilling to receive cisplatin) and in the NILE trial (for locally advanced or metastatic disease).
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