Imfinzi Regimen Improves Disease-Free Survival in Early Bladder Cancer

Imfinzi plus BCG induction and maintenance statistically and clinically meaningfully improved DFS in some with bladder cancer: © stock.adobe.com.

One year of treatment with Imfinzi (durvalumab) plus Bacillus Calmette-Guérin (BCG) induction and maintenance therapy showed a statistically and clinically meaningful improvement in disease-free survival (DFS) in patients with high-risk non-muscle invasive bladder cancer (NMIBC) versus BCG induction and maintenance therapy alone.

This information was shared in a news release from AstraZeneca which also shared that the trial was not statistically powered to formally test for overall survival; however, no detriment was found during a descriptive analysis.

The positive high-level results come from the POTOMAC phase 3 trial.

“These exciting data show that adding one year of [Imfinzi] to the current standard treatment significantly extends the time patients live without high-risk disease recurrence or progression,” Dr. Maria De Santis, head of the Interdisciplinary Uro-Oncology Section at Charité Universitätsmedizin Berlin, Germany, and a principal investigator in the POTOMAC trial, said in the news release. “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."

A second experimental arm that evaluated Imfinzi plus BCG induction-only therapy did not meet the endpoint of DFS when compared with BCG induction and maintenance therapy alone.

Data will be presented at a forthcoming medical meeting.

Currently, Imfinzi is approved by the Food and Drug Administration (FDA) in the United States, as well as in other countries for patients with muscle-invasive bladder cancer based on results from the NIAGARA phase 3 trial. The treatment continues to be studied across both early and late stages of bladder cancer, including in patients with muscle-invasive disease who cannot receive or choose not to take cisplatin as part of the VOLGA trial. It is also being explored in the NILE trial for patients with locally advanced or metastatic bladder cancer in various treatment combinations.

How Safe is Imfinzi Plus BCG Induction and Maintenance Therapy?

The safety and tolerability of Imfinzi plus BCG for both induction and maintenance therapy were consistent with the known safety profiles of each medicine, with no new safety concerns identified. In addition, adding Imfinzi did not compromise patients' ability to complete BCG treatment.

Patients should be regularly checked for symptoms that could signal an immune-related side effect and have lab tests including liver enzymes, kidney function, ACTH and thyroid levels before each dose, according to the release.

“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,” Cristian Massacesi, chief medical officer and oncology chief development officer, AstraZeneca, said in the news release, “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.”

What is the POTOMAC Study?

The POTOMAC trial is a randomized, open-label, global phase 3 study evaluating the immunotherapy Imfinzi in combination with BCG for patients with high-risk, BCG-naïve NMIBC who had already undergone transurethral resection of bladder tumor prior to enrollment.

A total of 1,018 patients were enrolled across more than 120 centers in 12 countries, including Canada and countries throughout Europe and Asia. Participants were randomized equally into three groups: Imfinzi with both BCG induction and maintenance therapy, Imfinzi with BCG induction therapy only, or standard-of-care BCG induction and maintenance therapy.

The trial’s primary goal was to measure DFS — the time from randomization until recurrence of high-risk disease or death from any cause — comparing Imfinzi with BCG induction and maintenance to standard BCG. Secondary endpoints included DFS for the induction-only Imfinzi group versus standard BCG, as well as overall survival at five years and safety outcomes for both experimental treatment arms.

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