The phase 3 POTOMAC trial found that combining durvalumab (Imfinzi) with BCG induction and maintenance therapy significantly improved outcomes for patients with BCG-naive, high-risk non–muscle-invasive bladder cancer (NMIBC). Patients receiving durvalumab with BCG induction and maintenance experienced a 32% reduction in the risk of disease-free survival (DFS) events (HR 0.68; P=0.0154), with benefits observed early and sustained throughout follow-up. In contrast, patients treated with durvalumab plus BCG induction only did not show a statistically significant DFS improvement compared to BCG alone.
While overall survival (OS) data are not yet mature, the addition of durvalumab did not negatively impact OS. Patient-reported quality of life remained largely unaffected by the combination therapy.
The regimen was generally well tolerated, with no new safety concerns or treatment-related deaths. The most common side effects were consistent with typical BCG therapy, including dysuria, hematuria, and frequent urination. Grade 3–4 adverse events were more frequent in the durvalumab/BCG induction and maintenance arm (21%) compared to the BCG-only arm (4%).
These findings support the use of durvalumab with BCG induction and maintenance as a potential new treatment option for patients with high-risk NMIBC.