Durvalumab Added to BCG Cuts Bladder Cancer Recurrence by 32% in Phase III Trial
New POTOMAC trial data show adding durvalumab immunotherapy to standard BCG treatment significantly reduces high-risk bladder cancer recurrence.
Summary
A large phase III clinical trial called POTOMAC found that adding durvalumab, an immunotherapy drug, to standard BCG treatment for high-risk non-muscle-invasive bladder cancer reduced the risk of disease recurrence or death by 32%. In the first year, 16% of patients on the combination therapy experienced a high-risk event versus 20% on BCG alone. The median time before a disease event was also significantly longer with durvalumab added. Fewer patients in the combination group needed bladder removal surgery. While the treatment showed clear benefits, it also came with higher rates of serious side effects — 21% experienced grade 3 or 4 adverse events compared to 4% in the BCG-only group. These findings were presented at the American Urological Association annual meeting.
Detailed Summary
Bladder cancer is among the most common cancers worldwide, and early-stage non-muscle-invasive forms carry a significant risk of recurrence even after standard treatment. The POTOMAC trial investigated whether adding durvalumab, a PD-L1 checkpoint inhibitor immunotherapy, to the established BCG regimen could improve outcomes for high-risk patients.
The phase III trial enrolled 1,018 patients across 116 sites in 12 countries. Patients were randomized to durvalumab plus BCG induction and maintenance, durvalumab plus BCG induction only, or BCG alone. The median patient age was 67–68 years, with 80% male participants. Primary results showed the combination reduced the risk of high-risk disease recurrence or death by 32% compared to BCG alone, meeting the trial's primary endpoint.
Early recurrence data were particularly striking. Within the first year, only 16% of combination-arm patients experienced a high-risk event versus 20% in the BCG-only group. The median time to a disease event was 14.1 months with durvalumab versus just 8.3 months without it. Among BCG-unresponsive patients, recurrences dropped from 81% to 65%, and bladder removal surgery fell from 25% to 8%.
For cancer patients and clinicians, these findings suggest a meaningful improvement in disease control without requiring immediate escalation to surgery. Preserving the bladder has major quality-of-life implications, making the reduction in cystectomy rates a particularly important outcome.
However, safety trade-offs are notable. Grade 3 or 4 treatment-related adverse events occurred in 21% of combination patients versus 4% in the BCG-only group. Serious adverse events were reported in 13% versus 4%, and discontinuation rates were higher. These side effect burdens will require careful patient selection and shared decision-making before this regimen becomes standard practice. Overall survival data showed a favorable trend but did not yet reach statistical significance.
Key Findings
- Durvalumab plus BCG reduced high-risk bladder cancer recurrence or death risk by 32% versus BCG alone.
- Median time to disease event was 14.1 months with durvalumab versus 8.3 months on BCG alone.
- Bladder removal surgery dropped from 25% to 8% among BCG-unresponsive patients receiving durvalumab.
- Grade 3/4 adverse events were substantially higher with durvalumab: 21% versus 4% on BCG alone.
- Papillary tumor subtypes showed 39–52% reduction in recurrence risk with the combination therapy.
Methodology
This is a meeting coverage news report from MedPage Today summarizing new analyses from the POTOMAC phase III randomized controlled trial presented at the 2026 American Urological Association annual meeting. The trial enrolled 1,018 patients across 12 countries, providing robust statistical power. As a conference presentation, full peer-reviewed publication has not yet been confirmed and data should be verified against the primary publication.
Study Limitations
Data are from a conference presentation and may not yet be peer-reviewed or fully published. Overall survival benefit showed only a trend and did not reach statistical significance. Higher adverse event and discontinuation rates with durvalumab require careful evaluation of patient fitness and risk tolerance before broad adoption.
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