Durvalumab + BCG combo cuts bladder cancer recurrence risk by 44% in key subgroup

A subgroup analysis from the phase 3 POTOMAC trial, presented at the 2026 ESMO Congress, shows that adding durvalumab (Imfinzi) to BCG induction and maintenance therapy significantly improved outcomes for patients with BCG-naive, high-risk, papillary-only non–muscle-invasive bladder cancer (NMIBC). At a median follow-up of nearly 61 months, the combination cut the risk of disease recurrence or death by 44% compared to BCG alone — with 48-month disease-free survival rates of 84% vs. 74%.

The benefit was even more pronounced in the T1 disease subset, where the combination reduced recurrence or death risk by 52%. Fewer patients in the durvalumab arm required cystectomy (3% vs. 5%), and early high-risk recurrences within 12 months were nearly halved. These results reinforce the final POTOMAC analysis published in The Lancet, which confirmed the combination met its primary endpoint.

By the Numbers:

• 44% reduction in recurrence/death risk with durvalumab + BCG vs. BCG alone (HR, 0.56)
• 48-month DFS: 84% (combo) vs. 74% (BCG alone)
• T1 subset: 52% risk reduction (HR, 0.48); 48-month DFS 85% vs. 73%
• Cystectomies: 3% vs. 5% in the papillary-only population
• Grade 3/4 adverse events: 34% (combo) vs. 16% (BCG alone)

Why it matters: Papillary-only tumors make up nearly two-thirds of the high-risk NMIBC population, and reducing early recurrences and the need for bladder removal is a major clinical priority. These findings position durvalumab plus BCG as a compelling new treatment option for this large patient subgroup.