Durvalumab + BCG earns FDA approval for bladder cancer — but optimizing the basics still comes first

The FDA's May 2026 approval of durvalumab (Imfinzi) plus BCG marks a meaningful step forward for patients with high-risk, BCG-naive non–muscle-invasive bladder cancer (NMIBC). Backed by the phase 3 POTOMAC trial — which enrolled 1,018 patients and showed a significant improvement in disease-free survival (DFS) with the combination — the regimen is now a Level 1 evidence–supported first-line option. But experts caution that real-world gaps in BCG delivery may be undermining outcomes before immunotherapy even enters the picture.

Urologist Tom Jayram, MD, emphasized at the 2026 LUGPA Annual Meeting that many patients progress not because their disease is inherently aggressive, but because BCG instillations are being done inconsistently. He advocates for thorough resection, standardized pathology, advanced imaging, and strict induction and maintenance schedules as the foundation of care. For younger, motivated patients who can tolerate the therapy, adding durvalumab offers a meaningful benefit — particularly in reducing cystectomy rates.

Key Takeaways:

• POTOMAC showed durvalumab + BCG reduced the risk of high-risk recurrence or death by 32% vs BCG alone (HR, 0.68); in papillary-only tumors, the risk reduction was 44% (HR, 0.56)
• Cystectomy-free survival — the endpoint patients care most about — also favored the durvalumab arm (HR, 0.69)
• Approximately 5–10% of patients may require lifelong thyroid hormone replacement due to immune-mediated side effects
• ctDNA positivity (detected in 35% of NMIBC patients in one study) may identify candidates for treatment intensification even before cystoscopy findings appear

Why it matters: With durvalumab now approved, the bladder cancer field faces a dual challenge — ensuring BCG is delivered correctly and identifying which patients truly benefit from combination therapy. Biomarker tools like ctDNA could be the key to smarter, more personalized treatment decisions.