The addition of durvalumab (Imfinzi) to BCG induction and maintenance therapy continued to show no detriment to overall survival (OS) at the planned 5-year analysis of the phase 3 POTOMAC trial (NCT03528694) and did not meaningfully affect patient-reported quality of life (QOL), according to data presented during the 2026 ASCO Annual Meeting.1
At a median follow-up of 72 months, the 5-year OS rate was 88% in the durvalumab plus BCG induction and maintenance arm (n = 339) vs 86% in the BCG induction and maintenance alone arm (n = 340; HR, 0.81, 95% CI, 0.54-1.19). The median OS was not reached in either arm. Across multiple patient-reported outcome (PRO) instruments, including the EORTC QLQ-C30 and EORTC QLQ-NMIBC24, adjusted mean changes from baseline were similar between treatment arms.
“These data further support 1 year of durvalumab in combination with BCG induction and maintenance as a new treatment for patients with BCG-naive, high-risk NMIBC,” Maria De Santis, MD, the head of the Interdisciplinary Uro-Oncology Section at Charite-University Medicine in Berlin, Germany, said during the presentation.
In May 2026, the FDA approved durvalumab (Imfinzi) in combination with BCG for the treatment of adult patients with BCG-naive, high-risk non–muscle-invasive bladder cancer (NMIBC). The regulatory decision was supported by prior data from POTOMAC, which demonstrated that durvalumab plus BCG induction and maintenance (n = 339) led to a statistically significant improvement in disease-free survival (DFS) compared with BCG induction and maintenance alone (n = 340; HR, 0.68; 95% CI, 0.50-0.93; P = .0154).
Key Findings From the POTOMAC 5-Year Analysis
- In May 2026, the FDA approved durvalumab in combination with BCG for the treatment of adult patients with BCG-naive, high-risk NMIBC.
- At a median follow-up of 72 months, the 5-year OS rate was 88% with durvalumab plus BCG induction and maintenance vs 86% with BCG induction and maintenance alone (HR, 0.81; 95% CI, 0.54–1.19); median OS was not reached in either arm.
- Adjusted mean changes from baseline on the EORTC QLQ-C30 and EORTC QLQ-NMIBC24 were similar between treatment arms and did not reach clinically meaningful thresholds.
How was POTOMAC designed?
POTOMAC enrolled patients aged 18 years or older with BCG-naive, high-risk NMIBC defined by at least 1 of the following: T1 disease, high-grade/G3 disease, carcinoma in situ (CIS), or multiple and recurrent large tumors (≥3 cm).
A total of 1018 patients were randomly assigned 1:1:1 to three arms: intravenous (IV) durvalumab at 1500 mg every 4 weeks for 13 cycles plus BCG induction and maintenance; durvalumab at 1500 mg IV every 4 weeks for 13 cycles plus BCG induction only; or BCG induction and maintenance alone.
The primary end point was DFS. Secondary end points included the 5-year OS rate and PROs, with data cutoffs of October 3, 2025, and April 3, 2025, respectively.
Patient characteristics were well balanced between the durvalumab plus BCG induction and maintenance and BCG induction and maintenance arms. Median age was 68 years (range, 24-90) and 67 years (range, 32-86), respectively; approximately 81% and 80% of the respective patients were male. Most patients had T1 disease (58% vs 62%) and an ECOG performance status of 0 (87% vs 89). High-risk papillary disease was present in 51% of patients in each arm.
What were the additional PRO data that were shared?
PRO assessments were conducted using 3 instruments: the EORTC QLQ-C30, the EORTC QLQ-NMIBC24, and the PRO-CTCAE. Baseline PRO scores were similar between arms, reflecting high QOL, high physical functioning, and low symptom burden at study entry.
On the EORTC QLQ-C30, adjusted mean changes from baseline showed modest deterioration in GHS/QoL (difference between arms: –2.7; 95% CI, –4.85 to –0.54) and physical functioning (difference: –2.6; 95% CI, –4.43 to –0.81), as well as increased fatigue (difference: 4.0; 95% CI, 1.50 to 6.46) in both treatment arms, with generally similar trajectories across arms over time. On the EORTC QLQ-NMIBC24, differences between arms for all 4 subscales— urinary symptoms, intravesical treatment issues, future perspective/worries, and sexual functioning—were not clinically meaningful.
Rates of PRO-CTCAE symptom worsening through Week 106 were largely comparable between investigational and control arms, consistent with the shared BCG treatment backbone across arms. For abdominal pain (interference), worsening was reported in 78% vs 68% of evaluable patients, respectively; for abdominal pain frequency, 67% vs 63%; and for painful urination severity, 83% vs 82%. For urinary frequency, the rate of PRO-CTCAE worsening was numerically higher with the combination vs BCG alone (80% vs 73% for frequency; 79% vs 69% for interference).
“The addition of durvalumab to BCG induction and maintenance continued to show no detriment at the planned 5-year OS analysis, and it did not have a major impact on patient-reported QOL,” De Santis concluded.
References
- De Santis M, Shore ND, Nishiyama H, et al. Durvalumab (D) in combination with BCG induction and maintenance (I+M) therapy for BCG-naïve, high-risk non-muscle-invasive bladder cancer (NMIBC): 5-year overall survival (OS) analysis and patient-reported outcomes (PROs) from POTOMAC. J Clin Oncol. 2026;44(suppl 16):4624. doi:10.1200/JCO.2026.44.16_suppl.4624
- FDA approves durvalumab in combination with Bacillus Calmette-Guerin for high-risk non-muscle invasive bladder cancer. FDA. May 28, 2026. Accessed June 1, 2026. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-durvalumab-combination-bacillus-calmette-guerin-high-risk-non-muscle-invasive-bladder
