Suzanne Merrill, MD, delivers deep-dive into CREST, POTOMAC in BCG-naïve NMIBC

In BCG-naïve non–muscle invasive bladder cancer (NMIBC), emerging options are largely focused on the combining BCG with immune checkpoint inhibitors (ICIs). The first data readout on one of these combinations was from the CREST trial (NCT04165317), which evaluated BCG in combination with sasanlimab. In the coming months, we can also expect to see data from the POTOMAC (NCT03528694) and PATAPSCO (NCT05943106) trials, which are evaluating BCG in combination with durvalumab (Imfinzi).

In a recent interview with Urology Times®, Suzanne B. Merrill, MD, FACS, unpacked key findings from the CREST trial and outlined data of interest from the POTOMAC and PATAPSCO trials, set to read out later this year. Merrill is a urologic oncologist at Colorado Urology, an affiliate of United Urology Group.

Overall, the phase 3 CREST trial demonstrated that adding sasanlimab to BCG induction (I) plus maintenance (M) led to a statistically significant improvement in event-free survival (EFS).¹ At 36 months, the estimated EFS was 82.1% with sasanlimab plus BCG I+M arm vs 74.8% with BCG I+M alone (HR, 0.68; 95% CI, 0.49 to 0.94; P = .0095).

“This is a difference of about 7.3%,” Merrill added. “There was no significant difference between what we called arm B, where we gave the immune checkpoint inhibitor plus BCG induction, vs BCG induction plus maintenance, emphasizing that the use of maintenance was very Important to seeing these impressive results or creating longer event-free survival.”

Another BCG/ICI regimen, BCG plus durvalumab, is being explored in the POTOMAC (international) and PATAPSCO (US) trials.

While full data from those studies are not yet available, topline results from the POTOMAC trial were shared in May 2025 by AstraZeneca.² Overall, the company reported that the addition of durvalumab to BCG I+M led to a statistically significant improvement in disease-free survival. Full results from the trial are expected to be shared at the upcoming European Society of Medical Oncology Congress in Berlin, Germany.

Based on what was seen in the CREST trial, Merrill suggested that key data points from POTOMAC will be on the impact of durvalumab on disease progression, as well as the safety profile of the agent.

REFERENCES

1. Shore ND, Powles TB, Bedke J, et al. Sasanlimab plus BCG in BCG-naive, high-risk non-muscle invasive bladder cancer: the randomized phase 3 CREST trial. Nat Med. 2025. doi:10.1038/s41591-025-03738-z

2. Patients lived significantly longer without high-risk disease recurrence or progression after one year of Imfinzi treatment plus Bacillus Calmette-Guérin (BCG) induction and maintenance therapy vs. BCG alone. News release. AstraZeneca. May 9, 2025. Accessed August 15, 2025. https://www.astrazeneca.com/media-centre/press-releases/2025/imfinzi-improved-dfs-in-early-bladder-cancer.html