Eugene Pietzak, MD, discusses trial of chemoimmunotherapy strategy in NMIBC

At the 2025 Society of Urology Oncology Annual Meeting in Phoenix, Arizona, Eugene Pietzak, MD, sat down with Urology Times® to discuss the background and design of the ongoing phase 3 GAIN trial (NCT07000084).¹ Overall, the study is assessing the safety and efficacy of a chemoimmunotherapy strategy comprised of intravesical gemcitabine with BCG vs re-treatment with BCG alone in patients with BCG-exposed non–muscle invasive bladder cancer (NMIBC).

Pietzak is a urologic surgeon at Memorial Sloan Kettering Cancer Center in New York, New York.

In total, the prospective, open-label study plans to enroll 330 patients across clinical trial sites in the US.² Notably, the inclusion criteria for the study is liberal, allowing for more than 1 prior BCG induction course/prior maintenance BCG, any prior systemic or intravesical agents for NMIBC (including gemcitabine), and non-invasive urothelial carcinoma of the prostatic urethra and treated upper tract urothelial carcinoma.

“We've tried to be more liberal in getting almost everyone [for whom a] reasonable urologist would consider re-treatment with BCG as a good option for them,” Pietzak explained. “We're really trying to make sure we could include those patients in this trial.”

The primary end point for the study is high-grade recurrence-free survival with GemBCG vs BCG alone. Secondary outcomes include 6-month complete response rate, durability of response, progression-free survival, cystectomy-free survival, BCG-unresponsive NMIBC-free survival, and the rate of grade 3 or higher adverse events.

Completion of the trial is expected in December 2028.

REFERENCES

1. Pietzak E. The GAIN trial: Gemcitabine alternating with intravesical BCG randomized against BCG alone for patients with recurrent “BCG-exposed” high-grade non-muscle invasive bladder cancer (ALLIANCE A032303) NCT07000084. Presented at: Society of Urologic Oncology Annual Meeting; December 2-5, 2025; Phoenix, Arizona. Abstract 131. https://suo-abstracts.secure-platform.com/a/gallery/rounds/24/details/4424

2. Testing the addition of an anti-cancer drug, gemcitabine, to usual treatment (BCG alone) in people whose non-muscle invasive bladder cancer (NMIBC) came back after prior BCG therapy (GAIN-BCG). ClinicalTrials.gov. Last updated November 5, 2025. Accessed December 8, 2025. https://clinicaltrials.gov/study/NCT07000084