(UroToday.com) The 2026 GU ASCO annual meeting featured a urothelial carcinoma session and a presentation by Dr. Gary Steinberg discussing results from the phase 3 BOND-003 trial Cohort C, specifically cystectomy free survival following cretostimogene grenadenorepvec in high risk BCG unresponsive non muscle invasive bladder cancer with CIS. A significant treatment gap exists for efficacious, well-tolerated bladder-sparing options for patients with high risk BCG unresponsive non muscle invasive bladder cancer with CIS. Cretostimogene is an oncolytic immunotherapy with dual mechanisms of action. It replicates in and lyses cancer cells with Rb-E2F pathway alterations, while simultaneously amplifying an anti-tumor immune response, further mediated by the GM-CSF transgene. BOND-003 is a phase-3 study evaluating the efficacy and safety of cretostimogene in patients with high risk BCG unresponsive non muscle invasive bladder cancer with CIS +/- HG Ta/T1 (Cohort C) and HG Ta/T1 only (Cohort P). At ASCO GU 2026, Dr. Steinberg and colleagues reported data on radical cystectomy performed post-recurrence or progression on Cohort C.
There were 112 patients enrolled. Participants had previously received adequate BCG and were considered BCG-unresponsive by the FDA definition. Cretostimogene treatment consisted of a 6 weekly induction course, followed by 3 weekly maintenance cycles every 3 months in year one and every 6 months during years 2-3:
Repeat induction was permitted at month 3 if persistent HG Ta or CIS. Response assessments included serial cystoscopy, urine cytology, and mandatory mapping biopsy at 12 months, with centralized review of all pathology. The primary endpoint was complete response at any time. Cystectomy free survival and progression free survival were key secondary endpoints.
The majority of patients are male (74%), white (62%), and > 65 years old (83%). As of the June 23, 2025, data cutoff (median follow-up of 25.8 months), the complete response rate at any time is 75.5% (83/110) (95% CI 66.3-83.2%). The 12- and 24- month complete response rate is 46.4% (51/110) (95% CI 36.8-56.1%) and 41.8% (46/110) (95% CI 32.5-51.6%), respectively:
Kaplan-Meier estimates of 12- and 24-month duration of response are 64.2% (95% CI 52.5-73.8%) and 60.1% (95% CI 48.2-70.0%), respectively, with a median duration of response of 27.9 months (95% CI 14.3-NE) and ongoing. The 12- and 24-month cystectomy free survival rates are 89.2 (95% CI 81.3-93.9) and 81.3% (71.8-87.8), respectively, with median cystectomy free survival not reached. Among 18 patients who underwent radical cystectomy post-disease recurrence or progression, 15 (83.3%) had non muscle invasive bladder cancer or pT0 on final pathology:
At 12- and 24- months, 96.4% are free from ≥T2 progression. Most adverse events were grade 1-2, with a 1 day median time to treatment related adverse event resolution. There was high treatment compliance, no treatment related discontinuations, and few missed (1.8%) or delayed (7.1%) doses.
Dr. Steinberg concluded his presentation discussing results from the phase 3 BOND-003 trial Cohort C with the following take-home points:
- Cretostimogene offers distinct advantages with its mechanism of action, efficacy, durability, and safety profile for the treatment of high risk BCG unresponsive non muscle invasive bladder cancer
- Furthermore, a significant proportion of patients receiving cretostimogene remained progression-free and avoided radical cystectomy
- Most patients who underwent radical cystectomy had NMIBC or pT0 on final pathology, maintaining a window of opportunity
- Ongoing and future investigations of cretostimogene, as monotherapy and in rational combinations, may address the considerable unmet need for patients with bladder cancer
Presented by: Gary D. Steinberg, MD, NYU Langone Health, New York, NY
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, Wellstar MCG Health, @zklaassen_md on Twitter during the 2026 American Society of Clinical Oncology Genitourinary (ASCO GU) cancers symposium held in San Francisco, CA, between February 26th and 28th, 2026.
Related content: BOND-003 Cohort C: Cystectomy Outcomes Following Cretostimogene in BCG-Unresponsive NMIBC - Gary Steinberg