Cretostimogene: Promising Bladder Cancer Results

The Phase III BOND-003 Cohort C study is in patients with high-risk non-muscle invasive bladder cancer (NMIBC) unresponsive to Bacillus Calmette Guerin (BCG) treatment with carcinoma in situ (CIS) with or without Ta or T1 disease. The study reported 75.5% complete response (CR) at any time, with 34 confirmed CRs at 24 months and 9 patients pending their 24-month assessment as of the cutoff date of March 14, 2025. The 12- and 24-month CR rates are 50.7% and 42.3% by K-M estimation, respectively. Median duration of response (DOR) is 28 months and is ongoing. Notably, 97.3% of patients were free from progression to muscle invasive disease at 24 months.

Additionally, Cohort P, which is in patients with BCG-unresponsive Ta/T1 disease without CIS, showed an estimated 90.5% (95% CI: 77.9, 100.0) high-grade recurrence-free survival at 3 and 9 months in 24 treated patients. A well-tolerated safety profile was observed, consistent with the data in Cohort C.

“We continue to see strong safety and efficacy, as well as best-in-disease durability and tolerability, with cretostimogene at the 24-month mark, in a high-risk, heavily pretreated NMIBC patient population,” said Gary D. Steinberg, M.D., Professor, Department of Urology at Rush University Medical Center.  “Now, we have Cohort P data demonstrating cretostimogene also has activity and efficacy in BCG-unresponsive patients with Ta/T1 lesions. This body of evidence demonstrates the power of cretostimogene’s unique dual mechanism of action, its potential to treat different tumor types across high-risk NMIBC, positioning it as a potential breakthrough, backbone therapy in bladder cancer treatment.”

A total of 110 highly pretreated patients are efficacy evaluable in the BOND-003 Cohort C study, which makes it the largest study in this patient population to date. These patients received a median of 12 prior BCG doses, some as high as 66. Prior intervening therapy also included intravesical chemotherapy (41.1%) and systemic immunotherapy (6.3%). Despite their highly pretreated conditions, patients tolerated cretostimogene treatment well. There were no Grade 3 or greater treatment-related adverse events (TRAEs) or deaths reported. Patients who experienced TRAEs of any grade had a median resolution time of one day. No treatment-related discontinuation of cretostimogene was observed. 97.3% of patients completed all expected treatments, demonstrating favorable patient adherence and compliance. The most common TRAEs (≥10%) were bladder spasm, pollakiuria, micturition urgency, dysuria, and hematuria.

“The compelling efficacy, durability, freedom from progression to muscle-invasive disease, and tolerability of cretostimogene offer potential, distinct advantages over existing therapies for the treatment of high-risk BCG-unresponsive NMIBC,” said Ambaw Bellete, President & Chief Operating Officer, CG Oncology. “Ongoing investigations of this promising monotherapy, as well as future combinations, have the potential to address a considerable unmet need for bladder cancer patients. This suggests that, if approved, cretostimogene will represent an important advancement for people suffering with bladder cancer, and we are working diligently to bring it forward to patients.”