Phase 2 Core-008 Readout of Cretostimogene Plus Gemcitabine in NMIBC

Key Takeaways

• Complete response was 83.3% with concurrent administration and 87.5% with sequential administration.
• No treatment-related grade 3 or higher adverse events were reported.
• Efficacy was described as comparable across arms, sequential administration appeared better tolerated, and follow-up is continuing.

In cohort CX of the phase 2 CORE-008 trial, intravesical cretostimogene grenadenorepvec plus gemcitabine produced complete response rates of 83.3% to 87.5% in high-risk BCG-exposed or BCG-unresponsive non-muscle invasive bladder cancer. These early findings were presented at the 2026 American Urological Association Annual Meeting. The cohort evaluated concurrent and sequential intravesical administration in this high-risk NMIBC population. The readout offers an early look at both schedules rather than a settled comparison between them.

Cohort CX is part of the phase 2 CORE-008 trial evaluating intravesical cretostimogene grenadenorepvec plus gemcitabine in patients with high-risk BCG-exposed or BCG-unresponsive non-muscle invasive bladder cancer. At the October 6, 2025 data cutoff, 54 patients were randomly assigned to receive the regimen through concurrent or sequential intravesical administration. The comparison focused on the early profile of the combination across the 2 delivery schedules in this enrolled population. The cohort was structured to compare administration schedules within a high-risk BCG-exposed or BCG-unresponsive NMIBC setting.

At a median follow-up of 6.6 months, CORE-008 cohort CX showed complete response rates of 83.3% in the concurrent cohort and 87.5% in the sequential cohort. Investigators characterized the combination as active and well tolerated in this early analysis. The numerical separation between schedules was presented descriptively rather than as evidence of a clear advantage for either approach. This efficacy readout remains limited to the reported follow-up window and the current cohort data.

No treatment-related grade 3 or higher adverse events were reported across the two administration approaches. Investigators also described efficacy as comparable between arms while noting that sequential administration appeared better tolerated. The combination was also discussed as supporting the feasibility of intravesical-only treatment strategies in this disease setting. These findings leave the schedule comparison as an early tolerability signal rather than a definitive ranking.

Continued follow-up is underway, and durability remains a critical outcome in the ongoing evaluation of this regimen. Commentators also noted that the study population was heterogeneous and that further investigation is needed to clarify which patients are most likely to benefit. No subgroup outcomes were reported for disease presentation or prior BCG exposure category within this summary. The early readout showed high complete response rates with no reported grade 3 or higher treatment-related adverse events, with longer follow-up still pending.