CG Oncology: cretostimogene combo shows high CR in NMIBC

CG Oncology has reported early efficacy and safety data from Cohort CX of its CORE-008 Phase 2 trial, evaluating intravesical cretostimogene grenadenorepvec in combination with gemcitabine in patients with high-risk non-muscle invasive bladder cancer (HR NMIBC). The results, presented at the Society of Urologic Oncology session of the 2026 American Urological Association Annual Meeting in Washington, D.C., show encouraging complete response rates and event-free survival across both BCG-exposed and BCG-unresponsive patient populations.

As of the 13 March 2026 data cut, high-grade event-free survival (HG-EFS) in the overall intention-to-treat (ITT) population stood at 96.0% at three months and 89.5% at six months, with a median follow-up of 6.6 months. In the CIS-containing population, complete response rates at any time reached 85.7% in the ITT population and 92.3% in the efficacy-evaluable population. Notably, no Grade 3 or greater treatment-related adverse events were recorded and no deaths were reported, a safety profile the company describes as well-tolerated. Efficacy was consistent across concurrent and sequential dosing schedules, which the company says underscores the flexibility of the regimen.

Clinical context

Vijay Kasturi, Chief Medical Officer of CG Oncology, said the combination study was designed to build on the monotherapy profile already established for cretostimogene, and that the early data demonstrate "robust clinical activity across both treatment schedules." Trinity Bivalacqua, Professor of Urology at the University of Pennsylvania and the study's lead investigator, highlighted the community-practice applicability of the findings: more than 80% of patients in Cohort CX were treated in community settings, a factor that could support broader adoption if the regimen gains approval.

The NMIBC treatment landscape has faced well-documented supply and access pressures, particularly around bacillus Calmette-Guérin (BCG), the standard intravesical immunotherapy. Persistent BCG shortages have driven demand for alternative or complementary intravesical regimens, and regulators on both sides of the Atlantic have signalled openness to bladder-sparing approaches. CG Oncology is positioning cretostimogene as a potential backbone therapy in this setting, with the Cohort CX data adding a combination arm to the evidence base alongside the existing BOND-003 Phase 3 trial in BCG-unresponsive disease and PIVOT-006 in intermediate-risk NMIBC.

Competitive landscape and next steps

Several companies are active in the HR NMIBC space with intravesical programmes, including chemotherapy combinations and novel immunotherapy candidates. CG Oncology's intravesical-only approach — avoiding systemic agents — is positioned as a practical advantage for community urologists, though longer-term durability data will be required to establish whether the combination offers a meaningful step forward over monotherapy or existing standard-of-care regimens.

CG Oncology has indicated it will present durability data from Cohort CX later in 2026, which will be the critical readout for investors and clinicians assessing whether the combination merits progression toward a registrational design. The company also operates an expanded access programme for BCG-unresponsive patients in North America, providing a real-world data stream that may support future regulatory submissions. Cretostimogene remains investigational; neither the FDA nor any other health authority has established its safety and efficacy for commercial use.