CG Oncology Reports Positive First Results from CORE‑008 Cohort CX Phase 2 Trial Evaluating Intravesical Combination Therapy in High-Risk BCG-Exposed and BCG-Unresponsive Patients

Rhea-AI Summary

CG Oncology (NASDAQ:CGON) reported first Phase 2 results from CORE‑008 Cohort CX, evaluating intravesical cretostimogene grenadenorepvec plus gemcitabine in high‑risk non‑muscle invasive bladder cancer patients who were BCG‑exposed or BCG‑unresponsive.

High‑grade event‑free survival was 96.0% at 3 months and 89.5% at 6 months (median follow‑up 6.6 months). In CIS‑containing patients, complete response rates were 85.7% (24/28) in the ITT population and 92.3% (24/26) in the efficacy‑evaluable population. Efficacy appeared comparable between concurrent and sequential regimens, and no Grade 3 or higher treatment‑related adverse events or deaths were reported.

Positive

• High‑grade event‑free survival of 96.0% at 3 months and 89.5% at 6 months
• CIS‑containing complete response rates of 85.7% ITT (24/28) and 92.3% efficacy‑evaluable (24/26)
• No Grade 3 or higher treatment‑related adverse events and no deaths observed
• Comparable efficacy across concurrent and sequential regimens and across BCG‑exposed and BCG‑unresponsive groups

Negative

• Median follow‑up of 6.6 months limits insight into long‑term durability
• Only early Phase 2 results; durability data and longer‑term outcomes are still pending

News Market Reaction – CGON

-3.75%

1 alert

-3.75% Session close to close

$5.90B Market Cap

0.0x Rel. Volume

In the May 15 session, CGON declined 3.75%, reflecting a moderate negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement details positive Phase 2 CORE‑008 Cohort CX results, with high‑grade event‑free su...

Analysis

This announcement details positive Phase 2 CORE‑008 Cohort CX results, with high‑grade event‑free survival of 96.0% at three months and 89.5% at six months plus CR rates up to 92.3%. The absence of Grade ≥3 treatment‑related adverse events supports a favorable safety profile. In context of prior Phase 1b and Phase 3 program updates, investors may track durability, larger datasets, and upcoming registrational milestones for cretostimogene.

Key Figures

HG-EFS 3 months: 96.0% HG-EFS 6 months: 89.5% CR rate ITT: 85.7% (24/28) +5 more

8 metrics

HG-EFS 3 months 96.0% High-grade event-free survival in ITT population at 3 months

HG-EFS 6 months 89.5% High-grade event-free survival in ITT population at 6 months

CR rate ITT 85.7% (24/28) Complete response in CIS-containing ITT population

CR rate Evaluable 92.3% (24/26) Complete response in CIS-containing efficacy evaluable population

Median follow-up 6.6 months Follow-up duration at March 13, 2026 data cutoff

Grade ≥3 TRAEs 0 events No Grade 3 or higher treatment-related adverse events reported

BCG-exposed share 65.6% Proportion of patients who were BCG-exposed

BCG-unresponsive share 34.5% Proportion of patients who were BCG-unresponsive

Previous Clinical trial Reports

2 past events · Latest: Jan 09 (Positive)

Same Type Pattern 2 events

Date	Event	Sentiment	24h Move	Catalyst
Jan 09	Phase 3 timeline update	Positive	+29.3%	Accelerated Phase 3 PIVOT‑006 topline data timing in IR NMIBC.
Nov 11	Phase 1b combo data	Positive	-0.6%	Nature Medicine publication of Phase 1b combination results in MIBC.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

Clinical trial updates have produced mixed reactions: one strong positive move and one slight decline, with an average move of 14.32% on similar headlines.

Recent Company History

Recent history shows CG Oncology steadily advancing cretostimogene in bladder cancer. On Jan 9, 2026, an accelerated Phase 3 PIVOT‑006 timeline in IR NMIBC drove a 29.26% move. A Nov 11, 2024 Nature Medicine Phase 1b combination publication saw a modest -0.63% reaction. Today’s CORE‑008 Cohort CX Phase 2 data fits this pattern of important clinical milestones that sometimes draw strong market interest and sometimes limited enthusiasm.

Key Terms

intravesical, non-muscle invasive bladder cancer, event-free survival, complete response, +4 more

8 terms

intravesical medical

"a Phase 2 study evaluating intravesical cretostimogene grenadenorepvec in combination"

Intravesical describes a medical treatment or procedure where a drug or therapy is placed directly into the bladder through a catheter rather than taken by mouth or injected into the bloodstream. For investors, it signals a focused delivery method that can increase local effectiveness and reduce whole‑body side effects, often affecting a product’s clinical value, patient convenience, regulatory path, and market niche — like watering a plant at its roots instead of spraying its leaves.

non-muscle invasive bladder cancer medical

"patients with high‑risk (HR) non‑muscle invasive bladder cancer (NMIBC)"

A form of bladder cancer that is confined to the inner lining of the bladder and has not grown into the deeper muscle layer; think of it like a stain on wallpaper rather than damage to the wall’s studs. It matters to investors because it has different treatment, monitoring and recurrence patterns than deeper cancers, driving demand for repeated outpatient procedures, local therapies and diagnostic tests that affect revenue, trial design and pricing dynamics in healthcare markets.

event-free survival medical

"high-grade event-free survival (HG-EFS), high complete response (CR) rates"

Event-free survival measures the length of time after a treatment or diagnosis during which a patient does not experience a predefined negative outcome, such as disease progression, relapse, or death. For investors, longer event-free survival in clinical trials signals that a therapy may be effective and durable, improving its chances of regulatory approval and commercial success — think of it like a warranty period before problems reappear.

complete response medical

"high complete response (CR) rates and a well-tolerated safety profile"

A complete response is a positive outcome in which a company’s efforts to address issues or questions fully resolve the problem, often meaning that no further action or investigation is needed. For investors, it signals that concerns have been thoroughly addressed, which can boost confidence in the company's stability or decision-making. Think of it like a doctor fully treating an illness, leaving no remaining symptoms.

treatment-related adverse events medical

"no Grade 3 or greater treatment-related adverse events (TRAEs) and no deaths"

Treatment-related adverse events are harmful or unwanted health effects that doctors or regulators determine were caused by a drug, vaccine, device, or other medical therapy. Investors care because how often and how severe these side effects are can shape regulatory approval, labeling, sales potential and legal risk — similar to how product defects can stop or damage a company's ability to sell an item.

oncolytic immunotherapy medical

"this intravesical oncolytic immunotherapy combined with chemotherapy as a bladder-sparing"

A type of cancer treatment that uses specially engineered viruses to infect and destroy tumor cells while also stimulating the patient’s immune system to recognize and attack cancer elsewhere—think of the virus as a guided seed that both blows up weeds and trains a gardening robot to find the rest. For investors, progress or setbacks in trials and approvals can sharply change a company’s value because outcomes tend to be binary (successful approval or failure) and can open large, high-value markets if effective.

bcg-unresponsive medical

"BCG-exposed and BCG-Unresponsive populations"

BCG-unresponsive describes a situation in which a patient’s bladder cancer does not shrink or returns despite receiving an adequate course of BCG, a common vaccine-based intravesical treatment used to stimulate the immune system in the bladder. For investors this matters because it defines a group of patients who need alternative therapies or procedures, shaping clinical trial eligibility, regulatory pathways, and the potential market for new drugs; think of it like weeds that resist the usual weed killer and require a different product.

phase 2 medical

"CORE‑008 Cohort CX, a Phase 2 study evaluating intravesical cretostimogene"

Phase 2 is the mid-stage clinical trial where a new drug or treatment is tested in a larger group of patients to see if it works and to keep checking safety after initial human testing. Think of it as a field test that proves whether a product actually delivers its promised benefit. Investors watch Phase 2 closely because its results strongly influence a medicine’s chances of reaching the market, the size of its potential sales, and the company’s valuation.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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- High CR rates at any time observed in the CIS-containing population with 85.7% and 92.3% in the ITT population and Efficacy Evaluable population, respectively

- High-Grade - EFS in the overall intention-to-treat population was 96.0% at 3 months and 89.5% at 6 months

- Efficacy was comparable across concurrent and sequential treatment arms and across both BCG-exposed and BCG-Unresponsive populations

DALLAS, May 15, 2026 (GLOBE NEWSWIRE) -- CG Oncology, Inc. (NASDAQ: CGON) today announced positive first results from CORE‑008 Cohort CX, a Phase 2 study evaluating intravesical cretostimogene grenadenorepvec in combination with gemcitabine sequential versus concurrent treatment schedules in patients with high‑risk (HR) non‑muscle invasive bladder cancer (NMIBC). This trial includes HR NMIBC patients who are either BCG‑exposed or BCG‑unresponsive. The data, which demonstrate encouraging high-grade event-free survival (HG-EFS), high complete response (CR) rates and a well-tolerated safety profile, will be presented tomorrow at the Society of Urologic Oncology (SUO) Session at the 2026 American Urological Association (AUA) Annual Meeting in Washington, D.C.

“Cohort CX was designed to assess whether combining cretostimogene with gemcitabine can further extend the strong clinical profile we have established with cretostimogene monotherapy,” said Vijay Kasturi, Chief Medical Officer of CG Oncology. “As the first prospective intravesical-only combination study of its kind, these early data demonstrate robust clinical activity across both treatment schedules, a favorable safety profile, and comparable efficacy. Importantly, the results reinforce the strategic potential of scalable intravesical-only combination regimens in high-risk NMIBC. We look forward to sharing durability data later this year.”

Efficacy and Safety Analysis: As of the March 13, 2026, data cut off, the overall HG-EFS was 96.0% at 3 months and 89.5% at 6 months, with a median follow-up of 6.6 months, in the overall intent-to-treat (ITT) population. There were no statistically significant differences in HG-EFS across concurrent and sequential treatment arms. High complete response (CR) rates at any time were observed in the CIS-containing population with 85.7% (95% CI, 67.3% – 96.0%) and 92.3% (95% CI, 74.9% - 99.1%) in the ITT population with 85.7% (24/28) (95% CI, 67.3%-96.0%) and Efficacy Evaluable population with 92.3% (24/26) (95% CI, 74.9%-99.1%), respectively. Furthermore, complete response rates were maintained across the treatment arms. A favorable safety and tolerability profile was observed with no Grade 3 or greater treatment-related adverse events (TRAEs) and no deaths reported. The majority of patients were male (78.2%), white (92.7%), and over 65 years of age (81.8%), with the cohort well‑balanced across concurrent and sequential treatment arms. Out of the overall population, 65.6% of patients were BCG-exposed and 34.5% were BCG-unresponsive. More than 80% of patients were treated in community practices.

“In Cohort CX, we observed consistent responses to the combination of cretostimogene and gemcitabine across both BCG-exposed and BCG-unresponsive populations,” said Trinity Bivalacqua, M.D., Ph.D., Professor of Urology at the University of Pennsylvania and lead investigator of CORE-008 Cohort CX. “These findings highlight the feasibility and encouraging clinical profile of this intravesical oncolytic immunotherapy combined with chemotherapy as a bladder-sparing approach that can be readily adopted in everyday practice. At a time when urologists face ongoing therapeutic constraints and supply challenges, expanding the intravesical treatment armamentarium has the potential to meaningfully improve care for patients across a wide range of NMIBC disease states.”

About CORE‑008
CORE‑008 is a randomized, Phase 2, multi‑arm, multi‑cohort clinical trial designed to evaluate the efficacy and safety of cretostimogene grenadenorepvec in a broad population of patients with high‑risk non‑muscle invasive bladder cancer (HR NMIBC), including BCG‑naïve, BCG‑exposed, and BCG‑unresponsive disease. Cohort CX of CORE‑008 evaluates the combination of intravesical cretostimogene with gemcitabine in patients with BCG‑exposed or BCG‑unresponsive HR NMIBC. The primary endpoint of Cohort CX is high‑grade event‑free survival, defined as high‑grade recurrence or persistence, progression to T1 disease, progression to T2 or higher disease, or death from any cause.

About Cretostimogene Grenadenorepvec
Cretostimogene is an investigational, intravesically delivered oncolytic immunotherapy that has been studied in a clinical development program, which includes more than 400 patients with Non-Muscle Invasive Bladder Cancer (NMIBC). This program includes two Phase 3 clinical trials: BOND-003 for high-risk BCG-unresponsive NMIBC and PIVOT-006 for intermediate-risk NMIBC. CG Oncology also has a Phase 2 trial, CORE-008, evaluating the safety and efficacy of cretostimogene in high-risk NMIBC. Additionally, we have initiated an Expanded Access Program for cretostimogene in North America for patients who are unresponsive to BCG and meet certain program eligibility requirements. Cretostimogene is an investigational candidate, and its safety and efficacy have not been established by the FDA or any other health authority.

About CG Oncology
CG Oncology is a late-stage clinical biopharmaceutical company focused on developing and commercializing a potential backbone bladder-sparing therapeutic for patients afflicted with bladder cancer. CG Oncology sees a world where urologic cancer patients may benefit from our innovative immunotherapies to live with dignity and have an enhanced quality of life. To learn more, please visit: www.cgoncology.com.

Forward-Looking Statements
CG Oncology cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. The forward-looking statements are based on our current beliefs and expectations and include, but are not limited to, the potential therapeutic benefits of cretostimogene for high-risk NMIBC patients, the strategic potential of combining cretostimogene with gemcitabine in high-risk NMIBC, that the combination of cretostimogene with gemcitabine will have robust clinical activity and a favorable safety profile, and that the combination of cretostimogene with gemcitabine will have the potential to meaningfully improve care for patients. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in our business, including, without limitation: interim results of a clinical trial are not necessarily indicative of final results and one or more of the clinical outcomes may materially change as patient enrollment continues, following more comprehensive reviews of the data, and as more patient data becomes available; potential delays in the commencement, enrollment and completion of clinical trials, including the BOND-003, PIVOT-006, and CORE‑008 cohort CX trials; we may use our capital resources sooner than expected and they may be insufficient to allow us to achieve our anticipated milestones; our dependence on third parties in connection with manufacturing, shipping and clinical and preclinical testing; results from earlier clinical trials and preclinical studies not necessarily being predictive of future results; unexpected adverse side effects or inadequate efficacy of cretostimogene that may limit its development, regulatory approval, and/or commercialization; and other risks described in our filings with the Securities and Exchange Commission (SEC), including under the heading “Risk Factors” in our annual report on Form 10-K and other filings that we make with the SEC from time to time (which are available at http://www.sec.gov). You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Contacts:

Media 
Sarah Connors
Vice President, Communications and Patient Advocacy, CG Oncology
sarah.connors@cgoncology.com

Investor Relations
Megan Knight
Vice President, Investor Relations, CG Oncology
megan.knight@cgoncology.com

FAQ

What did CG Oncology (NASDAQ:CGON) announce about the CORE‑008 Cohort CX Phase 2 trial on May 15 2026?

CG Oncology announced first results from the CORE‑008 Cohort CX Phase 2 trial of intravesical cretostimogene plus gemcitabine in high‑risk non‑muscle invasive bladder cancer. According to CG Oncology, the data include efficacy, safety, and comparisons of concurrent versus sequential treatment schedules.

What were the key efficacy results from CG Oncology (CGON) CORE‑008 Cohort CX trial?

The trial reported high‑grade event‑free survival of 96.0% at 3 months and 89.5% at 6 months in the intent‑to‑treat population. According to CG Oncology, CIS‑containing complete response rates reached 85.7% ITT and 92.3% in the efficacy‑evaluable group, with consistency across treatment arms.

How did complete response rates look in CIS‑containing patients in the CGON CORE‑008 Cohort CX study?

CIS‑containing patients achieved complete response rates of 85.7% (24/28) in the ITT population and 92.3% (24/26) in the efficacy‑evaluable population. According to CG Oncology, these response levels were maintained across both concurrent and sequential treatment schedules in the Phase 2 combination trial.

What safety profile was reported for cretostimogene plus gemcitabine in CG Oncology’s CORE‑008 Cohort CX trial?

The combination showed a favorable safety profile, with no Grade 3 or higher treatment‑related adverse events and no deaths. According to CG Oncology, these findings support the feasibility of an intravesical‑only combination regimen for high‑risk non‑muscle invasive bladder cancer patients.

Did CG Oncology’s CORE‑008 Cohort CX results differ between concurrent and sequential treatment arms?

Efficacy was reported as comparable between concurrent and sequential intravesical treatment schedules in the intent‑to‑treat population. According to CG Oncology, there were no statistically significant differences in high‑grade event‑free survival across arms, and complete response rates were maintained regardless of scheduling approach.