CG Oncology Reveals Data on Oncolytic Virus Behind Year’s Top IPO

CG Oncology has demonstrated promising results for its oncolytic immunotherapy in a late-stage bladder cancer study, reinforcing its successful public debut earlier this year. The company raised $380 million in an upsized IPO in January, marking one of the largest biotech IPOs since 2018. Notably, CG Oncology is among the few biotech firms whose stock has appreciated since its initial offering.

Impressive Response Rates

The recent data was presented at the American Urological Association (AUA) conference, showcasing results from the Phase III BOND-003 trial. This trial involved patients with high-risk non-muscle invasive bladder cancer (NMIBC) that did not respond to Bacillus Calmette-Guérin (BCG) therapy. The company's oncolytic virus, cretostimogene grenadenorepvec, achieved a complete response (CR) rate of 75.2% in 105 measurable patients, meeting the study's primary endpoint.

Among the 79 patients who achieved a CR, none required bladder removal or showed signs of nodal or metastatic progression. Additionally, 29 participants maintained their response for a year or longer, with the median duration of response yet to be determined. Importantly, there were no Grade 3 or higher treatment-related adverse events (TRAEs) or deaths reported. Only two patients experienced Grade 2 TRAEs linked to the oncolytic immunotherapy, while 62.5% of patients experienced some form of TRAE, such as bladder spasm, frequent urination, painful urination, urgency to urinate, and blood in the urine.

Need for Better Treatment Options

CG Oncology's CEO, Arthur Kuan, highlighted the significance of these results. Many patients who fail BCG therapy have limited options other than bladder removal surgery. Moreover, due to BCG shortages, even patients with intermediate or high-risk NMIBC often cannot access this standard-of-care treatment.

"There is a significant need for a local, well-tolerated, and effective bladder-preserving treatment for patients with intermediate and high-risk BCG-unresponsive NMIBC," Kuan said. He also mentioned that the company plans to announce by year-end when they expect to submit a regulatory application to the FDA for their treatment candidate.

Aiming for a Breakthrough

With no FDA-approved oncolytic viruses currently available, cretostimogene could become a pioneering immunotherapy. The treatment is engineered to replicate preferentially in cells with defective retinoblastoma (Rb) gene pathways, initiating an anti-tumor immune response. Two key modifications enhance its selectivity and potency: the addition of an E2F-1 promoter, which ensures the virus replicates only in and destroys Rb-defective tumor cells while sparing healthy cells, and the incorporation of the gene for granulocyte-macrophage colony-stimulating factor (GM-CSF). This cytokine is known to stimulate long-term anti-tumor activity.

Kuan explained that the inclusion of GM-CSF in the viral construct may prime the immune system and induce tumor-specific immunity, further boosting the treatment's effectiveness.

Overall, CG Oncology's promising clinical results and successful IPO reflect the potential of its oncolytic immunotherapy to address unmet needs in bladder cancer treatment, offering hope for patients who currently have limited options.