AACR 2022: Phase II Trial of Pembrolizumab Combined With Oncolytic Vaccine in Bladder Cancer

By: Lauren Harrison, MS
Posted: Friday, April 22, 2022

Initial data suggest safety and efficacy for the combination of the PD-1 inhibitor pembrolizumab with CG0070 as treatment for patients with bacillus Calmette-Guérin (BCG)–unresponsive non–muscle-invasive bladder cancer. CG0070 is an adenovirus-based oncolytic vaccine that has been engineered to express granulocyte macrophage–colony stimulating factor and replicate in tumor cells with mutations in RB. This work was presented at the American Association for Cancer Research (AACR) Annual Meeting 2022 (Abstract CT036) by Roger Li, MD, of the Moffit Cancer Center in Tampa, Florida.

This phase II trial will enroll a total of 35 patients with BCG-unresponsive carcinoma in situ of the bladder with or without Ta or T1 disease by the end of the study. Patients will be treated with intravesicular CG0070 at a dose of 1 x 10¹² viral particles along with 400 mg of intravenous pembrolizumab every 6 weeks. CG0070 will be given to patients weekly for 6 weeks as induction therapy, followed by weekly administration for 3 weeks as maintenance therapy at months 3, 6, 9, 12, and 18. Patients who are determined to have persistent carcinoma or high-grade disease at 3 months will undergo a second round of induction therapy. Pembrolizumab will continue to be administered for up to 24 months.

At the time of the data presentation, 10 patients were evaluable at the 3-month mark for efficacy. Based on a combination of measures including cystoscopy with biopsy, urine cytology, and radiographic imaging, the patients demonstrated a complete response rate of 100% at that time. Six of these patients reached the 6-month mark, and two reached the 12-month mark, and all continued to remain in complete response.

Treatment-related adverse events have consisted of transient grade 1 or 2 local and regional genitourinary symptoms. There were no grade 3 or 4 adverse events recorded to date.

Disclosures: For a full list of authors’ disclosures, visit abstractsonline.com.

AACR Annual Meeting 2022