SITC 2021: Vaccine Plus Pembrolizumab Under Study in Non–Muscle-Invasive Bladder Cancer
Posted: Wednesday, November 24, 2021
Roger Li, MD, of Moffitt Cancer Center, Tampa, Florida, and colleagues conducted CORE1—a study of the oncolytic serotype 5 adenovirus vaccine CG0070 combined with intravenous pembrolizumab—in patients with non–muscle-invasive bladder cancer. In phase I, patients previously treated with bacillus Calmette-Guérin (BCG) achieved an overall complete response rate of nearly 62% when treated with CG0070. Early preliminary clinical results, which were presented during the 2021 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 955), reported that all nine patients evaluable for efficacy thus far have achieved a complete response.
“If similar trends hold moving forward, we may have a game changer to combat BCG-unresponsive bladder cancer for patients with a significant unmet medical need,” commented Dr. Li in a press release.
The study authors focused on 35 patients with BCG-unresponsive carcinoma in situ with or without invasive papillary tumors. Participants will be treated with intravenous CG0070 in combination with 400 mg of intravenous pembrolizumab. CG0070 is to be administered six times weekly as induction and three times weekly as maintenance every 3 months for 18 months; pembrolizumab may be received for up to 24 months. Analysis will consist of cystoscopy with biopsy, CT/magnetic resonance urography, urine cytology, and bladder mapping biopsies at 12 months.
The primary endpoint is complete response at 12 months. At data cutoff of November 8, 2021, all nine patients evaluable for efficacy achieved a complete response at the initial 3-month time point. In addition, six patients have maintained a complete response through 6 months and three patients have maintained a complete response through 9 months. Secondary endpoints consist of progression-free survival, cystectomy-free survival, complete response at any time, safety, and duration of response.
Treatment-related adverse events included grade 1 or 2 transient urinary frequency (n = 3) and grade 1 flu-like symptoms, bladder spasms, painful urination, hematuria, and thyroiditis (n = 1 each). Notably, no grade 3 or higher adverse events have been reported.
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