Atezolizumab for Patients with Detectable Circulating Tumor DNA Following Radical Cystectomy for Muscle-Invasive Bladder Cancer
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Reviewed & Translated by Dat Tien Nguyen, B.A, ScM.
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Posted on January 23rd, 2026
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Radical cystectomy is the standard first-line treatment for patients diagnosed with muscle-invasive bladder cancer; however disease recurrence still happens in 50% of the cases. Adjuvant therapy can be conducted, but there is a risk of unnecessary treatment and side effects if there is no residual disease. Thus, it is important to find a marker that would indicate the persistence of remnant tumors. Circulating tumor DNA had been a useful indicator for colon cancer recurrence, so a study, funded by Roche, was conducted to evaluate the usage of atezolizumab to manage bladder cancer in patients with circulating tumor DNA.
The phase 3 clinical trial included 250 participants with a median age of around 68 years old. These patients had previously been diagnosed with muscle-invasive bladder cancer, with 72% of them at stage T3 or T4 disease. Radical cystectomy was performed between 6 to 24 weeks before trial enrollment. Biochemical analyses found that all of these patients had detectable circulating tumor DNA, and 35% of them have more than 5% of tumor cells expressing PD-L1. The patients were randomly assigned to be treated intravenously with either placebo or 1680 mg of atezolizumab every 4 weeks for 12 cycles. The atezolizumab is a monoclonal antibody that can bind to the PD-L1 expressed on tumor cells. Thereby, it interferes with the methods tumor cells used to downregulate and evade from the immune system.
After a 48-month follow-up period, the researchers found that the atezolizumab treatment was superior in increasing disease-free duration and survival time. To be specific, the average disease-free duration and survival time of patients treated with atezolizumab was 9.9 months and 32.8 months, respectively. This is significantly longer than the 4.8 and 21.1 months reported by the placebo group. Furthermore, the clinical effectiveness of atezolizumab is constant regardless of PD-L1 expression level. The researchers also noted that patients treated with atezolizumab experienced significant reduction in circulating tumor DNA; whereas, the concentration stayed constant in the placebo group.
The phase 3 clinical trial included 250 participants with a median age of around 68 years old. These patients had previously been diagnosed with muscle-invasive bladder cancer, with 72% of them at stage T3 or T4 disease. Radical cystectomy was performed between 6 to 24 weeks before trial enrollment. Biochemical analyses found that all of these patients had detectable circulating tumor DNA, and 35% of them have more than 5% of tumor cells expressing PD-L1. The patients were randomly assigned to be treated intravenously with either placebo or 1680 mg of atezolizumab every 4 weeks for 12 cycles. The atezolizumab is a monoclonal antibody that can bind to the PD-L1 expressed on tumor cells. Thereby, it interferes with the methods tumor cells used to downregulate and evade from the immune system.
After a 48-month follow-up period, the researchers found that the atezolizumab treatment was superior in increasing disease-free duration and survival time. To be specific, the average disease-free duration and survival time of patients treated with atezolizumab was 9.9 months and 32.8 months, respectively. This is significantly longer than the 4.8 and 21.1 months reported by the placebo group. Furthermore, the clinical effectiveness of atezolizumab is constant regardless of PD-L1 expression level. The researchers also noted that patients treated with atezolizumab experienced significant reduction in circulating tumor DNA; whereas, the concentration stayed constant in the placebo group.