The pioneering study uses a new approach to detect the presence of circulating tumour DNA (ctDNA) to accurately identify which patients with muscle-invasive bladder cancer would benefit from post-surgical treatment with immunotherapy. The ctDNA-guided adjuvant therapy with atezolizumab led to a significantly longer disease-free survival and overall survival in people with the aggressive cancer.
Professor Tom Powles, Professor of Genitourinary Oncology at Queen Mary University of London and Director of the Barts Cancer Centre, delivered results from the IMvigor011 trial, the first global phase III study pioneering a circulating tumour DNA (ctDNA)-guided approach to post-surgery treatment in muscle-invasive bladder cancer, during Monday's Presidential Symposium at ESMO, a global event showcasing cutting-edge cancer research to over 30,000 attendees.
Muscle-invasive bladder cancer is an aggressive disease that is treated with radial cystectomy, surgical removal of the bladder. While this is curative for many people, the disease will recur in around 50% of people. Disease recurrence is associated with poor prognosis and unfavourable survival rates. In those cases, adjuvant immunotherapy is recommended, but there is a lack of data showing a significant survival advantage with this approach.
A goal is to differentiate patients at high-risk of disease recurrence to undergo additional treatment, sparing other patients from unnecessary treatment. In the phase 3 IMvigor011 trial, researchers pioneered a new method that detects circulating tumour DNA (ct-DNA) in patients with muscle-invasive bladder cancer to identify those at high-risk of recurrence and administer a further treatment of intravenous atezolizumab, an immunotherapy.
The researchers enrolled participants with muscle-invasive bladder cancer who had undergone surgery and had no radiographic evidence of disease. Of the 761 patients enrolled, 250 patients tested ctDNA-positive and were eligible for the study.
The 250 eligible patients were randomised – 167 of them received intravenous atezolizumab, a therapeutic cancer treatment, and 83 received a placebo treatment every four weeks for up to one year. The median disease-free survival was 9.9 months with atezolizumab, compared with 4.8 months with placebo. The median overall survival was 32.8 months with atezolizumab, compared to 21.1 months with placebo. Among the 357 patients with persistent ctDNA-negative status, disease-free survival was at 95% at the end of the one-year monitoring period and 88% at two years.
Professor Tom Powles said:
"We have shown that using ctDNA to detect residual disease in patients with muscle-invasive bladder cancer enables us to determine which patients need treatment. Accurate and early detection of residual disease helps us to deliver early treatment interventions in those that need it, while sparing other patients from unnecessary – and potentially toxic and costly – treatment. This method could be used with other cancers, ultimately lead to earlier treatment interventions and better outcomes."
