TOMBOLA: ctDNA Testing Identifies Patients With Bladder Cancer Who May Benefit From Early Immunotherapy

Preliminary findings from the TOMBOLA trial presented at the European Society for Medical Oncology Congress 2024 indicate that circulating tumor DNA (ctDNA) testing could help identify patients with bladder cancer who would benefit from early post-cystectomy immunotherapy. In this national multicenter study conducted in Denmark, patients with non-metastatic muscle-invasive bladder cancer (MIBC) who underwent neoadjuvant chemotherapy (NAC) and radical cystectomy (RC) were monitored using serial ctDNA testing to detect minimal residual disease.

For the trial, Jorgen Bjerggaard Jensen, of Aarhus University Hospital, Aarhus, Denmark, and colleagues enrolled 153 patients, 57% of whom were ctDNA-positive after surgery, with 75% detected within four months. The median lead time between ctDNA detection and visible metastases on CT scans was 43 days, with 20% of ctDNA-positive patients eventually showing metastases. In contrast, only 3% of ctDNA-negative patients developed metastases during follow-up.

Patients who tested ctDNA-positive received adjuvant immunotherapy with atezolizumab, even without visible metastases on imaging, highlighting the potential of ctDNA as a biomarker for early treatment intervention. The results, including responses to immunotherapy, are expected after a clinical cutoff in August 2024.

The study authors note, “Serial measurements of ctDNA following NAC and RC is a highly specific method to identify patients that might benefit from early immunotherapy at a time of minimal metastatic disease,” offering a promising strategy for personalizing care and improving outcomes in high-risk MIBC patients.