Enfortumab vedotin plus pembrolizumab has become the preferred first-line systemic treatment for locally advanced or metastatic urothelial carcinoma. However, clinical responses remain heterogeneous, and validated biomarkers capable of showing whether a patient is benefiting from treatment in real time remain limited.
A multicenter real-world study evaluated whether longitudinal, personalized circulating tumor DNA testing could help monitor treatment response and identify patients at increased risk of progression during treatment with enfortumab vedotin with or without pembrolizumab.
The article, titled “Prognostic Implications of Personalized Circulating Tumor DNA Testing in Patients with Advanced Urothelial Carcinoma Treated with Enfortumab Vedotin ± Pembrolizumab,” was published in European Urology Oncology on June 30, 2026.
Authors: Kevin R. Reyes, Ryan Zhu, Cameron Herberts, Punashi Dutta, Ashley Wray, Beaux Mitchell, Syed Saqib Balkhi, Xiaolin Zhu, Carissa E. Chu, Sima P. Porten, Terence W. Friedlander, Jonathan Chou, Steven N. Seyedin, Shruti Sharma, Meenakshi Malhotra, Adam C. ElNaggar, Minetta C. Liu, Adanma Ayanambakkam, and Vadim S. Koshkin.
Background
Tumor-informed ctDNA testing has already shown prognostic value in localized muscle-invasive urothelial carcinoma, particularly after neoadjuvant treatment and cystectomy. However, evidence supporting longitudinal ctDNA monitoring in patients with locally advanced or metastatic disease receiving enfortumab vedotin with or without pembrolizumab remains limited.
The study assessed whether ctDNA status and changes during treatment were associated with radiographic response, progression-free survival, and overall survival.
Study Design
This exploratory, retrospective, multicenter analysis included 110 patients with locally advanced or metastatic urothelial carcinoma treated with enfortumab vedotin with or without pembrolizumab between April 2019 and April 2025.
A total of 545 plasma samples were analyzed using the personalized tumor-informed Signatera assay, with a median of four samples per patient. Of the 110 patients, 86 received enfortumab vedotin plus pembrolizumab and 24 received enfortumab vedotin alone. Most patients received treatment in the first-line setting.
Median clinical follow-up was 60.6 weeks for progression-free survival and 60.0 weeks for overall survival. Because the study was exploratory and had no predefined statistical analysis plan, the findings should be considered hypothesis-generating.
ctDNA Detection and Survival
Baseline samples were available for 78 patients, and ctDNA was detected in 93.6%. Within the first 12 weeks of treatment, ctDNA declined in 75.8% of evaluable patients, including complete ctDNA clearance in 33.9%.
Detectable ctDNA during treatment was consistently associated with poorer outcomes. At four to 12 weeks, ctDNA-positive patients had a median PFS of 24.1 weeks, while median PFS was not reached among ctDNA-negative patients. The HR for progression or death was 10.08.
The association remained evident at 12 to 24 weeks and beyond 24 weeks, with HRs of 11.84 and 6.77, respectively.
A similar pattern was observed for overall survival. At four to 12 weeks, median OS was 42.1 weeks among ctDNA-positive patients and was not reached among ctDNA-negative patients. The HR for death was 6.53. The corresponding HRs were 7.22 at 12 to 24 weeks and 3.81 beyond 24 weeks.
On-treatment ctDNA status remained independently prognostic after adjustment for age, sex, and ECOG performance status.
Early ctDNA Dynamics
Persistent ctDNA positivity during the first 12 weeks was associated with significantly shorter PFS and OS compared with ctDNA clearance or persistent negativity.
The HR was 8.96 for PFS and 4.58 for OS.
Patients whose ctDNA remained positive and continued to rise had the poorest outcomes. A decline without complete clearance was associated with shorter PFS but more intermediate OS, suggesting that the depth of molecular response may also be clinically relevant.
You can also read about FDA Approved Drugs for GU Cancers in the First Half of 2026 on OncoDaily.
Association with Radiographic Response
Among 62 patients with serial baseline and early on-treatment ctDNA samples, 80.6% showed persistent negativity or a decline from baseline, while 21 patients, or 33.8%, achieved complete ctDNA clearance.
Early ctDNA changes were strongly associated with best radiographic response. Clearance was more common among patients with complete or partial responses, whereas persistent positivity was more frequent among those with stable or progressive disease.
No patient with progressive disease as the best response achieved ctDNA clearance. In contrast, every patient with a complete response had either undetectable ctDNA or at least a 90% decline from baseline.
Separately, among 50 patients with serial on-treatment testing and confirmed progression, the median time from the first conversion to persistent ctDNA positivity to documented progression was 106 days.
Clinical Relevance
These findings support tumor-informed ctDNA as a dynamic prognostic biomarker during treatment with enfortumab vedotin with or without pembrolizumab.
Early clearance or a strong ctDNA decline was associated with more favorable radiographic responses and longer PFS and OS, while persistent or rising ctDNA identified patients at substantially increased risk of progression and death.
ctDNA may eventually complement imaging, clarify equivocal findings, and help identify patients who require closer monitoring. However, the study did not establish that changing treatment according to ctDNA results improves outcomes.
Limitations
The study was retrospective, and ctDNA collection and imaging schedules were not standardized. Patients received enfortumab vedotin alone or with pembrolizumab across different treatment lines, limiting regimen-specific interpretation.
Several subgroup analyses involved small numbers and wide confidence intervals. No correction for multiple testing was performed. The results therefore require prospective validation before ctDNA-guided treatment modification can be incorporated into clinical practice.
Takeaway
Personalized tumor-informed ctDNA monitoring provided strong prognostic information in patients with advanced urothelial carcinoma receiving enfortumab vedotin with or without pembrolizumab.
Early ctDNA clearance or a strong decline was associated with better treatment response and longer PFS and OS, while persistent or rising ctDNA identified patients at high risk of progression and death.
Prospective trials are needed to determine whether ctDNA can guide treatment intensification, switching, de-escalation, or consolidation strategies.
The full article is available in European Urology Oncology.
Find more videos on OncoDaily YouTube TV.