Liver metastases in advanced urothelial carcinoma (ARON-2): do pembrolizumab and avelumab make a difference in a poor-prognosis scenario?

Background Over the past decade, the treatment landscape for metastatic urothelial carcinoma (mUC) has improved significantly with the introduction of immunotherapy, targeted agents, and antibody–drug conjugates. The median overall survival (mOS) reached 36.7 months in cisplatin-eligible and 25.6 months in cisplatin-ineligible patients in the first-line setting and over 10 months post-platinum failure. However, liver metastases remain a known poor prognostic factor. Methods We conducted a retrospective analysis of mUC patients treated at 79 global institutions. Two cohorts were defined: cohort 1 included patients who progressed after platinum-based therapy and received pembrolizumab, and cohort 2 included patients who received avelumab as maintenance therapy. Treatments were administered between 1 January 2016 and 31 October 2024. Results Cohort 1 (n = 1,341) had an mOS of 17.5 months. Patients without liver metastases had significantly longer OS than those with liver involvement (20.1 vs . 9.4 months, p