Nature Communications, Published online: 17 June 2026; doi:10.1038/s41467-026-74570-3 Therapeutic options for patients with treatment-refractory metastatic urothelial carcinoma (mUC) are much needed. Here, the authors report the outcomes and translational analysis of the phase I/II ICRA trial evaluating whether paclitaxel plus tremelimumab (anti-CTLA-4) with or without durvalumab (anti-PD-L1) induces a tumor response in patients with mUC.