Targeted therapies for urothelial carcinoma: From FGFR inhibitors to next‑generation antibody-drug conjugates (Review).

Treatment of urothelial carcinoma (UC), particularly in metastatic or cisplatin‑ineligible patients, remains challenging because of limited durable responses to conventional chemotherapy and immune checkpoint inhibitors. Recent advances in targeted therapies, including FGFR inhibitors (for example, erdafitinib) and antibody‑drug conjugates (ADCs) targeting Nectin‑4 (enfortumab vedotin) and HER2 (disitamab vedotin), have reshaped treatment paradigms. FGFR3 alterations, which are present in 20‑40% of patients with advanced UC, predict sensitivity to FGFR tyrosine kinase inhibitors, whereas ADCs demonstrate efficacy across biomarker‑selected and unselected populations. However, clinical implementation is complicated by resistance mechanisms, such as kinase switching, phenotypic plasticity and tumor microenvironment interactions, as well as biomarker heterogeneity. The present review synthesizes current evidence on molecularly guided therapies, contrasts resistance mechanisms between FGFR inhibitors and ADCs, and evaluates strategies to overcome therapeutic limitations. By integrating translational insights and emerging preclinical data, it was aimed to provide a roadmap for optimizing biomarker‑driven approaches, novel combinations and next‑generation agents for the treatment of UC.