Trastuzumab deruxtecan in HER2-expressing urothelial carcinoma: current evidence, biomarker challenges, and future therapeutic strategies.
INTRODUCTION Urothelial carcinoma (UC) has become a prototype for antibody-drug conjugate (ADC)-based therapy, but relapse after first-line enfortumab vedotin plus pembrolizumab remains common. HER2 protein expression, ERBB2 amplification and activating mutations identify overlapping but distinct populations; this revi...