A Phase 3 Open-Label, Randomized Controlled Trial of T-bren (BL M07D1) vs. Platinum-based Chemotherapy in Patients With HER2 Expressing Metastatic Urothelial Cancer With Disease Progression on or After Anti-PD-(L)1-based Therapy

Inclusion Criteria: * Histologically or cytologically documented metastatic or surgically unresectable transitional cell carcinoma (TCC) of the urothelium involving the renal pelvis, ureter, bladder, or urethra. Minor histologic variants (ie, \<50% overall) are acceptable, provided that TCC is the dominant histology. * Disease progression or recurrence during or following anti-PD-(L)1-based therapy. * Fresh biopsy or archival tumor samples. * Documented HER2 expression by central laboratory testing. * Eligible to receive carboplatin or cisplatin in combination with gemcitabine. * At least 1 m…