Phase II trial of afatinib in patients with advanced/metastatic urothelial carcinoma (UC) with genetic alterations in ERBB receptors 1-3 who failed on platinum-based chemotherapy (CT).

TPS540Background: First-line treatment of patients (pts) with advanced/metastatic UC consists of platinum-based CT, with no well-established subsequent therapy for platinum-refractory disease. Although checkpoint inhibitors have shown promising results recently, targeted agents have generally not demonstrated significant clinical activity in this setting. Around 20% of UC harbor ERBB family genetic alterations, as such it may be a suitable therapeutic target (Knowles, Nat Rev Cancer 2015;15:25–41). The irreversible ERBB family blocker, afatinib, has shown activity in a Phase II trial in a subset of pts with UC who had ERBB2/ERBB3 aberrations (Choudhury, J Clin Oncol 2016;34:2165–71). This Phase II trial will evaluate afatinib in pts with UC molecularly selected for ERBB receptor alterations. Methods: This single-arm trial will assess the efficacy and safety of afatinib in pts with UC harboring ERBB2/ERBB3 mutations or ERBB2 amplification (Cohort A), or EGFR (ERBB1) amplification (Cohort B). Eligible pts a...