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).

Abstract

TPS540 Background: 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 are ≥18 years of age with ECOG PS 0–1, histologically confirmed advanced/metastatic UC of the bladder, upper tract or urethra, not amenable to surgery and progressing during or after platinum-based CT, with available archival tissue samples for pre-screening biomarker analysis. Pts will receive oral afatinib 40 mg/day until disease progression or discontinuation. Cohort A is enrolling in two stages, with Stage 2 enrollment based on anti-tumor activity observed. The primary endpoint is progression-free survival (PFS) rate at 6 months; secondary endpoints include objective response rate, PFS, overall survival, disease control rate, duration of response and tumor shrinkage. Trial objectives will be analyzed separately for the two cohorts. Safety and biomarker assessments will also be performed. The trial commenced in June 2016; as of October 4, 2017, 201 samples have been analyzed, with 24.3% and 8% of pts with genetic alterations potentially eligible for inclusion in Cohort A and B, respectively. To date, 12 pts have received study treatment in Cohort A and 6 in Cohort B; recruitment is ongoing. Clinical trial information: NCT02780687.