Targeted therapies in advanced biliary tract cancers—a narrative review

BACKGROUND AND OBJECTIVE: Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder cancer, are a relatively rare group of cancers with a poor prognosis. Over the past decade, the utilization of next-generation sequencing has led to the identification of multiple actionable somatic aberrations in BTCs. Subsequently, new therapies have been created to target these molecular alterations and have been incorporated into clinical practice. In this review, we outline therapies that have been previously studied, and those that are under investigation, to target genomic alterations with the goal of improving survival in patients with advanced disease. METHODS: A literature search was performed to identify phase I, II, and III trials of targeted therapies in patients with advanced BTCs published between January 1, 2010 and October 1, 2022. Medline (via PubMed) and ClinicalTrials.gov were searched for relevant studies and 415 trials were identified. The search strategy was performed using keywords including: biliary tract cancer, cholangiocarcinoma, gallbladder cancer, chemotherapy, targeted therapy, randomized trials, controlled trials, phase I, phase II, and phase III. Search results were imported into EndNote X 9.1. KEY CONTENT AND FINDINGS: Overall, immune checkpoint inhibitors, fibroblast growth factor receptor (FGFR) inhibitors, isocitrate dehydrogenase (IDH) inhibitors, and human epidermal growth factor receptor 2 (HER2)-directed therapies have all shown promising results with regard to efficacy in patients with advanced BTCs studied in clinical trials. A number of other agents have also been studied in early-phase trials. CONCLUSIONS: Targeted agents can improve survival in patients with advanced BTCs and have substantially increased the number of potential therapeutic options in patients with refractory disease. The therapeutic landscape of targeted therapies for patients with advanced BTCs continues to evolve based on improvements in detection of genomic alterations.