Is there any place for novel agents in treating biliary tract cancer?

Biliary tract cancer is an uncommon cancer in developed countries. In localized stages, surgery is the cornerstone of treatment with curative purpose. Conversely in advanced stages, chemotherapy with platinum-gemcitabine combination is the standard of care. Biliary tract cancers are a biologically heterogeneous group of malignancies, which perhaps explains the failure of targeted therapies in unselected patient populations to demonstrate benefit in advanced disease, although there are promises in selected populations (e.g. PD1/PD-L1 positive, BRAF^V600E-mutated or IDH1-mutant). In view of the limited benefit of second line therapies in metastatic biliary tract cancer, various targeted agents have been tested in progressive disease. Furthermore, several ongoing trials are using next-generation sequencing of multiple genes to identify molecular abnormalities in the tumors of patients with refractory cancers that may potentially be used in pretreated disease (e.g. FGFR or IDH genes). Immunotherapy with immune checkpoint inhibitors may be interesting for patients whose tumors have programmed cell death 1 ligand 1 (PD-L1) overexpression. Ongoing and future trials will further advance our knowledge toward the optimal treatment strategy for the management of biliary tract cancer in its different stages, starting from metastatic and then reaching early stages of disease. We here provided an overview of these novel treatment strategies for advanced biliary tract cancers not amenable of curative treatment modalities.