Systemic therapy of biliary tract cancer: The road to personalised strategies.

Biliary tract cancers (BTC), including cholangiocarcinoma, gallbladder cancer, and ampullary cancer, remain poor-prognosis tumours. Chemo-immunotherapy is now established as the first-line standard of care. In parallel, precision medicine is now well established in the form of targeted therapies. These have transformed outcomes for defined subgroups, particularly intrahepatic cholangiocarcinoma with FGFR2 fusions/rearrangements, where pemigatinib and futibatinib provide meaningful response rates and durable disease control. On top of this, next-generation FGFR inhibitors aim to address secondary resistance. IDH1-mutant cholangiocarcinoma benefits from ivosidenib, with multiple combination strategies currently under investigation. HER2-directed therapies, including zanidatamab and trastuzumab deruxtecan, have shown promising efficacy in HER2-amplified or strongly overexpressing BTC, with ongoing clinical trials in the first-line setting. Tumour-agnostic targets (BRAF V600E, MSI-H/dMMR, RET/NTRK/NRG1 fusions) and other emerging therapies are further broadening therapeutic opportunities. However, key barriers to implementation include heterogeneous biomarker testing, limited tissue availability, the need for DNA/RNA hybrid-capture sequencing, and evolving resistance biology, underscoring the importance of optimised diagnostics and innovative trial designs to realise personalised care in BTC. This review provides detailed insights on these therapies, and most importantly a view to what the future may hold.