Some targeted therapy agents showed promising results in patients with advanced BTC previously treated in the first-line setting.28–31 Ivosidenib, an isocitrate dehydrogenase-1 (IDH1) inhibitor, was well tolerated and showed a median PFS of 3.8 months and a median OS of 13.8 months in 73 patients with IDH1-mutant cholangiocarcinoma.28 An ongoing phase 3 trial (NCT02989857) is evaluating the efficacy of ivosidenib versus placebo in cholangiocarcinoma with IDH1 mutation. This evidence concerns the gene IDH1 and cholangiocarcinoma.