IDH1 and cholangiocarcinoma: The results of a randomized, double-blind, placebo-controlled phase 3 study (ClarIDHy) showed that ivosidenib can significantly improve the median PFS of patients with advanced IDH1 mutation CCA (2.7 months vs. 1.4 months, P < 0.0001), and has a good benefit in OS, but its objective response rate (tumor size reduction >30%) is only 2% (Abou-Alfa et al., 2020a).