Lowery MA, Burris HA, Janku F, et al. - Researchers conducted this phase 1 dose-escalation and expansion study to analyze the safety and activity of ivosidenib in individuals with isocitrate dehydrogenase-1 (IDH1)-mutant advanced cholangiocarcinoma. This investigation was performed at 12 clinical sites in the USA and one in France. Ivosidenib was administered orally at 200–1200 mg daily in 28-day cycles in a standard 3 + 3 design during dose escalation. Seventy-three individuals with mIDH1-cholangiocarcinoma were registered and received ivosidenib between March 14, 2014, and May 12, 2017. For patients with mIDH1-cholangiocarcinoma, ivosidenib might offer a well-tolerated option. In patients with previously treated nonresectable or metastatic mIDH1-cholangiocarcinoma, an ongoing, global phase 3 study is assessing ivosidenib compared with placebo. Fatigue, nausea, diarrhoea, abdominal pain, decreased appetite, vomiting, ascites, and anaemia were reported adverse events.