Ghassan Abou-Alfa, MD, Memorial Sloan Kettering Cancer Center, New York, NY, runs through the aims and initial findings of the ClarIDHy study (NCT02989857); a Phase III study of ivosidenib vs placebo in patients with advanced cholangiocarcinoma (CCA) with an IDH1 mutation. This interview took place at the European Society for Medical Oncology (ESMO) 2019 congress in Barcelona, Spain.