A phase III clinical trial, the CHONQUER study, was registered in 2023 (ClinicalTrials.gov ID: NCT06127407; Study CL3-95031-007) and it is now recruiting patients for evaluation of orally administered ivosidenib in patients with IDH1-mutated, locally advanced or metastatic conventional CS grades 1, 2, or 3 and not eligible for curative resection. Here, IDH1 is linked to Cowden syndrome 1.