The FDA approved ivosidenib, a small-molecule IDH1 inhibitor, for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) and an IDH1 mutation. This is the first IDH1 inhibitor approved for this indication, and the agent was approved simultaneously with the RealTime IDH1 Assay, a companion diagnostic designed to detect the IDH1 mutation.
The FDA based their decision on data from a single-arm study that evaluated the efficacy of ivosidenib in 174 patients with relapsed or refractory, IDH1-mutated AML. After a median follow-up of 8.3 months (range not provided), 32.8 percent of patients experienced complete remission (CR; defined as no disease evidence at follow-up and full recovery of posttreatment blood counts) or CR with partial hematologic recovery. These responses lasted for a median of 8.2 months (range not reported).
In addition, of the 110 participants who were transfusion-dependent at baseline, 37 percent went at least 56 days without requiring a transfusion after ivosidenib treatment.
The most common AEs associated with ivosidenib (≥20%) included fatigue, leukocytosis, arthralgia, diarrhea, dyspnea, edema, nausea, mucositis, prolonged electrocardiogram QT, rash, pyrexia, cough, and constipation.
Source: FDA news release, July 20, 2018.