The agency also approved the Abbott RealTime IDH1 Assay to test for the mutation.
Almost 4% of the 16,000 people diagnosed with MDS in the United States each year carry an isocitrate dehydrogenase-1 (IDH1) mutation, which increases their risk for poor outcomes, such as transformation to acute myeloid leukemia, Servier explained in a press announcement.
Ivosidenib is an IDH1 inhibitor that has previously been approved for IDH1-mutated AML and locally advanced or metastatic cholangiocarcinoma. The new approval makes it the only targeted therapy approved for relapsed or refractory MDS with the mutation, Servier said.
The FDA approval was based on a phase 1 study in 18 adults aged 61-82 years with IDH1-mutated relapsed or refractory MDS. Patients started at a dose of 500 mg daily in 28-day cycles until disease progression, unacceptable toxicity, or hematopoietic stem cell transplantation. Median treatment duration was 9.3 months, and one patient went on to receive a transplant.
Overall survival was a median of 35.7 months. Fifteen patients (83.3%) had an objective response and 7 (38.9%) went into complete remission after a median of 1.9 months of treatment. The median duration of remission had not been reached at data cutoff.
Among the 9 patients dependent on RBC or platelet transfusions at baseline, 6 (66.7%) no longer needed them during any 56-day post-baseline period.
Grade 3/4 adverse events in 5% or more of patients included arthralgia, hypertension, fatigue, mucositis, and leukocytosis.
Labeling carries a boxed warning of potentially fatal differentiation syndrome. Ivosidenib can also cause QTc prolongation.
A version of this article first appeared on Medscape.com.