The U.S. Food and Drug Administration Tuesday approved Idhifa (compound: enasidenib) of Celgene Corp. for treating adult patients with relapsed or refractory acute myeloid leukemia (AML) who have a specific isocitrate dehydrogenase-2 (IDH2) mutation.
AML is cancer that forms in the bone marrow and shows an increased number of abnormal white blood cells in the bloodstream and bone marrow. The U.S. National Cancer Institute at the National Institutes of Health estimates that about 21,380 people will be diagnosed with AML this year.
This is the first FDA approval for relapsed or refractory AML specifically with an IDH2 mutation. The FDA recently approved a companion diagnostic, the RealTime IDH2 Assay, used to detect the IDH2 mutation.
Idhifa works by blocking several enzymes that promote cell growth. If the IDH2 mutation is detected in blood or bone marrow samples using the RealTime IDH2 Assay, the patient is eligible for the treatment.
Idhifa’s approval was based on Study AG221-C-001 (NCT01915498), an open-label, single-arm, multicenter, clinical trial of that included 199 adults with relapsed or refractory AML who had IDH2 mutation detection, and were treated with Idhifa 100 mg orally daily. Complete response (CR) and complete response with partial hematologic recovery (CRh) rates, CR/CRh duration, and conversion from transfusion dependence to transfusion independence were the basis of approval.
The most common adverse reactions were nausea, vomiting, diarrhea, elevated bilirubin levels, and decreased appetite. Women who are pregnant or breastfeeding should not take Idhifa because it may cause harm to a developing fetus or a newborn baby.
“Idhifa is a targeted therapy that fills an unmet need for patients with relapsed or refractory AML who have an IDH2 mutation,” said Richard Pazdur, director of the FDA’s Oncology Center of Excellence. The use of Idhifa was associated with a complete remission in some patients and a reduction in the need for both red cell and platelet transfusions, he added.