Orphan Enzyme-blocker treats patients with a specific genetic marker.

Earlier this month, the FDA announced the approval of Celgene’s Idhifa (enasidenib), the first-ever orally administered therapy for patients who carry specific gene mutation and are afflicted with relapsed or refractory acute myloid leukemia (AML), an aggressive cancer that forms in bone marrow. FDA said Idhifa is approved for use with Abbott Laboratories’ RealTime IDH2 diagnostic assay that identifies specific IDH2 gene mutations and an AML patient’s candidacy for Idhifa therapy.

National Cancer Institute and National Institutes of Health statistics reveal approximately 21,000 people are diagnosed with AML each year and that in 2017 nearly 11,000 died from the disease. Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, explained Idhifa is a targeted therapy that fills a void for AML patients. And according to Pazdur, the treatment is also effective: “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.”

Celgene’s Idhifa is an isocratic dehydrogenase-2 inhibitor that inhibits cancer growth by blocking several key enzymes in patients with IDH2 mutation detected in blood or bone marrow samples assayed by the companion diagnostic test. The FDA said Idhifa’s efficacy was studied in a single-arm trial of 199 patients with AML and possessing IDH2 mutations. The trial found that after six months of treatment, 19% of patients experienced complete remission for a median of 8.2 months, and another 4% had complete remission and partial hematologic recovery after 9 months. Of the AML 157 patients requiring transfusions of platelets or blood at the beginning of the study, 34% no longer required transfusions after treatment.

Celgene originally began development of Idhifa with Agios Pharmaceuticals, obtaining an exclusive license for the commercialization of the personalized cancer fighter in 2013. Idhifa was also granted priority review and an Orphan Drug designation by the FDA in 2015.