Medication Monitor



Generic Name (Trade Name—Company)
Notes
August 3, 2017

Enasidenib

(Idhifa—Celgene)
FDA approves new targeted treatment for relapsed or refractory acute myeloid leukemia

FDA approved enasidenib for the treatment of adult patients with relapsed or refractory acute myeloid leukemia (AML) who have a specific genetic mutation. The drug is approved for use with a companion diagnostic, the RealTime IDH2 Assay (Abbott Laboratories), which is used to detect specific mutations in the isocitrate dehydrogenase-2 (IDH2) gene in patients with AML.

Enasidenib is an IDH2 inhibitor that 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 may be eligible for treatment with enasidenib.

Efficacy of enasidenib was studied in a single-arm trial of 199 patients with relapsed or refractory AML who had IDH2 mutations as detected by the RealTime IDH2 Assay. The trial measured the percentage of patients with no evidence of disease and full recovery of blood counts after treatment (complete remission [CR]), as well as patients with no evidence of disease and partial recovery of blood counts after treatment (complete remission with partial hematologic recovery [CRh]).

With a minimum of 6 months of treatment, 19% of patients experienced CR for a median 8.2 months, and 4% experienced CRh for a median 9.6 months. Of the 157 patients who required transfusions of blood or platelets because of AML at the start of the study, 34% no longer required transfusions after treatment with enasidenib.

Common adverse effects include nausea, vomiting, diarrhea, increased levels of bilirubin, and decreased appetite. Women who are pregnant or breastfeeding should not take enasidenib because it may cause harm to a developing fetus or newborn baby.

The prescribing information includes a boxed warning that an adverse reaction known as differentiation syndrome can occur and can be fatal if not treated. Sign and symptoms of differentiation syndrome may include fever, difficulty breathing, acute respiratory distress, inflammation in the lungs, fluid around the lungs or heart, rapid weight gain, swelling, or liver, kidney, or multiorgan dysfunction. At first sign of symptoms, patients should be treated with corticosteroids and monitored closely until symptoms go away.

Enasidenib was granted Priority Review and Orphan Drug designations.