Enasidenib Granted Priority Review by FDA

Enasidenib (formerly known as AG221) has been granted priority review by the U.S. Food and Drug Administration (FDA) for treatment of patients with relapsed or refractory acute myeloid leukemia (AML) with an isocitrate dehydrogenase 2 (IDH2) mutation.

Enasidenib is a targeted oral inhibitor of mutant IDH2. The FDA’s decision was based on results from the AG221-C-001 single-arm, phase I/II study of 198 patients treated with escalating doses of enasidenib. The drug was administered at an initial dose of 30 mg or 50 mg daily or twice daily, and the maximum tolerated dose was not reached.

Patients had the following hematologic diagnoses:

  • relapsed/refractory AML (70%)
  • untreated AML (17%)
  • myelodysplastic syndrome (7%)
  • another IDH2-mutant hematologic malignancy (6%)

The objective response rate from the trial was 42 percent and the complete response rate was 18 percent. An additional 14 percent of patients attained partial response. The most common adverse events were indirect hyperbilirubinemia (19%) and nausea (18%).

Source: Celgene press release, March 1, 2017.