FDA grants Idhifa® (enasidenib) approval for the treatment of R/R AML patients with IDH2 mutation

On 1^st August 2017, the U.S. Food and Drug Administration (FDA) granted approval to Idhifa® (enasidenib) for the treatment of adult patients with Relapsed or Refractory (R/R) Acute Myeloid Leukemia (AML) with an Isocitrate Dehydrogenase-2 (IDH2) mutation as detected by an FDA-approved test.¹ The approval comes after the priority review designation granted to enasidenib in March 2017, which was reported here.

This approval for enasidenib, a first in class, oral, selective inhibitor of mutations in IDH2, was based on results from the phase I/II AG-221 AML-001 study (NCT01915498). In this study, the efficacy of enasidenib, was assessed in R/R AML patients (median age = 68 years) with mutant IDH2. Patients were orally administered enasidenib at a starting dose of 100 mg daily until disease progression or unacceptable toxicity. The key results were:

• Complete Response/ Complete Response with Partial Hematologic Improvement (CR/CRh); 23%

The safety of enasidenib was also assessed in 214 R/R IDH2 mutated AML patients in this study. The key results were:

• 30-day and 60-day mortality rates were 4.2% (9/214) and 11.7% (25/214) respectively
• Adverse Events (AEs) included indirect hyperbilirubinemia and IDH-inhibitor-associated differentiation syndrome (14%)

In summary, enasidenib was well-tolerated and induced hematologic responses in mutant IDH2 R/R AML patients.² More results from this phase I/II AG-221 AML-001 study are reported here.

Idhifa® was approved alongside the Abbott RealTime™ IDH2 companion diagnostic test, which is FDA-approved as an aid in identifying IDH2 mutated AML patients for treatment with Idhifa®.