Enasidenib, an inhibitor of mutant IDH2 proteins, induces durable remissions in older patients with newly diagnosed acute myeloid leukemia

Leukemia. 2019 Nov;33(11):2575-2584. doi: 10.1038/s41375-019-0472-2. Epub 2019 Apr 9.

Abstract

Older adults with acute myeloid leukemia (AML) who are not fit for standard chemotherapy historically have poor outcomes. Approximately 12-15% of older patients with AML harbor isocitrate dehydrogenase 2 (IDH2) gene mutations. Enasidenib is an oral inhibitor of mutant IDH2 proteins. Among 39 patients with newly diagnosed mutant-IDH2 AML who received enasidenib monotherapy in this phase I/II trial, median age was 77 years (range 58-87) and 23 patients (59%) had had an antecedent hematologic disorder. The median number of enasidenib treatment cycles was 6.0 (range 1-35). The most common treatment-related adverse events were indirect hyperbilirubinemia (31%), nausea (23%), and fatigue, decreased appetite, and rash (18% each). Treatment-related grade 3-4 cytopenias were reported for eight patients (21%); there was no treatment-related grade 3-4 infections. Twelve patients achieved a response (overall response rate 30.8% [95% CI 17.0%, 47.6%]), including seven patients (18%) who attained complete remission. At a median follow-up of 8.4 months, the median duration of any response was not reached (NR). Median overall survival for all patients was 11.3 months (95% CI 5.7, 15.1), and was NR for responders. Oral, outpatient targeted treatment with enasidenib may benefit older adults with newly diagnosed mutant-IDH2 AML who are not candidates for cytotoxic regimens.

Publication types

  • Clinical Trial, Phase I
  • Clinical Trial, Phase II
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aminopyridines / therapeutic use*
  • Enzyme Inhibitors / therapeutic use
  • Female
  • Hematologic Diseases / complications
  • Humans
  • Isocitrate Dehydrogenase / antagonists & inhibitors*
  • Isocitrate Dehydrogenase / genetics*
  • Leukemia, Myeloid, Acute / drug therapy*
  • Male
  • Maximum Tolerated Dose
  • Middle Aged
  • Mutant Proteins / genetics
  • Mutation
  • Remission Induction
  • Treatment Outcome
  • Triazines / therapeutic use*

Substances

  • Aminopyridines
  • Enzyme Inhibitors
  • Mutant Proteins
  • Triazines
  • enasidenib
  • IDH2, human
  • Isocitrate Dehydrogenase