Adult patients with mutant-IDH2 relapsed/refractory (R/R) acute myeloid leukemia (AML) may benefit from continuous daily enasidenib, according to a study published in Blood.1

For this maximum tolerated dose (MTD)-determining phase 1/2 trial (ClinicalTrials.gov Identifier: NCT01915498), researchers assessed the safety and efficacy of enasidenib among 239 patients with R/R AML. In the dose-escalation phase, patients received 5 enasidenib dose levels ranging from 30 mg to 150 mg twice daily, and 8 dose levels once daily ranging from 50 mg to 650 mg. In the expansion phase, patients were separated into 4 arms and received the dose of enasidenib determined in the escalation phase.

A 100 mg once-daily dose was chosen for the expansion phase based on demonstrated efficacy and pharmacokinetic/pharmacodynamic profiles.

Among patients with R/R disease, 19.3% achieved complete remission (CR) and had a median overall survival of 19.7 months. The median overall survival was 9.3 months among all patients with R/R AML.

The overall response rate was 40.3% (95% CI, 33.0%-48.0%), with a median duration of 5.8 months. 

Eighty-two percent of patients had a treatment-related adverse event (AE). The most frequently reported treatment-related grade 3 to 4 AEs were indirect hyperbilirubinemia (12%) and IDH-inhibitor-associated differentiation syndrome (7%).

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Only 5% of patients discontinued therapy as a result of a treatment-related AE.

Reference

  1. Stein EM, Dinardo CD, Pollyea DA, et al. Enasidenib in mutant IDH2 relapsed or refractory acute myeloid leukemia. Blood. 2017 Aug 10. doi: 10.1182/blood-2017-04-779405 [Epub ahead of print]