Enasidenib as maintenance following allogeneic hematopoietic cell transplantation for IDH2-mutated myeloid malignancies.

Abstract

IDH2 (isocitrate dehydrogenase 2) mutations occur in approximately 15% of patients with acute myeloid leukemia (AML). The IDH2 inhibitor enasidenib was recently approved for IDH2-mutated relapsed or refractory AML. We conducted a multi-center, phase I trial of maintenance enasidenib following allogeneic hematopoietic cell transplantation (HCT) in patients with IDH2-mutated myeloid malignancies. Two dose levels, 50mg and 100mg daily were studied in a 3 × 3 dose-escalation design, with 10 additional patients treated at the recommended phase 2 dose (RP2D). Enasidenib was initiated between days 30 and 90 following HCT and continued for twelve 28-day cycles. Twenty-three patients were enrolled, of whom 19 initiated post-HCT maintenance. Two had myelodysplastic syndrome, and 17 had AML. All but 3 were in first complete remission. No dose limiting toxicities were observed, and the RP2D was established at 100mg daily. Attributable grade ≥3 toxicities were rare, with the most common being cytopenias. Eight patients stopped maintenance before completing 12 cycles, due to adverse events (n=3), pursuing treatment for graft-vs-host disease (GVHD) (n=2), clinician choice (n=1), relapse (n=1), and COVID infection (n=1). No cases of grade ≥3 acute GVHD were seen, and 12-month cumulative incidence of moderate/severe chronic GVHD was 42% (20-63%). Cumulative incidence of relapse was 16% (95% CI: 3.7-36%); 1 subject relapsed while receiving maintenance. Two-year progression-free and overall survival were 69% (95% CI: 39-86%) and 74% (95% CI, 44-90%), respectively. Enasidenib is safe, well-tolerated, with preliminary activity as maintenance therapy following HCT, and merits additional study. The study was registered at www.clinicaltrials.gov (#NCT03515512).

• Authors: Amir T Fathi, Haesook T Kim, Robert J Soiffer, Mark J Levis, Shuli Li, Annette S Kim, Alice S Mims, Zachariah DeFilipp, Areej El-Jawahri, Steven L McAfee, Andrew M Brunner, Rupa Narayan, Laura W Knight, Devon Kelley, Aj S Bottoms, Lindsey H Perry, Jonathan L Wahl, Jennifer Brock, Elayne Breton, Vincent T Ho, Yi-Bin Chen
• Journal: Blood advances (Blood Adv) Vol. 6 Issue 22 Pg. 5857-5865 (11 22 2022) ISSN: 2473-9537 [Electronic] United States
• PMID: 36150050 (Publication Type: Clinical Trial, Phase I, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.

Chemical References

• enasidenib

Topics

• Humans
• Graft vs Host Disease
• COVID-19
• Hematopoietic Stem Cell Transplantation (adverse effects)
• Leukemia, Myeloid, Acute (therapy, drug therapy)
• Myeloproliferative Disorders
• Recurrence