Testing the Addition of an IDH2 Inhibitor, Enasidenib, to Usual Treatment (Cedazuridine-Decitabine) for Higher-Risk Myelodysplastic Syndrome (MDS) with IDH2 Mutation (A MyeloMATCH Treatment Trial)

Summary

Objectives

PRIMARY OBJECTIVE:
I. To compare the complete remission (CR) rate of enasidenib + decitabine and cedazuridine (ASTX727) and ASTX727 monotherapy in patients with higher-risk IDH2-mutated MDS using International Working Group 2023 (IWG2023) response criteria.

SECONDARY OBJECTIVES:
I. To estimate the median event-free survival (EFS) at designated time point(s) for each treatment arm.
II. To estimate the median overall survival (OS) at designated time point(s) for each treatment arm.
III. To estimate the frequency and severity of toxicities with each regimen in this patient population.
IV. To estimate the median time to response for each treatment arm.
V. To estimate the median duration of response for each treatment arm.
VI. To estimate the IDH2 variant allele frequency (VAF) reduction for each treatment arm.
VII. To estimate the rate of allogeneic hematopoietic cell transplantation for each treatment arm.
VIII. To compare rates of partial response (PR), CR with limited count recovery (CRL), CR with partial count recovery (CRh), and hematologic improvement (HI) using IWG 2023 response criteria between treatment arms.
IX. To compare the measurable residual disease (MRD) kinetics by flow cytometry and next generation sequencing (NGS) at designated time point(s) at the end of cycle 4 & 6 and to assess any correlation with clinical outcomes (e.g. CR, EFS, OS).
X. To estimate the median time to transformation of MDS to acute myeloid leukemia (AML).

EXPLORATORY OBJECTIVES:
I. To estimate CR rate, median EFS, and median OS in patients treated with ASTX727 monotherapy that crossover to the treatment arm with ASTX727 + enasidenib after 6 cycles if CR is not achieved.
II. To estimate CR rate, median EFS, and median OS for patients based on Molecular International Prognostic Scoring System (IPSS-M) prognostic risk score at diagnosis, stratified for score level.
III. To estimate concordance between centrally-performed molecular studies and cytogenetics to those done locally.

OUTLINE: Patients are randomized to 1 of 2 regimens.

REGIMEN 1: Patients receive ASTX727 orally (PO) once daily (QD) on days 1-5 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients who do not achieve a CR, CRL, or CRh at the end of cycle 6 may cross-over to Regimen 2. Patients who experience CR, PR, or stable disease (SD) any time after 4 cycles of treatment may be reassessed in order to go to a higher myeloMATCH tier assignment or to Tier Advancement Pathway (TAP). Patients also undergo bone marrow biopsy and aspiration throughout the study. Patients may also undergo optional buccal swab on study, and/or optional additional bone marrow aspiration and blood sample collection on study and at disease progression.

REGIMEN 2: Patients receive ASTX727 PO QD on days 1-5 and enasidenib PO QD on days 1-28 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients who experience CR, PR, or SD any time after 4 cycles of treatment may be reassessed in order to go to a higher myeloMATCH tier assignment or to TAP. Patients also undergo bone marrow biopsy and aspiration throughout the study. Patients may also undergo optional buccal swab on study, and/or optional additional bone marrow aspiration and blood sample collection on study and at disease progression.

After completion of study treatment, patients are followed up every 6 months for up to 5 years after registration.