The current standard of care treatment for adult patients with acute myeloid leukemia (AML) consists of chemotherapy and, if indicated, donor stem cell transplantation.

Bleximenib blocks the interaction between a protein called menin and another protein called KMT2A in the leukemia cells. When this interaction is disrupted in AML with mutations in the NPM1 or KMT2A gene, bleximenib can cause leukemia cells to die.

The main objective is to assess if treatment with bleximenib, when added to chemotherapy treatment will improve treatment outcome in adult participants with newly diagnosed AML who present with mutations in the NPM1 or KMT2A genes.

This is a randomized, double-blind, placebo-controlled, phase 3 clinical trial. All of the participants will receive standard chemotherapy treatment, combined with either bleximenib or a placebo. A placebo is a substance that looks like the study medicine but has no active ingredients (e.g., a sugar pill). In a double blind trial neither the participant nor the doctor know if placebo or active study drug is given.

After the end of the protocol treatment there will be an observational follow-up of 4 years from the time of inclusion of the last patient. The results of the different treatment groups will be compared.

875 previously untreated patients with AML with a specific change in the DNA of the leukemia cells (a KMT2A rearrangement or a NPM1 mutation) will be included. Participants must be 18 years or older and considered eligible for intensive chemotherapy.

Inclusion Criteria:

1. ≥18 years of age (or the legal age of majority in the jurisdiction in which the study is taking place, whichever is greater) at the time of informed consent.
2. New diagnosis of AML (≥10% blasts in BM or peripheral blood) with mutated NPM1 or with recurring rearrangements involving KMT2A according to ICC 2022 criteria.
3. Considered eligible for intensive chemotherapy.
4. WHO/ECOG performance status ≤2.
5. Adequate renal and hepatic functions prior to randomization.

Exclusion Criteria:

1. Prior (chemo-)therapy for AML, including prior treatment with hypomethylating agents

2. Known active leukemic involvement of the central nervous system (CNS).

3. Recipient of solid organ transplant.

4. Cardiac disease:

   1. Any of the following within 6 months of randomization: myocardial infarction, uncontrolled/unstable angina, congestive heart failure (NYHA Class III or IV), uncontrolled or symptomatic arrhythmias, stroke, or transient ischemic attack.
   2. QTc interval using Fridericia's formula (QTcF) ≥470 ms. Prolonged QTc interval associated with bundle branch block or pacemaking is permitted.
   3. Left ventricular ejection fraction (LVEF) <40% by ECHO or MUGA scan obtained within 28 days prior to the start of study treatment.
   4. Previously received cumulative dose of any combination of anthracyclines or anthracenediones of ≥500 mg/m2.

5. Chronic respiratory disease requiring supplemental oxygen.

According to the current publication policy the protocol and Statistica! Analysis Plan ( SAP) will be shared. The principal lnvestigators can be contacted for IPD sharing after the publication of the study results. According to 'HOVON sample and/or Data request Form' theHOVON director; chair of theHOVON Acute Myeloid Leukemie working group, the study PI and Coordinating lnvestigator should approve data/sample sharing.

After the publication of primary endpoint analysis