Key Inclusion Criteria:

- Age ≥ 18 years.

- Individuals with histologically or pathologically confirmed diagnosis of relapsed or
refractory AML, ALL, or MPAL with documented FLT3 mutation, and/or Individuals with
histologically or pathologically confirmed diagnosis of their malignancy with
wild-type FLT3 (including those with MLL1-R and NPM1 mutations).

- ECOG performance status of 0-2.

- Adequate liver and renal function

- Adhere to the CYP3A4 inhibitor concomitant therapy use requirements, as follows:

- Arm A: Participants must not have received a moderate or strong CYP3A4 inhibitor for
at least 7 days prior to enrollment and are not anticipated to require such agents in
the near term (for at least 4 weeks).

- Arm B: Participants must have received a necessary azole antifungal(s) that is a
moderate or strong CYP3A4 inhibitor (excluding other moderate or strong CYP3A4
inhibitor[s]) for at least 7 days prior to enrollment and be able to continue such
azole antifungal(s) while on BMF-500 treatment for at least 4 weeks.

Key Exclusion Criteria:

- Significant cardiovascular disease including unstable angina pectoris, uncontrolled
hypertension or arrhythmia, history of cerebrovascular accident including transient
ischemic attack within 6 months prior to the first dose of the trial intervention.

- WBC count >50,000/µL (uncontrollable with cytoreductive therapy).

- Women who are pregnant or lactating or plan to become pregnant.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated 9/15/23. Questions regarding updates should be directed to the study team contact.