• Patients must be ≥18.

• For the Part 1 Dose-Escalation Phase, patients must be diagnosed with the following:

∙ Relapsed or refractory AML with myelomonocytic or monoblastic/monocytic differentiation according to the World Health Organization 2016 criteria and has failed treatment with available therapies known to be active for AML.

‣ Relapsed or refractory CMML and has failed treatment with available therapies known to be active for CMML

• Part 2 Expansion Phase:

∙ Relapsed or refractory LILRB4high AML with myelomonocytic or monoblastic/monocytic differentiation and has failed treatment with available therapies known to be active for AML.

‣ Hypomethylating-agent naive CMML regardless of LILRB4 expression levels.

‣ Newly diagnosed high LILRB4 expression monocytic AML patients considered to be ineligible for standard induction therapy.

• Patients must be amenable to serial BM aspirates/biopsies and peripheral blood sampling during the study.

• Patients must be able to understand and willing to sign an informed consent. A legally authorized representative may consent.

• Patients must have an ECOG performance status of 0 to 2

• Patients must have adequate hepatic function

• Patients must have adequate renal function

• Patients must be recovered from any clinically relevant toxic effects of any prior surgery, radiotherapy, or other therapy intended for the treatment of cancer.

⁃ Patients must be off systemic calcineurin inhibitors for at least 4 weeks prior to study drug treatment.

⁃ Female patients with reproductive potential must have a negative serum pregnancy test within 7 days prior to the start of therapy.