The purpose of this study is to test a new experimental drug called SAR443579 for the treatment of participants with relapsed or refractory acute myeloid leukemia (R/R AML), B-cell acute lymphoblastic leukemia (B-ALL), and high risk-myelodysplasia (HR-MDS).
Experimental means that it has not been approved by the US Food and Drug Administration (FDA) to be prescribed to patients.