RecruitingPhase 1Drug trialSL-401 in Combination With Azacitidine or Azacitidine/Venetoclax in Acute Myeloid Leukemia (AML), High-Risk Myelodysplastic Syndrome (MDS) or Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN)This research study is studying a drug as a possible treatment for diagnosis of AML, BPDCN and high-risk MDS. The interventions involved in this study are: * SL-401 * Azacitidine * Venetoclax