RecruitingPhase 2Drug trialVCA Regimen Followed by D-MAG Regimen on the Treatment of Elderly Patients With Newly Diagnosed Acute Myeloid Leukemia (AML)The purpose of this study is to evaluate the safety and efficacy of Venetoclax Combining Chidamide and Azacitidine (VCA) Followed by D-MAG Regimen on the Treatment of Elderly Patients With Newly Diagnosed Acute Myeloid Leukemia (AML)