A Clinical Study of 6MW3211 Monotherapy or Combination Therapy for AML or MDS

Inclusion Criteria: * Voluntarily participate in the study and sign the informed consent; * 18≤age≤75，Men or women； * AML patients (except acute promyelocytic leukemia) : subjects who meet the diagnostic criteria for relapsed/refractory AML according to the diagnostic criteria of 2021 Chinese Guidelines for the Diagnosis and Treatment of Relapsed and Refractory AML ； MDS patients: MDS patients were diagnosed as having moderate risk of recurrence/refractory (IPSS-R score \>3.5) according to WHO diagnostic criteria in 2016 * ECOG:0-2; * Survival expectation of at least 3 months; * Adequate organs and hematopoietic functions; only applicable for phase II : * Newly diagnosed AML with intolerance to standard induction chemotherapy who should meet one of following criterias: age ≥75 years; ECOG 2-3; chronic heart failure requiring treatment or EF≤50% or chronic stable angina pectoris; DLCO≤65% or FEV1≤65%;30ml/min≤CrCl\<45ml/min；1.5 x ULN\<total bilirubin≤3.0 x ULN * Newly diagnosed intermediate- and high-risk (International Prognostic Scoring System IPSS-R) MDS Exclusion criteria: * Myeloid proliferative diseases (MPN), including primary myelofibrosis (PMF), polycythemia vera (PV), chronic myelogenous leukemia (CML), and primary thrombocytopenia (ET); Or have myelodysplastic myeloid proliferative tumors (MDS-MPN), including chronic monocytic leukemia (CMML), atypical chronic myelogenous leukemia (aCML), juvenile granulomatous single-cell leukemia (JMML), and acute promyelocytic leukemia (M3); * Recurrence after allogeneic hematopoietic stem cell transplantation, or autologous hematopoietic stem cell transplantation within 1 year; * Known infiltration of central nervous system leukemia； * Active or uncontrolled autoimmune diseases； * Has a history of other malignancies； * Has known inherited or acquired hemorrhagic disorders； * Pregnant or lactating women；