Inclusion Criteria:

          -  Diagnosis of 1) Pathology diagnosis of AML (excluding acute promyelocytic leukemia
             [APL])

          -  Phase Ib dose finding cohort: Patients aged >= 18 years old with relapsed/refractory
             AML are eligible if they are not eligible for potentially curative therapy such as
             effective salvage therapy or hematopoietic stem cell transplantation or who refuse
             these options at the time of enrollment. Patients must have received at least one
             prior therapy for AML

          -  Phase Ib dose finding cohort: Patients may have received up to 2 prior therapies for
             AML (i.e. up to salvage 2 status allowed)

          -  Phase Ib dose finding cohort: Eastern Cooperative Oncology Group (ECOG) performance
             status =< 2

          -  Phase II (frontline cohort): Patients with newly diagnosed AML who are chemonaive who
             are ineligible for intensive chemotherapy based on EITHER:

               -  >= 75 years of age OR

               -  < 75 years of age with at least 1 of the following relevant comorbidities:

                    -  Poor performance status (ECOG) score of 2.

                    -  Clinically significant heart or lung comorbidities, as reflected by at least
                       1 of:

                         -  Left ventricular ejection fraction (LVEF) =< 50%.

                         -  Lung diffusing capacity for carbon monoxide (DLCO) =< 65% of expected.

                         -  Forced expiratory volume in 1 second (FEV1) =< 65% of expected.

                         -  Chronic stable angina or congestive heart failure controlled with
                            medication.

                    -  Other contraindication(s) to anthracycline therapy (must be documented).

                    -  Other comorbidity the investigator judges incompatible with intensive
                       remission induction chemotherapy, which must be documented and approved by
                       the principal investigator (PI)

          -  Phase II (frontline cohort): For patients with prior MDS or chronic myelomonocytic
             leukemia (CMML) or MPN who transformed to AML, therapy received for MDS, CMML, or MPN
             is NOT considered as prior therapy for AML. Patients with MDS or CMML treated with
             hypomethylating agent (HMA) therapies who progress to AML, and have no available
             therapies or are not candidates for available therapies, will be eligible at the time
             of progression to AML. Temporary prior measures such as apheresis, ATRA, steroids
             while diagnostic work-up of AML is being performed are allowed and not counted as a
             prior salvage

          -  Phase II (relapsed/refractory prior venetoclax naive cohort): Patients aged >= 18
             years old with relapsed/refractory AML are eligible if they are not eligible for
             potentially curative therapy such as effective salvage therapy or hematopoietic stem
             cell transplantation or who refuse these options at the time of enrollment. Patients
             must have received at least one prior therapy for AML. Patients may have received up
             to 2 prior therapies for AML (i.e. up to salvage 2 status allowed). Eastern
             Cooperative Oncology Group (ECOG) performance status =< 2. Patients must not have
             received prior venetoclax for MDS or AML

          -  Phase II (relapsed/refractory prior venetoclax exposed cohort): Patients aged >= 18
             years old with relapsed/refractory AML are eligible if they are not eligible for
             potentially curative therapy such as effective salvage therapy, targeted therapies, or
             hematopoietic stem cell transplantation or who refuse these options at the time of
             enrollment. Patients must have received at least one prior therapy for AML. Patients
             may have received up to 2 prior therapies for AML (i.e. up to salvage 2 status
             allowed). Eastern Cooperative Oncology Group (ECOG) performance status =< 2. Patients
             may have received prior venetoclax for MDS or AML

          -  Patients with newly diagnosed AML with poor risk karyotype or complex karyotype and/or
             TP53 deletions/mutations younger than 75 year old will be eligible for the Phase II
             (frontline cohort) regardless of eligibility or fitness for intensive chemotherapy

          -  For Phase II (frontline cohort): Patients must be chemonaive, i.e., not have received
             any chemotherapy (except hydrea or 1-2 doses of ara-C for transient control of
             hyperleukocytosis) for AML. They may have received transfusions, hematopoietic growth
             factors or vitamins for an antecedent hematological disorder (AHD) or for AML.
             Temporary prior measures such as apheresis, ATRA, steroids or hydrea while diagnostic
             work-up is being performed are allowed and not counted as a prior salvage. Supportive
             care therapy for MDS (growth factors, transfusions) will not be considered as prior
             therapy for MDS/AML and these patients will be enrolled to the frontline cohort of the
             study if they are otherwise eligible

          -  In the absence of rapidly progressing disease, the interval from prior treatment to
             time of initiation of protocol therapy will be at least 2 weeks or at least 5
             half-lives (whichever is shorter). The half-life for the therapy in question will be
             based on published pharmacokinetic literature (abstracts, manuscripts, investigator
             brochure's, or drug-administration manuals) and will be documented in the protocol
             eligibility document. The toxicity from prior therapy should have resolved to grade =<
             1, however alopecia and sensory neuropathy grade =< 2 not constituting a safety risk
             based on investigators judgement is acceptable. The use of chemotherapeutic or
             anti-leukemic agents is not permitted during the study with the following exceptions:
             (1) intrathecal (IT) therapy for patients with controlled central nervous system (CNS)
             leukemia at the discretion of the PI. (2) Use of 1-2 doses of cytarabine (up to 2
             g/m^2 each dose) for patients with rapidly proliferative disease is allowed before the
             start of study therapy and for the first four weeks on therapy. Since the effect of
             most immuno-oncology (IO)-agents, HMA-therapies, venetoclax may be delayed, use of
             hydroxyurea for patients with rapidly proliferative disease is allowed on study and
             before the start of study therapy and will not require a washout. These medications
             will be recorded in the case-report form

          -  Concurrent therapy for CNS prophylaxis or continuation of therapy for controlled CNS
             disease is permitted. Patients with a known history of CNS disease or leukemic brain
             metastasis must have been treated locally, have at least 2 consecutive LPs with no
             evidence of CNS leukemia, and must be clinically stable for at least 4 weeks prior to
             enrollment and have no ongoing neurological symptoms that in the opinion of the
             treating physician are related to the CNS disease (sequelae that are a consequence of
             the treatment of the CNS disease are acceptable)

          -  Creatinine clearance (CrCl) >= 30 mL/min calculated by the Cockcroft-Gault formula or
             measured by 24 hours' urine collection.

               -  For patients with body mass index (BMI) > 23, adjusted body weight and not ideal
                  body weight is the recommended parameter

          -  Direct bilirubin < 1.5 x ULN unless considered due to Gilbert's syndrome

          -  Aspartate aminotransferase or alanine aminotransferase =< 2.0 x ULN (aspartate
             aminotransferase or alanine aminotransferase =< 3.0 x ULN if deemed related to
             leukemia by the treating physician)

          -  White blood cell count < 15 x 10^9/L. Patients must have a white blood cell (WBC)
             count < 15 x 10^9/L prior to each dose of magrolimab in cycle 1. Hydroxyurea may be
             used to reduce the WBC count to =< 15 x 10^9/L

          -  Ability to understand and provide signed informed consent

          -  Females must be surgically or biologically sterile or postmenopausal (amenorrheic for
             at least 12 months) or if of childbearing potential, must have a negative serum or
             urine pregnancy test within 72 hours before the start of the treatment

          -  Women of childbearing potential must agree to use an adequate method of contraception
             during the study and until 4 months after the last treatment. Males must be surgically
             or biologically sterile or agree to use an adequate method of contraception during the
             study until 3 months after the last treatment. Adequate methods of contraception
             include:

               -  Total abstinence when this is in line with the preferred and usual lifestyle of
                  the patient. Periodic abstinence (e.g., calendar, ovulation, symptothermal,
                  post-ovulation methods) and withdrawal are not acceptable methods of
                  contraception.

               -  Female sterilization (have had surgical bilateral oophorectomy with or without
                  hysterectomy) or tubal ligation at least six weeks before taking study treatment.
                  In case of oophorectomy alone, only when the reproductive status of the woman has
                  been confirmed by follow up hormone level assessment

               -  Male sterilization (at least 6 months prior to screening). For female patients on
                  the study, the vasectomized male partner should be the sole partner for that
                  patient

               -  Combination of any of the two following (a+b or a+c or b+c)

                    1. Use of oral, injected or implanted hormonal methods of contraception or
                       other forms of hormonal contraception that have comparable efficacy (failure
                       rate < 1%), for example hormone vaginal ring or transdermal hormone
                       contraception

                    2. Placement of an intrauterine device (IUD) or intrauterine system (IUS)

                    3. Barrier methods of contraception: Condom or Occlusive cap (diaphragm or
                       cervical/vault caps) with spermicidal foam/gel/film/cream/ vaginal
                       suppository

               -  In case of use of oral contraception, women should have been stable on the same
                  pill before taking study treatment

               -  Note: Oral contraceptives are allowed but should be used in conjunction with a
                  barrier method of contraception due to unknown effect of drug-drug interaction.

               -  Women are considered post-menopausal and not of child bearing potential if they
                  have had 12 months of natural (spontaneous) amenorrhea with an appropriate
                  clinical profile (e.g. age appropriate, history of vasomotor symptoms) or have
                  had surgical bilateral oophorectomy (with or without hysterectomy) or tubal
                  ligation at least six weeks ago. In the case of oophorectomy alone, only when the
                  reproductive status of the woman has been confirmed by follow up hormone level
                  assessment is she considered not of child bearing potential.

               -  Male patients who are sexually active with a WOCBP and who have not had
                  vasectomies must be willing to use a barrier method of contraception during the
                  study and for 3 months after the last dose of magrolimab, venetoclax or
                  azacitidine, whichever ends later.

               -  Women who are pregnant or breastfeeding will not be eligible

        Exclusion Criteria:

          -  Patients with known allergy or hypersensitivity to magrolimab, venetoclax, azacitidine
             or any of their components

          -  Patients with any other known concurrent severe and/or uncontrolled medical condition
             including but not limited to diabetes, cardiovascular disease including hypertension,
             renal disease, or active uncontrolled infection, which could compromise participation
             in the study. Patients on active antineoplastic or radiation therapy for a concurrent
             malignancy at the time of screening. Maintenance therapy, hormonal therapy, or steroid
             therapy for well-controlled malignancy is allowed

          -  Prior organ transplantation including allogenic stem-cell transplantation within 3
             months prior to planned enrollment, active graft versus host disease (GVHD) > grade 1,
             or requiring transplant-related immunosuppression

          -  Known inherited or acquired bleeding disorders

          -  Prior treatment with a CD47 or SIRPalpha targeting agent

          -  Patients with symptomatic CNS leukemia or patients with poorly controlled CNS leukemia

          -  Patients with a known human immunodeficiency virus (HIV) infection that is not well
             controlled (i.e. any detectable circulating viral load) at the time of enrollment

          -  Patients with known positive hepatitis B or C infection by serology, with the
             exception of those with an undetectable viral load within 3 months (hepatitis B or C
             testing is not required prior to study entry). Subjects with serologic evidence of
             prior vaccination to hepatitis B virus (HBV) [i.e., hepatitis B surface antigen
             (HBsAg)-, and anti-HBs+] may participate

          -  Patients who have consumed grapefruit, grapefruit products, Seville oranges (including
             marmalade containing Seville oranges) or starfruit within 3 days prior to the
             initiation of study treatment

          -  Patients who have had any major surgical procedure within 14 days of day 1

          -  Other severe acute or chronic medical conditions that is active and not well
             controlled including colitis, inflammatory bowel disease, or psychiatric conditions
             including recent (within the past year) or active suicidal ideation or behavior; or
             laboratory abnormalities that may increase the risk associated with study
             participation or study treatment administration or may interfere with the
             interpretation of study results and, in the judgment of the investigator, would make
             the patient inappropriate for entry into this study

          -  Active and uncontrolled disease (active infection requiring systemic therapy or fever
             likely secondary to infection within prior 48 hours): prophylactic antibiotics or
             prolonged course of IV antibiotics for controlled infection are allowed, uncontrolled
             hypertension despite adequate medical therapy, active and uncontrolled congestive
             heart failure New York Heart Association (NYHA) class III/IV, clinically significant
             and uncontrolled arrhythmia) as judged by the treating physician

          -  Patients unwilling or unable to comply with the protocol