A Study Evaluating the Safety and Pharmacology of Atezolizumab Administered in Combination With Immunomodulatory Agents in Participants With Acute Myeloid Leukemia (AML)

Inclusion Criteria:

- Life expectancy of at least 12 weeks

- Diagnosis of AML per World Health Organization criteria

- Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1 or 2

- Specifically, for participants in Cohorts A1 and A2: Age greater than or equal to (>=)
18 years, disease progression or failure to achieve complete or partial response after
intensive cytotoxic therapy, participants cannot have received more than two prior
intensive regimens (e.g., induction + consolidation and one salvage therapy +
consolidation)

- Specifically, for participants in Cohorts A3 and A4: Treatment naïve participants
unfit for induction chemotherapy for AML as defined by the following: Age >= 70 or age
65 to 69 years with at least one of the following: ECOG performance status of 2,
Intermediate I/II or adverse risk cytogenetic and molecular alterations per ELN 2010
guidelines or secondary AML, or other comorbidity judged incompatible with intensive
chemotherapy

- Adequate end-organ function

- Willing and able to undergo a pre-treatment bone marrow aspirate and biopsy and
subsequent bone marrow aspirates and biopsies during treatment

- For women of childbearing potential: agreement to remain abstinent (refrain from
heterosexual intercourse) or use contraceptive methods that result in a failure rate
of less than (<) 1 percent (%) per year during the treatment period and for at least
30 days after the last dose of guadecitabine or 5 months after the last dose of
atezolizumab, whichever is longer

- For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use
contraceptive measures, and agreement to refrain from donating sperm

Exclusion Criteria:

- In Cohorts A3 and A4 only, participants with AML eligible for standard intensive
induction therapy with an anthracycline and cytarabine

- Prior allogeneic stem cell transplant or solid organ transplant

- Active central nervous system involvement by leukemia

- Pregnant or lactating, or intending to become pregnant during the study

- History of idiopathic pulmonary fibrosis, organizing pneumonitis, drug-induced
pneumonitis, idiopathic pneumonitis, or autoimmune disease

- Treatment with investigational therapy within 14 days prior to initiation of study
drug

- Any approved AML-related therapy within 14 days prior to enrollment

- Immunosuppressive therapy within 6 weeks of Cycle 1, Day 1

- Daily requirement for corticosteroids (> 10 mg prednisone daily or equivalent) (except
for inhalation corticosteroids) within 2 weeks prior to Cycle 1, Day 1

- Prior treatment with immune checkpoint blockade therapies (anti-cytotoxic
T-lymphocyte-associated protein 4 [anti-CTLA-4], anti-programmed death-1 [anti-PD-1]
or anti-PD-L1) or immune agonists (anti-cluster of differentiation [CD]137, anti-CD40,
anti-OX40)

- Treatment with systemic immunostimulatory agents within 4 weeks or 5 half-lives of the
drug, whichever is longer, prior to Cycle 1, Day 1

- Treatment with denosumab (or other receptor activator of nuclear factor kappa-B ligand
[RANKL] inhibitor) 4 weeks before the first dose and for 10 weeks after the last dose
of atezolizumab

- Administration of a live, attenuated vaccine within 4 weeks of Cycle 1, Day 1 or
anticipation that such a live attenuated vaccine will be required during the study

- Planned major surgery during the study

- Positive for hepatitis C virus (HCV) antibody at screening

- Active hepatitis B virus (HBV) infection

- Positive for human immunodeficiency virus (HIV)

- Illicit drug or alcohol abuse within 12 months prior to screening

- Poor peripheral venous access

- Active infection

- Serious infection requiring hospitalization or intravenous (IV) antibiotics within 14
days prior to enrollment

- Any serious medical condition or abnormality in clinical laboratory tests

- History or presence of an abnormal electrocardiogram (ECG)

- History of other malignancy within 2 years prior to screening

- Known hypersensitivity to biopharmaceuticals produced in Chinese hamster ovary cells
or any component of the atezolizumab or guadecitabine formulations

- History of severe allergic, anaphylactic or other hypersensitivity reactions to
chimeric or humanized antibodies or fusion proteins