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