A Study of Atezolizumab in Combination With Carboplatin Plus (+) Paclitaxel With or Without Bevacizumab Compared With Carboplatin+Paclitaxel+Bevacizumab in Participants With Stage IV Non-Squamous Non-Small Cell Lung Cancer (NSCLC)

Inclusion Criteria:

Eastern Cooperative Oncology Group performance status 0 or 1
Histologically or cytologically confirmed, Stage IV non-squamous NSCLC
Participants with no prior treatment for Stage IV non-squamous NSCLC
Known PD-L1 status as determined by immunohistochemistry assay performed on previously obtained archival tumor tissue or tissue obtained from a biopsy at screening
Measurable disease as defined by RECIST v1.1
Adequate hematologic and end organ function

Exclusion Criteria:

Cancer-Specific Exclusions:

Active or untreated central nervous system metastases
Malignancies other than NSCLC within 5 years prior to randomization, with the exception of those with a negligible risk of metastasis or death treated with expected curative outcome

General Medical Exclusions:

Pregnant or lactating women
History of autoimmune disease
History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography scan. History of radiation pneumonitis in the radiation field (fibrosis) is permitted
Positive test for human immunodeficiency virus
Active hepatitis B or hepatitis C
Severe infection within 4 weeks prior to randomization
Significant cardiovascular disease
Illness or condition that interferes with the participant's capacity to understand, follow and/or comply with study procedures

Exclusion Criteria Related to Medications:

Prior treatment with cluster of differentiation 137 agonists or immune checkpoint blockade therapies, anti-programmed death-1, and anti-PD-L1 therapeutic antibodies