A Study of Atezolizumab Plus Carboplatin and Etoposide With or Without Tiragolumab in Patients With Untreated Extensive-Stage Small Cell Lung Cancer

- Symptomatic or actively progressing central nervous system (CNS) metastases

- Malignancies other than small cell lung cancer (SCLC) within 5 years prior to randomization, with the exception of those with a negligible risk of metastasis or death treated with expected curative outcome

- Active or history of autoimmune disease or immune deficiency

- History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography (CT) scan

- Positive test result for human immunodeficiency virus (HIV)

- Active hepatitis B or hepatitis C

- Severe infection at the time of randomization

- Treatment with any other investigational agent within 28 days prior to initiation of study treatment

- Prior treatment with CD137 agonists or immune checkpoint blockade therapies, anti-CTLA-4, anti-TIGIT, anti-PD-1, and anti-PD-L1 therapeutic antibodies

- Treatment with systemic immunostimulatory agents within 4 weeks or 5 drug elimination half-lives prior to randomization