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

Inclusion Criteria

• Histologically or cytologically confirmed extensive-stage small cell lung cancer (ES-SCLC)
• No prior systemic treatment for ES-SCLC
• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1
• Measurable disease, as defined by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1)
• Adequate hematologic and end-organ function
• Treatment-free for at least 6 months since last chemo/radiotherapy, among those treated (with curative intent) with prior chemo/radiotherapy for limited-stage SCLC

Exclusion Criteria

• 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-cytotoxic T lymphocyte-associated protein 4 (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