The primary efficacy objective for this study is to evaluate non-progression rate (NPR) at 18
weeks in participants with advanced solid tumors treated with atezolizumab, defined as the
percentage of participants with complete response (CR), partial response (PR), or stable
disease (SD) as assessed by the investigator according to Response Evaluation Criteria in
Solid Tumors (RECIST) Version (v) 1.1, or according to disease-specific criteria for prostate
cancer and malignant pleural mesothelioma.