A Study to Evaluate the Safety and Pharmacokinetics of the Intravenous Fixed-Dose Combination (IV FDC) of Tiragolumab and Atezolizumab in Participants With Locally Advanced, Recurrent or Metastatic Solid Tumors

Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1

• Life expectancy >=12 weeks

• Adequate hematologic and end organ function

• Recovery (i.e., improvement to Grade 1 or better) from all acute toxicities fromprevious therapy, excluding alopecia

• For female participants of childbearing potential, negative serum pregnancy testwithin 14 days prior to initiation of study treatment (Day 1 of Cycle 1)

• For female participants of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraception, and agree to refrainfrom donating eggs during the treatment period and for 5 months after the final doseof tiragolumab and atezolizumab IV FDC

• For male participants: agreement to remain abstinent (refrain from heterosexualintercourse) or use a condom, and agree to refrain from donating sperm during thetreatment period and for 90 days after the final dose of tiragolumab andatezolizumab IV FDC to avoid exposing the embryo

Cancer-Specific Inclusion Criteria:

• Histologic documentation of locally advanced, recurrent, or metastatic malignancy,ineligible for definitive local therapy, for which a clinical trial of aninvestigational agent in combination with an anti-PD-L1 antibody is considered anacceptable treatment option. Participant must be informed of all standard of careoptions available for his/her cancer.

• No prior treatment with checkpoint inhibitor therapies (CPI-Naive)

• Measurable disease per Response Evaluation Criteria in Solid Tumors, Version 1.1 (RECIST v1.1)

• Submittal of archival tumor and/or fresh tumor tissue to the central laboratory forprogrammed death-1 (PD-L1) evaluation prior to enrollment

• PD-L1 selected tumors, as determined by the investigational VENTANA PD-L1 (SP263)immunohistochemistry (IHC) assay

Exclusion Criteria:

• Pregnancy or breastfeeding, or intention of becoming pregnant during the study orwithin 5 months after the final dose of tiragolumab and atezolizumab IV FDC

• Significant cardiovascular disease

• Known clinically significant liver disease

• Poorly controlled Type 2 diabetes mellitus

• Major surgical procedure within 28 days prior to Day 1 of Cycle 1 or anticipation ofneed for a major surgical procedure during the study

• Any other diseases, metabolic dysfunction, physical examination finding, and/orclinical laboratory finding giving reasonable suspicion of a disease or conditionthat contraindicates the use of an investigational drug or that may affect theinterpretation of the results or may render the participant at high risk fromtreatment complications

• History of autoimmune disease

• Treatment with systemic immunosuppressive medications within 2 weeks prior to Day 1of Cycle 1

• History of idiopathic pulmonary fibrosis, pneumonitis, organizing pneumonia, orevidence of active pneumonitis on screening chest computed tomography (CT) scan

• Severe infections within 4 weeks prior to Day 1 of Cycle 1 or recent infections/oralor IV antibiotics within 2 weeks prior to Day 1 of Cycle 1

Cancer-Specific Exclusion Criteria:

• Any anti-cancer therapy, whether investigational or approved within 3 weeks prior toinitiation of study treatment

• Prior treatment with immune checkpoint inhibitors (CPIs)

• Less than 5 drug-elimination half-lives (~100 days for typical monoclonal antibody [Mab]) from the last dose of monoclonal antibodies (MAbs), and MAb-Derived Therapies (excluding CPIs) and the proposed Day 1 of Cycle 1

• Less than 6 weeks between the last dose of prior immunomodulators and the proposedDay 1 of Cycle 1

• Less than 6 weeks or 5-drug-elimination half-lives, whichever is shorter, of priortreatment with cancer vaccines and/or cytokines have elapsed between the last doseand the proposed Cycle 1, Day 1

• Any history of an immune-mediated Grade 4 adverse event attributed to prior cancerimmunotherapy

• Any history of an immune-mediated Grade 3 adverse event attributed to prior cancerimmunotherapy that resulted in permanent discontinuation of the priorimmunotherapeutic agent and/or occurred </=6 months prior to Day 1 of Cycle 1

• Any immune-mediated adverse events related to prior cancer immunotherapy must haveresolved completely to baseline

• Adverse events from prior anti-cancer therapy that have not resolved to Grade <=1except for alopecia, vitiligo, or endocrinopathy managed with replacement therapy