A Study to Evaluate Safety, Pharmacokinetics and Anti-Tumor Activity of RO7300490, as Single Agent or in Combination With Atezolizumab in Participants With Advanced Solid Tumors

Inclusion Criteria:

• Life expectancy of >= 12 weeks.
• Histologically confirmed diagnosis of locally advanced and/or metastatic solid tumorsthat are not amenable to standard therapy.
• Radiologically measurable disease as defined by Response Evaluation Criteria in SolidTumors (RECIST) v1.1.
• Agreement to provide protocol-specific biopsy material.
• Adverse Events (AEs) from prior anti-cancer therapy resolved to Grade =<1.
• Adequate performance status and cardiovascular, hematological, liver, renal andcoagulation function.
• For female participants of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse), use contraceptive measures and refrain fromdonating eggs.
• For male participants: agreement to remain abstinent (refrain from heterosexualintercourse), use contraceptive measures and refrain from donating sperm.

Exclusion Criteria:

• Known central nervous system (CNS) primary tumors or metastases, includingleptomeningeal metastases, unless protocol-specific conditions are met.
• Active second invasive malignancy within two years prior to screening.
• Significant cardiovascular/cerebrovascular disease within 6 months prior to studytreatment start.
• Any other diseases, metabolic dysfunction, physical examination finding or clinicallaboratory finding that gives reasonable suspicion of a disease or condition thatwould contraindicate the use of an investigational drug.
• Prior allogeneic bone marrow transplantation or prior solid organ transplantation.
• Active or history of autoimmune disease.
• Known hypersensitivity to any of the components of RO7300490 formulation or tocomponents of atezolizumab formulation.
• Pregnancy, lactation or breastfeeding.
• Dementia or altered mental status that would prohibit informed consent.
• Major surgery or significant traumatic injury within 28 days prior to the first studydrug administration (excluding biopsies) or anticipation of the need for major surgeryduring study treatment.
• Treatment with radiotherapy, chemotherapy, hormonal therapy, targeted therapy,immunotherapy or investigational drug concurrent or within 28 days or 5 half-lives ofthe drug (whichever is shorter) before the first study drug administration.