Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Efficacy of Evixapodlin (Formerly GS-4224) in Participants With Advanced Solid Tumors

Key Inclusion Criteria:

* Dose Escalation Cohorts: Histologically or cytologically confirmed advanced malignant solid tumor that is refractory to or intolerant of all standard therapy or for which no standard therapy is available.
* Dose Expansion and 1000 mg twice a day (BID) Dose Escalation Cohorts: Individuals must have available sufficient and adequate formalin fixed tumor sample preferably from a biopsy of a tumor lesion obtained either at the time of or after the diagnosis of advanced disease has been made and from a site not previously irradiated. Alternatively, individuals must agree to have a biopsy taken prior to entering the study to provide adequate tissue. For the 1000 mg BID dose escalation cohort, individuals with melanoma, Merkel cell, microsatellite instability-high (MSI-H) cancers, and classical Hodgkin lymphoma (cHL) are not required to have archival or fresh biopsy tissue.
* Dose Escalation Biopsy Substudy and 1000 mg BID Dose Escalation Cohorts: Documented ligand 1 of programmed cell death protein 1 (PD-L1) expression in the tumor (tumor proportion score (TPS) ≥ 10% or combined positive score (CPS) ≥ 10). In the 1000 mg BID Cohort, PD-L1 expression will not be required for Merkel cell, melanoma, MSI-H cancers, and cHL.
* Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 2.
* Adequate organ function.

Key Exclusion Criteria:

* History or evidence of clinically significant disorder, condition, or disease that, in the opinion of the Investigator or Medical Monitor would pose a risk to individual safety or interfere with the study evaluations, procedures, or completion.
* Dose Escalation Cohorts: History of ≥ Grade 3 Adverse Events (AEs) during prior treatment with an immune checkpoint inhibitor, or history of discontinuation of treatment with an immune checkpoint inhibitor due to AEs.
* Dose Escalation 1000 mg BID and Dose Expansion Cohort: Prior treatment with an immune checkpoint inhibitor (anti-PD-1, anti-PD-L1, or anti- ligand 2 of programmed cell death protein 1 (PD-L2) antibodies).
* History of autoimmune disease (for example, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vascular thrombosis associated with antiphospholipid syndrome, Wegener's granulomatosis, Sjögren's syndrome, Bell's palsy, Guillain-Barré syndrome, multiple sclerosis, autoimmune thyroid disease, vasculitis, or glomerulonephritis).

Note: Other protocol defined Inclusion/Exclusion criteria may apply.