Study to Evaluate Adverse Events, and Change in Disease Activity, When Intravenously (IV) Infused With Livmoniplimab in Combination With IV Infused Budigalimab in Adult Participants With Hepatocellular Carcinoma (HCC)

• Budigalimab (Drug), also known as ABBV-181: Intravenous (IV) Infusion
• Livmoniplimab (Drug), also known as ABBV-151: Intravenous (IV) Infusion
• Lenvatinib (Drug): Oral: Capsule
• Sorafenib (Drug): Oral: Tablet

Primary outcomes

• Best Overall Response (BOR) per Investigator [Through Study Completion, Up to Approximately 27 Months]: BOR is defined as a subject achieving confirmed complete response (CR) or confirmed partial response (PR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) as determined by investigators at any time prior to subsequent anticancer therapy.

Secondary outcomes

• Duration of response (DOR) per Investigator [Through Study Completion, Up to Approximately 27 Months]: DOR is defined as the time from first confirmed CR or PR until the first documentation of progressive disease according to RECIST 1.1 as determined by investigators or death from any cause, whichever occurs first.
• Number of Participants with Progression-free Survival (PFS) [Through Study Completion, Up to Approximately 27 Months]: PFS is defined as the time from randomization until the first documentation of progressive disease according to RECIST 1.1 as determined by investigators or death from any cause, whichever occurs first.
• Overall Survival (OS) [Through Study Completion, Up to Approximately 27 Months]: OS is defined as the time from randomization until death from any cause.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Child-Pugh A classification.
* Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1.
* Received an immune checkpoint inhibitor in first-line (1L) hepatocellular carcinoma (HCC) treatment regimen.
* Adequate hematologic and end-organ function.
* Tissue biopsy at screening.
* Disease that is not amenable to surgical and/or locoregional therapies, or progressive disease after surgical and /or locoregional therapies.

Exclusion Criteria:

* Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases.
* Prior treatment with an approved tyrosine kinase inhibitor (for example sorafenib or Lenvatinib) in 1L HCC treatment regimen.
* History of malignancy other than hepatocellular carcinoma (HCC) within 5 years prior to screening.
* Hepatic encephalopathy or requirement for medications to prevent or control encephalopathy.
* Moderate or severe ascites requiring recurrent non-pharmacologic intervention to maintain symptomatic control.
* Coinfection with active HBV infection and active HCV infection.
* Prior history of grade 3 or higher immune-mediated adverse event or discontinuation due to immune-mediated adverse events.
* Prior history of recurrent grade 2 or higher interstitial lung disease/pneumonitis.

• ABBVIE INC., Study director, AbbVie