First-Line Nivolumab Plus Ipilimumab in Unresectable Hepatocellular Carcinoma (J-PROMISE)

Inclusion Criteria: * Participants aged ≥ 18 years at the time of consent * Participants with unresectable hepatocellular carcinoma (uHCC), defined as disease not eligible for curative surgical and/or locoregional therapies, or progressive disease after surgical and/or locoregional therapies * Child-Pugh class A (total score 5-6) * Participants who have not received prior systemic drug therapy for uHCC * Participants who relapsed more than 6 months after completion of postoperative adjuvant therapy are eligible * Participants who received lenvatinib in combination with transarterial chemoembolization (TACE) are eligible if the treating physician determined they were eligible for TACE; participants are excluded if TACE eligibility at the time of lenvatinib initiation is unclear * Participants scheduled to initiate nivolumab plus ipilimumab combination therapy between March 1, 2026 and February 28, 2027 * Nivolumab plus ipilimumab combination therapy is defined as nivolumab 80 mg and ipilimumab 3 mg/kg administered intravenously every 3 weeks for 4 cycles, followed by nivolumab monotherapy at 240 mg every 2 weeks or 480 mg every 4 weeks * Participants who provide written informed consent prior to initiation of nivolumab plus ipilimumab therapy Exclusion Criteria: * Known fibrolamellar hepatocellular carcinoma, sarcomatoid hepatocellular carcinoma, or mixed cholangiocarcinoma * Prior liver transplant * ECOG performance status ≥ 3 * Uncontrolled comorbidities despite treatment * Other advanced cancers requiring systemic therapy * Prior immuno-oncology treatment * Participation in interventional clinical trials at enrollment * Deemed unsuitable by investigator