This study will evaluate whether starting denosumab early, together with a locked uniform PD-1-based systemic therapy, can reduce skeletal-related events and delay worsening bone pain compared with a delayed/rescue bone-modifying strategy in patients with hepatocellular carcinoma and bone metastases. Participants will be randomly assigned in a 1:1 ratio to receive either early denosumab plus the same PD-1-based systemic therapy or the same systemic therapy with no routine prophylactic bone-modifying agent at baseline and rescue treatment only when predefined triggers occur. The primary outcome is skeletal-related event-free survival. Secondary outcomes include time to first skeletal-related event, pain outcomes, quality of life, intrahepatic antitumor activity at Week 12, progression-free survival, overall survival, and safety.