Comparative safety profiles of atezolizumab-bevacizumab vs tyrosine kinase inhibitors in advanced hepatocellular carcinoma: A FAERS-based study.

568 Background: Atezolizumab–bevacizumab (Atezo-Bev) has replaced tyrosine kinase inhibitors (TKIs) as the preferred first-line therapy for advanced HCC, but underlying cirrhosis or uncontrolled portal hypertension (PHTN) raise concerns for complications. Clinical trials underrepresent these high-risk patients, and comparative real-world safety data between these regimens remain limited. Post-marketing pharmacovigilance is needed to guide safer treatment selection. Methods: We conducted a retrospective study using Federal Adverse Event Reporting System (FAERS) data from Q1 2020 to Q1 2025. Reports involving Atezo-Bev and TKIs (sorafenib, lenvatinib, cabozantinib, regorafenib) were identified by drug name string-matching in patients with HCC and aggregated at the patient level. Events studied included variceal bleed, ascites, hepatic encephalopathy (HE), spontaneous bacterial peritonitis (SBP), PHTN, upper gastrointestinal bleed (UGIB), splanchnic thrombosis (SVT), portal vein thrombosis (PVT), neutropenia, hepatotoxicity, colitis, pneumonitis, hypothyroidism, immune-related adverse events (irAEs), and outcomes (death, hospitalization). Disproportionality was assessed using proportional reporting ratios (PRR) and reporting odds ratios (ROR) with 95% confidence intervals (CI) for Atezo-Bev compared to TKIs, with TKIs serving as the reference group. Statistical significance was set at p