Hepatobiliary Adverse Events Linked to Immune Checkpoint Inhibitors: A Real‐World Pharmacovigilance Analysis Using FAERS Data

Background Immune checkpoint inhibitors (ICIs) improve cancer outcomes but cause significant hepatobiliary toxicity (e.g., liver dysfunction, immune‐mediated liver disease). Prior studies were limited to small samples or case reports. This study evaluated hepatobiliary toxicity, risk variations, and temporal trends for six ICIs (PD‐1/PD‐L1 inhibitors) via the FDA Adverse Event Reporting System (FAERS) to guide safer use. Methods We analyzed 18 640 061 FAERS reports (2004–2024). Disproportionality analyses (ROR, PRR, EBGM, BCPNN) detected hepatobiliary toxicity signals. A Weibull model analyzed AE timing. Logistic regression assessed effects of age, gender, and weight. Results PD‐L1 inhibitors (Durvalumab, Atezolizumab) are associated more strongly with immune‐mediated liver disease/hepatic failure (ROR = 4.28–5.07). PD‐1 inhibitors (Nivolumab, Pembrolizumab) are linked more to hepatitis/liver abnormalities (ROR = 3.42–3.93). AE reports are common in males (53.32%) and patients > 65 years (43.43%), though demographics didn't alter risk ( p > 0.05). Median onset: 23 days (Toripalimab liver injury) vs. 84 days (Tislelizumab autoimmune hepatitis), supporting drug‐specific monitoring in the first three months. Conclusion Our FAERS analysis showed PD‐L1 inhibitors were more associated with immune‐mediated liver disease and hepatic failure, whereas PD‐1 inhibitors were linked to hepatitis and liver abnormalities, underscoring the need for drug‐specific monitoring.