Objective:

To investigate whether co-reported vonoprazan is associated with increased cholangitis reporting among patients treated with immune checkpoint inhibitors (ICIs).

Approach:

• Study Design: A pharmacovigilance study using VigiBase, the WHO global individual case safety report database, to analyze reports from its inception through December 1, 2025.
• Data Extraction: Case-level dataset extraction from VigiBase, including all reports with suspected duplicates removed.
• Drug Exposure Definitions: Identification of ICIs, vonoprazan, PPIs, and H2RAs using WHO Standardised Drug Groupings and Drug Dictionary.
• Adverse Event Outcome Definitions: Coding of adverse events using MedDRA, with specific endpoints for liver injury and cholangitis-related events.

Key Findings:

• Emerging data suggest an association between vonoprazan and increased reporting of cholangitis in patients treated with ICIs.
• Cholangitis is characterized by a cholestatic pattern of liver injury and is often refractory to corticosteroid therapy.
• No prior pharmacovigilance study has specifically evaluated vonoprazan-associated cholangitis.

Interpretation:

The study aims to clarify the association between vonoprazan and cholangitis reporting in the context of ICI treatment, which has not been systematically examined before.

Limitations:

• The study relies on pharmacovigilance data, which may include reporting biases.
• The cholangitis-related endpoint is a reporting phenotype and not a clinically adjudicated diagnosis.

Conclusion:

This analysis highlights the need for further investigation into the hepatobiliary safety profile of vonoprazan in patients receiving ICIs.