A Real-World Disproportionality Analysis of Avacopan in Anti-Neutrophil Cytoplasmic Antibodies Associated Vasculitis: Insights From FDA Adverse Event Reporting System.

Avacopan, an oral C5a receptor antagonist approved for treating anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis, has established efficacy and short-term safety from clinical trials, but its post-marketing adverse events (AEs) in real-world settings require further characterization. We conducted a retrospective analysis of the U.S. FDA Adverse Event Reporting System (FAERS) database from Q1 2022 to Q1 2025. After data cleaning, Avacopan-related AEs were extracted, coded using MedDRA terminology, and analyzed via four signal detection methods; subgroup analyses by age, sex, and reporter type were performed. Among 3529 reports, significant disproportionality signals emerged for known AEs (e.g., hepatobiliary disorders, serious infections) and unexpected signals including venous thromboembolism, cholestatic jaundice, and alopecia. Most AEs occurred within the first 30 days of treatment, with variations observed by age and sex. This study provides the first FAERS-based pharmacovigilance assessment of Avacopan, confirming known risks and identifying novel post-approval safety signals, underscoring the need for close early-treatment monitoring and personalized strategies. Further research is warranted to confirm emerging signals and explore their mechanisms.