FDA Identifies Cases of Serious Liver Injury in Patients Taking Tavneos (Avacopan) for Severe Active Anti-Neutrophil Cytoplasmic Autoantibody (ANCA)-Associated Vasculitis

Why It Matters

The alert highlights a previously under‑recognized hepatotoxic risk that could reshape prescribing practices and compel clinicians to adopt stricter safety monitoring for a drug increasingly used in rare vasculitis treatment.

Key Takeaways

• FDA reports 76 avacopan liver injury cases, 8 deaths.
• Median onset 46 days; monitoring needed early in treatment.
• Vanishing bile duct syndrome observed, 7 cases, 3 fatalities.
• Liver tests recommended biweekly then monthly for first six months.
• Most reports from Japan; possible regional reporting bias.

Pulse Analysis

Tavneos, approved in 2021 for severe ANCA‑associated vasculitis, quickly became a cornerstone therapy because it reduces reliance on high‑dose glucocorticoids. While clinical trials flagged mild hepatotoxicity, the recent FDA safety communication reveals a far more serious post‑marketing signal. Seventy‑six cases of drug‑induced liver injury (DILI) have been identified, with a striking 54 hospitalizations and eight deaths, underscoring that real‑world exposure can uncover rare but lethal adverse events that trials may miss.

The FDA’s analysis shows a median onset of liver injury at 46 days, emphasizing the need for vigilant early monitoring. Laboratory patterns were predominantly cholestatic or mixed, and seven patients suffered vanishing bile duct syndrome (VBDS), a progressive loss of bile ducts that can culminate in irreversible liver failure. Geographic clustering—66 cases from Japan—suggests either heightened reporting practices or potential pharmacogenomic factors, prompting regulators and clinicians to scrutinize regional data while remaining alert to similar risks elsewhere.

In response, the agency recommends a structured liver‑function testing schedule: biweekly panels during the first month, monthly through month six, and thereafter as clinically indicated. Prompt discontinuation of avacopan is advised when ALT or AST exceed three times the upper limit of normal, or when alkaline phosphatase surpasses two times the limit, especially if patients exhibit jaundice or pruritus. These measures aim to mitigate severe outcomes while preserving Tavneos’s therapeutic benefits. As the market watches, manufacturers may need to update labeling, and physicians might consider alternative agents or combination strategies to balance efficacy against emerging safety concerns.