⚠ ACTIVE FDA SAFETY REVIEW

Tavneos® Avacopan ADR & Pharmacovigilance
Report

C5a Receptor Antagonist · ANCA-Associated Vasculitis · Oral Selective Immunomodulator

0 Post-Marketing
DILI Cases
0 Fatal
Outcomes
0 Hospitaliz-
ations
0 Exposed
Patients (JP)
F C AVACOPAN C5aR ANTAGONIST VBDS VBDS — HISTOLOGICAL VIEW Right Lobe Left Lobe Portal Vein Bile Duct ⚠ Gallbladder Hepatic Vein Zone of Injury 5 cm PHARMACOVIGILANCE 2025–2026
Hepatic injury zone with VBDS histological magnification
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What is Tavneos?

Mechanism

Oral selective C5a receptor antagonist that blocks complement-mediated neutrophil activation — a key driver of ANCA-associated vasculitis.

Indications

Severe active ANCA-associated vasculitis (AAV) including Granulomatosis with Polyangiitis (GPA) and Microscopic Polyangiitis (MPA).

Combination Use

Used alongside rituximab or cyclophosphamide-based regimens as part of standard induction therapy for AAV.

2026 Status

Under active FDA & EMA safety review due to serious hepatotoxicity signals including fatal DILI and Vanishing Bile Duct Syndrome.

Severe Drug-Induced Liver Injury

The most important new pharmacovigilance signal identified in 2026 — serious hepatotoxicity with fatal outcomes.

FDA Drug Safety Communication — March 2026

The FDA identified 76 post-marketing cases of drug-induced liver injury (DILI), including 74 serious cases, 54 hospitalizations, and 8 deaths. Multiple cases of Vanishing Bile Duct Syndrome (VBDS) were reported.

76
Total DILI Cases
74
Serious Cases
54
Hospitalizations
8
Fatal Outcomes

Reported Hepatic ADRs

Elevated ALT / AST Moderate–Severe
Cholestatic Hepatitis Severe
Jaundice Moderate
Hyperbilirubinemia Moderate
Acute Liver Failure Severe
Vanishing Bile Duct Syndrome ⚠ Critical — New Signal

VBDS — The Major New Concern

Vanishing Bile Duct Syndrome

A rare but severe condition characterized by progressive destruction of intrahepatic bile ducts, leading to chronic cholestasis and irreversible liver damage.

Progressive bile duct destruction
Chronic cholestasis
Liver transplantation required
Death

Japan 2026 — Epicenter of Hepatic Fatalities

Japan reported the highest concentration of fatal hepatic cases, prompting temporary prescription restrictions.

🇯🇵
~20
Fatal Hepatic Cases
👥
~8,500
Exposed Patients
Temp.
Prescription Restriction
📋
Resumed
With Stronger Warnings

Possible Risk Factors Under Investigation

👴
Elderly Patients
Age-related hepatic vulnerability may increase susceptibility to DILI
Low Body Weight
Altered drug distribution and hepatic exposure in low-weight patients
🔬
CYP3A4 Interactions
Avacopan is a CYP3A4 substrate — inhibitors may elevate plasma levels
💊
Antifungals (Itraconazole)
Strong CYP3A4 inhibitors may significantly increase avacopan exposure
🧪
Vonoprazan (PPI)
Acid suppression drugs under investigation for potential interaction

2025 Real-World Safety Signals

A major FAERS pharmacovigilance analysis published in 2025 identified disproportionate reporting signals beyond clinical trial observations.

Disproportionate Reporting Signals Detected

Hepatotoxicity
High Signal
Sepsis
Significant
Hypertransaminasemia
High Signal
Alopecia
Moderate
Hearing Disorders / Deafness
Emerging
Serious Infections
Significant

Complete ADR Profile — Clinical & Post-Marketing

Adverse Drug Reaction Severity Source
NauseaMild–ModerateClinical Trial
HeadacheMildClinical Trial
HypertensionModerateClinical Trial
Elevated Liver EnzymesModerate–SevereBoth
RashMild–ModerateClinical Trial
FatigueMildClinical Trial
DiarrheaMildClinical Trial
AlopeciaMildPost-Marketing
Hearing DisordersModeratePost-Marketing
Serious Infections / SepsisSevereBoth
HepatitisSeverePost-Marketing
Vanishing Bile Duct Syndrome⚠ Potentially FatalPost-Marketing
Acute Liver Failure⚠ Potentially FatalPost-Marketing

Global Regulatory Response

🇺🇸 FDA
January 2026

Voluntary Withdrawal Request

The FDA reportedly requested voluntary withdrawal of Tavneos from the U.S. market citing safety concerns, liver toxicity, and questions regarding ADVOCATE trial data adjudication. Amgen declined and continues discussions with regulators.

Status: Active Discussions
🇺🇸 FDA
March 2026

Drug Safety Communication Issued

FDA issued a major Drug Safety Communication identifying 76 post-marketing DILI cases, 8 deaths, and multiple VBDS cases. Most reports originated from Japan.

Status: Communication Issued
🇪🇺 EMA
January 2026

Article-20 Safety Review Initiated

The European Medicines Agency initiated an Article-20 safety review of Tavneos due to serious liver injury reports, fatal hepatotoxicity cases, and reassessment of the benefit-risk balance.

Status: Review Ongoing
🇯🇵 Japan PMDA
2026

Temporary Prescription Restriction

Japanese regulators temporarily restricted new prescriptions following ~20 fatal hepatic cases among ~8,500 exposed patients. Use was later resumed with stronger warnings and mandatory liver monitoring.

Status: Resumed with Restrictions
Amgen Official Position

"Amgen declined the FDA's request for voluntary withdrawal and continues discussions with regulators regarding the benefit-risk profile of Tavneos in ANCA-associated vasculitis."

→ Amgen Official Statement (2026)

2026 Monitoring Recommendations

Patients receiving avacopan require intensive hepatic surveillance throughout treatment.

01

Baseline Assessment

  • Complete liver function tests (LFTs)
  • ALT, AST, ALP, GGT
  • Total & direct bilirubin
  • Drug interaction review
02

Ongoing Monitoring

  • Frequent ALT/AST monitoring
  • Bilirubin surveillance
  • Clinical signs: jaundice, pruritus
  • Symptom diary for patients
03

Drug Interaction Review

  • Avoid strong CYP3A4 inhibitors
  • Caution with itraconazole
  • Review acid suppression therapy
  • Reassess in elderly / low-weight

Discontinuation Triggers

  • ALT/AST > 3× ULN with symptoms
  • Any jaundice or dark urine
  • Bilirubin elevation
  • Signs of cholestasis

Overall 2026 Pharmacovigilance Assessment

Benefit in AAV Significant
Hepatic Safety Concern High
FDA Safety Concern Active
EMA Review Ongoing
Major New ADR Signal VBDS
Monitoring Requirement Intensive LFT Monitoring
Overall PV Status Under Close International Review

2025–2026 Publications & Reports