Possible Legal Compensation Cases for People Who Developed Tavneos Liver Injury

(Posted by Tom Lamb at Drug Injury Watch)

We had been reporting on Tavneos liver risks earlier this year, as seen below:

Tavneos Warnings For VBDS Liver Side Effect Increased In April 2026 (May 1, 2026)

Tavneos Lawsuits for Drug Injury After Possible Tavneos Recall (April 17, 2026)

Tavneos Liver Injury Drug Safety Communication Issued by FDA in Late March 2026 (March 31, 2026)

The FDA approved Tavneos (avacopan) in 2021 to treat anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV).

In this article, we highlight a Brief Report published on August 24, 2026, in the medical journal Arthritis & Rheumatology, “Hepatotoxicity of Avacopan: Real-World Incidence and Confirmed Cases of Severe Drug-Induced Liver Injury in a US National Rheumatology Registry“.

From this August 2026 medical journal article about liver risks associated with Tavneos (avacopan), we get the following excerpts:

• Objective: Avacopan, an oral C5a receptor inhibitor, was approved for antineutrophil cytoplasmic antibody–associated vasculitis (AAV) in 2021. Following US Food and Drug Administration (FDA) reports of 76 worldwide drug-induced liver injury (DILI) cases (66 in Japan and five in the United States), the agency requested market withdrawal, which the manufacturer declined. US risk has not been quantified using real-world data. This study estimated the incidence of hepatic enzyme elevations among US avacopan users and characterized confirmed DILI cases.
• Results: Among 238 patients with AAV treated with avacopan, liver enzyme elevations during treatment were uncommon: five patients had elevated AST, three ALT, four Alk Phos, and two total bilirubin, with incidence rates of 4.24 (95% confidence interval [CI] 1.77–10.19), 2.67 (95% CI 0.86–8.27), 3.56 (95% CI 1.34–9.49), and 1.80 (95% CI 0.45–7.19) per 100 person-years, respectively. Median time to first hepatic enzyme screening was 32 days, with testing intervals averaging 125 days. Two DILI cases (0.8%) were identified, both with RUCAM scores of 9 (highly probable causality), including one with histologically confirmed severe hepatocellular injury.

Some commentary and contextual information concerning the Tavneos liver risk findings of that recent Arthritis & Rheumatology medical journal report on Tavneos liver risks comes from this August 24, 2026, MedPage Today article, “U.S. Registry Data Confirm Liver Risk With Controversial Vasculitis Drug“:

The new report is likely to bolster concerns about hepatotoxicity, insofar as it involves patients receiving the drug in routine practice, based on relatively systematic data collected in the American College of Rheumatology’s RISE registry. More than 1,000 U.S. rheumatology practices contribute to RISE — about 25% of the total — covering an estimated 3.5 million patients. Roberts and colleagues searched RISE for patients with at least one recorded prescription for [Tavneos (avacopan)] from October 2021 to March 2025, along with an [autoantibody (ANCA)-associated vasculitis (AAV)] diagnosis as indicated by ICD-9/10 codes, coming up with 238.

Liver enzyme elevations were identified mostly using the FDA’s standard definitions: three times the upper limit of normal for aspartate and alanine aminotransferase and twice the upper limit of normal for alkaline phosphatase. The FDA also considers elevations in bilirubin as an important marker, but has not specified a threshold; therefore, the study authors defined it as >2 mg/dL, which is twice the upper limit of normal at most clinical labs, they said.

Patients having at least two enzymes elevated were then evaluated for [drug-induced liver injury (DILI)], which involved contacting their treating clinicians to obtain more detailed information….

Now, with new evidence based on well-established medical registry data confirming Tavneos liver risks, we continue to investigate possible legal compensation cases for people who developed Tavneos drug-induced liver injury (DILI) and Tavneos-related vanishing bile duct syndrome (VBDS).

These Tavneos lawsuits would be filed against Amgen, as the responsible drug company, alleging that it failed to warn about these Tavneos liver risks.

If you developed a Tavneos liver injury and want your case reviewed as a potential lawsuit against Amgen, you can submit a Drug Injury Case Evaluation Form online. Or, instead, you can contact drug injury lawyer Tom Lamb at TJL@LambLawOffice.com or 910-256-2971.

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