Avacopan (Tavneos) Fatal Liver Damage Lawsuit Lawyers

Patients Diagnosed With Drug-Induced Liver Injury After Taking Avacopan May Have Grounds to File a Lawsuit

What Parker Waichman LLP Found

• The FDA linked Avacopan to 76 serious liver injury cases with evidence suggesting a causal connection.
• Eight deaths were reported, including fatal cases involving vanishing bile duct syndrome.
• The FDA asked that Tavneos be withdrawn from the market, but the manufacturer declined.
• Many reported injuries involved hospitalization, severe cholestatic liver damage, or mixed liver injury patterns.
• Patients who developed liver problems after taking Tavneos may have grounds to file a product liability lawsuit.

The U.S. Food and Drug Administration has issued a serious safety warning for Avacopan (Tavneos) following post-marketing reports of drug-induced liver injury. Unlike routine label updates, the FDA has requested the drug’s removal from the market. This development significantly impacts patients, healthcare providers, and families assessing the risks of this treatment.

Tavneos was approved in 2021 as an adjunctive treatment for adults with severe ANCA-associated vasculitis, including granulomatosis with polyangiitis and microscopic polyangiitis. These life-threatening autoimmune conditions require potent medications to control inflammation and prevent organ damage, making drug safety critical. When a treatment for severe disease is linked to fatal liver injuries, the legal and medical consequences can be significant.

According to the FDA, global post-marketing data reviewed through October 9, 2024, identified 76 cases of drug-induced liver injury with enough evidence to suggest a causal connection to Avacopan. Of those cases, 54 required hospitalization. Eight deaths were reported. Seven cases involved biopsy-confirmed vanishing bile duct syndrome, a rare but devastating condition that can cause lasting liver damage as bile ducts are progressively destroyed. The FDA has said these fatal outcomes and VBDS reports represent new safety concerns beyond what was already known about hepatotoxicity during clinical development.

This warning raises urgent questions for affected patients. When did the manufacturer know, or when should it have known, about these severe liver complications? Were physicians and patients adequately informed? Did the drug’s warnings accurately reflect the seriousness of the risk? These issues are central to potential product liability litigation.

What Is Tavneos and Why Was It Prescribed?

Tavneos, or Avacopan, is a complement 5a receptor inhibitor used as part of the treatment for severe ANCA-associated vasculitis. It was approved to be used along with standard therapy, including glucocorticoids and other medications. The drug entered the market as a newer treatment option for a difficult autoimmune disease population. Patients with ANCA vasculitis often face major health challenges involving the kidneys, lungs, nerves, and other organs, so a medication that promised disease control without some of the burdens associated with long-term steroid use understandably drew attention.

The approval was based largely on the phase III ADVOCATE trial. In that study, remission at week 26 was seen in 72.3% of patients in the Avacopan group and 70.1% of patients in the prednisone taper group, meeting noninferiority criteria. Sustained remission at week 52 was seen in 65.7% of the Avacopan group compared to 54.9% in the prednisone group, which was statistically significant. Those numbers helped support approval, but the later safety reports changed the picture.

A drug may show treatment value in a clinical setting and still present dangers that only become clearer after wider public use. That is why post-marketing surveillance matters. Once a drug is prescribed across a larger and more medically diverse population, harmful patterns can emerge that were not fully understood during preapproval trials. The FDA’s current stance suggests that the growing reports of severe liver injury may have altered the agency’s view of whether the drug’s benefits continue to outweigh its risks.

For patients and families, this distinction matters. A drug does not need to be useless to become the subject of litigation. If a medicine carries a serious danger that was not adequately disclosed, not adequately investigated, or not properly acted upon once warning signs appeared, injured consumers may have the right to pursue compensation.

The Liver Injuries Reported by the FDA

The injuries described by the FDA are not limited to mild changes in liver tests. They include severe, life-threatening outcomes and fatalities. Drug-induced liver injury can range from reversible lab abnormalities to permanent organ damage, liver failure, the need for transplant, or death. What makes the Tavneos warning especially concerning is the severity of the reported cases and the presence of vanishing bile duct syndrome.

VBDS is a rare condition involving progressive destruction and disappearance of bile ducts within the liver. Without functioning bile ducts, bile cannot move properly through the liver and digestive system. This can lead to cholestatic injury, worsening jaundice, extreme itching, fatigue, poor absorption, progressive liver dysfunction, and permanent damage. In some cases, the injury may continue even after the drug is stopped.

The FDA noted that among the 76 DILI cases with evidence suggesting a causal link, seven were biopsy-confirmed VBDS cases, and all required hospitalization. The median time to onset of liver injury was 46 days, with a range of 22 to 140 days. That timeline is important because it may help patients and lawyers evaluate whether an injury occurring within weeks or months of starting Avacopan could be connected to the medication.

The reported injury patterns were also significant. Thirty-eight of the DILI cases showed cholestatic or mixed injury patterns, often with major elevations in alkaline phosphatase and total bilirubin. In the VBDS cases, some patients had cholestatic or mixed patterns, and others had hepatocellular injury. These are not trivial findings. They point to serious physiological damage and create a clearer factual basis for claims that the medication may trigger substantial liver toxicity.

Patients who developed jaundice, dark urine, pale stools, itching, upper abdominal pain, nausea, unusual fatigue, or abnormal liver testing after taking Tavneos may want to examine whether the drug contributed to the injury. In litigation, hospital records, liver panels, pathology results, and medication timelines often become central pieces of evidence.

Why the FDA Wants the Drug Pulled From the Market

In January, the FDA asked that Avacopan be voluntarily withdrawn from the market. That request appears to have been driven by concerns not only about postmarketing liver injury reports but also about the clinical trial data underlying the drug’s approval. A request for market withdrawal is a serious escalation. It signals that the agency may believe stronger action is needed than continued monitoring alone.

Amgen declined the FDA’s request and has publicly stated that it does not intend to pull the drug from the market. The company has said patient safety comes first and that it remains in communication with the FDA. It also stated that it proposed adding VBDS to the drug’s labeling in 2024 based on cases reported outside the United States, and that request remains pending. Amgen has maintained that Tavneos remains an important treatment with a favorable benefit-risk profile.

That disagreement between the FDA and the manufacturer may become important in future lawsuits. When a federal regulator expresses concern serious enough to seek removal of a drug, plaintiffs may argue that the manufacturer should have acted more aggressively to protect patients. Cases may focus on whether label warnings were timely and strong enough, whether additional physician communications should have been issued sooner, and whether the manufacturer gave enough weight to post-marketing injury signals.

These lawsuits may also examine whether the drug should have carried stronger warnings about severe liver injury and whether monitoring recommendations alone are enough to prevent irreversible harm. Public criticism has already emerged on that point, including questions about why the prescribing information does not contain a boxed warning for fatal liver disease.

Signs, Symptoms, and Medical Consequences of Tavneos Liver Injury

One of the most important parts of this issue is understanding how liver injury may present. Some patients first notice symptoms that seem vague or easy to dismiss. Others experience rapidly worsening illness. Common warning signs associated with serious liver injury can include jaundice, fatigue, itching, abdominal pain, nausea, vomiting, loss of appetite, dark urine, pale stools, swelling, or confusion in severe cases. Bloodwork may show elevations in ALT, AST, alkaline phosphatase, bilirubin, or other markers suggesting liver damage.

The FDA has advised physicians treating patients with Avacopan to conduct regular liver panel testing and discontinue the drug if patients develop symptomatic cholestasis or significant enzyme elevations. The agency stated that treatment should be stopped if ALT or AST rise to more than three times the upper limit of normal or if alkaline phosphatase rises above two times the upper limit of normal. If abnormalities or symptoms do not improve, the FDA advises referral to a hepatologist.

That advice may help some patients, but it does not erase the harm already reported. Once severe cholestatic injury or VBDS begins, the outcome may be difficult to reverse. Some patients may require prolonged hospitalization, invasive testing, multiple specialist consultations, long-term medication, transplant evaluation, or permanent lifestyle changes. For families dealing with fatal outcomes, the losses are even more severe.

In civil litigation, damages may include emergency care costs, hospitalization, follow-up treatment, lost wages, diminished earning capacity, pain and suffering, disability, and wrongful death damages where permitted by law. The seriousness of the reported injuries means these are not minor claims. They may involve major financial and personal losses.

Legal Claims Patients May Be Able to Pursue

Patients injured by Tavneos may have several possible legal theories depending on the facts of the case and the law of the state where the claim is filed. One common claim is failure to warn. In these cases, plaintiffs may argue that the manufacturer did not provide adequate warnings about the true nature, severity, or likelihood of severe liver injury, fatal DILI, or VBDS.

Another possible claim is defective design, though these claims are often more complex in pharmaceutical litigation. Plaintiffs may also allege negligent pharmacovigilance, negligent post-marketing surveillance, or negligent failure to update labeling once serious reports accumulated. Some cases may focus on whether the manufacturer moved quickly enough after learning of severe adverse events and whether stronger warnings should have been issued earlier to doctors, pharmacies, hospitals, and patients.

A successful lawsuit generally requires proof that the patient took Tavneos, developed liver injury, and that the drug was a substantial factor in causing that harm. Evidence may include pharmacy records, treatment notes, liver biopsy results, lab results, hospital records, timing of symptom onset, and physician testimony. In some matters, internal company records and regulatory communications may also become important during discovery.

The fact that the FDA wants the drug withdrawn could play an important role in litigation. While every case still depends on proof, regulatory action of this kind often strengthens public attention on whether the product carries unreasonable risks or insufficient warnings.

Lawsuit FAQs

Who may qualify for a Tavneos lawsuit?

A person may have a claim if that individual took Tavneos or Avacopan and later developed drug-induced liver injury, vanishing bile duct syndrome, liver failure, or other serious liver complications. A family may also have a wrongful death claim if a loved one died after suffering a liver injury that may be tied to the drug.

What evidence is helpful in a case involving liver injury from Tavneos?

Useful evidence often includes pharmacy records, prescription history, hospital records, liver function testing, pathology reports, biopsy results, imaging studies, and notes from treating physicians. A timeline showing when the medication started and when symptoms appeared can be especially important.

Does the FDA warning mean every injured patient automatically wins a case?

No. The FDA warning is important, but each claim still must be supported by medical proof and evidence connecting the injury to the drug. The warning can strengthen a case, especially where the medical records match the kinds of injuries described by the FDA.

What if the patient already had other health problems?

Many patients taking medications already have serious medical conditions. That does not prevent a claim. The key question is whether Tavneos caused or substantially contributed to the liver injury. Lawyers often work with medical records and treating physicians’ opinions to evaluate causation.

Can a case be filed if the drug is still on the market?

Yes. A drug does not have to be formally removed from the market before a lawsuit can be filed. Claims can be brought when a patient suffers harm that may have been caused by a dangerous drug, especially where serious safety concerns have already been raised.

What compensation may be available?

Compensation can include medical bills, future treatment costs, lost income, pain and suffering, permanent disability, and other losses. In fatal cases, a wrongful death action may seek damages tied to the loss suffered by surviving family members.

Contact Parker Waichman LLP For a Free Case Review

Patients and families dealing with liver injury after use of Tavneos may have important legal rights. Parker Waichman LLP is reviewing claims involving Avacopan, drug-induced liver injury, vanishing bile duct syndrome, liver failure, and fatal outcomes. The firm offers free consultations for individuals who believe this medication caused serious harm.

Call 1-800-YOUR-LAWYER (1-800-968-7529) for a free case evaluation. Regardless of your location or where your injury occurred, our nationwide product injury law firm is ready to assist you.