Tavneos Lawsuit 2026: FDA Moves to Ban the Drug After 8 Deaths — Are You Eligible to Sue?

Overview: Why Tavneos Is Now at the Center of a Major Legal Storm

Tavneos (avacopan), once heralded as a breakthrough treatment for a rare and devastating autoimmune disease, is now at the epicenter of one of the most alarming pharmaceutical controversies of 2026. The U.S. Food and Drug Administration (FDA) has formally proposed to withdraw the drug's approval from the U.S. market, citing serious postmarketing liver injuries resulting in deaths and stunning allegations that the clinical trial data used to secure the drug's approval was manipulated [10]. Meanwhile, law firms across the country are aggressively investigating potential product liability and wrongful death lawsuits on behalf of patients who suffered life-altering or fatal complications after taking Tavneos [6].

If you or a loved one took Tavneos and suffered liver injury, liver failure, vanishing bile duct syndrome, or death, you may have a viable legal claim — and the window to act is opening right now. This article breaks down everything you need to know: what the FDA found, what the science shows, what the drug maker knew, and what your legal options are.

What Is Tavneos and Who Takes It?

Tavneos (avacopan), developed by ChemoCentryx and later acquired by Amgen in October 2022, is indicated as an adjunctive treatment for adults with severe active anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) — specifically granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) [28]. These are rare, life-threatening diseases that cause inflammation of blood vessels, often leading to severe organ damage. The drug received FDA approval on October 7, 2021, following results from the pivotal Phase III ADVOCATE clinical study [10].

Since its approval, more than 8,000 patients have been treated with Tavneos in the United States, and approximately 20,000 patients currently rely on it as an important treatment option [32]. Given the severity of the underlying disease and the lack of alternatives for many patients, the ongoing regulatory crisis surrounding Tavneos has created a deeply complex — and dangerous — situation for thousands of Americans [17].

The FDA's Bombshell: Proposed Withdrawal, Data Fraud Allegations, and a Safety Crisis

The FDA Formally Moves to Pull Tavneos from the Market

On April 30, 2026, the FDA published a notice in the Federal Register formally proposing to withdraw approval of Tavneos and offering Amgen an opportunity for a hearing [12]. This came after the FDA had already taken the extraordinary step of formally requesting in January 2026 that Amgen voluntarily withdraw the drug from the U.S. market — a request Amgen refused [19]. The FDA's proposal to withdraw is based on two separate but equally alarming grounds: serious safety concerns about liver toxicity and allegations that the original clinical trial data was manipulated to fraudulently obtain FDA approval [13].

Alleged Clinical Trial Data Manipulation: A Scandal at the Core

Perhaps most damning is the FDA's conclusion that unblinded study personnel from ChemoCentryx manipulated the results of the pivotal Phase III ADVOCATE study — the very study that convinced the FDA to approve Tavneos in the first place [15]. The FDA asserts that a statistical analysis conducted after database lock found that the avacopan treatment group did not actually achieve statistically significant superiority on the primary endpoint of sustained remission [14]. Yet this unfavorable original analysis was allegedly never disclosed to the FDA in ChemoCentryx's new drug application, a potential violation of federal regulations [12].

The FDA further stated that the application for approval contained "untrue statements of material fact," and that the manipulation was designed to make the drug appear effective when the original analysis did not support that conclusion [13]. This is an extraordinarily rare and serious accusation in the world of pharmaceutical regulation. The FDA's investigation was reportedly triggered in part by the "Walton Report" — an expert analysis by Marc Walton, M.D., Ph.D., filed in a related securities fraud lawsuit in May 2025 [11].

The FDA's March 2026 Drug Safety Communication

On March 31, 2026, the FDA issued a formal Drug Safety Communication, alerting patients and healthcare professionals about serious postmarketing cases of drug-induced liver injury (DILI), some fatal, associated with Tavneos [13]. This public safety alert was a critical warning sign that the drug's postmarketing safety profile was far worse than what had been disclosed during premarket clinical trials.

The Death Toll: 76 Liver Injury Cases, 8 Deaths, and a Rare Fatal Syndrome

The FDA's Postmarketing Safety Data

The numbers are staggering. The FDA identified 76 postmarketing cases of drug-induced liver injury (DILI) with "reasonable evidence of a causal association" with Tavneos use, reported through October 9, 2024 [10]. Of these 76 cases, 74 resulted in serious outcomes [10]. Specifically:

• 54 hospitalizations were recorded among the 76 DILI cases [10].

• 8 deaths were attributed to Tavneos-associated liver injury [10].

• 7 cases of vanishing bile duct syndrome (VBDS) were identified, of which 3 were fatal [10].

The FDA emphasized that while liver toxicity was a known risk identified in premarket clinical trials and listed on the drug's label, vanishing bile duct syndrome (VBDS) and DILI cases with fatal outcomes are considered new safety concerns [13]. In other words, patients and physicians were not adequately warned about the true severity of the liver risks they were taking.

What Is Vanishing Bile Duct Syndrome (VBDS)?

Vanishing bile duct syndrome is a rare and devastating form of liver damage characterized by the progressive destruction and disappearance of bile ducts within the liver [27]. Once bile ducts are destroyed, they cannot regenerate. VBDS can lead to permanent liver damage, liver failure, and death [36]. The FDA identified 7 biopsy-confirmed VBDS cases among Tavneos patients, with 3 resulting in death [10]. The median time from Tavneos initiation to DILI onset across identified VBDS cases was just 46 days — with a range of only 33 to 59 days — meaning patients can develop life-threatening liver injury alarmingly quickly after starting the drug [13].

The Japan Data: 20 Fatal Liver Injury Cases

The safety crisis extends well beyond U.S. borders. In Japan, where Kissei Pharmaceutical holds the license for Tavneos, out of over 8,500 patients treated with the drug, there were 20 fatal cases of serious liver injury, though a direct causal relationship could not be determined for all cases [1]. Following these alarming findings, Kissei temporarily paused new prescriptions for the drug before resuming them on May 21, 2026, with significantly updated safety precautions and prescribing information that included explicit warnings on serious liver injury and mandatory monitoring requirements [26]. Amgen has attributed the higher incidence of fatal liver injuries in Japan to less aggressive monitoring practices in that country [32].

Symptoms of Tavneos Liver Injury: What Patients and Families Should Know

Given the rapid onset of serious liver injury in some patients — sometimes within weeks of starting Tavneos — it is critical that patients and their loved ones recognize the warning signs of drug-induced liver injury (DILI) and vanishing bile duct syndrome [13]. Key symptoms include [18]:

• Yellowing of the skin or eyes (jaundice)

• Itchy skin

• Pain in the upper right side of the abdomen

• Extreme fatigue or weakness

• Dark or brown (tea-colored) urine

• Unusual bleeding or bruising

• Loss of appetite

• Nausea and vomiting

Beyond liver injury, other serious side effects reported with Tavneos include serious allergic reactions (such as angioedema), Hepatitis B virus (HBV) reactivation, and serious infections including pneumonia and urinary tract infections [29]. If you or a loved one experienced any of these symptoms after taking Tavneos, seek medical attention immediately and consult a qualified attorney about your legal rights.

Amgen's Response: Denial, Refusal, and a Pending Hearing

Amgen has consistently and forcefully pushed back against the FDA's findings. The company explicitly disagrees with the FDA's assessment of both the drug's effectiveness and the alleged data manipulation in the ADVOCATE study [32]. In a June 12, 2026 update, Amgen reiterated its confidence in Tavneos as an "important and effective medicine" for severe active ANCA-associated vasculitis, citing an evidence base of "at least 23 published real-world studies globally involving more than 1,200 reported patients" [2].

On June 14, 2026, Amgen formally requested a hearing with the FDA to challenge the agency's proposal to withdraw marketing authorization [3]. The company committed to providing comprehensive data and diagnostic evaluations to the FDA by June 29, 2026, to address the agency's concerns [33]. The public comment period for the FDA's proposal to withdraw approval also closes on June 29, 2026 [12].

Critically, despite the FDA's repeated warnings and the proposed market withdrawal, Amgen has not issued a voluntary recall of Tavneos [20]. This means the drug remains on the U.S. market while the regulatory process plays out — a situation that legal experts say significantly expands the potential universe of harmed patients and the scope of future litigation.

Notably, on May 29, 2026, Amgen did update the U.S. prescribing information for Tavneos to include additional safety language regarding the risk of vanishing bile duct syndrome and updated guidelines for liver panel monitoring and discontinuation [4]. Critics argue this update was too little, too late — patients had already been harmed for years without adequate warning [21].

The Legal Landscape: Is Tavneos the Next Mass Tort?

Current Litigation Status

As of June 25, 2026, no formal Multi-District Litigation (MDL) or certified class action has been announced for Tavneos drug injury claims [6]. However, the absence of a formal MDL designation does not mean the litigation landscape is quiet — far from it. Numerous law firms across the United States are actively and aggressively investigating potential product liability and wrongful death lawsuits on behalf of patients who suffered serious liver complications, including DILI, VBDS, liver failure, and death after taking Tavneos [23][24].

The pattern here is unmistakable and well-known to mass tort attorneys: a dangerous drug remains on the market, injuries mount, regulators act, investigations begin, and ultimately, formal consolidated litigation follows. Tavneos is currently in the investigation and early filing phase — the exact stage at which injured patients can often secure the best legal representation and position themselves most favorably for potential compensation [25].

The Securities Fraud Lawsuit: A Key Legal Precedent

Separate from the drug injury claims, a securities fraud lawsuit was filed against ChemoCentryx in May 2021, alleging the company misled investors about the safety, efficacy, and FDA application status of Tavneos [5]. In August 2025, a U.S. District Judge in California granted summary judgment in favor of ChemoCentryx (now Amgen), with the rationale for the decision remaining under seal [5]. While this outcome favored the defendant in the securities context, the underlying allegations — particularly those concerning data manipulation and concealed safety information — are directly relevant to the drug injury lawsuits being investigated today [11].

The Walton Report, filed in that securities litigation in May 2025, was the expert analysis that first alleged statistical manipulation of the ADVOCATE study data [11]. The FDA subsequently launched its own investigation based in part on that report, and ultimately confirmed the data manipulation allegations [15]. This progression — from private litigation to FDA regulatory action — is a powerful evidentiary chain that plaintiff attorneys in the drug injury cases will almost certainly leverage.

Potential Legal Theories in Tavneos Lawsuits

Based on the publicly available evidence, potential Tavneos lawsuits are likely to pursue multiple legal theories [21][23]:

• Failure to Warn: Plaintiffs will argue that Amgen and ChemoCentryx failed to adequately warn patients and physicians about the true risk of DILI, VBDS, and fatal liver injury — particularly given the new evidence that VBDS and fatal DILI were not adequately disclosed as risks until 2026 [13].

• Defective Design: Plaintiffs may argue the drug's benefit-risk profile, properly understood, renders it unreasonably dangerous for consumer use [10].

• Fraud and Misrepresentation: The FDA's findings that the ADVOCATE study data was manipulated and that the original NDA contained "untrue statements of material fact" could support fraud-based claims [12].

• Negligence: Claims that ChemoCentryx and Amgen failed to exercise reasonable care in designing, testing, manufacturing, and marketing Tavneos [22].

• Wrongful Death: For families of the 8 patients who died from Tavneos-associated liver injury, wrongful death claims are a primary avenue for seeking justice [6].

Why This Could Become a Major Mass Tort: The Hallmarks Are All There

Legal experts tracking pharmaceutical litigation identify several key factors that typically propel a drug injury situation into full-scale mass tort litigation. Tavneos checks virtually every box [8][9]:

1. A Large Exposed Population: Over 8,000 patients treated in the U.S. since 2021, with approximately 20,000 currently relying on the drug [32].

2. Serious, Documented Injuries: 76 DILI cases with 54 hospitalizations, 8 deaths, and 7 VBDS cases — all with "reasonable evidence" of causal association according to the FDA [10].

3. FDA Regulatory Action: A proposed market withdrawal is one of the strongest signals the litigation community watches for [12].

4. Allegations of Corporate Misconduct: The data manipulation allegations go beyond ordinary failure-to-warn claims and could support punitive damages [15].

5. Multiple Active Law Firm Investigations: When multiple plaintiff firms simultaneously launch investigations, formal litigation — and often MDL consolidation — typically follows [6][21][22][23].

6. Inadequate Label Warnings: The FDA's own findings confirm that VBDS and fatal DILI were not recognized as risks until postmarketing surveillance, and the label was not updated to include VBDS language until May 29, 2026 — years after patients began suffering [4][13].

Key Timeline: How We Got Here

Understanding the full timeline of the Tavneos controversy is essential for evaluating both the legal and regulatory landscape [10][12][13][19][20][26][32]:

• October 7, 2021: FDA approves Tavneos (avacopan) based on the Phase III ADVOCATE study [10].

• October 2022: Amgen acquires ChemoCentryx, inheriting all Tavneos-related liabilities [4].

• May 2021: Securities fraud lawsuit filed against ChemoCentryx alleging investor deception about Tavneos safety and efficacy [5].

• May 2025: The Walton Report filed in securities litigation, alleging ADVOCATE study data manipulation [11].

• August 2025: U.S. District Court in California grants summary judgment for ChemoCentryx in the securities fraud case [5].

• January 2026: FDA formally requests Amgen voluntarily withdraw Tavneos; Amgen refuses [19].

• March 31, 2026: FDA issues Drug Safety Communication warning about fatal DILI cases [13].

• April 30, 2026: FDA publishes formal notice in Federal Register proposing market withdrawal of Tavneos [12].

• May 21, 2026: Japan's Kissei Pharmaceutical resumes prescriptions with updated safety warnings after a brief pause [26].

• May 29, 2026: Amgen updates U.S. prescribing information to add VBDS warning and enhanced liver monitoring guidelines [4].

• June 12, 2026: Amgen issues public update reaffirming confidence in Tavneos; the Vasculitis Foundation urges patients not to stop treatment without consulting their doctors [37].

• June 14, 2026: Amgen formally requests FDA hearing to challenge proposed withdrawal [3].

• June 29, 2026: Deadline for Amgen to submit data to FDA; public comment period closes [12][32].

What About Patients Who Still Need Tavneos?

The Vasculitis Foundation, the primary patient advocacy organization for ANCA-associated vasculitis, issued a statement acknowledging the ongoing regulatory discussions and strongly advising patients not to discontinue Tavneos treatment without first consulting their healthcare provider [37]. This is critical advice: for patients with severe GPA or MPA, stopping treatment abruptly could trigger life-threatening disease flares. The legal crisis surrounding Tavneos does not mean all patients should immediately stop the drug — it means patients deserve full, honest information about the risks, and those who have been harmed deserve justice [17].

Patients currently taking Tavneos should work closely with their physicians to monitor liver function, understand the warning signs of DILI and VBDS, and discuss alternative treatment options if appropriate [18]. The FDA's updated guidance calls for enhanced liver panel monitoring and clear discontinuation rules if liver injury is suspected [4].

Who May Qualify for a Tavneos Lawsuit?

Law firms investigating Tavneos injury claims are currently evaluating potential plaintiffs who meet specific criteria [6][21][22][23][24][25]. You may have a viable legal claim if you or a loved one:

• Took Tavneos (avacopan) at any point after its FDA approval in October 2021

• Were diagnosed with drug-induced liver injury (DILI) while taking or after taking Tavneos

• Were diagnosed with vanishing bile duct syndrome (VBDS)

• Suffered liver failure requiring hospitalization

• Required a liver transplant

• Lost a family member to Tavneos-related liver injury or liver failure

Even if you are still currently taking Tavneos and have not yet experienced liver complications, it may be worth consulting with an attorney to understand your rights, particularly given the FDA's ongoing proposed market withdrawal [25].

No Settlements Yet — But That Can Change Quickly

As of June 25, 2026, no settlements or jury verdicts have been announced in Tavneos drug injury lawsuits [6]. This is not unusual — litigation of this nature typically begins with an investigation phase, followed by individual lawsuit filings, potential consolidation into an MDL, discovery, and then either settlements or trials. The absence of settlements today simply reflects how early in the process this litigation is [21].

History shows that pharmaceutical mass torts involving documented deaths, regulatory action, and allegations of corporate fraud often result in significant compensation for injured patients and their families [8][9]. The facts surrounding Tavneos — particularly the FDA's data manipulation findings and the documented death toll — create a factual predicate that plaintiff attorneys find highly compelling.

What to Do If You Were Harmed by Tavneos

If you believe you or a loved one suffered serious harm from Tavneos, here are the immediate steps legal experts recommend [25][23]:

1. Seek medical attention if you have not already done so and are experiencing any symptoms of liver injury.

2. Preserve medical records documenting your Tavneos prescription, dosing history, and any liver-related diagnoses or hospitalizations.

3. Do not discard medication packaging or any pharmacy records related to Tavneos.

4. Consult a qualified mass tort attorney who specializes in pharmaceutical injury cases. Most offer free, confidential consultations with no upfront fees.

5. Act promptly, as statutes of limitations — the legal deadlines for filing lawsuits — vary by state and can be as short as two years from the date of injury or discovery of harm.

Conclusion: The Legal Storm Around Tavneos Is Just Beginning

The convergence of an FDA-proposed market withdrawal, allegations of clinical trial data fraud, 76 documented liver injury cases, 8 confirmed deaths, and aggressive law firm investigations creates a legal environment that is almost certain to produce significant litigation [10][12][15][6]. Whether Tavneos ultimately generates a formal MDL designation — joining the ranks of Vioxx, Zofran, and other major pharmaceutical mass torts — remains to be seen, but the foundational elements are unmistakably present [8][9].

For thousands of patients who were prescribed Tavneos without adequate warning of its liver risks, and for the families of those who died, the legal system may offer the only avenue for accountability and compensation. The clock is ticking — both on the FDA's regulatory process and on the statute of limitations for potential plaintiffs. If Tavneos harmed you or someone you love, now is the time to get informed and get legal help [25][6].

Disclaimer: This article is intended for informational purposes only and does not constitute legal advice. If you believe you have a legal claim related to Tavneos, please consult with a qualified attorney in your jurisdiction.