NEJM Retracts Tavneos Trial Paper as FDA, EMA Both Move to Pull Amgen Drug From Market

The New England Journal of Medicine has retracted the 2021 paper detailing the pivotal clinical trial that supported approval of Amgen's rare-disease drug Tavneos (avacopan), citing concerns that patient outcome data were altered and that some researchers had been unblinded during the trial.¹

The retraction was requested by two academic authors of the study after an FDA investigation found that results for nine patients had been changed.

According to the retraction note itself, the primary endpoint assessments for nine patients were readjudicated after database lock and trial unblinding, without the knowledge of the two requesting authors. "This was not disclosed in the article and is inconsistent with proper research conduct," the editors wrote. "The editors therefore retract the article."²

According to Reuters, an Amgen spokesperson said the company "takes scientific integrity seriously and respects the role of journals in upholding the peer review process," and noted that results of a re-adjudication of the trial's data by the Duke Clinical Research Institute will be shared with the FDA as part of the company's hearing submission, due by July 29, and submitted for publication. The spokesperson confirmed Tavneos remains on the market in the US.

FDA cites false statements and safety concerns

The retraction follows a series of escalating actions from the FDA. In April, the agency's Center for Drug Evaluation and Research (CDER) proposed withdrawing Tavneos' approval entirely, citing a lack of proven effectiveness and false statements of material fact in the original application.³

CDER stated that new information, which only became known to the agency more than three years after approval, showed that unblinded study personnel manipulated the results of the pivotal clinical study so the drug appeared effective when the original analysis did not support that conclusion.

The agency also said the applicant did not disclose the original analysis to FDA, in violation of FDA regulations.

"CDER can no longer conclude that there is, or has ever been, a valid demonstration that Tavneos is effective for its approved use," the agency stated, noting it has issued a notice of opportunity for a hearing to ChemoCentryx, the Amgen subsidiary that holds the application.

Separately, in March, the FDA identified 76 cases of drug-induced liver injury with evidence suggesting a causal link to Tavneos, including seven cases of vanishing bile duct syndrome, a rare and potentially permanent condition affecting the liver's bile ducts. Eight deaths were reported among those cases.

Tavneos was originally approved in October 2021 to treat severe active ANCA-associated vasculitis, a group of rare diseases that cause inflammation in small to medium-sized blood vessels and can damage organs including the kidneys and lungs.

EMA recommends revoking European authorization

Europe's drug regulator has taken parallel action. Last week, the EMA's human medicines committee (CHMP) recommended revoking Tavneos' marketing authorization in the European Union, concluding that the drug's benefits are no longer proven to outweigh its risks.⁴

The EMA review centered on the Advocate study, the 331-patient trial that originally supported the drug's EU approval by showing Tavneos was at least as effective as a 20-week course of high-dose corticosteroids in inducing remission, with better long-term remission rates at 52 weeks.

After reviewing the totality of available data and new information about how the study data were handled, the CHMP concluded that the Advocate study was conducted in breach of good clinical practice principles, and that the data provided at the time of the original assessment were incorrect and misleading.

The committee determined that supportive post-marketing data and post-hoc analyses were not sufficient on their own to demonstrate the drug's benefits.

The CHMP is recommending that no new patients start treatment with Tavneos and that existing patients be switched to suitable alternatives. Given the drug's association with drug-induced liver injury and vanishing bile duct syndrome, including fatal cases, the agency is also recommending close liver function monitoring for patients still on or recently treated with the drug: at least every two weeks for those in their first three months of treatment, and every four weeks for up to six months for those who have been on the drug longer. If vanishing bile duct syndrome is suspected, the agency says Tavneos must be immediately discontinued.

The CHMP's recommendation will now be forwarded to the European Commission, which will issue a final, legally binding decision applicable across all EU member states.

What happens next

In the US, Tavneos will remain on the market until Amgen voluntarily removes the drug or the FDA Commissioner mandates its withdrawal following a hearing process. The FDA has recommended that healthcare professionals discuss Tavneos and other available treatment options with patients while a final decision on the drug's marketing status is pending.

Amgen has engaged an independent research firm to review the Tavneos data as it prepares to defend the drug's benefits ahead of its FDA hearing.

References

1. Medical journal retracts paper on Amgen’s Tavneos drug trial after FDA findings. Reuters. June 29, 2026. Accessed June 30, 2026. https://www.reuters.com/legal/litigation/medical-journal-retracts-paper-amgens-tavneos-drug-trial-after-fda-findings-2026-06-29/

2. Retraction: Jayne DRW et al. Avacopan for the Treatment of ANCA-Associated Vasculitis, N Engl J Med 2021;384:599-609. Eric J. Rubin, MD, PhD. N Engl J Med. June 26, 2026. Accessed June 30, 2026. https://www.nejm.org/doi/full/10.1056/NEJMe2608684

3. CDER proposes to withdraw approval of TAVNEOS. FDA. April 27, 2026. Accessed June 30, 2026. https://www.fda.gov/drugs/drug-alerts-and-statements/cder-proposes-withdraw-approval-tavneos

4. EMA recommends revoking marketing authorisation for Tavneos. EMA. June 26, 2026. Accessed June 30, 2026. https://www.ema.europa.eu/en/news/ema-recommends-revoking-marketing-authorisation-tavneos