CAMBRIDGE — The New England Journal of Medicine retracted a 2021 clinical trial article supporting Amgen's drug Tavneos on June 29, 2026. The journal cited concerns that patient outcome data were altered and that some researchers had been unblinded.

Two academic authors of the 2021 study requested the retraction. This request followed a US Food and Drug Administration (FDA) investigation which found results for nine patients were altered. The FDA investigation also found that some researchers were informed which patients received Tavneos and which did not. The journal stated that these changes to the data were not disclosed in the article.

In April 2026, the FDA's Center for Drug Evaluation and Research proposed withdrawing Tavneos' approval. The Center for Drug Evaluation and Research cited a lack of proven effectiveness and false statements in the original application as reasons for the proposed withdrawal. In March 2026, the FDA identified 76 cases of drug-induced liver injury, with evidence suggesting a causal link to Tavneos. These cases included seven instances of vanishing bile duct syndrome, a rare condition that can cause permanent liver damage. Eight deaths were reported among the identified cases.

Europe's drug regulator recommended revoking the marketing authorization for Tavneos on June 23, 2026, citing concerns over the integrity of the trial data. Tavneos was approved in October 2021 to treat severe active ANCA-associated vasculitis, a condition that inflames small blood vessels and can damage organs such as the kidneys and lungs.

An Amgen spokesperson said the company "takes scientific integrity seriously and respects the role of journals in upholding the peer review process." The spokesperson added that results of a "re-adjudication" of the trial's results by the Duke Clinical Research Institute "will be shared with the FDA as part of our hearing submission due by July 29 and submitted for publication." The spokesperson also stated that "TAVNEOS remains on the market in the U.S." These developments impact the availability of Tavneos for treating severe active ANCA-associated vasculitis and suggest ongoing regulatory review of the drug's status.