Medical Journal Retracts Paper on Amgen’s Tavneos Drug Trial After FDA Findings
The medical journal *The New England Journal of Medicine* retracted a 2019 paper on Amgen’s Tavneos drug trial following findings by the U.S. Food and Drug Administration in April 2026. FDA officials said unblinded study personnel manipulated clinical trial data, resulting in misleading efficacy claims and prompting the agency to propose withdrawing approval of Tavneos for ANCA-associated vasculitis.
On April 27–28, 2026, the U.S. Food and Drug Administration’s Center for Drug Evaluation and Research (CDER) proposed withdrawing approval of Tavneos (avacopan), citing a lack of evidence that the drug is effective for treating severe active ANCA-associated vasculitis. The agency’s Notice of Opportunity for Hearing (NOOH) states that unblinded personnel involved in the pivotal ADVOCATE clinical trial manipulated data, altering endpoint adjudications so that the drug appeared effective, despite the original November 2019 analysis showing no statistically significant superiority over control treatment. The FDA said this original analysis was not disclosed during the approval application process, and that only the favorable re-adjudicated results were submitted, violating regulations requiring full disclosure of all relevant data.
CDER’s NOOH formally states it can no longer conclude there is valid substantial evidence supporting Tavneos’ effectiveness for its approved indication.
The agency also highlighted serious safety concerns, including 76 reported cases of drug-induced liver injury (DILI), seven of which involved vanishing bile duct syndrome (VBDS), a rare and potentially irreversible liver condition. Among these cases, eight deaths were documented, with the FDA indicating evidence of a causal link to Tavneos. While hepatotoxicity was a known risk from premarket trials and listed in product labeling, the emergence of VBDS and fatal DILI cases represents new, serious post-marketing safety signals. The FDA emphasized these safety concerns must be weighed alongside the now-questioned efficacy data in its decision to propose withdrawal.
Despite the proposal, Tavneos remains on the U.S. market during the formal withdrawal process. The NOOH outlines procedural rights for ChemoCentryx Inc., a wholly owned subsidiary of Amgen Inc., the sponsor of Tavneos. Under FDA regulations, ChemoCentryx has until June 1, 2026, to request a formal hearing. If a hearing is requested, the FDA Commissioner will decide whether to hold a public hearing and ultimately whether to withdraw approval. The FDA clarified that the proposal to withdraw is not itself a removal, and Tavneos stays legally approved and available until any final regulatory action.
Amgen has expressed confidence in Tavneos’ effectiveness and benefit-risk profile, citing clinical data and several years of real-world evidence. The company said withdrawal “would be neither in the best interest of patients nor consistent with statutory criteria,” according to a June 1, 2026, letter posted online. Earlier, on January 16, 2026, the FDA requested that ChemoCentryx voluntarily withdraw Tavneos over concerns about the re-adjudication process involving nine of 331 patients in the pivotal trial. Amgen responded on January 28, 2026, stating it did not intend to withdraw the drug. The company has engaged the Duke Clinical Research Institute to independently reevaluate the trial data, with the review beginning in February 2026. Amgen plans to submit a new analysis to the FDA by June 29, 2026, as part of a broader evidence package supporting continued approval.
The New England Journal of Medicine (NEJM), which published the ADVOCATE trial results, confirmed it is investigating allegations of research misconduct following the FDA’s findings of data manipulation. Bloomberg reported that NEJM is reviewing whether trial data were altered to present Tavneos as more effective than the original analysis indicated. The journal’s investigation focuses on whether good clinical practice standards were breached and if the published outcomes accurately reflect unmanipulated data. As of now, NEJM has acknowledged the investigation but has not announced any final actions or retractions.
In Europe, the European Medicines Agency (EMA) announced on June 26, 2026, that its Committee for Medicinal Products for Human Use (CHMP) recommends revoking the marketing authorization for Tavneos. The EMA cited breaches of good clinical practice in the pivotal study and described the data as “incorrect, misleading and no longer reliable” for demonstrating effectiveness. The agency noted that post-approval data and additional analyses failed to prove Tavneos’ benefits, echoing the FDA’s concerns. The EMA also referenced the 76 cases of drug-induced liver injury identified by the FDA but focused primarily on data integrity and efficacy in its recommendation. The CHMP advised that no new patients start Tavneos and that existing patients be switched to suitable alternatives, pending a final decision from the European Commission.
Patient advocacy groups have communicated that the FDA’s proposal to withdraw Tavneos does not constitute immediate removal from the market and that the drug remains approved and available during the ongoing regulatory process. They emphasized that the FDA’s position centers on the manipulation of the ADVOCATE trial’s primary endpoint, with the agency asserting that only the original November 2019 analysis, which showed no significant efficacy, is valid. Patients currently receiving Tavneos are advised to consult their physicians and monitor for liver-related symptoms while staying informed about evolving regulatory decisions.
The FDA’s formal withdrawal process will proceed based on whether ChemoCentryx requests a hearing by June 1, 2026. The outcome will depend on regulatory review of both the efficacy concerns raised by the manipulated trial data and the serious liver safety signals documented post-marketing. Meanwhile, Amgen’s ongoing data reevaluation and the NEJM’s investigation into the trial’s integrity remain critical components influencing regulatory and clinical perspectives on Tavneos.
