As Amgen’s rare disease medicine Tavneos comes under intensifying pressure from the FDA, the company faces a new hurdle with a leading medical journal’s retraction of the drug’s pivotal study data.
Monday, the New England Journal of Medicine said it’s retracting the phase 3 study results on Tavneos first published in 2021.
An investigation by the FDA has concluded that “the primary end-point assessments in nine patients were readjudicated after database lock and trial unblinding,” according to the retraction notice.
“This was not disclosed in the article and is inconsistent with proper research conduct,” the notice continues.
Tavneos won FDA approval back in 2021 as a treatment for anti-neutrophil cytoplasmic antibody-associated (ANCA) vasculitis, a rare autoimmune disease that causes damage to patients’ small blood vessels and eventually leads to organ failure, especially in the kidneys.
ChemoCentryx had developed the drug and won the FDA’s approval before its $3.7 billion sale to Amgen. Even before the FDA approval, agency staffers raised concerns with the study data. After ChemoCentryx’s stock price collapsed on that news, certain investors filed a lawsuit alleging the biotech knew of the FDA’s concerns but downplayed them. Amgen eventually prevailed in that legal action from the investors.
More recently, the FDA in January sent Amgen a request to pull the medicine from the market based on its reassessment of the trial conduct and its updated view of the drug’s risk-benefit profile.
Amgen has resisted that withdrawal push, prompting the FDA to double down in April with a formal proposal to pull the drug over “manipulated” trial data. Even under that pressure, Amgen didn’t buckle and said it would carefully assess its next steps.
Now, the sides are gearing up for a hearing on the drug and its data. As part of that process, Amgen has hired a third-party reviewer to provide its own assessment of the trial results.
An Amgen spokesperson said the company “takes scientific integrity seriously and respects the role of journals in upholding the peer review process.”
“In February 2026, Amgen proactively initiated an independent, fully blinded re-adjudication of the primary endpoint results from the ADVOCATE study conducted by the Duke Clinical Research Institute,” the spokesperson added. “Those results will be shared with the FDA as part of our hearing submission due by July 29 and submitted for publication.”
Besides the data integrity issue, the FDA in March rolled out a safety communication flagging dozens of cases of drug-induced liver injury with “reasonable evidence” of a link to Tavneos. Among the 76 cases flagged in the agency’s adverse event database, 54 involved hospitalizations and eight patients died, according to the agency. And in Japan, after 20 reports of patient deaths related to liver injuries, authorities recently added new safety precautions to the drug’s label.
Over in Europe, Tavneos took another hit last week with the EU regulator’s decision to revoke its endorsement.