The FDA says Tavneos was approved on the basis of manipulated trial data and has proposed withdrawing it, while Amgen insists the drug works. The EU has already removed it and the UK plans to follow.
In April, the US Food and Drug Administration sent Amgen a letter proposing that Tavneos, a drug for the rare autoimmune condition ANCA-associated vasculitis, be withdrawn from the US market. The agency cited reports of serious, sometimes fatal, liver injury and argued the drug now lacks "substantial evidence" that it works. Tavneos was approved on October 7, 2021, after an advisory committee voted narrowly in favour despite doubts about the pivotal trial's design. Since then, the New England Journal of Medicine has retracted the trial paper at the request of its two academic authors, the drug has been taken off the market in the European Union, and the United Kingdom has announced it will remove it too.
The FDA alleges that employees of ChemoCentryx, the company that ran the trial and was later acquired by Amgen for nearly $4 billion, reassessed the remission status of a handful of patients after the study data were unblinded, in breach of the trial protocol, and that the patients were selected to produce the result needed for approval. According to the report, the original analysis had found no better one-year remission rates for Tavneos than for standard treatment, and neither the original result nor the reassessment was disclosed to the agency. The evidence emerged through an investor lawsuit, for which a proposed $69 million settlement was due to be considered at a hearing on October 29. Tracy Beth Høeg, the FDA's acting director of drug evaluation, told Undark the drug has been linked to eight deaths and dozens of hospitalizations and that "we don't know if it works."
Amgen rejects the conclusion. In a 104-page submission to the FDA in July, it said the "totality of the evidence supports the continued availability of TAVNEOS," that ChemoCentryx's reassessment was meant to correct a small number of errors, that none of the underlying data were changed, and that the earlier company had no legal duty to disclose it. Some independent experts also consider the drug effective, and patients hope it can reduce reliance on steroids, whose side effects can be severe. Tavneos costs about $220,000 a year and reached nearly half a billion dollars in sales in fiscal 2025. The FDA's final decision in the United States has not been made, and the case highlights how hard it is to withdraw an approved drug once it is on the market.
