Last week added another significant step to the avacopan story: on 29 June 2026, the New England Journal of Medicine retracted the original 2021 ADVOCATE article on Tavneos.
The New England Journal of Medicine is among the most trusted medical journals in the world — when it publishes something, doctors everywhere take notice.
What is a retraction?
A retraction is not a small correction. It is the strongest step a scientific journal can take: it formally withdraws the article and no longer stands behind it. The paper doesn’t disappear — it stays visible, but clearly marked as retracted, so anyone reading it knows it can no longer be relied upon. In medicine, retractions are rare. When one reaches a study as important as ADVOCATE — the one that underpinned approval across the world — it carries real weight.
Who initiated this retraction?
The NEJM did not do this on it’s own. The article had four authors, and two of them requested the retraction: Professor David Jayne and Professor Peter Merkel, the academic doctors who led the trial. The other two authors came from Chemocentryx, the company that developed avacopan and ran the study.
That split is not a technicality.
It means the independent scientists who give a study its credibility chose to step away from it, stating plainly that they had not known about the changes made to the data.
When the academic authors themselves ask for a paper to be withdrawn, that is about as clear a signal as science gives.
What is the impact on patients?
Not much. This will not change the outcome or decisions made by the FDA or EMA but it brings things full circle: the same study that prompted the FDA and EMA to act has now also led to the formal retraction of the original paper, at the request of the academic authors themselves.
A word on the companies involved.
The names can be confusing, so briefly: avacopan was developed by ChemoCentryx, which also ran the ADVOCATE trial. ChemoCentryx was later acquired by Amgen, so in the United States any action today is directed at Amgen — ChemoCentryx itself no longer exists. In Europe, Tavneos is sold by CSL Vifor, which holds the EU marketing authorisation. It is important to be clear that CSL Vifor had no part in the ADVOCATE trial or in the data concerns behind it; it simply markets a product that was authorised by the EMA.
Last but not least.
We keep emphasizing it: If patients come to you: reassure them, and remind them that no one should change or stop any treatment on their own. That conversation belongs with their own doctor.