The Tavneos story is getting more bizarre by the day: since January 2026 FDA is haggling with Amgen about a withdrawal. The Agency’s reasoning is described in detail in their April 26 statement and mentioned in numerous Pharma newsletters. The key issue is and was the unblinded re-adjudication of the pivotal ADVANCE study data, making the outcome look superior in the avacopan arm.
In an effort to keep Tavneos on the market, Amgen argues that the drug is safer than portrayed by FDA. The company also believes it is efficacious in ANCA vasculitis based on the ‘totality of the data’ which include post-marketing trials and patient testimonials.
Amgen asked DCRI for an independent review of the ADVANCE study data. This effort backfired: DCRI’s assessment did not support the re-adjudicated analysis; instead, it confirmed the original analysis which showed no superiority over the comparison arm.
As we explained in an earlier blog (https://allphasepharma.com/dir/2026/07/14/7499/avacopan-advocate-study-design/), there was a trend in favor of avacopan in the subgroup of patients. However, the control arm in this group received only short-term Rituxan without immune suppression for the rest of the year. We felt that this study design was seriously biased; since then, we learned that the FDA had similar concerns.
Amgen’s lawyers produced a lengthy, legalistic and highly sophistic document arguing that re-adjudication of data is not unheard of in the world of NDA submissions. They defended the actions of Chemocentryx as being merely a sign of a thorough data cleaning effort. According to them, flipping the outcomes of a handful of cases after unblinding is not unheard of. They argued that there was no need to inform FDA of these steps, which they presented as routine, well-intentioned company QC practices.
In the meantime, mainly based on the FDA April 26 report, regulatory agencies all over the world have stopped the marketing authorization of Tavneos. A few days ago, CHMP released an assessment report, which clearly explains why the approval was revoked in Europe. The UK’s MHRA allows no new patients and with a full withdrawal period in early 2027 when the drug approval will be rescinded.
So, what is the FDA waiting for? The drug is in limbo, and so are patients and caregivers. We can only speculate but have a sinister hunch too. Let’s go over the most plausible reasons in the form of a multiple choice questionnaire for your input (feel free to add your reason if not listed):
Thank you in advance for your considered input – much appreciated! We will tally all responses and revert. We promise there will be no re-adjudication of the vote in any way.
We will release poll results after the November midterm elections as we don’t want to influence the vote.
ABBREVIATIONS
CHMP Committee for Medicinal Products for Human Use
DCRI Duke Clinical Research Institute
MHRA Medicines and Healthcare Products Regulatory Agency
