The FDA revisited years-old data issues around Tavneos (avacopan) and asked Amgen to consider withdrawing the drug; Amgen pushed back and said it is unwilling to pull the product from the market. The FDA’s concerns center on patient-level re-adjudication and interpretation of primary endpoint results from the pivotal trial, alongside hepatotoxicity signals raised in safety reviews. Amgen stated it is in discussions with the agency and defended the integrity of the original trial data. The dispute could prompt additional labeling updates, post-market studies, or advisory committee review—outcomes that would affect prescriber confidence and commercial performance for a drug approved in 2021. Regulatory outcomes here will influence how sponsors handle long-term trial data stewardship and re-adjudication processes. Investors and clinicians alike will watch FDA communications and Amgen’s planned responses for signals on enforcement and precedent.