Regulatory scrutiny of Tavneos (avacopan) intensified after the FDA requested Amgen withdraw the drug amid questions over trial re‑adjudication and liver‑safety signals. Amgen publicly declined to pull the product, saying it is unaware of issues with the underlying trial data and that it is engaging with regulators. The standoff centers on interpretation of pivotal trial endpoints and post‑approval safety follow‑up; Amgen said it will respond to FDA questions as discussions continue. The dispute highlights growing regulatory focus on data integrity and benefit‑risk reassessments for approved medicines.