The U.S. Food and Drug Administration has asked Amgen to withdraw Tavneos (avacopan) following scrutiny of old trial re‑adjudication practices and concerns over benefit‑risk signals; Amgen has publicly declined the request and said it will engage with regulators. The dispute centers on re‑adjudicated primary endpoint data for nine patients in the pivotal trial and subsequent benefit‑risk assessment, with hepatotoxicity noted as an infrequent but discussed safety event. Amgen called the request surprising and said it is not aware of any issue with the underlying patient data. The episode exposes procedural tensions around post‑hoc data handling and regulatory review of complex endpoint adjudications — matters that can affect approval durability and commercial continuity for rare‑disease drugs. Investors and policymakers will watch follow‑on interactions between Amgen and the FDA closely: an adverse regulatory outcome could set precedent for revisiting approvals based on re‑analysis practices, while a negotiated resolution would reassure sponsors about the stability of long‑standing regulatory decisions.