The FDA proposed withdrawing Amgen’s Tavneos (avacopan) NDA, alleging “untrue statements” were included in the approval application. The proposed action targets the approval of the C5aR antagonist used for vasculitis and follows Amgen’s 2022 purchase of Chemocentryx for $3.7 billion. The FDA’s action, as described in the reporting, escalates regulatory scrutiny around the integrity of the clinical evidence package supporting approval. For Amgen and the broader specialty rare-disease/immune portfolio, the proposal adds to a growing pressure point for developers on data transparency and submission accuracy. The decision process now moves through regulatory steps tied to the agency’s withdrawal proposal, with implications for patients, prescribers, and future submissions in closely related immunology areas.