Amgen is contesting FDA concerns over Tavneos (avacopan), arguing for an independent review as the agency faces pressure to revisit whether the rare vasculitis drug should remain on the market. The FDA’s position is reported to be tied to safety risks and allegations surrounding clinical trial data and processes linked to securities fraud litigation involving ChemoCentryx, the original developer. The dispute puts Tavneos at the center of an FDA decision dynamic where evidentiary integrity and post-approval risk-benefit assessments collide. For Amgen, the review request is a direct attempt to preserve access while clarifying what the agency will rely on. Biopharma watchers will monitor how this case balances regulatory authority with disputes originating from corporate and litigation contexts—especially for other marketed drugs with contested data histories.