Amgen escalated its dispute with the FDA over Tavneos (avacopan), seeking an independent review to keep the rare vasculitis drug on the market. The FDA’s action is tied to concerns triggered by securities fraud litigation involving ChemoCentryx, which originally developed Tavneos, with the regulator reportedly focused on safety risks and alleged trial data manipulation. The move spotlights how litigation and trial-adjacent evidence can drive downstream regulatory outcomes even after initial approvals, leaving rare disease stakeholders watching closely for what the FDA requires next.