Amgen is pushing back against the FDA as the agency weighs withdrawing Tavneos (avacopan), a rare vasculitis drug. According to the report, FDA concerns were raised in connection with securities fraud litigation involving ChemoCentryx, the company that originally developed Tavneos, and the agency has cited safety risks and alleged manipulation of clinical trial data. Amgen has asked the FDA to rely on an independent review of evidence to determine whether Tavneos should remain on the market. The dispute highlights how litigation and data-integrity allegations can feed into regulatory decisions years after initial approval. For investors and clinicians, the case underscores the operational importance of audit trails and trial documentation in rare-disease approvals, where evidence packages can be tightly scrutinized.