Amid ongoing FDA scrutiny, Amgen filed a label supplement for Tavneos (avacopan) while the agency escalates efforts to withdraw the treatment from the U.S. market. The move signals that FDA’s concerns are not confined to post-market surveillance and could affect availability. The controversy centers on alleged integrity issues in the pivotal study supporting the current indication, with FDA stating it can no longer conclude that Tavneos has valid evidence of effectiveness for approved use. The regulatory pathway is therefore moving from routine labeling to potential market action. Biotechs watching Tavneos are likely to focus on how FDA applies data-integrity and evidentiary standards to accelerated reviews and label-supporting trials, particularly in immunology with complex endpoints and analysis populations.