Amgen Formally Submits Re-Analysis and Real-World Data to FDA to Defend Tavneos Against Withdrawal

Amgen Formally Submits Re-Analysis and Real-World Data to FDA to Defend Tavneos Against Withdrawal

The high-stakes regulatory battle over the future of Amgen's oral complement C5a receptor inhibitor, Tavneos (avacopan), has reached a critical juncture. On July 23, 2026, Amgen formally submitted an extensive clinical and scientific defense package to the U.S. Food and Drug Administration (FDA) to challenge the agency’s proposed withdrawal of the drug from the U.S. market.

The FDA's Center for Drug Evaluation and Research (CDER) proposed to withdraw approval of Tavneos under Docket No. FDA-2026-N-1321, citing a lack of substantial evidence of effectiveness and material misstatements of fact in the original application submitted by ChemoCentryx (which Amgen acquired in 2022 for $3.7 billion). The crisis was further compounded in June 2026 when The New England Journal of Medicine (NEJM) retracted the pivotal ADVOCATE clinical trial paper that supported the drug's 2021 approval (Amgen's Tavneos Faces Regulatory Collapse Following NEJM Retraction and FDA Withdrawal Proposal).

Amgen's Defense Package and Hearing Request

In its July 23, 2026 submission, Amgen requested a formal hearing before the FDA Commissioner to contest the withdrawal proposal. Amgen's defense relies on:

• A re-analysis of the ADVOCATE clinical trial data performed by the Duke Clinical Research Institute (DCRI), which Amgen argues confirms the robust therapeutic benefit of Tavneos.
• Real-world evidence (RWE) from clinical practice demonstrating the positive benefit-risk profile of the drug in patients with severe active ANCA-associated vasculitis (AAV).
• Proactive safety and efficacy data showing that Tavneos successfully reduces the need for toxic systemic glucocorticoids.¹

Amgen had a strict deadline of July 29, 2026, to submit all supporting data and analyses to the FDA.

Vasculitis Community Rallies in Support

The proposed withdrawal has drawn significant concern from the rare disease community. The Vasculitis Foundation reported that the FDA received 143 public comments by the June 29, 2026 comment deadline, with many patients, caregivers, and clinicians sharing their clinical experiences and urging the FDA to keep the drug available.

Tavneos remains on the U.S. market and available to patients pending a final determination by the FDA Commissioner or if Amgen decides to voluntarily withdraw it.

In an official statement, Amgen declared:

"Amgen strongly disagrees with the FDA's proposal to withdraw TAVNEOS from the U.S. market... We believe it is important that the FDA fully consider the totality of the scientific evidence, the significant unmet needs of people living with AAV, and the voices of patients before making a final decision."