Amgen's Tavneos Faces Global Regulatory Withdrawals as July 29 FDA Hearing Deadline Approaches
The global regulatory and scientific crisis surrounding Amgen's rare autoimmune drug Tavneos (avacopan) has intensified dramatically. Following the June 29, 2026, retraction of its pivotal Phase 3 ADVOCATE trial publication by The New England Journal of Medicine (NEJM), Amgen is actively preparing its final defense ahead of a critical FDA hearing submission deadline on July 29, 2026.
The NEJM Retraction and Data Manipulation Accusations
The NEJM retracted the 2021 study after an FDA investigation uncovered evidence that study personnel had altered primary clinical outcomes. Specifically, the FDA discovered that endpoint assessments for nine trial patients were selectively readjudicated and modified after the clinical trial database had been locked, a practice inconsistent with proper scientific conduct.
Despite the retraction and subsequent regulatory maneuvers, Amgen continues to defend Tavneos, which was the centerpiece of its $3.7 billion acquisition of ChemoCentryx in 2022. A spokesperson for Amgen stated:
"The NEJM concluded that an aspect of the data analysis was 'inconsistent with proper research conduct.' Specifically, endpoint assessments for nine patients were readjudicated after all the clinical trial data had been collected and the database locked... In February 2026, Amgen proactively initiated an independent, fully blinded re-adjudication of the primary endpoint results from the ADVOCATE study conducted by the Duke Clinical Research Institute. Those results will be shared with the FDA as part of our hearing submission due by July 29 and submitted for publication."
Commercial and Clinical Impact of Proposed Withdrawal
Tavneos is a fast-growing asset for Amgen. Sales hit $459 million in 2025 (representing 1% of Amgen's total revenue) and jumped 32% in the first quarter of 2026. If the FDA successfully forces a withdrawal, the financial impact extends to Amgen's balance sheet, where intangible assets associated with Tavneos are valued at $2.4 billion ($2.3 billion of which is tied directly to the U.S. market).
Patient advocacy groups, including the Eosinophilic & Rare Disease Cooperative and the Vasculitis Foundation, have formally urged the FDA to keep the drug on the market, arguing that alternatives to Tavneos carry severe systemic toxicity risks.