Amgen continues to defend its rare disease drug Tavneos amid mounting global regulatory pressure, according to a July 10 report. The company faces increased scrutiny following the U.S. Food and Drug Administration's proposal in April to withdraw approval of the drug, a retraction of a pivotal clinical trial paper by the New England Journal of Medicine, and recommendations from European regulators to revoke authorization.
Amgen acquired Tavneos in 2022 through its $3.7 billion purchase of ChemoCentryx, shortly after the FDA approved the drug for treating ANCA-associated vasculitis. In January, Amgen declined an FDA request to voluntarily withdraw Tavneos over concerns about data integrity in ChemoCentryx’s pivotal trial. The FDA formally proposed withdrawal three months later. Amgen has since requested a hearing on the matter and initiated an independent re-adjudication of primary endpoint results from the ADVOCATE study conducted by 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," an Amgen spokesperson said.
The NEJM retracted a key paper supporting Tavneos’ approval after concluding that certain endpoint assessments were readjudicated post-database lock, which it found inconsistent with proper research conduct—a concern echoed by U.S. regulators. Despite this, Amgen maintains that available evidence supports continued use: "Amgen takes scientific integrity seriously and respects the role of journals in upholding the peer review process," according to its spokesperson.
Tavneos accounted for about one percent of Amgen’s revenues last year but remains one of its fastest-growing products; sales rose 62% last year and another 32% in early 2024, with $459 million generated—92% from U.S. sales alone. Analysts had projected future growth before doubts intensified around regulatory challenges; RBC Capital Markets estimated potential sales could reach $1.1 billion by 2034 if current issues are resolved.
Withdrawal would have financial implications beyond lost revenue: intangible assets tied to Tavneos were valued at $2.4 billion at March-end, most related to U.S market prospects following Amgen's acquisition of ChemoCentryx. Patient groups such as Eosinophilic & Rare Disease Cooperative have urged regulators not to remove Tavneos from market access due to limited alternatives for those affected by ANCA vasculitis.
The next steps depend on how regulators assess public comments received before June 29 and additional materials that Amgen may submit until July 29.
