The New England Journal of Medicine has retracted a pivotal publication supporting the approval of Amgen's oral C5a receptor inhibitor, Tavneos, at the request of two of the study's academic authors.
The authors requested the retraction after alleging that, without their knowledge, the primary endpoint assessments for nine patients were re-adjudicated after the trial database had been locked and unblinded. They cited the FDA's ongoing investigation into allegations that data supporting Tavneos' approval were manipulated.
The retraction comes amid increasing regulatory scrutiny of the drug. Earlier this year, the FDA twice asked Amgen to voluntarily withdraw Tavneos from the market following postmarketing reports linking the drug to severe drug-induced liver injury (DILI), including cases of vanishing bile duct syndrome (VBDS). Amgen declined both requests, stating that it does not intend to withdraw the product.
Tavneos received FDA approval in 2021 as an adjunctive treatment for adults with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. Approval was based primarily on results from the phase 3 ADVOCATE trial, which randomized patients to receive either avacopan or a prednisone taper, each in combination with standard-of-care therapy consisting of either cyclophosphamide or rituximab.
Tavneos was originally developed by ChemoCentryx, which Amgen acquired for approximately $3.7 billion in 2022.