The FDA issued a safety alert identifying 76 cases of drug-induced liver injury (DILI) linked to Amgen's Tavneos (avacopan), with reasonable evidence of causal association, including eight deaths.
Seven cases involved biopsy-confirmed vanishing bile duct syndrome, leading to hospitalization in all and death in three.
74 of the 76 DILI cases required hospitalization.
In January, FDA requested Amgen voluntarily withdraw Tavneos due to liver toxicity and data concerns, but Amgen refused, citing a favorable benefit-risk profile.
Tavneos, approved in 2021 for ANCA-associated vasculitis, was acquired by Amgen in 2022 for $3.7 billion and generated $423 million in 2025.
FDA recommends liver function monitoring every two weeks for the first month, then monthly for five months, and stopping treatment if liver enzymes elevate.