The Food and Drug Administration (FDA) announced on Apr. 1 that it has identified eight deaths and 76 cases of liver injury among patients treated with Amgen’s rare disease drug, Tavneos. The findings come from postmarketing data provided by Amgen as well as reports from the FDA’s own surveillance system.
The announcement is significant for healthcare providers and patients using Tavneos, which is prescribed for severe active anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis—a group of rare autoimmune inflammatory disorders affecting blood vessels. According to the FDA, "hepatotoxicity is a serious adverse reaction" previously identified in clinical trials and noted in product labeling, but the newly reported cases of drug-induced liver injury (DILI) and vanishing bile duct syndrome—especially those resulting in death—"represent new safety concerns."
Of the 76 DILI cases flagged by the agency, seven involved biopsy-confirmed vanishing bile duct syndrome; all required hospitalization, with three resulting in death. In total, 74 out of the 76 affected patients needed hospital care. The FDA recommended that healthcare providers monitor their patients’ liver function every two weeks during the first month of treatment with Tavneos, then monthly for five months before adjusting as needed thereafter. Treatment should be discontinued if abnormal elevations in liver enzyme levels are detected.
Amgen acquired Tavneos through its $3.7 billion purchase of ChemoCentryx in 2022; the drug was approved a year earlier for treating ANCA-associated vasculitis. In a statement to Endpoints News regarding these risks, an Amgen spokesperson said: “Amgen is not aware of any issues with the underlying patient data and after review of the relevant clinical data and years of real-world evidence, Amgen is confident that Tavneos demonstrates effectiveness and a favorable benefit-risk profile.” The company had previously notified regulators about vanishing bile duct syndrome risk linked to Tavneos and requested an update to its label reflecting this concern—a request still pending.
Earlier this year, following concerns over trial data handling by ChemoCentryx as well as incidents involving liver toxicity related to benefit-risk balance, the FDA asked Amgen to withdraw Tavneos from market circulation. However, Amgen declined this request.
The agency’s latest safety notice did not provide updates on ongoing discussions between FDA officials and Amgen regarding potential withdrawal actions.
