The FDA in January asked Amgen to pull Tavneos from the market, citing liver toxicity issues that affected the drug’s overall risk-benefit profile. The pharma refused.
The FDA has flagged eight deaths and 76 cases of liver injury in patients treated with Amgen’s rare disease therapy Tavneos—a drug that was recently the subject of a standoff between the regulator and the pharma.
Drawing on postmarketing data from Amgen and incidents reported in the FDA’s own surveillance system, the agency flagged cases of drug-induced liver injury (DILI) “with reasonable evidence of a causal association” with Tavneos, according to a safety alert issued Tuesday.
Seven of the 76 cases involved biopsy-confirmed vanishing bile duct syndrome, a complication of DILI that had a reasonable causal link to Tavneos. All seven of these patients required hospitalization, and three died. All told, 74 of the 76 patients with DILI had serious outcomes necessitating hospital care, the FDA said on Tuesday.
Amgen had previously informed the FDA of the vanishing bile duct syndrome risk associated with Tavneos, a company spokesperson said in a statement to Endpoints News. The pharma in 2024 asked the regulator to update the drug’s label to reflect this safety signal, but the spokesperson noted that this request is still pending.
The FDA in its communique on Tuesday acknowledged that “hepatotoxicity is a serious adverse reaction” that has been “identified in premarket clinical trials and described in product labelling” for Tavneos. Still, DILI and vanishing bile duct syndrome, especially those with fatal outcomes, “represent new safety concerns,” the agency asserted.
Healthcare providers should monitor their patients’ liver function through panel testing every two weeks during the first month of treatment, before spreading out to monthly for the next five months and then as needed thereafter, the regulator recommended. Tavneos treatment should be stopped if abnormal elevations in liver enzyme levels occur.
Tavneos came to Amgen in 2022, when the pharma dropped $3.7 billion to acquire ChemoCentryx. The drug was approved in 2021 for severe active anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. ANCA vasculitis refers to a group of rare autoimmune inflammatory disorders affecting the blood vessels. When left unchecked, the disease can damage organs, including the kidneys, lungs and brain.
Tavneos earned $423 million in 2025.
In January, the FDA asked Amgen to pull Tavneos from the market, raising concerns with how ChemoCentryx re-adjudicated the primary outcome for nine of more than 330 patients in the pivotal study that led to the drug’s approval. The regulator also raised incidences of liver toxicities in the context of the drug’s benefit-risk profile.
Amgen turned down this request. “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 pharma said in a statement at the time.
The FDA’s safety notice on Tuesday did not provide updates on its discussions with Amgen regarding the withdrawal of Tavneos.
