FDA Issues Safety Alert on Amgen Vasculitis Drug

Rare Daily Staff

The Food and Drug Administration is warning that Amgen’s rare‑disease drug Tavneos can cause serious, sometimes fatal, liver injury, adding new concern around a treatment many people with ANCA‑associated vasculitis have come to rely on.

In a March 31 safety alert, the agency said it had found 76 cases of drug‑induced liver injury in people taking Tavneos, including 74 serious cases, 54 hospitalizations and eight deaths. Regulators also pointed to seven cases of vanishing bile duct syndrome, a rare and severe type of liver damage, three of which were fatal.

ANCA-associated vasculitis is a systemic disease in which over-activation of the complement pathway further activates neutrophils, leading to inflammation and destruction of small blood vessels. This results in organ damage and failure, with the kidney as the major target, and is fatal if not treated. Currently, treatment for ANCA-associated vasculitis consists of courses of non-specific immuno-suppressants, combined with the administration of daily steroids for prolonged periods of time, which can be associated with significant clinical risk including death from infection.

Tavneos is a oral therapy taken with other medicines, such as steroids, to treat adults with certain severe types of ANCA‑associated vasculitis, including granulomatosis with polyangiitis and microscopic polyangiitis. It is currently the only FDA‑approved pill that specifically targets these rare autoimmune diseases, which cause inflammation in small blood vessels and can seriously damage organs such as the kidneys and lungs.

In its alert, FDA urged doctors to stop Tavneos quickly in patients with severe active ANCA‑associated vasculitis if key liver enzymes rise well above normal or if patients develop signs of cholestasis, when bile flow from the liver is reduced or blocked. Symptoms can include yellowing of the skin or eyes and intense itching. If abnormal tests or symptoms do not get better, the agency says patients should be referred to a liver specialist, and doctors should consider other treatment options.

The new warning comes on top of a separate dispute between FDA and Amgen over the drug’s overall benefits and risks and how some of the original clinical‑trial data were handled. In January, the agency asked Amgen’s ChemoCentryx unit to voluntarily withdraw Tavneos from the U.S. market, but Amgen responded that it would not do so. It had said it would keep working with regulators while the drug stays available.

In February, Amgen said Tavneos has been used by more than 7,000 patients since its 2021 approval and that liver problems have long been recognized as an infrequent risk, with instructions in the prescribing information for regular blood tests to monitor liver health. The company continues to argue that the medicine plays an important role for people with severe ANCA‑associated vasculitis and that its overall benefit–risk profile remains positive.

FDA is urging anyone on Tavneos to contact a health‑care professional right away if they notice possible signs of liver injury, such as unusual tiredness, nausea, vomiting, itching, pale stools, yellowing of the skin or eyes, dark urine, a swollen abdomen, or pain in the upper right side of the belly. Clinicians, in turn, are being advised to stop Tavneos in patients who meet the new liver‑test thresholds or have these symptoms, consider other vasculitis treatments, and refer stubborn cases to liver experts.