Twenty patients in Japan taking Amgen's oral complement 5a inhibitor, Tavneos, have died since the drug’s launch in 2022, according to a safety alert from Kissei Pharmaceutical, Amgen’s Japanese partner.
Kissei issued a statement encouraging health care professionals to “exercise careful administration of Tavneos” due to severe drug-induced liver injury identified in patients taking the drug.
Media outlets, seeing the regulatory notification in Japan, picked up the story, which Amgen says “lacked important context.” According to Amgen, the reported 20 fatal cases of serious liver injury came from over 8,500 patients treated with Tavneos in Japan and “include cases for which a causal relationship with the product could not be determined.”
Amgen says there have been no known deaths in the U.S. linked to serious liver injury, including vanishing bile duct syndrome (VBDS), in the more than 8,000 patients in the U.S. treated with Tavneos. The U.S FDA, however, claims otherwise, reiterating its request that Amgen voluntarily withdraw the drug back in March. According to the agency, there is "reasonable evidence of a causal association" between Tavneos use and liver injury. The FDA says a total of 76 patients have suffered drug-induced liver injury (DILI), including 54 hospitalizations and eight deaths. In three of the fatal cases, the patients developed VBDS.
Amgen has no intention of withdrawing the medication from the market. The FDA advises physicians who have patients taking the drug to carry out regular liver panel testing to check for symptomatic cholestasis and abnormally high levels of alanine aminotransferase or aspartate aminotransferase.
Tavneos treats active anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. It received FDA approval in 2021 as an adjunctive treatment, with patients typically taking the drug alongside glucocorticoids.