The FDA has previously linked eight deaths in the U.S. to Tavneos and has alleged that doctored data were used to support the drug application that led to its approval in 2021.
The problems keep coming for Amgen’s autoimmune drug Tavneos, with the product now linked to several deaths.
In Japan, 20 patients on Tavneos have died since the drug’s launch in 2022, according to an automated translation of a Japanese-language safety alert from Kissei Pharmaceutical, Amgen’s Japanese partner in charge of distributing the drug there. Most of the mortalities were linked to vanishing bile duct syndrome (VBS), a complication of drug-induced liver injury (DILI), the company said.
It’s not clear if Tavneos was the direct cause of the deaths, but Kissei nevertheless discouraged doctors from giving the drug to new patients and recommended informing patients already on treatment of the liver risks potentially linked to the product.
Kissei confirmed its caution in a news release on Friday, noting that healthcare professionals should “exercise careful administration” of Tavneos. Kissei has kicked off an information campaign to doctors “urging them to refrain from using this drug for new patients and to carefully assess the continuation of treatment for existing patients,” according to the release.
Amgen sought to provide context to these deaths in a Friday statement. Kissei’s report flagged 20 deaths “from over 8,500 patients who have been treated with Tavneos in Japan,” the pharma said. “These figures include cases for which a causal relationship with the product could not be determined.”
Moreover, there have been no known Tavneos-linked deaths in the U.S. stemming from serious liver injury, according to Amgen. The FDA in March, however, flagged 76 cases of VBS and eight deaths in patients treated with the drug. The agency at the time said that the liver toxicities and deaths had “reasonable evidence of causal association” with Tavneos.
“Tavneos is an important and effective medicine,” Amgen said on Friday. “Based on all available data, Amgen continues to believe Tavneos demonstrates effectiveness and a favorable benefit-risk profile.”
The last few months have been difficult for the Tavneos franchise. In January, the FDA surprised Amgen by asking the pharma to pull Tavneos from the market, pointing to issues with how ChemoCentryx—the original developer of the drug—re-adjudicated the primary endpoint in the study that led to the product’s approval. Amgen denied the request.
Last month, the FDA alleged that doctored data were filed to support Tavneos’ initial approval.
“New information that only became known to CDER [the Center for Drug Evaluation and Research] more than three years after approval shows that unblinded study personnel manipulated the results of the pivotal clinical study so the drug looked effective when the original analysis did not support that conclusion,” the agency said in a statement at the time, though the regulator didn’t provide evidence backing up these claims.
Because of this alleged manipulation, however, the agency said that it “can no longer conclude that there is, or has ever been, a valid demonstration that Tavneos is effective.”
Amgen acquired ChemoCentryx, and Tavneos by extension, in 2022 for $3.7 billion.
